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Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001/*
2 * Infrastructure for profiling code inserted by 'gcc -pg'.
3 *
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
6 *
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
9 *
10 * Based on code in the latency_tracer, that is:
11 *
12 * Copyright (C) 2004-2006 Ingo Molnar
Nadia Yvette Chambers6d49e352012-12-06 10:39:54 +010013 * Copyright (C) 2004 Nadia Yvette Chambers
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +020014 */
15
Steven Rostedt3d083392008-05-12 21:20:42 +020016#include <linux/stop_machine.h>
17#include <linux/clocksource.h>
18#include <linux/kallsyms.h>
Steven Rostedt5072c592008-05-12 21:20:43 +020019#include <linux/seq_file.h>
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -080020#include <linux/suspend.h>
Steven Rostedt (Red Hat)8434dc92015-01-20 12:13:40 -050021#include <linux/tracefs.h>
Steven Rostedt3d083392008-05-12 21:20:42 +020022#include <linux/hardirq.h>
Ingo Molnar2d8b8202008-02-23 16:55:50 +010023#include <linux/kthread.h>
Steven Rostedt5072c592008-05-12 21:20:43 +020024#include <linux/uaccess.h>
Steven Rostedt5855fea2011-12-16 19:27:42 -050025#include <linux/bsearch.h>
Paul Gortmaker56d82e02011-05-26 17:53:52 -040026#include <linux/module.h>
Ingo Molnar2d8b8202008-02-23 16:55:50 +010027#include <linux/ftrace.h>
Steven Rostedtb0fc4942008-05-12 21:20:43 +020028#include <linux/sysctl.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090029#include <linux/slab.h>
Steven Rostedt5072c592008-05-12 21:20:43 +020030#include <linux/ctype.h>
Steven Rostedt68950612011-12-16 17:06:45 -050031#include <linux/sort.h>
Steven Rostedt3d083392008-05-12 21:20:42 +020032#include <linux/list.h>
Steven Rostedt59df055f2009-02-14 15:29:06 -050033#include <linux/hash.h>
Paul E. McKenney3f379b02010-03-05 15:03:25 -080034#include <linux/rcupdate.h>
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +020035
Steven Rostedtad8d75f2009-04-14 19:39:12 -040036#include <trace/events/sched.h>
Steven Rostedt8aef2d22009-03-24 01:10:15 -040037
Steven Rostedt2af15d62009-05-28 13:37:24 -040038#include <asm/setup.h>
Abhishek Sagar395a59d2008-06-21 23:47:27 +053039
Steven Rostedt0706f1c2009-03-23 23:12:58 -040040#include "trace_output.h"
Steven Rostedtbac429f2009-03-20 12:50:56 -040041#include "trace_stat.h"
Steven Rostedt3d083392008-05-12 21:20:42 +020042
Steven Rostedt6912896e2008-10-23 09:33:03 -040043#define FTRACE_WARN_ON(cond) \
Steven Rostedt0778d9a2011-04-29 10:36:31 -040044 ({ \
45 int ___r = cond; \
46 if (WARN_ON(___r)) \
Steven Rostedt6912896e2008-10-23 09:33:03 -040047 ftrace_kill(); \
Steven Rostedt0778d9a2011-04-29 10:36:31 -040048 ___r; \
49 })
Steven Rostedt6912896e2008-10-23 09:33:03 -040050
51#define FTRACE_WARN_ON_ONCE(cond) \
Steven Rostedt0778d9a2011-04-29 10:36:31 -040052 ({ \
53 int ___r = cond; \
54 if (WARN_ON_ONCE(___r)) \
Steven Rostedt6912896e2008-10-23 09:33:03 -040055 ftrace_kill(); \
Steven Rostedt0778d9a2011-04-29 10:36:31 -040056 ___r; \
57 })
Steven Rostedt6912896e2008-10-23 09:33:03 -040058
Steven Rostedt8fc0c702009-02-16 15:28:00 -050059/* hash bits for specific function selection */
60#define FTRACE_HASH_BITS 7
61#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
Steven Rostedt33dc9b12011-05-02 17:34:47 -040062#define FTRACE_HASH_DEFAULT_BITS 10
63#define FTRACE_HASH_MAX_BITS 12
Steven Rostedt8fc0c702009-02-16 15:28:00 -050064
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +090065#ifdef CONFIG_DYNAMIC_FTRACE
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -040066#define INIT_OPS_HASH(opsname) \
67 .func_hash = &opsname.local_hash, \
68 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -040069#define ASSIGN_OPS_HASH(opsname, val) \
70 .func_hash = val, \
71 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +090072#else
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -040073#define INIT_OPS_HASH(opsname)
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -040074#define ASSIGN_OPS_HASH(opsname, val)
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +090075#endif
76
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -040077static struct ftrace_ops ftrace_list_end __read_mostly = {
78 .func = ftrace_stub,
Steven Rostedt (Red Hat)395b97a2013-03-27 09:31:28 -040079 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -040080 INIT_OPS_HASH(ftrace_list_end)
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -040081};
82
Steven Rostedt4eebcc82008-05-12 21:20:48 +020083/* ftrace_enabled is a method to turn ftrace on or off */
84int ftrace_enabled __read_mostly;
Steven Rostedtd61f82d2008-05-12 21:20:43 +020085static int last_ftrace_enabled;
Steven Rostedtb0fc4942008-05-12 21:20:43 +020086
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -040087/* Current function tracing op */
88struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -050089/* What to set function_trace_op to */
90static struct ftrace_ops *set_function_trace_op;
Steven Rostedt60a7ecf2008-11-05 16:05:44 -050091
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -040092static bool ftrace_pids_enabled(struct ftrace_ops *ops)
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -040093{
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -040094 struct trace_array *tr;
95
96 if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
97 return false;
98
99 tr = ops->private;
100
101 return tr->function_pids != NULL;
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -0400102}
103
104static void ftrace_update_trampoline(struct ftrace_ops *ops);
105
Steven Rostedt4eebcc82008-05-12 21:20:48 +0200106/*
107 * ftrace_disabled is set when an anomaly is discovered.
108 * ftrace_disabled is much stronger than ftrace_enabled.
109 */
110static int ftrace_disabled __read_mostly;
111
Steven Rostedt52baf112009-02-14 01:15:39 -0500112static DEFINE_MUTEX(ftrace_lock);
Steven Rostedtb0fc4942008-05-12 21:20:43 +0200113
Steven Rostedtb8489142011-05-04 09:27:52 -0400114static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200115ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
Steven Rostedt2b499382011-05-03 22:49:52 -0400116static struct ftrace_ops global_ops;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200117
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400118#if ARCH_SUPPORTS_FTRACE_OPS
119static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -0400120 struct ftrace_ops *op, struct pt_regs *regs);
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400121#else
122/* See comment below, where ftrace_ops_list_func is defined */
123static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
124#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
125#endif
Steven Rostedtb8489142011-05-04 09:27:52 -0400126
Steven Rostedt0a016402012-11-02 17:03:03 -0400127/*
128 * Traverse the ftrace_global_list, invoking all entries. The reason that we
Steven Rostedt1bb539c2013-05-28 14:38:43 -0400129 * can use rcu_dereference_raw_notrace() is that elements removed from this list
Steven Rostedt0a016402012-11-02 17:03:03 -0400130 * are simply leaked, so there is no need to interact with a grace-period
Steven Rostedt1bb539c2013-05-28 14:38:43 -0400131 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
Steven Rostedt0a016402012-11-02 17:03:03 -0400132 * concurrent insertions into the ftrace_global_list.
133 *
134 * Silly Alpha and silly pointer-speculation compiler optimizations!
135 */
136#define do_for_each_ftrace_op(op, list) \
Steven Rostedt1bb539c2013-05-28 14:38:43 -0400137 op = rcu_dereference_raw_notrace(list); \
Steven Rostedt0a016402012-11-02 17:03:03 -0400138 do
139
140/*
141 * Optimized for just a single item in the list (as that is the normal case).
142 */
143#define while_for_each_ftrace_op(op) \
Steven Rostedt1bb539c2013-05-28 14:38:43 -0400144 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
Steven Rostedt0a016402012-11-02 17:03:03 -0400145 unlikely((op) != &ftrace_list_end))
146
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +0900147static inline void ftrace_ops_init(struct ftrace_ops *ops)
148{
149#ifdef CONFIG_DYNAMIC_FTRACE
150 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -0400151 mutex_init(&ops->local_hash.regex_lock);
152 ops->func_hash = &ops->local_hash;
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +0900153 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
154 }
155#endif
156}
157
Steven Rostedtea701f12012-07-20 13:08:05 -0400158/**
159 * ftrace_nr_registered_ops - return number of ops registered
160 *
161 * Returns the number of ftrace_ops registered and tracing functions
162 */
163int ftrace_nr_registered_ops(void)
164{
165 struct ftrace_ops *ops;
166 int cnt = 0;
167
168 mutex_lock(&ftrace_lock);
169
170 for (ops = ftrace_ops_list;
171 ops != &ftrace_list_end; ops = ops->next)
172 cnt++;
173
174 mutex_unlock(&ftrace_lock);
175
176 return cnt;
177}
178
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400179static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -0400180 struct ftrace_ops *op, struct pt_regs *regs)
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500181{
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -0400182 struct trace_array *tr = op->private;
183
184 if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid))
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500185 return;
186
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -0400187 op->saved_func(ip, parent_ip, op, regs);
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500188}
189
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200190/**
Steven Rostedt3d083392008-05-12 21:20:42 +0200191 * clear_ftrace_function - reset the ftrace function
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200192 *
Steven Rostedt3d083392008-05-12 21:20:42 +0200193 * This NULLs the ftrace function and in essence stops
194 * tracing. There may be lag
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200195 */
Steven Rostedt3d083392008-05-12 21:20:42 +0200196void clear_ftrace_function(void)
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200197{
Steven Rostedt3d083392008-05-12 21:20:42 +0200198 ftrace_trace_function = ftrace_stub;
199}
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200200
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -0500201static void per_cpu_ops_disable_all(struct ftrace_ops *ops)
Jiri Olsae2484912012-02-15 15:51:48 +0100202{
203 int cpu;
204
205 for_each_possible_cpu(cpu)
206 *per_cpu_ptr(ops->disabled, cpu) = 1;
207}
208
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -0500209static int per_cpu_ops_alloc(struct ftrace_ops *ops)
Jiri Olsae2484912012-02-15 15:51:48 +0100210{
211 int __percpu *disabled;
212
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -0500213 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU)))
214 return -EINVAL;
215
Jiri Olsae2484912012-02-15 15:51:48 +0100216 disabled = alloc_percpu(int);
217 if (!disabled)
218 return -ENOMEM;
219
220 ops->disabled = disabled;
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -0500221 per_cpu_ops_disable_all(ops);
Jiri Olsae2484912012-02-15 15:51:48 +0100222 return 0;
223}
224
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -0500225static void ftrace_sync(struct work_struct *work)
226{
227 /*
228 * This function is just a stub to implement a hard force
229 * of synchronize_sched(). This requires synchronizing
230 * tasks even in userspace and idle.
231 *
232 * Yes, function tracing is rude.
233 */
234}
235
236static void ftrace_sync_ipi(void *data)
237{
238 /* Probably not needed, but do it anyway */
239 smp_rmb();
240}
241
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -0500242#ifdef CONFIG_FUNCTION_GRAPH_TRACER
243static void update_function_graph_func(void);
Steven Rostedt (Red Hat)55577202015-09-29 19:06:50 -0400244
245/* Both enabled by default (can be cleared by function_graph tracer flags */
246static bool fgraph_sleep_time = true;
247static bool fgraph_graph_time = true;
248
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -0500249#else
250static inline void update_function_graph_func(void) { }
251#endif
252
Steven Rostedt (Red Hat)00ccbf22015-02-19 15:56:14 +0100253
254static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
255{
256 /*
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -0500257 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
Steven Rostedt (Red Hat)00ccbf22015-02-19 15:56:14 +0100258 * then it needs to call the list anyway.
259 */
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -0500260 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU |
261 FTRACE_OPS_FL_RCU) || FTRACE_FORCE_LIST_FUNC)
Steven Rostedt (Red Hat)00ccbf22015-02-19 15:56:14 +0100262 return ftrace_ops_list_func;
263
264 return ftrace_ops_get_func(ops);
265}
266
Steven Rostedt2b499382011-05-03 22:49:52 -0400267static void update_ftrace_function(void)
268{
269 ftrace_func_t func;
270
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400271 /*
Steven Rostedt (Red Hat)f7aad4e2014-09-10 10:42:46 -0400272 * Prepare the ftrace_ops that the arch callback will use.
273 * If there's only one ftrace_ops registered, the ftrace_ops_list
274 * will point to the ops we want.
275 */
276 set_function_trace_op = ftrace_ops_list;
277
278 /* If there's no ftrace_ops registered, just call the stub function */
279 if (ftrace_ops_list == &ftrace_list_end) {
280 func = ftrace_stub;
281
282 /*
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400283 * If we are at the end of the list and this ops is
Steven Rostedt47409742012-07-20 11:04:44 -0400284 * recursion safe and not dynamic and the arch supports passing ops,
285 * then have the mcount trampoline call the function directly.
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400286 */
Steven Rostedt (Red Hat)f7aad4e2014-09-10 10:42:46 -0400287 } else if (ftrace_ops_list->next == &ftrace_list_end) {
Steven Rostedt (Red Hat)00ccbf22015-02-19 15:56:14 +0100288 func = ftrace_ops_get_list_func(ftrace_ops_list);
Steven Rostedt (Red Hat)f7aad4e2014-09-10 10:42:46 -0400289
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400290 } else {
291 /* Just use the default ftrace_ops */
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -0500292 set_function_trace_op = &ftrace_list_end;
Steven Rostedtb8489142011-05-04 09:27:52 -0400293 func = ftrace_ops_list_func;
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400294 }
Steven Rostedt2b499382011-05-03 22:49:52 -0400295
Steven Rostedt (Red Hat)5f8bf2d22014-07-15 11:05:12 -0400296 update_function_graph_func();
297
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -0500298 /* If there's no change, then do nothing more here */
299 if (ftrace_trace_function == func)
300 return;
301
302 /*
303 * If we are using the list function, it doesn't care
304 * about the function_trace_ops.
305 */
306 if (func == ftrace_ops_list_func) {
307 ftrace_trace_function = func;
308 /*
309 * Don't even bother setting function_trace_ops,
310 * it would be racy to do so anyway.
311 */
312 return;
313 }
314
315#ifndef CONFIG_DYNAMIC_FTRACE
316 /*
317 * For static tracing, we need to be a bit more careful.
318 * The function change takes affect immediately. Thus,
319 * we need to coorditate the setting of the function_trace_ops
320 * with the setting of the ftrace_trace_function.
321 *
322 * Set the function to the list ops, which will call the
323 * function we want, albeit indirectly, but it handles the
324 * ftrace_ops and doesn't depend on function_trace_op.
325 */
326 ftrace_trace_function = ftrace_ops_list_func;
327 /*
328 * Make sure all CPUs see this. Yes this is slow, but static
329 * tracing is slow and nasty to have enabled.
330 */
331 schedule_on_each_cpu(ftrace_sync);
332 /* Now all cpus are using the list ops. */
333 function_trace_op = set_function_trace_op;
334 /* Make sure the function_trace_op is visible on all CPUs */
335 smp_wmb();
336 /* Nasty way to force a rmb on all cpus */
337 smp_call_function(ftrace_sync_ipi, NULL, 1);
338 /* OK, we are all set to update the ftrace_trace_function now! */
339#endif /* !CONFIG_DYNAMIC_FTRACE */
340
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400341 ftrace_trace_function = func;
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400342}
343
Jiaxing Wang7eea4fc2014-04-20 23:10:43 +0800344int using_ftrace_ops_list_func(void)
345{
346 return ftrace_trace_function == ftrace_ops_list_func;
347}
348
Steven Rostedt2b499382011-05-03 22:49:52 -0400349static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
Steven Rostedt3d083392008-05-12 21:20:42 +0200350{
Steven Rostedt2b499382011-05-03 22:49:52 -0400351 ops->next = *list;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200352 /*
Steven Rostedtb8489142011-05-04 09:27:52 -0400353 * We are entering ops into the list but another
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200354 * CPU might be walking that list. We need to make sure
355 * the ops->next pointer is valid before another CPU sees
Steven Rostedtb8489142011-05-04 09:27:52 -0400356 * the ops pointer included into the list.
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200357 */
Steven Rostedt2b499382011-05-03 22:49:52 -0400358 rcu_assign_pointer(*list, ops);
359}
Steven Rostedt3d083392008-05-12 21:20:42 +0200360
Steven Rostedt2b499382011-05-03 22:49:52 -0400361static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
362{
363 struct ftrace_ops **p;
364
365 /*
366 * If we are removing the last function, then simply point
367 * to the ftrace_stub.
368 */
369 if (*list == ops && ops->next == &ftrace_list_end) {
370 *list = &ftrace_list_end;
371 return 0;
372 }
373
374 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
375 if (*p == ops)
376 break;
377
378 if (*p != ops)
379 return -1;
380
381 *p = (*p)->next;
382 return 0;
383}
384
Steven Rostedt (Red Hat)f3bea492014-07-02 23:23:31 -0400385static void ftrace_update_trampoline(struct ftrace_ops *ops);
386
Steven Rostedt2b499382011-05-03 22:49:52 -0400387static int __register_ftrace_function(struct ftrace_ops *ops)
388{
Steven Rostedt (Red Hat)591dffd2014-01-10 16:17:45 -0500389 if (ops->flags & FTRACE_OPS_FL_DELETED)
390 return -EINVAL;
391
Steven Rostedtb8489142011-05-04 09:27:52 -0400392 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
393 return -EBUSY;
394
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900395#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
Steven Rostedt08f6fba2012-04-30 16:20:23 -0400396 /*
397 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
398 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
399 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
400 */
401 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
402 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
403 return -EINVAL;
404
405 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
406 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
407#endif
408
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400409 if (!core_kernel_data((unsigned long)ops))
410 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
411
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -0500412 if (ops->flags & FTRACE_OPS_FL_PER_CPU) {
413 if (per_cpu_ops_alloc(ops))
Jiri Olsae2484912012-02-15 15:51:48 +0100414 return -ENOMEM;
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -0500415 }
416
417 add_ftrace_ops(&ftrace_ops_list, ops);
Steven Rostedtb8489142011-05-04 09:27:52 -0400418
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -0400419 /* Always save the function, and reset at unregistering */
420 ops->saved_func = ops->func;
421
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -0400422 if (ftrace_pids_enabled(ops))
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -0400423 ops->func = ftrace_pid_func;
424
Steven Rostedt (Red Hat)f3bea492014-07-02 23:23:31 -0400425 ftrace_update_trampoline(ops);
426
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400427 if (ftrace_enabled)
428 update_ftrace_function();
Steven Rostedt3d083392008-05-12 21:20:42 +0200429
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200430 return 0;
431}
432
Ingo Molnare309b412008-05-12 21:20:51 +0200433static int __unregister_ftrace_function(struct ftrace_ops *ops)
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200434{
Steven Rostedt2b499382011-05-03 22:49:52 -0400435 int ret;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200436
Steven Rostedtb8489142011-05-04 09:27:52 -0400437 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
438 return -EBUSY;
439
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -0500440 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
Steven Rostedtb8489142011-05-04 09:27:52 -0400441
Steven Rostedt2b499382011-05-03 22:49:52 -0400442 if (ret < 0)
443 return ret;
Steven Rostedtb8489142011-05-04 09:27:52 -0400444
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400445 if (ftrace_enabled)
446 update_ftrace_function();
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200447
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -0400448 ops->func = ops->saved_func;
449
Steven Rostedte6ea44e2009-02-14 01:42:44 -0500450 return 0;
Steven Rostedt3d083392008-05-12 21:20:42 +0200451}
452
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500453static void ftrace_update_pid_func(void)
454{
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -0400455 struct ftrace_ops *op;
456
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400457 /* Only do something if we are tracing something */
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500458 if (ftrace_trace_function == ftrace_stub)
KOSAKI Motohiro10dd3eb2009-03-06 15:29:04 +0900459 return;
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500460
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -0400461 do_for_each_ftrace_op(op, ftrace_ops_list) {
462 if (op->flags & FTRACE_OPS_FL_PID) {
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -0400463 op->func = ftrace_pids_enabled(op) ?
464 ftrace_pid_func : op->saved_func;
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -0400465 ftrace_update_trampoline(op);
466 }
467 } while_for_each_ftrace_op(op);
468
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400469 update_ftrace_function();
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500470}
471
Steven Rostedt493762f2009-03-23 17:12:36 -0400472#ifdef CONFIG_FUNCTION_PROFILER
473struct ftrace_profile {
474 struct hlist_node node;
475 unsigned long ip;
476 unsigned long counter;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400477#ifdef CONFIG_FUNCTION_GRAPH_TRACER
478 unsigned long long time;
Chase Douglase330b3b2010-04-26 14:02:05 -0400479 unsigned long long time_squared;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400480#endif
Steven Rostedt493762f2009-03-23 17:12:36 -0400481};
482
483struct ftrace_profile_page {
484 struct ftrace_profile_page *next;
485 unsigned long index;
486 struct ftrace_profile records[];
487};
488
Steven Rostedtcafb1682009-03-24 20:50:39 -0400489struct ftrace_profile_stat {
490 atomic_t disabled;
491 struct hlist_head *hash;
492 struct ftrace_profile_page *pages;
493 struct ftrace_profile_page *start;
494 struct tracer_stat stat;
495};
496
Steven Rostedt493762f2009-03-23 17:12:36 -0400497#define PROFILE_RECORDS_SIZE \
498 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
499
500#define PROFILES_PER_PAGE \
501 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
502
Steven Rostedtfb9fb012009-03-25 13:26:41 -0400503static int ftrace_profile_enabled __read_mostly;
504
505/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
Steven Rostedt493762f2009-03-23 17:12:36 -0400506static DEFINE_MUTEX(ftrace_profile_lock);
507
Steven Rostedtcafb1682009-03-24 20:50:39 -0400508static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
Steven Rostedt493762f2009-03-23 17:12:36 -0400509
Namhyung Kim20079eb2013-04-10 08:55:50 +0900510#define FTRACE_PROFILE_HASH_BITS 10
511#define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
Steven Rostedt493762f2009-03-23 17:12:36 -0400512
Steven Rostedt493762f2009-03-23 17:12:36 -0400513static void *
514function_stat_next(void *v, int idx)
515{
516 struct ftrace_profile *rec = v;
517 struct ftrace_profile_page *pg;
518
519 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
520
521 again:
Li Zefan0296e422009-06-26 11:15:37 +0800522 if (idx != 0)
523 rec++;
524
Steven Rostedt493762f2009-03-23 17:12:36 -0400525 if ((void *)rec >= (void *)&pg->records[pg->index]) {
526 pg = pg->next;
527 if (!pg)
528 return NULL;
529 rec = &pg->records[0];
530 if (!rec->counter)
531 goto again;
532 }
533
534 return rec;
535}
536
537static void *function_stat_start(struct tracer_stat *trace)
538{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400539 struct ftrace_profile_stat *stat =
540 container_of(trace, struct ftrace_profile_stat, stat);
541
542 if (!stat || !stat->start)
543 return NULL;
544
545 return function_stat_next(&stat->start->records[0], 0);
Steven Rostedt493762f2009-03-23 17:12:36 -0400546}
547
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400548#ifdef CONFIG_FUNCTION_GRAPH_TRACER
549/* function graph compares on total time */
550static int function_stat_cmp(void *p1, void *p2)
551{
552 struct ftrace_profile *a = p1;
553 struct ftrace_profile *b = p2;
554
555 if (a->time < b->time)
556 return -1;
557 if (a->time > b->time)
558 return 1;
559 else
560 return 0;
561}
562#else
563/* not function graph compares against hits */
Steven Rostedt493762f2009-03-23 17:12:36 -0400564static int function_stat_cmp(void *p1, void *p2)
565{
566 struct ftrace_profile *a = p1;
567 struct ftrace_profile *b = p2;
568
569 if (a->counter < b->counter)
570 return -1;
571 if (a->counter > b->counter)
572 return 1;
573 else
574 return 0;
575}
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400576#endif
Steven Rostedt493762f2009-03-23 17:12:36 -0400577
578static int function_stat_headers(struct seq_file *m)
579{
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400580#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Rasmus Villemoesfa6f0cc2014-11-08 21:42:10 +0100581 seq_puts(m, " Function "
582 "Hit Time Avg s^2\n"
583 " -------- "
584 "--- ---- --- ---\n");
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400585#else
Rasmus Villemoesfa6f0cc2014-11-08 21:42:10 +0100586 seq_puts(m, " Function Hit\n"
587 " -------- ---\n");
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400588#endif
Steven Rostedt493762f2009-03-23 17:12:36 -0400589 return 0;
590}
591
592static int function_stat_show(struct seq_file *m, void *v)
593{
594 struct ftrace_profile *rec = v;
595 char str[KSYM_SYMBOL_LEN];
Li Zefan3aaba202010-08-23 16:50:12 +0800596 int ret = 0;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400597#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Steven Rostedt34886c82009-03-25 21:00:47 -0400598 static struct trace_seq s;
599 unsigned long long avg;
Chase Douglase330b3b2010-04-26 14:02:05 -0400600 unsigned long long stddev;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400601#endif
Li Zefan3aaba202010-08-23 16:50:12 +0800602 mutex_lock(&ftrace_profile_lock);
603
604 /* we raced with function_profile_reset() */
605 if (unlikely(rec->counter == 0)) {
606 ret = -EBUSY;
607 goto out;
608 }
Steven Rostedt493762f2009-03-23 17:12:36 -0400609
Umesh Tiwari8e436ca2015-06-22 16:58:08 +0530610#ifdef CONFIG_FUNCTION_GRAPH_TRACER
611 avg = rec->time;
612 do_div(avg, rec->counter);
613 if (tracing_thresh && (avg < tracing_thresh))
614 goto out;
615#endif
616
Steven Rostedt493762f2009-03-23 17:12:36 -0400617 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400618 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
Steven Rostedt493762f2009-03-23 17:12:36 -0400619
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400620#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Rasmus Villemoesfa6f0cc2014-11-08 21:42:10 +0100621 seq_puts(m, " ");
Steven Rostedt34886c82009-03-25 21:00:47 -0400622
Chase Douglase330b3b2010-04-26 14:02:05 -0400623 /* Sample standard deviation (s^2) */
624 if (rec->counter <= 1)
625 stddev = 0;
626 else {
Juri Lelli52d85d72013-06-12 12:03:18 +0200627 /*
628 * Apply Welford's method:
629 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
630 */
631 stddev = rec->counter * rec->time_squared -
632 rec->time * rec->time;
633
Chase Douglase330b3b2010-04-26 14:02:05 -0400634 /*
635 * Divide only 1000 for ns^2 -> us^2 conversion.
636 * trace_print_graph_duration will divide 1000 again.
637 */
Juri Lelli52d85d72013-06-12 12:03:18 +0200638 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
Chase Douglase330b3b2010-04-26 14:02:05 -0400639 }
640
Steven Rostedt34886c82009-03-25 21:00:47 -0400641 trace_seq_init(&s);
642 trace_print_graph_duration(rec->time, &s);
643 trace_seq_puts(&s, " ");
644 trace_print_graph_duration(avg, &s);
Chase Douglase330b3b2010-04-26 14:02:05 -0400645 trace_seq_puts(&s, " ");
646 trace_print_graph_duration(stddev, &s);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400647 trace_print_seq(m, &s);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400648#endif
649 seq_putc(m, '\n');
Li Zefan3aaba202010-08-23 16:50:12 +0800650out:
651 mutex_unlock(&ftrace_profile_lock);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400652
Li Zefan3aaba202010-08-23 16:50:12 +0800653 return ret;
Steven Rostedt493762f2009-03-23 17:12:36 -0400654}
655
Steven Rostedtcafb1682009-03-24 20:50:39 -0400656static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
Steven Rostedt493762f2009-03-23 17:12:36 -0400657{
658 struct ftrace_profile_page *pg;
659
Steven Rostedtcafb1682009-03-24 20:50:39 -0400660 pg = stat->pages = stat->start;
Steven Rostedt493762f2009-03-23 17:12:36 -0400661
662 while (pg) {
663 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
664 pg->index = 0;
665 pg = pg->next;
666 }
667
Steven Rostedtcafb1682009-03-24 20:50:39 -0400668 memset(stat->hash, 0,
Steven Rostedt493762f2009-03-23 17:12:36 -0400669 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
670}
671
Steven Rostedtcafb1682009-03-24 20:50:39 -0400672int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
Steven Rostedt493762f2009-03-23 17:12:36 -0400673{
674 struct ftrace_profile_page *pg;
Steven Rostedt318e0a72009-03-25 20:06:34 -0400675 int functions;
676 int pages;
Steven Rostedt493762f2009-03-23 17:12:36 -0400677 int i;
678
679 /* If we already allocated, do nothing */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400680 if (stat->pages)
Steven Rostedt493762f2009-03-23 17:12:36 -0400681 return 0;
682
Steven Rostedtcafb1682009-03-24 20:50:39 -0400683 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
684 if (!stat->pages)
Steven Rostedt493762f2009-03-23 17:12:36 -0400685 return -ENOMEM;
686
Steven Rostedt318e0a72009-03-25 20:06:34 -0400687#ifdef CONFIG_DYNAMIC_FTRACE
688 functions = ftrace_update_tot_cnt;
689#else
690 /*
691 * We do not know the number of functions that exist because
692 * dynamic tracing is what counts them. With past experience
693 * we have around 20K functions. That should be more than enough.
694 * It is highly unlikely we will execute every function in
695 * the kernel.
696 */
697 functions = 20000;
698#endif
699
Steven Rostedtcafb1682009-03-24 20:50:39 -0400700 pg = stat->start = stat->pages;
Steven Rostedt493762f2009-03-23 17:12:36 -0400701
Steven Rostedt318e0a72009-03-25 20:06:34 -0400702 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
703
Namhyung Kim39e30cd2013-04-01 21:46:24 +0900704 for (i = 1; i < pages; i++) {
Steven Rostedt493762f2009-03-23 17:12:36 -0400705 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
Steven Rostedt493762f2009-03-23 17:12:36 -0400706 if (!pg->next)
Steven Rostedt318e0a72009-03-25 20:06:34 -0400707 goto out_free;
Steven Rostedt493762f2009-03-23 17:12:36 -0400708 pg = pg->next;
709 }
710
711 return 0;
Steven Rostedt318e0a72009-03-25 20:06:34 -0400712
713 out_free:
714 pg = stat->start;
715 while (pg) {
716 unsigned long tmp = (unsigned long)pg;
717
718 pg = pg->next;
719 free_page(tmp);
720 }
721
Steven Rostedt318e0a72009-03-25 20:06:34 -0400722 stat->pages = NULL;
723 stat->start = NULL;
724
725 return -ENOMEM;
Steven Rostedt493762f2009-03-23 17:12:36 -0400726}
727
Steven Rostedtcafb1682009-03-24 20:50:39 -0400728static int ftrace_profile_init_cpu(int cpu)
Steven Rostedt493762f2009-03-23 17:12:36 -0400729{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400730 struct ftrace_profile_stat *stat;
Steven Rostedt493762f2009-03-23 17:12:36 -0400731 int size;
732
Steven Rostedtcafb1682009-03-24 20:50:39 -0400733 stat = &per_cpu(ftrace_profile_stats, cpu);
734
735 if (stat->hash) {
Steven Rostedt493762f2009-03-23 17:12:36 -0400736 /* If the profile is already created, simply reset it */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400737 ftrace_profile_reset(stat);
Steven Rostedt493762f2009-03-23 17:12:36 -0400738 return 0;
739 }
740
741 /*
742 * We are profiling all functions, but usually only a few thousand
743 * functions are hit. We'll make a hash of 1024 items.
744 */
745 size = FTRACE_PROFILE_HASH_SIZE;
746
Steven Rostedtcafb1682009-03-24 20:50:39 -0400747 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
Steven Rostedt493762f2009-03-23 17:12:36 -0400748
Steven Rostedtcafb1682009-03-24 20:50:39 -0400749 if (!stat->hash)
Steven Rostedt493762f2009-03-23 17:12:36 -0400750 return -ENOMEM;
751
Steven Rostedt318e0a72009-03-25 20:06:34 -0400752 /* Preallocate the function profiling pages */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400753 if (ftrace_profile_pages_init(stat) < 0) {
754 kfree(stat->hash);
755 stat->hash = NULL;
Steven Rostedt493762f2009-03-23 17:12:36 -0400756 return -ENOMEM;
757 }
758
759 return 0;
760}
761
Steven Rostedtcafb1682009-03-24 20:50:39 -0400762static int ftrace_profile_init(void)
763{
764 int cpu;
765 int ret = 0;
766
Miao Xiec4602c12013-12-16 15:20:01 +0800767 for_each_possible_cpu(cpu) {
Steven Rostedtcafb1682009-03-24 20:50:39 -0400768 ret = ftrace_profile_init_cpu(cpu);
769 if (ret)
770 break;
771 }
772
773 return ret;
774}
775
Steven Rostedt493762f2009-03-23 17:12:36 -0400776/* interrupts must be disabled */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400777static struct ftrace_profile *
778ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
Steven Rostedt493762f2009-03-23 17:12:36 -0400779{
780 struct ftrace_profile *rec;
781 struct hlist_head *hhd;
Steven Rostedt493762f2009-03-23 17:12:36 -0400782 unsigned long key;
783
Namhyung Kim20079eb2013-04-10 08:55:50 +0900784 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
Steven Rostedtcafb1682009-03-24 20:50:39 -0400785 hhd = &stat->hash[key];
Steven Rostedt493762f2009-03-23 17:12:36 -0400786
787 if (hlist_empty(hhd))
788 return NULL;
789
Steven Rostedt1bb539c2013-05-28 14:38:43 -0400790 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
Steven Rostedt493762f2009-03-23 17:12:36 -0400791 if (rec->ip == ip)
792 return rec;
793 }
794
795 return NULL;
796}
797
Steven Rostedtcafb1682009-03-24 20:50:39 -0400798static void ftrace_add_profile(struct ftrace_profile_stat *stat,
799 struct ftrace_profile *rec)
Steven Rostedt493762f2009-03-23 17:12:36 -0400800{
801 unsigned long key;
802
Namhyung Kim20079eb2013-04-10 08:55:50 +0900803 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
Steven Rostedtcafb1682009-03-24 20:50:39 -0400804 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
Steven Rostedt493762f2009-03-23 17:12:36 -0400805}
806
Steven Rostedt318e0a72009-03-25 20:06:34 -0400807/*
808 * The memory is already allocated, this simply finds a new record to use.
809 */
Steven Rostedt493762f2009-03-23 17:12:36 -0400810static struct ftrace_profile *
Steven Rostedt318e0a72009-03-25 20:06:34 -0400811ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
Steven Rostedt493762f2009-03-23 17:12:36 -0400812{
813 struct ftrace_profile *rec = NULL;
814
Steven Rostedt318e0a72009-03-25 20:06:34 -0400815 /* prevent recursion (from NMIs) */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400816 if (atomic_inc_return(&stat->disabled) != 1)
Steven Rostedt493762f2009-03-23 17:12:36 -0400817 goto out;
818
Steven Rostedt493762f2009-03-23 17:12:36 -0400819 /*
Steven Rostedt318e0a72009-03-25 20:06:34 -0400820 * Try to find the function again since an NMI
821 * could have added it
Steven Rostedt493762f2009-03-23 17:12:36 -0400822 */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400823 rec = ftrace_find_profiled_func(stat, ip);
Steven Rostedt493762f2009-03-23 17:12:36 -0400824 if (rec)
Steven Rostedtcafb1682009-03-24 20:50:39 -0400825 goto out;
Steven Rostedt493762f2009-03-23 17:12:36 -0400826
Steven Rostedtcafb1682009-03-24 20:50:39 -0400827 if (stat->pages->index == PROFILES_PER_PAGE) {
828 if (!stat->pages->next)
829 goto out;
830 stat->pages = stat->pages->next;
Steven Rostedt493762f2009-03-23 17:12:36 -0400831 }
832
Steven Rostedtcafb1682009-03-24 20:50:39 -0400833 rec = &stat->pages->records[stat->pages->index++];
Steven Rostedt493762f2009-03-23 17:12:36 -0400834 rec->ip = ip;
Steven Rostedtcafb1682009-03-24 20:50:39 -0400835 ftrace_add_profile(stat, rec);
Steven Rostedt493762f2009-03-23 17:12:36 -0400836
Steven Rostedt493762f2009-03-23 17:12:36 -0400837 out:
Steven Rostedtcafb1682009-03-24 20:50:39 -0400838 atomic_dec(&stat->disabled);
Steven Rostedt493762f2009-03-23 17:12:36 -0400839
840 return rec;
841}
842
Steven Rostedt493762f2009-03-23 17:12:36 -0400843static void
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400844function_profile_call(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -0400845 struct ftrace_ops *ops, struct pt_regs *regs)
Steven Rostedt493762f2009-03-23 17:12:36 -0400846{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400847 struct ftrace_profile_stat *stat;
Steven Rostedt493762f2009-03-23 17:12:36 -0400848 struct ftrace_profile *rec;
849 unsigned long flags;
Steven Rostedt493762f2009-03-23 17:12:36 -0400850
851 if (!ftrace_profile_enabled)
852 return;
853
Steven Rostedt493762f2009-03-23 17:12:36 -0400854 local_irq_save(flags);
Steven Rostedtcafb1682009-03-24 20:50:39 -0400855
Christoph Lameterbdffd892014-04-29 14:17:40 -0500856 stat = this_cpu_ptr(&ftrace_profile_stats);
Steven Rostedt0f6ce3d2009-06-01 21:51:28 -0400857 if (!stat->hash || !ftrace_profile_enabled)
Steven Rostedtcafb1682009-03-24 20:50:39 -0400858 goto out;
859
860 rec = ftrace_find_profiled_func(stat, ip);
Steven Rostedt493762f2009-03-23 17:12:36 -0400861 if (!rec) {
Steven Rostedt318e0a72009-03-25 20:06:34 -0400862 rec = ftrace_profile_alloc(stat, ip);
Steven Rostedt493762f2009-03-23 17:12:36 -0400863 if (!rec)
864 goto out;
865 }
866
867 rec->counter++;
868 out:
869 local_irq_restore(flags);
870}
871
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400872#ifdef CONFIG_FUNCTION_GRAPH_TRACER
873static int profile_graph_entry(struct ftrace_graph_ent *trace)
874{
Namhyung Kim8861dd32016-08-31 11:55:29 +0900875 int index = trace->depth;
876
Steven Rostedta1e2e312011-08-09 12:50:46 -0400877 function_profile_call(trace->func, 0, NULL, NULL);
Namhyung Kim8861dd32016-08-31 11:55:29 +0900878
879 if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
880 current->ret_stack[index].subtime = 0;
881
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400882 return 1;
883}
884
885static void profile_graph_return(struct ftrace_graph_ret *trace)
886{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400887 struct ftrace_profile_stat *stat;
Steven Rostedta2a16d62009-03-24 23:17:58 -0400888 unsigned long long calltime;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400889 struct ftrace_profile *rec;
Steven Rostedtcafb1682009-03-24 20:50:39 -0400890 unsigned long flags;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400891
892 local_irq_save(flags);
Christoph Lameterbdffd892014-04-29 14:17:40 -0500893 stat = this_cpu_ptr(&ftrace_profile_stats);
Steven Rostedt0f6ce3d2009-06-01 21:51:28 -0400894 if (!stat->hash || !ftrace_profile_enabled)
Steven Rostedtcafb1682009-03-24 20:50:39 -0400895 goto out;
896
Steven Rostedt37e44bc2010-04-27 21:04:24 -0400897 /* If the calltime was zero'd ignore it */
898 if (!trace->calltime)
899 goto out;
900
Steven Rostedta2a16d62009-03-24 23:17:58 -0400901 calltime = trace->rettime - trace->calltime;
902
Steven Rostedt (Red Hat)55577202015-09-29 19:06:50 -0400903 if (!fgraph_graph_time) {
Steven Rostedta2a16d62009-03-24 23:17:58 -0400904 int index;
905
906 index = trace->depth;
907
908 /* Append this call time to the parent time to subtract */
909 if (index)
910 current->ret_stack[index - 1].subtime += calltime;
911
912 if (current->ret_stack[index].subtime < calltime)
913 calltime -= current->ret_stack[index].subtime;
914 else
915 calltime = 0;
916 }
917
Steven Rostedtcafb1682009-03-24 20:50:39 -0400918 rec = ftrace_find_profiled_func(stat, trace->func);
Chase Douglase330b3b2010-04-26 14:02:05 -0400919 if (rec) {
Steven Rostedta2a16d62009-03-24 23:17:58 -0400920 rec->time += calltime;
Chase Douglase330b3b2010-04-26 14:02:05 -0400921 rec->time_squared += calltime * calltime;
922 }
Steven Rostedta2a16d62009-03-24 23:17:58 -0400923
Steven Rostedtcafb1682009-03-24 20:50:39 -0400924 out:
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400925 local_irq_restore(flags);
926}
927
928static int register_ftrace_profiler(void)
929{
930 return register_ftrace_graph(&profile_graph_return,
931 &profile_graph_entry);
932}
933
934static void unregister_ftrace_profiler(void)
935{
936 unregister_ftrace_graph();
937}
938#else
Paul McQuadebd38c0e2011-05-31 20:51:55 +0100939static struct ftrace_ops ftrace_profile_ops __read_mostly = {
Steven Rostedtfb9fb012009-03-25 13:26:41 -0400940 .func = function_profile_call,
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +0900941 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -0400942 INIT_OPS_HASH(ftrace_profile_ops)
Steven Rostedt493762f2009-03-23 17:12:36 -0400943};
944
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400945static int register_ftrace_profiler(void)
946{
947 return register_ftrace_function(&ftrace_profile_ops);
948}
949
950static void unregister_ftrace_profiler(void)
951{
952 unregister_ftrace_function(&ftrace_profile_ops);
953}
954#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
955
Steven Rostedt493762f2009-03-23 17:12:36 -0400956static ssize_t
957ftrace_profile_write(struct file *filp, const char __user *ubuf,
958 size_t cnt, loff_t *ppos)
959{
960 unsigned long val;
Steven Rostedt493762f2009-03-23 17:12:36 -0400961 int ret;
962
Peter Huewe22fe9b52011-06-07 21:58:27 +0200963 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
964 if (ret)
Steven Rostedt493762f2009-03-23 17:12:36 -0400965 return ret;
966
967 val = !!val;
968
969 mutex_lock(&ftrace_profile_lock);
970 if (ftrace_profile_enabled ^ val) {
971 if (val) {
972 ret = ftrace_profile_init();
973 if (ret < 0) {
974 cnt = ret;
975 goto out;
976 }
977
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400978 ret = register_ftrace_profiler();
979 if (ret < 0) {
980 cnt = ret;
981 goto out;
982 }
Steven Rostedt493762f2009-03-23 17:12:36 -0400983 ftrace_profile_enabled = 1;
984 } else {
985 ftrace_profile_enabled = 0;
Steven Rostedt0f6ce3d2009-06-01 21:51:28 -0400986 /*
987 * unregister_ftrace_profiler calls stop_machine
988 * so this acts like an synchronize_sched.
989 */
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400990 unregister_ftrace_profiler();
Steven Rostedt493762f2009-03-23 17:12:36 -0400991 }
992 }
993 out:
994 mutex_unlock(&ftrace_profile_lock);
995
Jiri Olsacf8517c2009-10-23 19:36:16 -0400996 *ppos += cnt;
Steven Rostedt493762f2009-03-23 17:12:36 -0400997
998 return cnt;
999}
1000
1001static ssize_t
1002ftrace_profile_read(struct file *filp, char __user *ubuf,
1003 size_t cnt, loff_t *ppos)
1004{
Steven Rostedtfb9fb012009-03-25 13:26:41 -04001005 char buf[64]; /* big enough to hold a number */
Steven Rostedt493762f2009-03-23 17:12:36 -04001006 int r;
1007
1008 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
1009 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
1010}
1011
1012static const struct file_operations ftrace_profile_fops = {
1013 .open = tracing_open_generic,
1014 .read = ftrace_profile_read,
1015 .write = ftrace_profile_write,
Arnd Bergmann6038f372010-08-15 18:52:59 +02001016 .llseek = default_llseek,
Steven Rostedt493762f2009-03-23 17:12:36 -04001017};
1018
Steven Rostedtcafb1682009-03-24 20:50:39 -04001019/* used to initialize the real stat files */
1020static struct tracer_stat function_stats __initdata = {
Steven Rostedtfb9fb012009-03-25 13:26:41 -04001021 .name = "functions",
1022 .stat_start = function_stat_start,
1023 .stat_next = function_stat_next,
1024 .stat_cmp = function_stat_cmp,
1025 .stat_headers = function_stat_headers,
1026 .stat_show = function_stat_show
Steven Rostedtcafb1682009-03-24 20:50:39 -04001027};
1028
Steven Rostedt (Red Hat)8434dc92015-01-20 12:13:40 -05001029static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
Steven Rostedt493762f2009-03-23 17:12:36 -04001030{
Steven Rostedtcafb1682009-03-24 20:50:39 -04001031 struct ftrace_profile_stat *stat;
Steven Rostedt493762f2009-03-23 17:12:36 -04001032 struct dentry *entry;
Steven Rostedtcafb1682009-03-24 20:50:39 -04001033 char *name;
Steven Rostedt493762f2009-03-23 17:12:36 -04001034 int ret;
Steven Rostedtcafb1682009-03-24 20:50:39 -04001035 int cpu;
Steven Rostedt493762f2009-03-23 17:12:36 -04001036
Steven Rostedtcafb1682009-03-24 20:50:39 -04001037 for_each_possible_cpu(cpu) {
1038 stat = &per_cpu(ftrace_profile_stats, cpu);
1039
Geliang Tang6363c6b2016-03-15 22:12:34 +08001040 name = kasprintf(GFP_KERNEL, "function%d", cpu);
Steven Rostedtcafb1682009-03-24 20:50:39 -04001041 if (!name) {
1042 /*
1043 * The files created are permanent, if something happens
1044 * we still do not free memory.
1045 */
Steven Rostedtcafb1682009-03-24 20:50:39 -04001046 WARN(1,
1047 "Could not allocate stat file for cpu %d\n",
1048 cpu);
1049 return;
1050 }
1051 stat->stat = function_stats;
Steven Rostedtcafb1682009-03-24 20:50:39 -04001052 stat->stat.name = name;
1053 ret = register_stat_tracer(&stat->stat);
1054 if (ret) {
1055 WARN(1,
1056 "Could not register function stat for cpu %d\n",
1057 cpu);
1058 kfree(name);
1059 return;
1060 }
Steven Rostedt493762f2009-03-23 17:12:36 -04001061 }
1062
Steven Rostedt (Red Hat)8434dc92015-01-20 12:13:40 -05001063 entry = tracefs_create_file("function_profile_enabled", 0644,
Steven Rostedt493762f2009-03-23 17:12:36 -04001064 d_tracer, NULL, &ftrace_profile_fops);
1065 if (!entry)
Joe Perchesa395d6a2016-03-22 14:28:09 -07001066 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
Steven Rostedt493762f2009-03-23 17:12:36 -04001067}
1068
1069#else /* CONFIG_FUNCTION_PROFILER */
Steven Rostedt (Red Hat)8434dc92015-01-20 12:13:40 -05001070static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
Steven Rostedt493762f2009-03-23 17:12:36 -04001071{
1072}
1073#endif /* CONFIG_FUNCTION_PROFILER */
1074
Ingo Molnar73d3fd92009-02-17 11:48:18 +01001075static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1076
Pratyush Anand1619dc32015-03-06 23:58:06 +05301077#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1078static int ftrace_graph_active;
1079#else
1080# define ftrace_graph_active 0
1081#endif
1082
Steven Rostedt3d083392008-05-12 21:20:42 +02001083#ifdef CONFIG_DYNAMIC_FTRACE
Ingo Molnar73d3fd92009-02-17 11:48:18 +01001084
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001085static struct ftrace_ops *removed_ops;
1086
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04001087/*
1088 * Set when doing a global update, like enabling all recs or disabling them.
1089 * It is not set when just updating a single ftrace_ops.
1090 */
1091static bool update_all_ops;
1092
Steven Rostedt99ecdc42008-08-15 21:40:05 -04001093#ifndef CONFIG_FTRACE_MCOUNT_RECORD
Steven Rostedtcb7be3b2008-10-23 09:33:05 -04001094# error Dynamic ftrace depends on MCOUNT_RECORD
Steven Rostedt99ecdc42008-08-15 21:40:05 -04001095#endif
1096
Steven Rostedt8fc0c702009-02-16 15:28:00 -05001097static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
1098
Steven Rostedtb6887d72009-02-17 12:32:04 -05001099struct ftrace_func_probe {
Steven Rostedt8fc0c702009-02-16 15:28:00 -05001100 struct hlist_node node;
Steven Rostedtb6887d72009-02-17 12:32:04 -05001101 struct ftrace_probe_ops *ops;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05001102 unsigned long flags;
1103 unsigned long ip;
1104 void *data;
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04001105 struct list_head free_list;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05001106};
1107
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001108struct ftrace_func_entry {
1109 struct hlist_node hlist;
1110 unsigned long ip;
1111};
1112
1113struct ftrace_hash {
1114 unsigned long size_bits;
1115 struct hlist_head *buckets;
1116 unsigned long count;
Steven Rostedt07fd5512011-05-05 18:03:47 -04001117 struct rcu_head rcu;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001118};
1119
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001120/*
1121 * We make these constant because no one should touch them,
1122 * but they are used as the default "empty hash", to avoid allocating
1123 * it all the time. These are in a read only section such that if
1124 * anyone does try to modify it, it will cause an exception.
1125 */
1126static const struct hlist_head empty_buckets[1];
1127static const struct ftrace_hash empty_hash = {
1128 .buckets = (struct hlist_head *)empty_buckets,
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001129};
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001130#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
Steven Rostedt5072c592008-05-12 21:20:43 +02001131
Steven Rostedt2b499382011-05-03 22:49:52 -04001132static struct ftrace_ops global_ops = {
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04001133 .func = ftrace_stub,
1134 .local_hash.notrace_hash = EMPTY_HASH,
1135 .local_hash.filter_hash = EMPTY_HASH,
1136 INIT_OPS_HASH(global_ops)
1137 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -04001138 FTRACE_OPS_FL_INITIALIZED |
1139 FTRACE_OPS_FL_PID,
Steven Rostedtf45948e2011-05-02 12:29:25 -04001140};
1141
Steven Rostedt (Red Hat)aec0be22014-11-18 21:14:11 -05001142/*
1143 * This is used by __kernel_text_address() to return true if the
Steven Rostedt (Red Hat)0af26492014-11-20 10:05:36 -05001144 * address is on a dynamically allocated trampoline that would
Steven Rostedt (Red Hat)aec0be22014-11-18 21:14:11 -05001145 * not return true for either core_kernel_text() or
1146 * is_module_text_address().
1147 */
1148bool is_ftrace_trampoline(unsigned long addr)
1149{
1150 struct ftrace_ops *op;
1151 bool ret = false;
1152
1153 /*
1154 * Some of the ops may be dynamically allocated,
1155 * they are freed after a synchronize_sched().
1156 */
1157 preempt_disable_notrace();
1158
1159 do_for_each_ftrace_op(op, ftrace_ops_list) {
1160 /*
1161 * This is to check for dynamically allocated trampolines.
1162 * Trampolines that are in kernel text will have
1163 * core_kernel_text() return true.
1164 */
1165 if (op->trampoline && op->trampoline_size)
1166 if (addr >= op->trampoline &&
1167 addr < op->trampoline + op->trampoline_size) {
1168 ret = true;
1169 goto out;
1170 }
1171 } while_for_each_ftrace_op(op);
1172
1173 out:
1174 preempt_enable_notrace();
1175
1176 return ret;
1177}
1178
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001179struct ftrace_page {
1180 struct ftrace_page *next;
Steven Rostedta7900872011-12-16 16:23:44 -05001181 struct dyn_ftrace *records;
Steven Rostedt431aa3f2009-01-06 12:43:01 -05001182 int index;
Steven Rostedta7900872011-12-16 16:23:44 -05001183 int size;
David Milleraa5e5ce2008-05-13 22:06:56 -07001184};
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001185
Steven Rostedta7900872011-12-16 16:23:44 -05001186#define ENTRY_SIZE sizeof(struct dyn_ftrace)
1187#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001188
1189/* estimate from running different kernels */
1190#define NR_TO_INIT 10000
1191
1192static struct ftrace_page *ftrace_pages_start;
1193static struct ftrace_page *ftrace_pages;
1194
Steven Rostedt (Red Hat)68f40962014-05-01 12:44:50 -04001195static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash)
Steven Rostedt06a51d92011-12-19 19:07:36 -05001196{
1197 return !hash || !hash->count;
1198}
1199
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001200static struct ftrace_func_entry *
1201ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1202{
1203 unsigned long key;
1204 struct ftrace_func_entry *entry;
1205 struct hlist_head *hhd;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001206
Steven Rostedt06a51d92011-12-19 19:07:36 -05001207 if (ftrace_hash_empty(hash))
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001208 return NULL;
1209
1210 if (hash->size_bits > 0)
1211 key = hash_long(ip, hash->size_bits);
1212 else
1213 key = 0;
1214
1215 hhd = &hash->buckets[key];
1216
Steven Rostedt1bb539c2013-05-28 14:38:43 -04001217 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001218 if (entry->ip == ip)
1219 return entry;
1220 }
1221 return NULL;
1222}
1223
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001224static void __add_hash_entry(struct ftrace_hash *hash,
1225 struct ftrace_func_entry *entry)
1226{
1227 struct hlist_head *hhd;
1228 unsigned long key;
1229
1230 if (hash->size_bits)
1231 key = hash_long(entry->ip, hash->size_bits);
1232 else
1233 key = 0;
1234
1235 hhd = &hash->buckets[key];
1236 hlist_add_head(&entry->hlist, hhd);
1237 hash->count++;
1238}
1239
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001240static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1241{
1242 struct ftrace_func_entry *entry;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001243
1244 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1245 if (!entry)
1246 return -ENOMEM;
1247
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001248 entry->ip = ip;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001249 __add_hash_entry(hash, entry);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001250
1251 return 0;
1252}
1253
1254static void
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001255free_hash_entry(struct ftrace_hash *hash,
1256 struct ftrace_func_entry *entry)
1257{
1258 hlist_del(&entry->hlist);
1259 kfree(entry);
1260 hash->count--;
1261}
1262
1263static void
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001264remove_hash_entry(struct ftrace_hash *hash,
1265 struct ftrace_func_entry *entry)
1266{
1267 hlist_del(&entry->hlist);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001268 hash->count--;
1269}
1270
1271static void ftrace_hash_clear(struct ftrace_hash *hash)
1272{
1273 struct hlist_head *hhd;
Sasha Levinb67bfe02013-02-27 17:06:00 -08001274 struct hlist_node *tn;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001275 struct ftrace_func_entry *entry;
1276 int size = 1 << hash->size_bits;
1277 int i;
1278
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001279 if (!hash->count)
1280 return;
1281
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001282 for (i = 0; i < size; i++) {
1283 hhd = &hash->buckets[i];
Sasha Levinb67bfe02013-02-27 17:06:00 -08001284 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001285 free_hash_entry(hash, entry);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001286 }
1287 FTRACE_WARN_ON(hash->count);
1288}
1289
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001290static void free_ftrace_hash(struct ftrace_hash *hash)
1291{
1292 if (!hash || hash == EMPTY_HASH)
1293 return;
1294 ftrace_hash_clear(hash);
1295 kfree(hash->buckets);
1296 kfree(hash);
1297}
1298
Steven Rostedt07fd5512011-05-05 18:03:47 -04001299static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1300{
1301 struct ftrace_hash *hash;
1302
1303 hash = container_of(rcu, struct ftrace_hash, rcu);
1304 free_ftrace_hash(hash);
1305}
1306
1307static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1308{
1309 if (!hash || hash == EMPTY_HASH)
1310 return;
1311 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1312}
1313
Jiri Olsa5500fa52012-02-15 15:51:54 +01001314void ftrace_free_filter(struct ftrace_ops *ops)
1315{
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09001316 ftrace_ops_init(ops);
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04001317 free_ftrace_hash(ops->func_hash->filter_hash);
1318 free_ftrace_hash(ops->func_hash->notrace_hash);
Jiri Olsa5500fa52012-02-15 15:51:54 +01001319}
1320
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001321static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1322{
1323 struct ftrace_hash *hash;
1324 int size;
1325
1326 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1327 if (!hash)
1328 return NULL;
1329
1330 size = 1 << size_bits;
Thomas Meyer47b0edc2011-11-29 22:08:00 +01001331 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001332
1333 if (!hash->buckets) {
1334 kfree(hash);
1335 return NULL;
1336 }
1337
1338 hash->size_bits = size_bits;
1339
1340 return hash;
1341}
1342
1343static struct ftrace_hash *
1344alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1345{
1346 struct ftrace_func_entry *entry;
1347 struct ftrace_hash *new_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001348 int size;
1349 int ret;
1350 int i;
1351
1352 new_hash = alloc_ftrace_hash(size_bits);
1353 if (!new_hash)
1354 return NULL;
1355
1356 /* Empty hash? */
Steven Rostedt06a51d92011-12-19 19:07:36 -05001357 if (ftrace_hash_empty(hash))
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001358 return new_hash;
1359
1360 size = 1 << hash->size_bits;
1361 for (i = 0; i < size; i++) {
Sasha Levinb67bfe02013-02-27 17:06:00 -08001362 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001363 ret = add_hash_entry(new_hash, entry->ip);
1364 if (ret < 0)
1365 goto free_hash;
1366 }
1367 }
1368
1369 FTRACE_WARN_ON(new_hash->count != hash->count);
1370
1371 return new_hash;
1372
1373 free_hash:
1374 free_ftrace_hash(new_hash);
1375 return NULL;
1376}
1377
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001378static void
Steven Rostedt (Red Hat)84261912014-08-18 13:21:08 -04001379ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001380static void
Steven Rostedt (Red Hat)84261912014-08-18 13:21:08 -04001381ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001382
Masami Hiramatsuf8b8be82014-11-21 05:25:16 -05001383static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1384 struct ftrace_hash *new_hash);
1385
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001386static int
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001387ftrace_hash_move(struct ftrace_ops *ops, int enable,
1388 struct ftrace_hash **dst, struct ftrace_hash *src)
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001389{
1390 struct ftrace_func_entry *entry;
Sasha Levinb67bfe02013-02-27 17:06:00 -08001391 struct hlist_node *tn;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001392 struct hlist_head *hhd;
Steven Rostedt07fd5512011-05-05 18:03:47 -04001393 struct ftrace_hash *new_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001394 int size = src->count;
1395 int bits = 0;
Masami Hiramatsuf8b8be82014-11-21 05:25:16 -05001396 int ret;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001397 int i;
1398
Masami Hiramatsuf8b8be82014-11-21 05:25:16 -05001399 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1400 if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1401 return -EINVAL;
1402
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001403 /*
1404 * If the new source is empty, just free dst and assign it
1405 * the empty_hash.
1406 */
1407 if (!src->count) {
Masami Hiramatsu5c27c772014-06-17 11:04:42 +00001408 new_hash = EMPTY_HASH;
1409 goto update;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001410 }
1411
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001412 /*
1413 * Make the hash size about 1/2 the # found
1414 */
1415 for (size /= 2; size; size >>= 1)
1416 bits++;
1417
1418 /* Don't allocate too much */
1419 if (bits > FTRACE_HASH_MAX_BITS)
1420 bits = FTRACE_HASH_MAX_BITS;
1421
Steven Rostedt07fd5512011-05-05 18:03:47 -04001422 new_hash = alloc_ftrace_hash(bits);
1423 if (!new_hash)
Masami Hiramatsu5c27c772014-06-17 11:04:42 +00001424 return -ENOMEM;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001425
1426 size = 1 << src->size_bits;
1427 for (i = 0; i < size; i++) {
1428 hhd = &src->buckets[i];
Sasha Levinb67bfe02013-02-27 17:06:00 -08001429 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001430 remove_hash_entry(src, entry);
Steven Rostedt07fd5512011-05-05 18:03:47 -04001431 __add_hash_entry(new_hash, entry);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001432 }
1433 }
1434
Masami Hiramatsu5c27c772014-06-17 11:04:42 +00001435update:
Masami Hiramatsuf8b8be82014-11-21 05:25:16 -05001436 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1437 if (enable) {
1438 /* IPMODIFY should be updated only when filter_hash updating */
1439 ret = ftrace_hash_ipmodify_update(ops, new_hash);
1440 if (ret < 0) {
1441 free_ftrace_hash(new_hash);
1442 return ret;
1443 }
1444 }
1445
Masami Hiramatsu5c27c772014-06-17 11:04:42 +00001446 /*
1447 * Remove the current set, update the hash and add
1448 * them back.
1449 */
Steven Rostedt (Red Hat)84261912014-08-18 13:21:08 -04001450 ftrace_hash_rec_disable_modify(ops, enable);
Masami Hiramatsu5c27c772014-06-17 11:04:42 +00001451
Steven Rostedt07fd5512011-05-05 18:03:47 -04001452 rcu_assign_pointer(*dst, new_hash);
Steven Rostedt07fd5512011-05-05 18:03:47 -04001453
Steven Rostedt (Red Hat)84261912014-08-18 13:21:08 -04001454 ftrace_hash_rec_enable_modify(ops, enable);
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001455
Masami Hiramatsu5c27c772014-06-17 11:04:42 +00001456 return 0;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001457}
1458
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001459static bool hash_contains_ip(unsigned long ip,
1460 struct ftrace_ops_hash *hash)
1461{
1462 /*
1463 * The function record is a match if it exists in the filter
1464 * hash and not in the notrace hash. Note, an emty hash is
1465 * considered a match for the filter hash, but an empty
1466 * notrace hash is considered not in the notrace hash.
1467 */
1468 return (ftrace_hash_empty(hash->filter_hash) ||
1469 ftrace_lookup_ip(hash->filter_hash, ip)) &&
1470 (ftrace_hash_empty(hash->notrace_hash) ||
1471 !ftrace_lookup_ip(hash->notrace_hash, ip));
1472}
1473
Steven Rostedt265c8312009-02-13 12:43:56 -05001474/*
Steven Rostedtb8489142011-05-04 09:27:52 -04001475 * Test the hashes for this ops to see if we want to call
1476 * the ops->func or not.
1477 *
1478 * It's a match if the ip is in the ops->filter_hash or
1479 * the filter_hash does not exist or is empty,
1480 * AND
1481 * the ip is not in the ops->notrace_hash.
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04001482 *
1483 * This needs to be called with preemption disabled as
1484 * the hashes are freed with call_rcu_sched().
Steven Rostedtb8489142011-05-04 09:27:52 -04001485 */
1486static int
Steven Rostedt (Red Hat)195a8af2013-07-23 22:06:15 -04001487ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
Steven Rostedtb8489142011-05-04 09:27:52 -04001488{
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001489 struct ftrace_ops_hash hash;
Steven Rostedtb8489142011-05-04 09:27:52 -04001490 int ret;
1491
Steven Rostedt (Red Hat)195a8af2013-07-23 22:06:15 -04001492#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1493 /*
1494 * There's a small race when adding ops that the ftrace handler
1495 * that wants regs, may be called without them. We can not
1496 * allow that handler to be called if regs is NULL.
1497 */
1498 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1499 return 0;
1500#endif
1501
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001502 hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash);
1503 hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash);
Steven Rostedtb8489142011-05-04 09:27:52 -04001504
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001505 if (hash_contains_ip(ip, &hash))
Steven Rostedtb8489142011-05-04 09:27:52 -04001506 ret = 1;
1507 else
1508 ret = 0;
Steven Rostedtb8489142011-05-04 09:27:52 -04001509
1510 return ret;
1511}
1512
1513/*
Steven Rostedt265c8312009-02-13 12:43:56 -05001514 * This is a double for. Do not use 'break' to break out of the loop,
1515 * you must use a goto.
1516 */
1517#define do_for_each_ftrace_rec(pg, rec) \
1518 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1519 int _____i; \
1520 for (_____i = 0; _____i < pg->index; _____i++) { \
1521 rec = &pg->records[_____i];
1522
1523#define while_for_each_ftrace_rec() \
1524 } \
1525 }
Abhishek Sagarecea6562008-06-21 23:47:53 +05301526
Steven Rostedt5855fea2011-12-16 19:27:42 -05001527
1528static int ftrace_cmp_recs(const void *a, const void *b)
1529{
Steven Rostedta650e022012-04-25 13:48:13 -04001530 const struct dyn_ftrace *key = a;
1531 const struct dyn_ftrace *rec = b;
Steven Rostedt5855fea2011-12-16 19:27:42 -05001532
Steven Rostedta650e022012-04-25 13:48:13 -04001533 if (key->flags < rec->ip)
Steven Rostedt5855fea2011-12-16 19:27:42 -05001534 return -1;
Steven Rostedta650e022012-04-25 13:48:13 -04001535 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1536 return 1;
1537 return 0;
1538}
1539
Michael Ellerman04cf31a2016-03-24 22:04:01 +11001540/**
1541 * ftrace_location_range - return the first address of a traced location
1542 * if it touches the given ip range
1543 * @start: start of range to search.
1544 * @end: end of range to search (inclusive). @end points to the last byte
1545 * to check.
1546 *
1547 * Returns rec->ip if the related ftrace location is a least partly within
1548 * the given address range. That is, the first address of the instruction
1549 * that is either a NOP or call to the function tracer. It checks the ftrace
1550 * internal tables to determine if the address belongs or not.
1551 */
1552unsigned long ftrace_location_range(unsigned long start, unsigned long end)
Steven Rostedta650e022012-04-25 13:48:13 -04001553{
1554 struct ftrace_page *pg;
1555 struct dyn_ftrace *rec;
1556 struct dyn_ftrace key;
1557
1558 key.ip = start;
1559 key.flags = end; /* overload flags, as it is unsigned long */
1560
1561 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1562 if (end < pg->records[0].ip ||
1563 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1564 continue;
1565 rec = bsearch(&key, pg->records, pg->index,
1566 sizeof(struct dyn_ftrace),
1567 ftrace_cmp_recs);
1568 if (rec)
Steven Rostedtf0cf9732012-04-25 14:39:54 -04001569 return rec->ip;
Steven Rostedta650e022012-04-25 13:48:13 -04001570 }
1571
Steven Rostedt5855fea2011-12-16 19:27:42 -05001572 return 0;
1573}
1574
Steven Rostedtc88fd862011-08-16 09:53:39 -04001575/**
1576 * ftrace_location - return true if the ip giving is a traced location
1577 * @ip: the instruction pointer to check
1578 *
Steven Rostedtf0cf9732012-04-25 14:39:54 -04001579 * Returns rec->ip if @ip given is a pointer to a ftrace location.
Steven Rostedtc88fd862011-08-16 09:53:39 -04001580 * That is, the instruction that is either a NOP or call to
1581 * the function tracer. It checks the ftrace internal tables to
1582 * determine if the address belongs or not.
1583 */
Steven Rostedtf0cf9732012-04-25 14:39:54 -04001584unsigned long ftrace_location(unsigned long ip)
Steven Rostedtc88fd862011-08-16 09:53:39 -04001585{
Steven Rostedta650e022012-04-25 13:48:13 -04001586 return ftrace_location_range(ip, ip);
1587}
Steven Rostedtc88fd862011-08-16 09:53:39 -04001588
Steven Rostedta650e022012-04-25 13:48:13 -04001589/**
1590 * ftrace_text_reserved - return true if range contains an ftrace location
1591 * @start: start of range to search
1592 * @end: end of range to search (inclusive). @end points to the last byte to check.
1593 *
1594 * Returns 1 if @start and @end contains a ftrace location.
1595 * That is, the instruction that is either a NOP or call to
1596 * the function tracer. It checks the ftrace internal tables to
1597 * determine if the address belongs or not.
1598 */
Sasha Levind88471c2013-01-09 18:09:20 -05001599int ftrace_text_reserved(const void *start, const void *end)
Steven Rostedta650e022012-04-25 13:48:13 -04001600{
Steven Rostedtf0cf9732012-04-25 14:39:54 -04001601 unsigned long ret;
1602
1603 ret = ftrace_location_range((unsigned long)start,
1604 (unsigned long)end);
1605
1606 return (int)!!ret;
Steven Rostedtc88fd862011-08-16 09:53:39 -04001607}
1608
Steven Rostedt (Red Hat)4fbb48c2014-04-30 22:35:48 -04001609/* Test if ops registered to this rec needs regs */
1610static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1611{
1612 struct ftrace_ops *ops;
1613 bool keep_regs = false;
1614
1615 for (ops = ftrace_ops_list;
1616 ops != &ftrace_list_end; ops = ops->next) {
1617 /* pass rec in as regs to have non-NULL val */
1618 if (ftrace_ops_test(ops, rec->ip, rec)) {
1619 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1620 keep_regs = true;
1621 break;
1622 }
1623 }
1624 }
1625
1626 return keep_regs;
1627}
1628
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001629static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
Steven Rostedted926f92011-05-03 13:25:24 -04001630 int filter_hash,
1631 bool inc)
1632{
1633 struct ftrace_hash *hash;
1634 struct ftrace_hash *other_hash;
1635 struct ftrace_page *pg;
1636 struct dyn_ftrace *rec;
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001637 bool update = false;
Steven Rostedted926f92011-05-03 13:25:24 -04001638 int count = 0;
1639 int all = 0;
1640
1641 /* Only update if the ops has been registered */
1642 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001643 return false;
Steven Rostedted926f92011-05-03 13:25:24 -04001644
1645 /*
1646 * In the filter_hash case:
1647 * If the count is zero, we update all records.
1648 * Otherwise we just update the items in the hash.
1649 *
1650 * In the notrace_hash case:
1651 * We enable the update in the hash.
1652 * As disabling notrace means enabling the tracing,
1653 * and enabling notrace means disabling, the inc variable
1654 * gets inversed.
1655 */
1656 if (filter_hash) {
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04001657 hash = ops->func_hash->filter_hash;
1658 other_hash = ops->func_hash->notrace_hash;
Steven Rostedt06a51d92011-12-19 19:07:36 -05001659 if (ftrace_hash_empty(hash))
Steven Rostedted926f92011-05-03 13:25:24 -04001660 all = 1;
1661 } else {
1662 inc = !inc;
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04001663 hash = ops->func_hash->notrace_hash;
1664 other_hash = ops->func_hash->filter_hash;
Steven Rostedted926f92011-05-03 13:25:24 -04001665 /*
1666 * If the notrace hash has no items,
1667 * then there's nothing to do.
1668 */
Steven Rostedt06a51d92011-12-19 19:07:36 -05001669 if (ftrace_hash_empty(hash))
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001670 return false;
Steven Rostedted926f92011-05-03 13:25:24 -04001671 }
1672
1673 do_for_each_ftrace_rec(pg, rec) {
1674 int in_other_hash = 0;
1675 int in_hash = 0;
1676 int match = 0;
1677
Steven Rostedt (Red Hat)b7ffffb2016-01-07 15:40:01 -05001678 if (rec->flags & FTRACE_FL_DISABLED)
1679 continue;
1680
Steven Rostedted926f92011-05-03 13:25:24 -04001681 if (all) {
1682 /*
1683 * Only the filter_hash affects all records.
1684 * Update if the record is not in the notrace hash.
1685 */
Steven Rostedtb8489142011-05-04 09:27:52 -04001686 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
Steven Rostedted926f92011-05-03 13:25:24 -04001687 match = 1;
1688 } else {
Steven Rostedt06a51d92011-12-19 19:07:36 -05001689 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1690 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
Steven Rostedted926f92011-05-03 13:25:24 -04001691
1692 /*
Steven Rostedt (Red Hat)19eab4a2014-05-07 15:06:14 -04001693 * If filter_hash is set, we want to match all functions
1694 * that are in the hash but not in the other hash.
Steven Rostedted926f92011-05-03 13:25:24 -04001695 *
Steven Rostedt (Red Hat)19eab4a2014-05-07 15:06:14 -04001696 * If filter_hash is not set, then we are decrementing.
1697 * That means we match anything that is in the hash
1698 * and also in the other_hash. That is, we need to turn
1699 * off functions in the other hash because they are disabled
1700 * by this hash.
Steven Rostedted926f92011-05-03 13:25:24 -04001701 */
1702 if (filter_hash && in_hash && !in_other_hash)
1703 match = 1;
1704 else if (!filter_hash && in_hash &&
Steven Rostedt06a51d92011-12-19 19:07:36 -05001705 (in_other_hash || ftrace_hash_empty(other_hash)))
Steven Rostedted926f92011-05-03 13:25:24 -04001706 match = 1;
1707 }
1708 if (!match)
1709 continue;
1710
1711 if (inc) {
1712 rec->flags++;
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04001713 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001714 return false;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001715
1716 /*
1717 * If there's only a single callback registered to a
1718 * function, and the ops has a trampoline registered
1719 * for it, then we can call it directly.
1720 */
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001721 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001722 rec->flags |= FTRACE_FL_TRAMP;
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001723 else
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001724 /*
1725 * If we are adding another function callback
1726 * to this function, and the previous had a
Steven Rostedt (Red Hat)bce0b6c2014-08-20 23:57:04 -04001727 * custom trampoline in use, then we need to go
1728 * back to the default trampoline.
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001729 */
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001730 rec->flags &= ~FTRACE_FL_TRAMP;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001731
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001732 /*
1733 * If any ops wants regs saved for this function
1734 * then all ops will get saved regs.
1735 */
1736 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1737 rec->flags |= FTRACE_FL_REGS;
Steven Rostedted926f92011-05-03 13:25:24 -04001738 } else {
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04001739 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001740 return false;
Steven Rostedted926f92011-05-03 13:25:24 -04001741 rec->flags--;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001742
Steven Rostedt (Red Hat)4fbb48c2014-04-30 22:35:48 -04001743 /*
1744 * If the rec had REGS enabled and the ops that is
1745 * being removed had REGS set, then see if there is
1746 * still any ops for this record that wants regs.
1747 * If not, we can stop recording them.
1748 */
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04001749 if (ftrace_rec_count(rec) > 0 &&
Steven Rostedt (Red Hat)4fbb48c2014-04-30 22:35:48 -04001750 rec->flags & FTRACE_FL_REGS &&
1751 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1752 if (!test_rec_ops_needs_regs(rec))
1753 rec->flags &= ~FTRACE_FL_REGS;
1754 }
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001755
1756 /*
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001757 * If the rec had TRAMP enabled, then it needs to
1758 * be cleared. As TRAMP can only be enabled iff
1759 * there is only a single ops attached to it.
1760 * In otherwords, always disable it on decrementing.
1761 * In the future, we may set it if rec count is
1762 * decremented to one, and the ops that is left
1763 * has a trampoline.
1764 */
1765 rec->flags &= ~FTRACE_FL_TRAMP;
1766
1767 /*
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001768 * flags will be cleared in ftrace_check_record()
1769 * if rec count is zero.
1770 */
Steven Rostedted926f92011-05-03 13:25:24 -04001771 }
1772 count++;
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001773
1774 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1775 update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
1776
Steven Rostedted926f92011-05-03 13:25:24 -04001777 /* Shortcut, if we handled all records, we are done. */
1778 if (!all && count == hash->count)
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001779 return update;
Steven Rostedted926f92011-05-03 13:25:24 -04001780 } while_for_each_ftrace_rec();
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001781
1782 return update;
Steven Rostedted926f92011-05-03 13:25:24 -04001783}
1784
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001785static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
Steven Rostedted926f92011-05-03 13:25:24 -04001786 int filter_hash)
1787{
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001788 return __ftrace_hash_rec_update(ops, filter_hash, 0);
Steven Rostedted926f92011-05-03 13:25:24 -04001789}
1790
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001791static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
Steven Rostedted926f92011-05-03 13:25:24 -04001792 int filter_hash)
1793{
Jiri Olsa84b6d3e2016-03-16 15:34:32 +01001794 return __ftrace_hash_rec_update(ops, filter_hash, 1);
Steven Rostedted926f92011-05-03 13:25:24 -04001795}
1796
Steven Rostedt (Red Hat)84261912014-08-18 13:21:08 -04001797static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1798 int filter_hash, int inc)
1799{
1800 struct ftrace_ops *op;
1801
1802 __ftrace_hash_rec_update(ops, filter_hash, inc);
1803
1804 if (ops->func_hash != &global_ops.local_hash)
1805 return;
1806
1807 /*
1808 * If the ops shares the global_ops hash, then we need to update
1809 * all ops that are enabled and use this hash.
1810 */
1811 do_for_each_ftrace_op(op, ftrace_ops_list) {
1812 /* Already done */
1813 if (op == ops)
1814 continue;
1815 if (op->func_hash == &global_ops.local_hash)
1816 __ftrace_hash_rec_update(op, filter_hash, inc);
1817 } while_for_each_ftrace_op(op);
1818}
1819
1820static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1821 int filter_hash)
1822{
1823 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1824}
1825
1826static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1827 int filter_hash)
1828{
1829 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1830}
1831
Masami Hiramatsuf8b8be82014-11-21 05:25:16 -05001832/*
1833 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1834 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1835 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1836 * Note that old_hash and new_hash has below meanings
1837 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1838 * - If the hash is EMPTY_HASH, it hits nothing
1839 * - Anything else hits the recs which match the hash entries.
1840 */
1841static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1842 struct ftrace_hash *old_hash,
1843 struct ftrace_hash *new_hash)
1844{
1845 struct ftrace_page *pg;
1846 struct dyn_ftrace *rec, *end = NULL;
1847 int in_old, in_new;
1848
1849 /* Only update if the ops has been registered */
1850 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1851 return 0;
1852
1853 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
1854 return 0;
1855
1856 /*
1857 * Since the IPMODIFY is a very address sensitive action, we do not
1858 * allow ftrace_ops to set all functions to new hash.
1859 */
1860 if (!new_hash || !old_hash)
1861 return -EINVAL;
1862
1863 /* Update rec->flags */
1864 do_for_each_ftrace_rec(pg, rec) {
Steven Rostedt (Red Hat)546fece2016-11-14 16:31:49 -05001865
1866 if (rec->flags & FTRACE_FL_DISABLED)
1867 continue;
1868
Masami Hiramatsuf8b8be82014-11-21 05:25:16 -05001869 /* We need to update only differences of filter_hash */
1870 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1871 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1872 if (in_old == in_new)
1873 continue;
1874
1875 if (in_new) {
1876 /* New entries must ensure no others are using it */
1877 if (rec->flags & FTRACE_FL_IPMODIFY)
1878 goto rollback;
1879 rec->flags |= FTRACE_FL_IPMODIFY;
1880 } else /* Removed entry */
1881 rec->flags &= ~FTRACE_FL_IPMODIFY;
1882 } while_for_each_ftrace_rec();
1883
1884 return 0;
1885
1886rollback:
1887 end = rec;
1888
1889 /* Roll back what we did above */
1890 do_for_each_ftrace_rec(pg, rec) {
Steven Rostedt (Red Hat)546fece2016-11-14 16:31:49 -05001891
1892 if (rec->flags & FTRACE_FL_DISABLED)
1893 continue;
1894
Masami Hiramatsuf8b8be82014-11-21 05:25:16 -05001895 if (rec == end)
1896 goto err_out;
1897
1898 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1899 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1900 if (in_old == in_new)
1901 continue;
1902
1903 if (in_new)
1904 rec->flags &= ~FTRACE_FL_IPMODIFY;
1905 else
1906 rec->flags |= FTRACE_FL_IPMODIFY;
1907 } while_for_each_ftrace_rec();
1908
1909err_out:
1910 return -EBUSY;
1911}
1912
1913static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
1914{
1915 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1916
1917 if (ftrace_hash_empty(hash))
1918 hash = NULL;
1919
1920 return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
1921}
1922
1923/* Disabling always succeeds */
1924static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
1925{
1926 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1927
1928 if (ftrace_hash_empty(hash))
1929 hash = NULL;
1930
1931 __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
1932}
1933
1934static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1935 struct ftrace_hash *new_hash)
1936{
1937 struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
1938
1939 if (ftrace_hash_empty(old_hash))
1940 old_hash = NULL;
1941
1942 if (ftrace_hash_empty(new_hash))
1943 new_hash = NULL;
1944
1945 return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
1946}
1947
Steven Rostedt (Red Hat)b05086c2015-11-25 14:13:11 -05001948static void print_ip_ins(const char *fmt, const unsigned char *p)
Steven Rostedt05736a42008-09-22 14:55:47 -07001949{
1950 int i;
1951
1952 printk(KERN_CONT "%s", fmt);
1953
1954 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1955 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1956}
1957
Steven Rostedt (Red Hat)4fd32792014-10-24 17:56:04 -04001958static struct ftrace_ops *
1959ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
Steven Rostedt (Red Hat)39daa7b2015-11-25 15:12:38 -05001960static struct ftrace_ops *
1961ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
Steven Rostedt (Red Hat)4fd32792014-10-24 17:56:04 -04001962
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05001963enum ftrace_bug_type ftrace_bug_type;
Steven Rostedt (Red Hat)b05086c2015-11-25 14:13:11 -05001964const void *ftrace_expected;
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05001965
1966static void print_bug_type(void)
1967{
1968 switch (ftrace_bug_type) {
1969 case FTRACE_BUG_UNKNOWN:
1970 break;
1971 case FTRACE_BUG_INIT:
1972 pr_info("Initializing ftrace call sites\n");
1973 break;
1974 case FTRACE_BUG_NOP:
1975 pr_info("Setting ftrace call site to NOP\n");
1976 break;
1977 case FTRACE_BUG_CALL:
1978 pr_info("Setting ftrace call site to call ftrace function\n");
1979 break;
1980 case FTRACE_BUG_UPDATE:
1981 pr_info("Updating ftrace call site to call a different ftrace function\n");
1982 break;
1983 }
1984}
1985
Steven Rostedtc88fd862011-08-16 09:53:39 -04001986/**
1987 * ftrace_bug - report and shutdown function tracer
1988 * @failed: The failed type (EFAULT, EINVAL, EPERM)
Steven Rostedt (Red Hat)4fd32792014-10-24 17:56:04 -04001989 * @rec: The record that failed
Steven Rostedtc88fd862011-08-16 09:53:39 -04001990 *
1991 * The arch code that enables or disables the function tracing
1992 * can call ftrace_bug() when it has detected a problem in
1993 * modifying the code. @failed should be one of either:
1994 * EFAULT - if the problem happens on reading the @ip address
1995 * EINVAL - if what is read at @ip is not what was expected
1996 * EPERM - if the problem happens on writting to the @ip address
1997 */
Steven Rostedt (Red Hat)4fd32792014-10-24 17:56:04 -04001998void ftrace_bug(int failed, struct dyn_ftrace *rec)
Steven Rostedtb17e8a32008-11-14 16:21:19 -08001999{
Steven Rostedt (Red Hat)4fd32792014-10-24 17:56:04 -04002000 unsigned long ip = rec ? rec->ip : 0;
2001
Steven Rostedtb17e8a32008-11-14 16:21:19 -08002002 switch (failed) {
2003 case -EFAULT:
2004 FTRACE_WARN_ON_ONCE(1);
2005 pr_info("ftrace faulted on modifying ");
2006 print_ip_sym(ip);
2007 break;
2008 case -EINVAL:
2009 FTRACE_WARN_ON_ONCE(1);
2010 pr_info("ftrace failed to modify ");
2011 print_ip_sym(ip);
Steven Rostedt (Red Hat)b05086c2015-11-25 14:13:11 -05002012 print_ip_ins(" actual: ", (unsigned char *)ip);
Steven Rostedt (Red Hat)4fd32792014-10-24 17:56:04 -04002013 pr_cont("\n");
Steven Rostedt (Red Hat)b05086c2015-11-25 14:13:11 -05002014 if (ftrace_expected) {
2015 print_ip_ins(" expected: ", ftrace_expected);
2016 pr_cont("\n");
2017 }
Steven Rostedtb17e8a32008-11-14 16:21:19 -08002018 break;
2019 case -EPERM:
2020 FTRACE_WARN_ON_ONCE(1);
2021 pr_info("ftrace faulted on writing ");
2022 print_ip_sym(ip);
2023 break;
2024 default:
2025 FTRACE_WARN_ON_ONCE(1);
2026 pr_info("ftrace faulted on unknown error ");
2027 print_ip_sym(ip);
2028 }
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05002029 print_bug_type();
Steven Rostedt (Red Hat)4fd32792014-10-24 17:56:04 -04002030 if (rec) {
2031 struct ftrace_ops *ops = NULL;
2032
2033 pr_info("ftrace record flags: %lx\n", rec->flags);
2034 pr_cont(" (%ld)%s", ftrace_rec_count(rec),
2035 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2036 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2037 ops = ftrace_find_tramp_ops_any(rec);
Steven Rostedt (Red Hat)39daa7b2015-11-25 15:12:38 -05002038 if (ops) {
2039 do {
2040 pr_cont("\ttramp: %pS (%pS)",
2041 (void *)ops->trampoline,
2042 (void *)ops->func);
2043 ops = ftrace_find_tramp_ops_next(rec, ops);
2044 } while (ops);
2045 } else
Steven Rostedt (Red Hat)4fd32792014-10-24 17:56:04 -04002046 pr_cont("\ttramp: ERROR!");
2047
2048 }
2049 ip = ftrace_get_addr_curr(rec);
Steven Rostedt (Red Hat)39daa7b2015-11-25 15:12:38 -05002050 pr_cont("\n expected tramp: %lx\n", ip);
Steven Rostedt (Red Hat)4fd32792014-10-24 17:56:04 -04002051 }
Steven Rostedtb17e8a32008-11-14 16:21:19 -08002052}
2053
Steven Rostedtc88fd862011-08-16 09:53:39 -04002054static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
Steven Rostedt5072c592008-05-12 21:20:43 +02002055{
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08002056 unsigned long flag = 0UL;
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01002057
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05002058 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2059
Steven Rostedt (Red Hat)b7ffffb2016-01-07 15:40:01 -05002060 if (rec->flags & FTRACE_FL_DISABLED)
2061 return FTRACE_UPDATE_IGNORE;
2062
Steven Rostedt982c3502008-11-15 16:31:41 -05002063 /*
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01002064 * If we are updating calls:
Steven Rostedt982c3502008-11-15 16:31:41 -05002065 *
Steven Rostedted926f92011-05-03 13:25:24 -04002066 * If the record has a ref count, then we need to enable it
2067 * because someone is using it.
Steven Rostedt982c3502008-11-15 16:31:41 -05002068 *
Steven Rostedted926f92011-05-03 13:25:24 -04002069 * Otherwise we make sure its disabled.
2070 *
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01002071 * If we are disabling calls, then disable all records that
Steven Rostedted926f92011-05-03 13:25:24 -04002072 * are enabled.
Steven Rostedt982c3502008-11-15 16:31:41 -05002073 */
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04002074 if (enable && ftrace_rec_count(rec))
Steven Rostedted926f92011-05-03 13:25:24 -04002075 flag = FTRACE_FL_ENABLED;
Steven Rostedt5072c592008-05-12 21:20:43 +02002076
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002077 /*
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002078 * If enabling and the REGS flag does not match the REGS_EN, or
2079 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2080 * this record. Set flags to fail the compare against ENABLED.
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002081 */
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002082 if (flag) {
2083 if (!(rec->flags & FTRACE_FL_REGS) !=
2084 !(rec->flags & FTRACE_FL_REGS_EN))
2085 flag |= FTRACE_FL_REGS;
2086
2087 if (!(rec->flags & FTRACE_FL_TRAMP) !=
2088 !(rec->flags & FTRACE_FL_TRAMP_EN))
2089 flag |= FTRACE_FL_TRAMP;
2090 }
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002091
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08002092 /* If the state of this record hasn't changed, then do nothing */
2093 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
Steven Rostedtc88fd862011-08-16 09:53:39 -04002094 return FTRACE_UPDATE_IGNORE;
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08002095
2096 if (flag) {
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002097 /* Save off if rec is being enabled (for return value) */
2098 flag ^= rec->flags & FTRACE_FL_ENABLED;
2099
2100 if (update) {
Steven Rostedtc88fd862011-08-16 09:53:39 -04002101 rec->flags |= FTRACE_FL_ENABLED;
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002102 if (flag & FTRACE_FL_REGS) {
2103 if (rec->flags & FTRACE_FL_REGS)
2104 rec->flags |= FTRACE_FL_REGS_EN;
2105 else
2106 rec->flags &= ~FTRACE_FL_REGS_EN;
2107 }
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002108 if (flag & FTRACE_FL_TRAMP) {
2109 if (rec->flags & FTRACE_FL_TRAMP)
2110 rec->flags |= FTRACE_FL_TRAMP_EN;
2111 else
2112 rec->flags &= ~FTRACE_FL_TRAMP_EN;
2113 }
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002114 }
2115
2116 /*
2117 * If this record is being updated from a nop, then
2118 * return UPDATE_MAKE_CALL.
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002119 * Otherwise,
2120 * return UPDATE_MODIFY_CALL to tell the caller to convert
Steven Rostedt (Red Hat)f1b2f2b2014-05-07 16:09:49 -04002121 * from the save regs, to a non-save regs function or
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002122 * vice versa, or from a trampoline call.
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002123 */
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05002124 if (flag & FTRACE_FL_ENABLED) {
2125 ftrace_bug_type = FTRACE_BUG_CALL;
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002126 return FTRACE_UPDATE_MAKE_CALL;
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05002127 }
Steven Rostedt (Red Hat)f1b2f2b2014-05-07 16:09:49 -04002128
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05002129 ftrace_bug_type = FTRACE_BUG_UPDATE;
Steven Rostedt (Red Hat)f1b2f2b2014-05-07 16:09:49 -04002130 return FTRACE_UPDATE_MODIFY_CALL;
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08002131 }
2132
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002133 if (update) {
2134 /* If there's no more users, clear all flags */
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04002135 if (!ftrace_rec_count(rec))
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002136 rec->flags = 0;
2137 else
Steven Rostedt (Red Hat)b24d4432015-03-04 23:10:28 -05002138 /*
2139 * Just disable the record, but keep the ops TRAMP
2140 * and REGS states. The _EN flags must be disabled though.
2141 */
2142 rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2143 FTRACE_FL_REGS_EN);
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002144 }
Steven Rostedtc88fd862011-08-16 09:53:39 -04002145
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05002146 ftrace_bug_type = FTRACE_BUG_NOP;
Steven Rostedtc88fd862011-08-16 09:53:39 -04002147 return FTRACE_UPDATE_MAKE_NOP;
2148}
2149
2150/**
2151 * ftrace_update_record, set a record that now is tracing or not
2152 * @rec: the record to update
2153 * @enable: set to 1 if the record is tracing, zero to force disable
2154 *
2155 * The records that represent all functions that can be traced need
2156 * to be updated when tracing has been enabled.
2157 */
2158int ftrace_update_record(struct dyn_ftrace *rec, int enable)
2159{
2160 return ftrace_check_record(rec, enable, 1);
2161}
2162
2163/**
2164 * ftrace_test_record, check if the record has been enabled or not
2165 * @rec: the record to test
2166 * @enable: set to 1 to check if enabled, 0 if it is disabled
2167 *
2168 * The arch code may need to test if a record is already set to
2169 * tracing to determine how to modify the function code that it
2170 * represents.
2171 */
2172int ftrace_test_record(struct dyn_ftrace *rec, int enable)
2173{
2174 return ftrace_check_record(rec, enable, 0);
2175}
2176
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002177static struct ftrace_ops *
Steven Rostedt (Red Hat)5fecaa02014-07-24 16:00:31 -04002178ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2179{
2180 struct ftrace_ops *op;
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002181 unsigned long ip = rec->ip;
Steven Rostedt (Red Hat)5fecaa02014-07-24 16:00:31 -04002182
2183 do_for_each_ftrace_op(op, ftrace_ops_list) {
2184
2185 if (!op->trampoline)
2186 continue;
2187
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002188 if (hash_contains_ip(ip, op->func_hash))
Steven Rostedt (Red Hat)5fecaa02014-07-24 16:00:31 -04002189 return op;
2190 } while_for_each_ftrace_op(op);
2191
2192 return NULL;
2193}
2194
2195static struct ftrace_ops *
Steven Rostedt (Red Hat)39daa7b2015-11-25 15:12:38 -05002196ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2197 struct ftrace_ops *op)
2198{
2199 unsigned long ip = rec->ip;
2200
2201 while_for_each_ftrace_op(op) {
2202
2203 if (!op->trampoline)
2204 continue;
2205
2206 if (hash_contains_ip(ip, op->func_hash))
2207 return op;
2208 }
2209
2210 return NULL;
2211}
2212
2213static struct ftrace_ops *
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002214ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2215{
2216 struct ftrace_ops *op;
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002217 unsigned long ip = rec->ip;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002218
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002219 /*
2220 * Need to check removed ops first.
2221 * If they are being removed, and this rec has a tramp,
2222 * and this rec is in the ops list, then it would be the
2223 * one with the tramp.
2224 */
2225 if (removed_ops) {
2226 if (hash_contains_ip(ip, &removed_ops->old_hash))
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002227 return removed_ops;
2228 }
2229
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002230 /*
2231 * Need to find the current trampoline for a rec.
2232 * Now, a trampoline is only attached to a rec if there
2233 * was a single 'ops' attached to it. But this can be called
2234 * when we are adding another op to the rec or removing the
2235 * current one. Thus, if the op is being added, we can
2236 * ignore it because it hasn't attached itself to the rec
Steven Rostedt (Red Hat)4fc40902014-10-24 14:48:35 -04002237 * yet.
2238 *
2239 * If an ops is being modified (hooking to different functions)
2240 * then we don't care about the new functions that are being
2241 * added, just the old ones (that are probably being removed).
2242 *
2243 * If we are adding an ops to a function that already is using
2244 * a trampoline, it needs to be removed (trampolines are only
2245 * for single ops connected), then an ops that is not being
2246 * modified also needs to be checked.
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002247 */
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002248 do_for_each_ftrace_op(op, ftrace_ops_list) {
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002249
2250 if (!op->trampoline)
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002251 continue;
2252
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002253 /*
2254 * If the ops is being added, it hasn't gotten to
2255 * the point to be removed from this tree yet.
2256 */
2257 if (op->flags & FTRACE_OPS_FL_ADDING)
2258 continue;
2259
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002260
Steven Rostedt (Red Hat)4fc40902014-10-24 14:48:35 -04002261 /*
2262 * If the ops is being modified and is in the old
2263 * hash, then it is probably being removed from this
2264 * function.
2265 */
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002266 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2267 hash_contains_ip(ip, &op->old_hash))
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002268 return op;
Steven Rostedt (Red Hat)4fc40902014-10-24 14:48:35 -04002269 /*
2270 * If the ops is not being added or modified, and it's
2271 * in its normal filter hash, then this must be the one
2272 * we want!
2273 */
2274 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2275 hash_contains_ip(ip, op->func_hash))
2276 return op;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002277
2278 } while_for_each_ftrace_op(op);
2279
2280 return NULL;
2281}
2282
2283static struct ftrace_ops *
2284ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2285{
2286 struct ftrace_ops *op;
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002287 unsigned long ip = rec->ip;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002288
2289 do_for_each_ftrace_op(op, ftrace_ops_list) {
2290 /* pass rec in as regs to have non-NULL val */
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002291 if (hash_contains_ip(ip, op->func_hash))
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002292 return op;
2293 } while_for_each_ftrace_op(op);
2294
2295 return NULL;
2296}
2297
Steven Rostedt (Red Hat)7413af12014-05-06 21:34:14 -04002298/**
2299 * ftrace_get_addr_new - Get the call address to set to
2300 * @rec: The ftrace record descriptor
2301 *
2302 * If the record has the FTRACE_FL_REGS set, that means that it
2303 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2304 * is not not set, then it wants to convert to the normal callback.
2305 *
2306 * Returns the address of the trampoline to set to
2307 */
2308unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2309{
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002310 struct ftrace_ops *ops;
2311
2312 /* Trampolines take precedence over regs */
2313 if (rec->flags & FTRACE_FL_TRAMP) {
2314 ops = ftrace_find_tramp_ops_new(rec);
2315 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
Steven Rostedt (Red Hat)bce0b6c2014-08-20 23:57:04 -04002316 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2317 (void *)rec->ip, (void *)rec->ip, rec->flags);
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002318 /* Ftrace is shutting down, return anything */
2319 return (unsigned long)FTRACE_ADDR;
2320 }
2321 return ops->trampoline;
2322 }
2323
Steven Rostedt (Red Hat)7413af12014-05-06 21:34:14 -04002324 if (rec->flags & FTRACE_FL_REGS)
2325 return (unsigned long)FTRACE_REGS_ADDR;
2326 else
2327 return (unsigned long)FTRACE_ADDR;
2328}
2329
2330/**
2331 * ftrace_get_addr_curr - Get the call address that is already there
2332 * @rec: The ftrace record descriptor
2333 *
2334 * The FTRACE_FL_REGS_EN is set when the record already points to
2335 * a function that saves all the regs. Basically the '_EN' version
2336 * represents the current state of the function.
2337 *
2338 * Returns the address of the trampoline that is currently being called
2339 */
2340unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2341{
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002342 struct ftrace_ops *ops;
2343
2344 /* Trampolines take precedence over regs */
2345 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2346 ops = ftrace_find_tramp_ops_curr(rec);
2347 if (FTRACE_WARN_ON(!ops)) {
Joe Perchesa395d6a2016-03-22 14:28:09 -07002348 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2349 (void *)rec->ip, (void *)rec->ip);
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002350 /* Ftrace is shutting down, return anything */
2351 return (unsigned long)FTRACE_ADDR;
2352 }
2353 return ops->trampoline;
2354 }
2355
Steven Rostedt (Red Hat)7413af12014-05-06 21:34:14 -04002356 if (rec->flags & FTRACE_FL_REGS_EN)
2357 return (unsigned long)FTRACE_REGS_ADDR;
2358 else
2359 return (unsigned long)FTRACE_ADDR;
2360}
2361
Steven Rostedtc88fd862011-08-16 09:53:39 -04002362static int
2363__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
2364{
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002365 unsigned long ftrace_old_addr;
Steven Rostedtc88fd862011-08-16 09:53:39 -04002366 unsigned long ftrace_addr;
2367 int ret;
2368
Steven Rostedt (Red Hat)7c0868e2014-05-08 07:01:21 -04002369 ftrace_addr = ftrace_get_addr_new(rec);
Steven Rostedtc88fd862011-08-16 09:53:39 -04002370
Steven Rostedt (Red Hat)7c0868e2014-05-08 07:01:21 -04002371 /* This needs to be done before we call ftrace_update_record */
2372 ftrace_old_addr = ftrace_get_addr_curr(rec);
2373
2374 ret = ftrace_update_record(rec, enable);
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002375
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05002376 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2377
Steven Rostedtc88fd862011-08-16 09:53:39 -04002378 switch (ret) {
2379 case FTRACE_UPDATE_IGNORE:
2380 return 0;
2381
2382 case FTRACE_UPDATE_MAKE_CALL:
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05002383 ftrace_bug_type = FTRACE_BUG_CALL;
Steven Rostedtc88fd862011-08-16 09:53:39 -04002384 return ftrace_make_call(rec, ftrace_addr);
2385
2386 case FTRACE_UPDATE_MAKE_NOP:
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05002387 ftrace_bug_type = FTRACE_BUG_NOP;
Steven Rostedt (Red Hat)39b55522014-08-17 20:59:10 -04002388 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002389
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002390 case FTRACE_UPDATE_MODIFY_CALL:
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05002391 ftrace_bug_type = FTRACE_BUG_UPDATE;
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002392 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
Steven Rostedtc88fd862011-08-16 09:53:39 -04002393 }
2394
2395 return -1; /* unknow ftrace bug */
Steven Rostedt5072c592008-05-12 21:20:43 +02002396}
2397
Steven Rostedte4f5d542012-04-27 09:13:18 -04002398void __weak ftrace_replace_code(int enable)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002399{
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002400 struct dyn_ftrace *rec;
2401 struct ftrace_page *pg;
Steven Rostedt6a24a242009-02-17 11:20:26 -05002402 int failed;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002403
Steven Rostedt45a4a232011-04-21 23:16:46 -04002404 if (unlikely(ftrace_disabled))
2405 return;
2406
Steven Rostedt265c8312009-02-13 12:43:56 -05002407 do_for_each_ftrace_rec(pg, rec) {
Steven Rostedt (Red Hat)546fece2016-11-14 16:31:49 -05002408
2409 if (rec->flags & FTRACE_FL_DISABLED)
2410 continue;
2411
Steven Rostedte4f5d542012-04-27 09:13:18 -04002412 failed = __ftrace_replace_code(rec, enable);
Zhaoleifa9d13c2009-03-13 17:16:34 +08002413 if (failed) {
Steven Rostedt (Red Hat)4fd32792014-10-24 17:56:04 -04002414 ftrace_bug(failed, rec);
Steven Rostedt3279ba32009-10-07 16:57:56 -04002415 /* Stop processing */
2416 return;
Steven Rostedt265c8312009-02-13 12:43:56 -05002417 }
2418 } while_for_each_ftrace_rec();
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002419}
2420
Steven Rostedtc88fd862011-08-16 09:53:39 -04002421struct ftrace_rec_iter {
2422 struct ftrace_page *pg;
2423 int index;
2424};
2425
2426/**
2427 * ftrace_rec_iter_start, start up iterating over traced functions
2428 *
2429 * Returns an iterator handle that is used to iterate over all
2430 * the records that represent address locations where functions
2431 * are traced.
2432 *
2433 * May return NULL if no records are available.
2434 */
2435struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2436{
2437 /*
2438 * We only use a single iterator.
2439 * Protected by the ftrace_lock mutex.
2440 */
2441 static struct ftrace_rec_iter ftrace_rec_iter;
2442 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2443
2444 iter->pg = ftrace_pages_start;
2445 iter->index = 0;
2446
2447 /* Could have empty pages */
2448 while (iter->pg && !iter->pg->index)
2449 iter->pg = iter->pg->next;
2450
2451 if (!iter->pg)
2452 return NULL;
2453
2454 return iter;
2455}
2456
2457/**
2458 * ftrace_rec_iter_next, get the next record to process.
2459 * @iter: The handle to the iterator.
2460 *
2461 * Returns the next iterator after the given iterator @iter.
2462 */
2463struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2464{
2465 iter->index++;
2466
2467 if (iter->index >= iter->pg->index) {
2468 iter->pg = iter->pg->next;
2469 iter->index = 0;
2470
2471 /* Could have empty pages */
2472 while (iter->pg && !iter->pg->index)
2473 iter->pg = iter->pg->next;
2474 }
2475
2476 if (!iter->pg)
2477 return NULL;
2478
2479 return iter;
2480}
2481
2482/**
2483 * ftrace_rec_iter_record, get the record at the iterator location
2484 * @iter: The current iterator location
2485 *
2486 * Returns the record that the current @iter is at.
2487 */
2488struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2489{
2490 return &iter->pg->records[iter->index];
2491}
2492
Abhishek Sagar492a7ea52008-05-25 00:10:04 +05302493static int
Steven Rostedt31e88902008-11-14 16:21:19 -08002494ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002495{
Steven Rostedt593eb8a2008-10-23 09:32:59 -04002496 int ret;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002497
Steven Rostedt45a4a232011-04-21 23:16:46 -04002498 if (unlikely(ftrace_disabled))
2499 return 0;
2500
Shaohua Li25aac9d2009-01-09 11:29:40 +08002501 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
Steven Rostedt593eb8a2008-10-23 09:32:59 -04002502 if (ret) {
Steven Rostedt (Red Hat)02a392a2015-11-25 12:50:47 -05002503 ftrace_bug_type = FTRACE_BUG_INIT;
Steven Rostedt (Red Hat)4fd32792014-10-24 17:56:04 -04002504 ftrace_bug(ret, rec);
Abhishek Sagar492a7ea52008-05-25 00:10:04 +05302505 return 0;
Steven Rostedt37ad5082008-05-12 21:20:48 +02002506 }
Abhishek Sagar492a7ea52008-05-25 00:10:04 +05302507 return 1;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002508}
2509
Steven Rostedt000ab692009-02-17 13:35:06 -05002510/*
2511 * archs can override this function if they must do something
2512 * before the modifying code is performed.
2513 */
2514int __weak ftrace_arch_code_modify_prepare(void)
2515{
2516 return 0;
2517}
2518
2519/*
2520 * archs can override this function if they must do something
2521 * after the modifying code is performed.
2522 */
2523int __weak ftrace_arch_code_modify_post_process(void)
2524{
2525 return 0;
2526}
2527
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002528void ftrace_modify_all_code(int command)
2529{
Steven Rostedt (Red Hat)59338f72013-08-31 01:04:07 -04002530 int update = command & FTRACE_UPDATE_TRACE_FUNC;
Petr Mladekcd210672014-02-24 17:12:21 +01002531 int err = 0;
Steven Rostedt (Red Hat)59338f72013-08-31 01:04:07 -04002532
2533 /*
2534 * If the ftrace_caller calls a ftrace_ops func directly,
2535 * we need to make sure that it only traces functions it
2536 * expects to trace. When doing the switch of functions,
2537 * we need to update to the ftrace_ops_list_func first
2538 * before the transition between old and new calls are set,
2539 * as the ftrace_ops_list_func will check the ops hashes
2540 * to make sure the ops are having the right functions
2541 * traced.
2542 */
Petr Mladekcd210672014-02-24 17:12:21 +01002543 if (update) {
2544 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2545 if (FTRACE_WARN_ON(err))
2546 return;
2547 }
Steven Rostedt (Red Hat)59338f72013-08-31 01:04:07 -04002548
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002549 if (command & FTRACE_UPDATE_CALLS)
2550 ftrace_replace_code(1);
2551 else if (command & FTRACE_DISABLE_CALLS)
2552 ftrace_replace_code(0);
2553
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -05002554 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2555 function_trace_op = set_function_trace_op;
2556 smp_wmb();
2557 /* If irqs are disabled, we are in stop machine */
2558 if (!irqs_disabled())
2559 smp_call_function(ftrace_sync_ipi, NULL, 1);
Petr Mladekcd210672014-02-24 17:12:21 +01002560 err = ftrace_update_ftrace_func(ftrace_trace_function);
2561 if (FTRACE_WARN_ON(err))
2562 return;
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -05002563 }
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002564
2565 if (command & FTRACE_START_FUNC_RET)
Petr Mladekcd210672014-02-24 17:12:21 +01002566 err = ftrace_enable_ftrace_graph_caller();
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002567 else if (command & FTRACE_STOP_FUNC_RET)
Petr Mladekcd210672014-02-24 17:12:21 +01002568 err = ftrace_disable_ftrace_graph_caller();
2569 FTRACE_WARN_ON(err);
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002570}
2571
Ingo Molnare309b412008-05-12 21:20:51 +02002572static int __ftrace_modify_code(void *data)
Steven Rostedt3d083392008-05-12 21:20:42 +02002573{
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002574 int *command = data;
2575
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002576 ftrace_modify_all_code(*command);
Steven Rostedt5a45cfe2008-11-26 00:16:24 -05002577
Steven Rostedtc88fd862011-08-16 09:53:39 -04002578 return 0;
2579}
2580
2581/**
2582 * ftrace_run_stop_machine, go back to the stop machine method
2583 * @command: The command to tell ftrace what to do
2584 *
2585 * If an arch needs to fall back to the stop machine method, the
2586 * it can call this function.
2587 */
2588void ftrace_run_stop_machine(int command)
2589{
2590 stop_machine(__ftrace_modify_code, &command, NULL);
2591}
2592
2593/**
2594 * arch_ftrace_update_code, modify the code to trace or not trace
2595 * @command: The command that needs to be done
2596 *
2597 * Archs can override this function if it does not need to
2598 * run stop_machine() to modify code.
2599 */
2600void __weak arch_ftrace_update_code(int command)
2601{
2602 ftrace_run_stop_machine(command);
2603}
2604
2605static void ftrace_run_update_code(int command)
2606{
2607 int ret;
2608
2609 ret = ftrace_arch_code_modify_prepare();
2610 FTRACE_WARN_ON(ret);
2611 if (ret)
2612 return;
Steven Rostedtc88fd862011-08-16 09:53:39 -04002613
2614 /*
2615 * By default we use stop_machine() to modify the code.
2616 * But archs can do what ever they want as long as it
2617 * is safe. The stop_machine() is the safest, but also
2618 * produces the most overhead.
2619 */
2620 arch_ftrace_update_code(command);
2621
Steven Rostedt000ab692009-02-17 13:35:06 -05002622 ret = ftrace_arch_code_modify_post_process();
2623 FTRACE_WARN_ON(ret);
Steven Rostedt3d083392008-05-12 21:20:42 +02002624}
2625
Steven Rostedt (Red Hat)8252ecf2014-10-24 14:56:01 -04002626static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05002627 struct ftrace_ops_hash *old_hash)
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002628{
2629 ops->flags |= FTRACE_OPS_FL_MODIFYING;
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05002630 ops->old_hash.filter_hash = old_hash->filter_hash;
2631 ops->old_hash.notrace_hash = old_hash->notrace_hash;
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002632 ftrace_run_update_code(command);
Steven Rostedt (Red Hat)8252ecf2014-10-24 14:56:01 -04002633 ops->old_hash.filter_hash = NULL;
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05002634 ops->old_hash.notrace_hash = NULL;
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002635 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2636}
2637
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002638static ftrace_func_t saved_ftrace_func;
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05002639static int ftrace_start_up;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05002640
Steven Rostedt (Red Hat)12cce592014-07-03 15:48:16 -04002641void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2642{
2643}
2644
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -05002645static void per_cpu_ops_free(struct ftrace_ops *ops)
Jiri Slabydb0fbad2014-03-10 21:42:11 +01002646{
2647 free_percpu(ops->disabled);
2648}
2649
Steven Rostedtdf4fc312008-11-26 00:16:23 -05002650static void ftrace_startup_enable(int command)
2651{
2652 if (saved_ftrace_func != ftrace_trace_function) {
2653 saved_ftrace_func = ftrace_trace_function;
2654 command |= FTRACE_UPDATE_TRACE_FUNC;
2655 }
2656
2657 if (!command || !ftrace_enabled)
2658 return;
2659
2660 ftrace_run_update_code(command);
2661}
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002662
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002663static void ftrace_startup_all(int command)
2664{
2665 update_all_ops = true;
2666 ftrace_startup_enable(command);
2667 update_all_ops = false;
2668}
2669
Steven Rostedta1cd6172011-05-23 15:24:25 -04002670static int ftrace_startup(struct ftrace_ops *ops, int command)
Steven Rostedt3d083392008-05-12 21:20:42 +02002671{
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002672 int ret;
Steven Rostedtb8489142011-05-04 09:27:52 -04002673
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002674 if (unlikely(ftrace_disabled))
Steven Rostedta1cd6172011-05-23 15:24:25 -04002675 return -ENODEV;
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002676
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002677 ret = __register_ftrace_function(ops);
2678 if (ret)
2679 return ret;
2680
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05002681 ftrace_start_up++;
Steven Rostedt3d083392008-05-12 21:20:42 +02002682
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002683 /*
2684 * Note that ftrace probes uses this to start up
2685 * and modify functions it will probe. But we still
2686 * set the ADDING flag for modification, as probes
2687 * do not have trampolines. If they add them in the
2688 * future, then the probes will need to distinguish
2689 * between adding and updating probes.
2690 */
2691 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
Steven Rostedt (Red Hat)66209a52014-05-06 21:57:49 -04002692
Masami Hiramatsuf8b8be82014-11-21 05:25:16 -05002693 ret = ftrace_hash_ipmodify_enable(ops);
2694 if (ret < 0) {
2695 /* Rollback registration process */
2696 __unregister_ftrace_function(ops);
2697 ftrace_start_up--;
2698 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2699 return ret;
2700 }
2701
Jiri Olsa7f50d062016-03-16 15:34:33 +01002702 if (ftrace_hash_rec_enable(ops, 1))
2703 command |= FTRACE_UPDATE_CALLS;
Steven Rostedted926f92011-05-03 13:25:24 -04002704
Steven Rostedtdf4fc312008-11-26 00:16:23 -05002705 ftrace_startup_enable(command);
Steven Rostedta1cd6172011-05-23 15:24:25 -04002706
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002707 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2708
Steven Rostedta1cd6172011-05-23 15:24:25 -04002709 return 0;
Steven Rostedt3d083392008-05-12 21:20:42 +02002710}
2711
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002712static int ftrace_shutdown(struct ftrace_ops *ops, int command)
Steven Rostedt3d083392008-05-12 21:20:42 +02002713{
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002714 int ret;
Steven Rostedtb8489142011-05-04 09:27:52 -04002715
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002716 if (unlikely(ftrace_disabled))
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002717 return -ENODEV;
2718
2719 ret = __unregister_ftrace_function(ops);
2720 if (ret)
2721 return ret;
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002722
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05002723 ftrace_start_up--;
Frederic Weisbecker9ea1a152009-06-20 06:52:21 +02002724 /*
2725 * Just warn in case of unbalance, no need to kill ftrace, it's not
2726 * critical but the ftrace_call callers may be never nopped again after
2727 * further ftrace uses.
2728 */
2729 WARN_ON_ONCE(ftrace_start_up < 0);
2730
Masami Hiramatsuf8b8be82014-11-21 05:25:16 -05002731 /* Disabling ipmodify never fails */
2732 ftrace_hash_ipmodify_disable(ops);
Jiri Olsa7f50d062016-03-16 15:34:33 +01002733
2734 if (ftrace_hash_rec_disable(ops, 1))
2735 command |= FTRACE_UPDATE_CALLS;
Steven Rostedtb8489142011-05-04 09:27:52 -04002736
Namhyung Kima737e6d2014-06-12 23:56:12 +09002737 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
Steven Rostedtb8489142011-05-04 09:27:52 -04002738
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002739 if (saved_ftrace_func != ftrace_trace_function) {
2740 saved_ftrace_func = ftrace_trace_function;
2741 command |= FTRACE_UPDATE_TRACE_FUNC;
2742 }
2743
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002744 if (!command || !ftrace_enabled) {
2745 /*
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -05002746 * If these are per_cpu ops, they still need their
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002747 * per_cpu field freed. Since, function tracing is
2748 * not currently active, we can just free them
2749 * without synchronizing all CPUs.
2750 */
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -05002751 if (ops->flags & FTRACE_OPS_FL_PER_CPU)
2752 per_cpu_ops_free(ops);
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002753 return 0;
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002754 }
Steven Rostedt3d083392008-05-12 21:20:42 +02002755
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002756 /*
2757 * If the ops uses a trampoline, then it needs to be
2758 * tested first on update.
2759 */
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002760 ops->flags |= FTRACE_OPS_FL_REMOVING;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002761 removed_ops = ops;
2762
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002763 /* The trampoline logic checks the old hashes */
2764 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2765 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2766
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002767 ftrace_run_update_code(command);
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002768
Steven Rostedt (Red Hat)84bde622014-09-12 14:21:13 -04002769 /*
2770 * If there's no more ops registered with ftrace, run a
2771 * sanity check to make sure all rec flags are cleared.
2772 */
2773 if (ftrace_ops_list == &ftrace_list_end) {
2774 struct ftrace_page *pg;
2775 struct dyn_ftrace *rec;
2776
2777 do_for_each_ftrace_rec(pg, rec) {
Alexei Starovoitov977c1f92016-11-07 15:14:20 -08002778 if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
Steven Rostedt (Red Hat)84bde622014-09-12 14:21:13 -04002779 pr_warn(" %pS flags:%lx\n",
2780 (void *)rec->ip, rec->flags);
2781 } while_for_each_ftrace_rec();
2782 }
2783
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002784 ops->old_hash.filter_hash = NULL;
2785 ops->old_hash.notrace_hash = NULL;
2786
2787 removed_ops = NULL;
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002788 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002789
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002790 /*
2791 * Dynamic ops may be freed, we must make sure that all
2792 * callers are done before leaving this function.
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -05002793 * The same goes for freeing the per_cpu data of the per_cpu
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002794 * ops.
2795 *
2796 * Again, normal synchronize_sched() is not good enough.
2797 * We need to do a hard force of sched synchronization.
2798 * This is because we use preempt_disable() to do RCU, but
2799 * the function tracers can be called where RCU is not watching
2800 * (like before user_exit()). We can not rely on the RCU
2801 * infrastructure to do the synchronization, thus we must do it
2802 * ourselves.
2803 */
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -05002804 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU)) {
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002805 schedule_on_each_cpu(ftrace_sync);
2806
Steven Rostedt (Red Hat)12cce592014-07-03 15:48:16 -04002807 arch_ftrace_trampoline_free(ops);
2808
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -05002809 if (ops->flags & FTRACE_OPS_FL_PER_CPU)
2810 per_cpu_ops_free(ops);
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002811 }
2812
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002813 return 0;
Steven Rostedt3d083392008-05-12 21:20:42 +02002814}
2815
Ingo Molnare309b412008-05-12 21:20:51 +02002816static void ftrace_startup_sysctl(void)
Steven Rostedtb0fc4942008-05-12 21:20:43 +02002817{
Pratyush Anand1619dc32015-03-06 23:58:06 +05302818 int command;
2819
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002820 if (unlikely(ftrace_disabled))
2821 return;
2822
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002823 /* Force update next time */
2824 saved_ftrace_func = NULL;
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05002825 /* ftrace_start_up is true if we want ftrace running */
Pratyush Anand1619dc32015-03-06 23:58:06 +05302826 if (ftrace_start_up) {
2827 command = FTRACE_UPDATE_CALLS;
2828 if (ftrace_graph_active)
2829 command |= FTRACE_START_FUNC_RET;
Steven Rostedt (Red Hat)524a3862015-03-06 19:55:13 -05002830 ftrace_startup_enable(command);
Pratyush Anand1619dc32015-03-06 23:58:06 +05302831 }
Steven Rostedtb0fc4942008-05-12 21:20:43 +02002832}
2833
Ingo Molnare309b412008-05-12 21:20:51 +02002834static void ftrace_shutdown_sysctl(void)
Steven Rostedtb0fc4942008-05-12 21:20:43 +02002835{
Pratyush Anand1619dc32015-03-06 23:58:06 +05302836 int command;
2837
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002838 if (unlikely(ftrace_disabled))
2839 return;
2840
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05002841 /* ftrace_start_up is true if ftrace is running */
Pratyush Anand1619dc32015-03-06 23:58:06 +05302842 if (ftrace_start_up) {
2843 command = FTRACE_DISABLE_CALLS;
2844 if (ftrace_graph_active)
2845 command |= FTRACE_STOP_FUNC_RET;
2846 ftrace_run_update_code(command);
2847 }
Steven Rostedtb0fc4942008-05-12 21:20:43 +02002848}
2849
Thomas Gleixnera5a1d1c2016-12-21 20:32:01 +01002850static u64 ftrace_update_time;
Steven Rostedt3d083392008-05-12 21:20:42 +02002851unsigned long ftrace_update_tot_cnt;
2852
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002853static inline int ops_traces_mod(struct ftrace_ops *ops)
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002854{
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002855 /*
2856 * Filter_hash being empty will default to trace module.
2857 * But notrace hash requires a test of individual module functions.
2858 */
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04002859 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2860 ftrace_hash_empty(ops->func_hash->notrace_hash);
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002861}
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002862
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002863/*
2864 * Check if the current ops references the record.
2865 *
2866 * If the ops traces all functions, then it was already accounted for.
2867 * If the ops does not trace the current record function, skip it.
2868 * If the ops ignores the function via notrace filter, skip it.
2869 */
2870static inline bool
2871ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2872{
2873 /* If ops isn't enabled, ignore it */
2874 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2875 return 0;
2876
Steven Rostedt (Red Hat)b7ffffb2016-01-07 15:40:01 -05002877 /* If ops traces all then it includes this function */
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002878 if (ops_traces_mod(ops))
Steven Rostedt (Red Hat)b7ffffb2016-01-07 15:40:01 -05002879 return 1;
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002880
2881 /* The function must be in the filter */
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04002882 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2883 !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002884 return 0;
2885
2886 /* If in notrace hash, we ignore it too */
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04002887 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002888 return 0;
2889
2890 return 1;
2891}
2892
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01002893static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
Steven Rostedt3d083392008-05-12 21:20:42 +02002894{
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002895 struct ftrace_page *pg;
Lai Jiangshane94142a2009-03-13 17:51:27 +08002896 struct dyn_ftrace *p;
Thomas Gleixnera5a1d1c2016-12-21 20:32:01 +01002897 u64 start, stop;
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01002898 unsigned long update_cnt = 0;
Steven Rostedt (Red Hat)b7ffffb2016-01-07 15:40:01 -05002899 unsigned long rec_flags = 0;
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002900 int i;
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002901
Ingo Molnar750ed1a2008-05-12 21:20:46 +02002902 start = ftrace_now(raw_smp_processor_id());
Steven Rostedt3d083392008-05-12 21:20:42 +02002903
Steven Rostedt (Red Hat)b7ffffb2016-01-07 15:40:01 -05002904 /*
2905 * When a module is loaded, this function is called to convert
2906 * the calls to mcount in its text to nops, and also to create
2907 * an entry in the ftrace data. Now, if ftrace is activated
2908 * after this call, but before the module sets its text to
2909 * read-only, the modification of enabling ftrace can fail if
2910 * the read-only is done while ftrace is converting the calls.
2911 * To prevent this, the module's records are set as disabled
2912 * and will be enabled after the call to set the module's text
2913 * to read-only.
2914 */
2915 if (mod)
2916 rec_flags |= FTRACE_FL_DISABLED;
2917
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01002918 for (pg = new_pgs; pg; pg = pg->next) {
Abhishek Sagarf22f9a82008-06-21 23:50:29 +05302919
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002920 for (i = 0; i < pg->index; i++) {
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002921
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002922 /* If something went wrong, bail without enabling anything */
2923 if (unlikely(ftrace_disabled))
2924 return -1;
Steven Rostedt3d083392008-05-12 21:20:42 +02002925
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002926 p = &pg->records[i];
Steven Rostedt (Red Hat)b7ffffb2016-01-07 15:40:01 -05002927 p->flags = rec_flags;
Abhishek Sagar0eb96702008-06-01 21:47:30 +05302928
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002929 /*
2930 * Do the initial record conversion from mcount jump
2931 * to the NOP instructions.
2932 */
2933 if (!ftrace_code_disable(mod, p))
2934 break;
Jiri Olsa5cb084b2009-10-13 16:33:53 -04002935
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01002936 update_cnt++;
Jiri Olsa5cb084b2009-10-13 16:33:53 -04002937 }
Steven Rostedt3d083392008-05-12 21:20:42 +02002938 }
2939
Ingo Molnar750ed1a2008-05-12 21:20:46 +02002940 stop = ftrace_now(raw_smp_processor_id());
Steven Rostedt3d083392008-05-12 21:20:42 +02002941 ftrace_update_time = stop - start;
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01002942 ftrace_update_tot_cnt += update_cnt;
Steven Rostedt3d083392008-05-12 21:20:42 +02002943
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02002944 return 0;
2945}
2946
Steven Rostedta7900872011-12-16 16:23:44 -05002947static int ftrace_allocate_records(struct ftrace_page *pg, int count)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002948{
Steven Rostedta7900872011-12-16 16:23:44 -05002949 int order;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002950 int cnt;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002951
Steven Rostedta7900872011-12-16 16:23:44 -05002952 if (WARN_ON(!count))
2953 return -EINVAL;
2954
2955 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002956
2957 /*
Steven Rostedta7900872011-12-16 16:23:44 -05002958 * We want to fill as much as possible. No more than a page
2959 * may be empty.
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002960 */
Steven Rostedta7900872011-12-16 16:23:44 -05002961 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2962 order--;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002963
Steven Rostedta7900872011-12-16 16:23:44 -05002964 again:
2965 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2966
2967 if (!pg->records) {
2968 /* if we can't allocate this size, try something smaller */
2969 if (!order)
2970 return -ENOMEM;
2971 order >>= 1;
2972 goto again;
2973 }
2974
2975 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
2976 pg->size = cnt;
2977
2978 if (cnt > count)
2979 cnt = count;
2980
2981 return cnt;
2982}
2983
2984static struct ftrace_page *
2985ftrace_allocate_pages(unsigned long num_to_init)
2986{
2987 struct ftrace_page *start_pg;
2988 struct ftrace_page *pg;
2989 int order;
2990 int cnt;
2991
2992 if (!num_to_init)
2993 return 0;
2994
2995 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
2996 if (!pg)
2997 return NULL;
2998
2999 /*
3000 * Try to allocate as much as possible in one continues
3001 * location that fills in all of the space. We want to
3002 * waste as little space as possible.
3003 */
3004 for (;;) {
3005 cnt = ftrace_allocate_records(pg, num_to_init);
3006 if (cnt < 0)
3007 goto free_pages;
3008
3009 num_to_init -= cnt;
3010 if (!num_to_init)
3011 break;
3012
3013 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3014 if (!pg->next)
3015 goto free_pages;
3016
3017 pg = pg->next;
3018 }
3019
3020 return start_pg;
3021
3022 free_pages:
Namhyung Kim1f61be002014-06-11 17:06:53 +09003023 pg = start_pg;
3024 while (pg) {
Steven Rostedta7900872011-12-16 16:23:44 -05003025 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3026 free_pages((unsigned long)pg->records, order);
3027 start_pg = pg->next;
3028 kfree(pg);
3029 pg = start_pg;
3030 }
3031 pr_info("ftrace: FAILED to allocate memory for functions\n");
3032 return NULL;
3033}
3034
Steven Rostedt5072c592008-05-12 21:20:43 +02003035#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3036
3037struct ftrace_iterator {
Steven Rostedt98c4fd02010-09-10 11:47:43 -04003038 loff_t pos;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003039 loff_t func_pos;
3040 struct ftrace_page *pg;
3041 struct dyn_ftrace *func;
3042 struct ftrace_func_probe *probe;
3043 struct trace_parser parser;
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003044 struct ftrace_hash *hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003045 struct ftrace_ops *ops;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003046 int hidx;
3047 int idx;
3048 unsigned flags;
Steven Rostedt5072c592008-05-12 21:20:43 +02003049};
3050
Ingo Molnare309b412008-05-12 21:20:51 +02003051static void *
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003052t_hash_next(struct seq_file *m, loff_t *pos)
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003053{
3054 struct ftrace_iterator *iter = m->private;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003055 struct hlist_node *hnd = NULL;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003056 struct hlist_head *hhd;
3057
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003058 (*pos)++;
Steven Rostedt98c4fd02010-09-10 11:47:43 -04003059 iter->pos = *pos;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003060
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003061 if (iter->probe)
3062 hnd = &iter->probe->node;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003063 retry:
3064 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
3065 return NULL;
3066
3067 hhd = &ftrace_func_hash[iter->hidx];
3068
3069 if (hlist_empty(hhd)) {
3070 iter->hidx++;
3071 hnd = NULL;
3072 goto retry;
3073 }
3074
3075 if (!hnd)
3076 hnd = hhd->first;
3077 else {
3078 hnd = hnd->next;
3079 if (!hnd) {
3080 iter->hidx++;
3081 goto retry;
3082 }
3083 }
3084
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003085 if (WARN_ON_ONCE(!hnd))
3086 return NULL;
3087
3088 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
3089
3090 return iter;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003091}
3092
3093static void *t_hash_start(struct seq_file *m, loff_t *pos)
3094{
3095 struct ftrace_iterator *iter = m->private;
3096 void *p = NULL;
Li Zefand82d6242009-06-24 09:54:54 +08003097 loff_t l;
3098
Steven Rostedt69a30832011-12-19 15:21:16 -05003099 if (!(iter->flags & FTRACE_ITER_DO_HASH))
3100 return NULL;
3101
Steven Rostedt2bccfff2010-09-09 08:43:22 -04003102 if (iter->func_pos > *pos)
3103 return NULL;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003104
Li Zefand82d6242009-06-24 09:54:54 +08003105 iter->hidx = 0;
Steven Rostedt2bccfff2010-09-09 08:43:22 -04003106 for (l = 0; l <= (*pos - iter->func_pos); ) {
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003107 p = t_hash_next(m, &l);
Li Zefand82d6242009-06-24 09:54:54 +08003108 if (!p)
3109 break;
3110 }
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003111 if (!p)
3112 return NULL;
3113
Steven Rostedt98c4fd02010-09-10 11:47:43 -04003114 /* Only set this if we have an item */
3115 iter->flags |= FTRACE_ITER_HASH;
3116
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003117 return iter;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003118}
3119
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003120static int
3121t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003122{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003123 struct ftrace_func_probe *rec;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003124
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003125 rec = iter->probe;
3126 if (WARN_ON_ONCE(!rec))
3127 return -EIO;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003128
Steven Rostedt809dcf22009-02-16 23:06:01 -05003129 if (rec->ops->print)
3130 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
3131
Steven Rostedtb375a112009-09-17 00:05:58 -04003132 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003133
3134 if (rec->data)
3135 seq_printf(m, ":%p", rec->data);
3136 seq_putc(m, '\n');
3137
3138 return 0;
3139}
3140
3141static void *
Steven Rostedt5072c592008-05-12 21:20:43 +02003142t_next(struct seq_file *m, void *v, loff_t *pos)
3143{
3144 struct ftrace_iterator *iter = m->private;
Steven Rostedtfc13cb02011-12-19 14:41:25 -05003145 struct ftrace_ops *ops = iter->ops;
Steven Rostedt5072c592008-05-12 21:20:43 +02003146 struct dyn_ftrace *rec = NULL;
3147
Steven Rostedt45a4a232011-04-21 23:16:46 -04003148 if (unlikely(ftrace_disabled))
3149 return NULL;
3150
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003151 if (iter->flags & FTRACE_ITER_HASH)
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003152 return t_hash_next(m, pos);
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003153
Steven Rostedt5072c592008-05-12 21:20:43 +02003154 (*pos)++;
Jiri Olsa1106b692011-02-16 17:35:34 +01003155 iter->pos = iter->func_pos = *pos;
Steven Rostedt5072c592008-05-12 21:20:43 +02003156
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05003157 if (iter->flags & FTRACE_ITER_PRINTALL)
Steven Rostedt57c072c2010-09-14 11:21:11 -04003158 return t_hash_start(m, pos);
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05003159
Steven Rostedt5072c592008-05-12 21:20:43 +02003160 retry:
3161 if (iter->idx >= iter->pg->index) {
3162 if (iter->pg->next) {
3163 iter->pg = iter->pg->next;
3164 iter->idx = 0;
3165 goto retry;
3166 }
3167 } else {
3168 rec = &iter->pg->records[iter->idx++];
Steven Rostedt32082302011-12-16 14:42:37 -05003169 if (((iter->flags & FTRACE_ITER_FILTER) &&
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003170 !(ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))) ||
Steven Rostedt0183fb12008-11-07 22:36:02 -05003171
Steven Rostedt41c52c02008-05-22 11:46:33 -04003172 ((iter->flags & FTRACE_ITER_NOTRACE) &&
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003173 !ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) ||
Steven Rostedt647bcd02011-05-03 14:39:21 -04003174
3175 ((iter->flags & FTRACE_ITER_ENABLED) &&
Steven Rostedt (Red Hat)23ea9c42013-05-09 19:31:48 -04003176 !(rec->flags & FTRACE_FL_ENABLED))) {
Steven Rostedt647bcd02011-05-03 14:39:21 -04003177
Steven Rostedt5072c592008-05-12 21:20:43 +02003178 rec = NULL;
3179 goto retry;
3180 }
3181 }
3182
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003183 if (!rec)
Steven Rostedt57c072c2010-09-14 11:21:11 -04003184 return t_hash_start(m, pos);
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003185
3186 iter->func = rec;
3187
3188 return iter;
Steven Rostedt5072c592008-05-12 21:20:43 +02003189}
3190
Steven Rostedt98c4fd02010-09-10 11:47:43 -04003191static void reset_iter_read(struct ftrace_iterator *iter)
3192{
3193 iter->pos = 0;
3194 iter->func_pos = 0;
Dan Carpenter70f77b32012-06-09 19:10:27 +03003195 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
Steven Rostedt5072c592008-05-12 21:20:43 +02003196}
3197
3198static void *t_start(struct seq_file *m, loff_t *pos)
3199{
3200 struct ftrace_iterator *iter = m->private;
Steven Rostedtfc13cb02011-12-19 14:41:25 -05003201 struct ftrace_ops *ops = iter->ops;
Steven Rostedt5072c592008-05-12 21:20:43 +02003202 void *p = NULL;
Li Zefan694ce0a2009-06-24 09:54:19 +08003203 loff_t l;
Steven Rostedt5072c592008-05-12 21:20:43 +02003204
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003205 mutex_lock(&ftrace_lock);
Steven Rostedt45a4a232011-04-21 23:16:46 -04003206
3207 if (unlikely(ftrace_disabled))
3208 return NULL;
3209
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05003210 /*
Steven Rostedt98c4fd02010-09-10 11:47:43 -04003211 * If an lseek was done, then reset and start from beginning.
3212 */
3213 if (*pos < iter->pos)
3214 reset_iter_read(iter);
3215
3216 /*
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05003217 * For set_ftrace_filter reading, if we have the filter
3218 * off, we can short cut and just print out that all
3219 * functions are enabled.
3220 */
Namhyung Kim8c006cf2014-06-13 16:24:06 +09003221 if ((iter->flags & FTRACE_ITER_FILTER &&
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003222 ftrace_hash_empty(ops->func_hash->filter_hash)) ||
Namhyung Kim8c006cf2014-06-13 16:24:06 +09003223 (iter->flags & FTRACE_ITER_NOTRACE &&
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003224 ftrace_hash_empty(ops->func_hash->notrace_hash))) {
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05003225 if (*pos > 0)
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003226 return t_hash_start(m, pos);
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05003227 iter->flags |= FTRACE_ITER_PRINTALL;
Chris Wrightdf091622010-09-09 16:34:59 -07003228 /* reset in case of seek/pread */
3229 iter->flags &= ~FTRACE_ITER_HASH;
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05003230 return iter;
3231 }
3232
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003233 if (iter->flags & FTRACE_ITER_HASH)
3234 return t_hash_start(m, pos);
3235
Steven Rostedt98c4fd02010-09-10 11:47:43 -04003236 /*
3237 * Unfortunately, we need to restart at ftrace_pages_start
3238 * every time we let go of the ftrace_mutex. This is because
3239 * those pointers can change without the lock.
3240 */
Li Zefan694ce0a2009-06-24 09:54:19 +08003241 iter->pg = ftrace_pages_start;
3242 iter->idx = 0;
3243 for (l = 0; l <= *pos; ) {
3244 p = t_next(m, p, &l);
3245 if (!p)
3246 break;
Liming Wang50cdaf02008-11-28 12:13:21 +08003247 }
walimis5821e1b2008-11-15 15:19:06 +08003248
Steven Rostedt69a30832011-12-19 15:21:16 -05003249 if (!p)
3250 return t_hash_start(m, pos);
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003251
3252 return iter;
Steven Rostedt5072c592008-05-12 21:20:43 +02003253}
3254
3255static void t_stop(struct seq_file *m, void *p)
3256{
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003257 mutex_unlock(&ftrace_lock);
Steven Rostedt5072c592008-05-12 21:20:43 +02003258}
3259
Steven Rostedt (Red Hat)15d5b022014-07-03 14:51:36 -04003260void * __weak
3261arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3262{
3263 return NULL;
3264}
3265
3266static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3267 struct dyn_ftrace *rec)
3268{
3269 void *ptr;
3270
3271 ptr = arch_ftrace_trampoline_func(ops, rec);
3272 if (ptr)
3273 seq_printf(m, " ->%pS", ptr);
3274}
3275
Steven Rostedt5072c592008-05-12 21:20:43 +02003276static int t_show(struct seq_file *m, void *v)
3277{
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05003278 struct ftrace_iterator *iter = m->private;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003279 struct dyn_ftrace *rec;
Steven Rostedt5072c592008-05-12 21:20:43 +02003280
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003281 if (iter->flags & FTRACE_ITER_HASH)
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003282 return t_hash_show(m, iter);
Steven Rostedt8fc0c702009-02-16 15:28:00 -05003283
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05003284 if (iter->flags & FTRACE_ITER_PRINTALL) {
Namhyung Kim8c006cf2014-06-13 16:24:06 +09003285 if (iter->flags & FTRACE_ITER_NOTRACE)
Rasmus Villemoesfa6f0cc2014-11-08 21:42:10 +01003286 seq_puts(m, "#### no functions disabled ####\n");
Namhyung Kim8c006cf2014-06-13 16:24:06 +09003287 else
Rasmus Villemoesfa6f0cc2014-11-08 21:42:10 +01003288 seq_puts(m, "#### all functions enabled ####\n");
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05003289 return 0;
3290 }
3291
Steven Rostedt4aeb6962010-09-09 10:00:28 -04003292 rec = iter->func;
3293
Steven Rostedt5072c592008-05-12 21:20:43 +02003294 if (!rec)
3295 return 0;
3296
Steven Rostedt647bcd02011-05-03 14:39:21 -04003297 seq_printf(m, "%ps", (void *)rec->ip);
Steven Rostedt (Red Hat)9674b2f2014-05-09 16:54:59 -04003298 if (iter->flags & FTRACE_ITER_ENABLED) {
Steven Rostedt (Red Hat)030f4e12015-12-01 12:24:45 -05003299 struct ftrace_ops *ops;
Steven Rostedt (Red Hat)15d5b022014-07-03 14:51:36 -04003300
Masami Hiramatsuf8b8be82014-11-21 05:25:16 -05003301 seq_printf(m, " (%ld)%s%s",
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04003302 ftrace_rec_count(rec),
Masami Hiramatsuf8b8be82014-11-21 05:25:16 -05003303 rec->flags & FTRACE_FL_REGS ? " R" : " ",
3304 rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
Steven Rostedt (Red Hat)9674b2f2014-05-09 16:54:59 -04003305 if (rec->flags & FTRACE_FL_TRAMP_EN) {
Steven Rostedt (Red Hat)5fecaa02014-07-24 16:00:31 -04003306 ops = ftrace_find_tramp_ops_any(rec);
Steven Rostedt (Red Hat)39daa7b2015-11-25 15:12:38 -05003307 if (ops) {
3308 do {
3309 seq_printf(m, "\ttramp: %pS (%pS)",
3310 (void *)ops->trampoline,
3311 (void *)ops->func);
Steven Rostedt (Red Hat)030f4e12015-12-01 12:24:45 -05003312 add_trampoline_func(m, ops, rec);
Steven Rostedt (Red Hat)39daa7b2015-11-25 15:12:38 -05003313 ops = ftrace_find_tramp_ops_next(rec, ops);
3314 } while (ops);
3315 } else
Rasmus Villemoesfa6f0cc2014-11-08 21:42:10 +01003316 seq_puts(m, "\ttramp: ERROR!");
Steven Rostedt (Red Hat)030f4e12015-12-01 12:24:45 -05003317 } else {
3318 add_trampoline_func(m, NULL, rec);
Steven Rostedt (Red Hat)9674b2f2014-05-09 16:54:59 -04003319 }
3320 }
3321
Rasmus Villemoesfa6f0cc2014-11-08 21:42:10 +01003322 seq_putc(m, '\n');
Steven Rostedt5072c592008-05-12 21:20:43 +02003323
3324 return 0;
3325}
3326
James Morris88e9d342009-09-22 16:43:43 -07003327static const struct seq_operations show_ftrace_seq_ops = {
Steven Rostedt5072c592008-05-12 21:20:43 +02003328 .start = t_start,
3329 .next = t_next,
3330 .stop = t_stop,
3331 .show = t_show,
3332};
3333
Ingo Molnare309b412008-05-12 21:20:51 +02003334static int
Steven Rostedt5072c592008-05-12 21:20:43 +02003335ftrace_avail_open(struct inode *inode, struct file *file)
3336{
3337 struct ftrace_iterator *iter;
Steven Rostedt5072c592008-05-12 21:20:43 +02003338
Steven Rostedt4eebcc82008-05-12 21:20:48 +02003339 if (unlikely(ftrace_disabled))
3340 return -ENODEV;
3341
Jiri Olsa50e18b92012-04-25 10:23:39 +02003342 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3343 if (iter) {
3344 iter->pg = ftrace_pages_start;
3345 iter->ops = &global_ops;
Ingo Molnar4bf39a92008-05-12 21:20:46 +02003346 }
Steven Rostedt5072c592008-05-12 21:20:43 +02003347
Jiri Olsa50e18b92012-04-25 10:23:39 +02003348 return iter ? 0 : -ENOMEM;
Steven Rostedt5072c592008-05-12 21:20:43 +02003349}
3350
Steven Rostedt647bcd02011-05-03 14:39:21 -04003351static int
3352ftrace_enabled_open(struct inode *inode, struct file *file)
3353{
3354 struct ftrace_iterator *iter;
Steven Rostedt647bcd02011-05-03 14:39:21 -04003355
Jiri Olsa50e18b92012-04-25 10:23:39 +02003356 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3357 if (iter) {
3358 iter->pg = ftrace_pages_start;
3359 iter->flags = FTRACE_ITER_ENABLED;
3360 iter->ops = &global_ops;
Steven Rostedt647bcd02011-05-03 14:39:21 -04003361 }
3362
Jiri Olsa50e18b92012-04-25 10:23:39 +02003363 return iter ? 0 : -ENOMEM;
Steven Rostedt647bcd02011-05-03 14:39:21 -04003364}
3365
Steven Rostedtfc13cb02011-12-19 14:41:25 -05003366/**
3367 * ftrace_regex_open - initialize function tracer filter files
3368 * @ops: The ftrace_ops that hold the hash filters
3369 * @flag: The type of filter to process
3370 * @inode: The inode, usually passed in to your open routine
3371 * @file: The file, usually passed in to your open routine
3372 *
3373 * ftrace_regex_open() initializes the filter files for the
3374 * @ops. Depending on @flag it may process the filter hash or
3375 * the notrace hash of @ops. With this called from the open
3376 * routine, you can use ftrace_filter_write() for the write
3377 * routine if @flag has FTRACE_ITER_FILTER set, or
3378 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
Steven Rostedt (Red Hat)098c8792013-12-21 17:39:40 -05003379 * tracing_lseek() should be used as the lseek routine, and
Steven Rostedtfc13cb02011-12-19 14:41:25 -05003380 * release must call ftrace_regex_release().
3381 */
3382int
Steven Rostedtf45948e2011-05-02 12:29:25 -04003383ftrace_regex_open(struct ftrace_ops *ops, int flag,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003384 struct inode *inode, struct file *file)
Steven Rostedt5072c592008-05-12 21:20:43 +02003385{
3386 struct ftrace_iterator *iter;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003387 struct ftrace_hash *hash;
Steven Rostedt5072c592008-05-12 21:20:43 +02003388 int ret = 0;
3389
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09003390 ftrace_ops_init(ops);
3391
Steven Rostedt4eebcc82008-05-12 21:20:48 +02003392 if (unlikely(ftrace_disabled))
3393 return -ENODEV;
3394
Steven Rostedt5072c592008-05-12 21:20:43 +02003395 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3396 if (!iter)
3397 return -ENOMEM;
3398
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003399 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
3400 kfree(iter);
3401 return -ENOMEM;
3402 }
3403
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003404 iter->ops = ops;
3405 iter->flags = flag;
3406
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003407 mutex_lock(&ops->func_hash->regex_lock);
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003408
Steven Rostedtf45948e2011-05-02 12:29:25 -04003409 if (flag & FTRACE_ITER_NOTRACE)
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003410 hash = ops->func_hash->notrace_hash;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003411 else
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003412 hash = ops->func_hash->filter_hash;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003413
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003414 if (file->f_mode & FMODE_WRITE) {
Namhyung Kimef2fbe12014-06-11 17:06:54 +09003415 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3416
3417 if (file->f_flags & O_TRUNC)
3418 iter->hash = alloc_ftrace_hash(size_bits);
3419 else
3420 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3421
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003422 if (!iter->hash) {
3423 trace_parser_put(&iter->parser);
3424 kfree(iter);
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003425 ret = -ENOMEM;
3426 goto out_unlock;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003427 }
3428 }
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003429
Steven Rostedt5072c592008-05-12 21:20:43 +02003430 if (file->f_mode & FMODE_READ) {
3431 iter->pg = ftrace_pages_start;
Steven Rostedt5072c592008-05-12 21:20:43 +02003432
3433 ret = seq_open(file, &show_ftrace_seq_ops);
3434 if (!ret) {
3435 struct seq_file *m = file->private_data;
3436 m->private = iter;
Li Zefan79fe2492009-09-22 13:54:28 +08003437 } else {
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003438 /* Failed */
3439 free_ftrace_hash(iter->hash);
Li Zefan79fe2492009-09-22 13:54:28 +08003440 trace_parser_put(&iter->parser);
Steven Rostedt5072c592008-05-12 21:20:43 +02003441 kfree(iter);
Li Zefan79fe2492009-09-22 13:54:28 +08003442 }
Steven Rostedt5072c592008-05-12 21:20:43 +02003443 } else
3444 file->private_data = iter;
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003445
3446 out_unlock:
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003447 mutex_unlock(&ops->func_hash->regex_lock);
Steven Rostedt5072c592008-05-12 21:20:43 +02003448
3449 return ret;
3450}
3451
Steven Rostedt41c52c02008-05-22 11:46:33 -04003452static int
3453ftrace_filter_open(struct inode *inode, struct file *file)
3454{
Steven Rostedt (Red Hat)e3b3e2e2013-11-11 23:07:14 -05003455 struct ftrace_ops *ops = inode->i_private;
3456
3457 return ftrace_regex_open(ops,
Steven Rostedt69a30832011-12-19 15:21:16 -05003458 FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
3459 inode, file);
Steven Rostedt41c52c02008-05-22 11:46:33 -04003460}
3461
3462static int
3463ftrace_notrace_open(struct inode *inode, struct file *file)
3464{
Steven Rostedt (Red Hat)e3b3e2e2013-11-11 23:07:14 -05003465 struct ftrace_ops *ops = inode->i_private;
3466
3467 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003468 inode, file);
Steven Rostedt41c52c02008-05-22 11:46:33 -04003469}
3470
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003471/* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3472struct ftrace_glob {
3473 char *search;
3474 unsigned len;
3475 int type;
3476};
3477
Thiago Jung Bauermann7132e2d2016-04-25 18:56:14 -03003478/*
3479 * If symbols in an architecture don't correspond exactly to the user-visible
3480 * name of what they represent, it is possible to define this function to
3481 * perform the necessary adjustments.
3482*/
3483char * __weak arch_ftrace_match_adjust(char *str, const char *search)
3484{
3485 return str;
3486}
3487
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003488static int ftrace_match(char *str, struct ftrace_glob *g)
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003489{
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003490 int matched = 0;
Li Zefan751e9982010-01-14 10:53:02 +08003491 int slen;
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003492
Thiago Jung Bauermann7132e2d2016-04-25 18:56:14 -03003493 str = arch_ftrace_match_adjust(str, g->search);
3494
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003495 switch (g->type) {
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003496 case MATCH_FULL:
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003497 if (strcmp(str, g->search) == 0)
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003498 matched = 1;
3499 break;
3500 case MATCH_FRONT_ONLY:
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003501 if (strncmp(str, g->search, g->len) == 0)
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003502 matched = 1;
3503 break;
3504 case MATCH_MIDDLE_ONLY:
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003505 if (strstr(str, g->search))
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003506 matched = 1;
3507 break;
3508 case MATCH_END_ONLY:
Li Zefan751e9982010-01-14 10:53:02 +08003509 slen = strlen(str);
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003510 if (slen >= g->len &&
3511 memcmp(str + slen - g->len, g->search, g->len) == 0)
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003512 matched = 1;
3513 break;
Masami Hiramatsu60f1d5e2016-10-05 20:58:15 +09003514 case MATCH_GLOB:
3515 if (glob_match(g->search, str))
3516 matched = 1;
3517 break;
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003518 }
3519
3520 return matched;
3521}
3522
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003523static int
Dmitry Safonovf0a3b152015-09-29 19:46:13 +03003524enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
Steven Rostedt996e87b2011-04-26 16:11:03 -04003525{
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003526 struct ftrace_func_entry *entry;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003527 int ret = 0;
3528
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003529 entry = ftrace_lookup_ip(hash, rec->ip);
Dmitry Safonovf0a3b152015-09-29 19:46:13 +03003530 if (clear_filter) {
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003531 /* Do nothing if it doesn't exist */
3532 if (!entry)
3533 return 0;
3534
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003535 free_hash_entry(hash, entry);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003536 } else {
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003537 /* Do nothing if it exists */
3538 if (entry)
3539 return 0;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003540
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003541 ret = add_hash_entry(hash, rec->ip);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003542 }
3543 return ret;
Steven Rostedt996e87b2011-04-26 16:11:03 -04003544}
3545
Steven Rostedt64e7c442009-02-13 17:08:48 -05003546static int
Dmitry Safonov0b507e12015-09-29 19:46:15 +03003547ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
3548 struct ftrace_glob *mod_g, int exclude_mod)
Steven Rostedt64e7c442009-02-13 17:08:48 -05003549{
3550 char str[KSYM_SYMBOL_LEN];
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003551 char *modname;
Steven Rostedt64e7c442009-02-13 17:08:48 -05003552
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003553 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3554
Dmitry Safonov0b507e12015-09-29 19:46:15 +03003555 if (mod_g) {
3556 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
3557
3558 /* blank module name to match all modules */
3559 if (!mod_g->len) {
3560 /* blank module globbing: modname xor exclude_mod */
3561 if ((!exclude_mod) != (!modname))
3562 goto func_match;
3563 return 0;
3564 }
3565
3566 /* not matching the module */
3567 if (!modname || !mod_matches) {
3568 if (exclude_mod)
3569 goto func_match;
3570 else
3571 return 0;
3572 }
3573
3574 if (mod_matches && exclude_mod)
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003575 return 0;
3576
Dmitry Safonov0b507e12015-09-29 19:46:15 +03003577func_match:
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003578 /* blank search means to match all funcs in the mod */
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003579 if (!func_g->len)
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003580 return 1;
3581 }
3582
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003583 return ftrace_match(str, func_g);
Steven Rostedt64e7c442009-02-13 17:08:48 -05003584}
3585
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003586static int
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003587match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003588{
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003589 struct ftrace_page *pg;
3590 struct dyn_ftrace *rec;
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003591 struct ftrace_glob func_g = { .type = MATCH_FULL };
Dmitry Safonov0b507e12015-09-29 19:46:15 +03003592 struct ftrace_glob mod_g = { .type = MATCH_FULL };
3593 struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
3594 int exclude_mod = 0;
Li Zefan311d16d2009-12-08 11:15:11 +08003595 int found = 0;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003596 int ret;
Dmitry Safonovf0a3b152015-09-29 19:46:13 +03003597 int clear_filter;
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003598
Dmitry Safonov0b507e12015-09-29 19:46:15 +03003599 if (func) {
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003600 func_g.type = filter_parse_regex(func, len, &func_g.search,
3601 &clear_filter);
3602 func_g.len = strlen(func_g.search);
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003603 }
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003604
Dmitry Safonov0b507e12015-09-29 19:46:15 +03003605 if (mod) {
3606 mod_g.type = filter_parse_regex(mod, strlen(mod),
3607 &mod_g.search, &exclude_mod);
3608 mod_g.len = strlen(mod_g.search);
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003609 }
3610
Steven Rostedt52baf112009-02-14 01:15:39 -05003611 mutex_lock(&ftrace_lock);
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003612
3613 if (unlikely(ftrace_disabled))
3614 goto out_unlock;
3615
Steven Rostedt265c8312009-02-13 12:43:56 -05003616 do_for_each_ftrace_rec(pg, rec) {
Steven Rostedt (Red Hat)546fece2016-11-14 16:31:49 -05003617
3618 if (rec->flags & FTRACE_FL_DISABLED)
3619 continue;
3620
Dmitry Safonov0b507e12015-09-29 19:46:15 +03003621 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
Dmitry Safonovf0a3b152015-09-29 19:46:13 +03003622 ret = enter_record(hash, rec, clear_filter);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003623 if (ret < 0) {
3624 found = ret;
3625 goto out_unlock;
3626 }
Li Zefan311d16d2009-12-08 11:15:11 +08003627 found = 1;
Steven Rostedt265c8312009-02-13 12:43:56 -05003628 }
3629 } while_for_each_ftrace_rec();
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003630 out_unlock:
Steven Rostedt52baf112009-02-14 01:15:39 -05003631 mutex_unlock(&ftrace_lock);
Li Zefan311d16d2009-12-08 11:15:11 +08003632
3633 return found;
Steven Rostedt5072c592008-05-12 21:20:43 +02003634}
3635
Steven Rostedt64e7c442009-02-13 17:08:48 -05003636static int
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003637ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
Steven Rostedt64e7c442009-02-13 17:08:48 -05003638{
Dmitry Safonovf0a3b152015-09-29 19:46:13 +03003639 return match_records(hash, buff, len, NULL);
Steven Rostedt64e7c442009-02-13 17:08:48 -05003640}
3641
Steven Rostedt64e7c442009-02-13 17:08:48 -05003642
Steven Rostedtf6180772009-02-14 00:40:25 -05003643/*
3644 * We register the module command as a template to show others how
3645 * to register the a command as well.
3646 */
3647
3648static int
Steven Rostedt43dd61c2011-07-07 11:09:22 -04003649ftrace_mod_callback(struct ftrace_hash *hash,
Dmitry Safonovf0a3b152015-09-29 19:46:13 +03003650 char *func, char *cmd, char *module, int enable)
Steven Rostedtf6180772009-02-14 00:40:25 -05003651{
Dmitry Safonov5e3949f2015-09-29 19:46:12 +03003652 int ret;
Steven Rostedtf6180772009-02-14 00:40:25 -05003653
3654 /*
3655 * cmd == 'mod' because we only registered this func
3656 * for the 'mod' ftrace_func_command.
3657 * But if you register one func with multiple commands,
3658 * you can tell which command was used by the cmd
3659 * parameter.
3660 */
Dmitry Safonovf0a3b152015-09-29 19:46:13 +03003661 ret = match_records(hash, func, strlen(func), module);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003662 if (!ret)
Dmitry Safonov5e3949f2015-09-29 19:46:12 +03003663 return -EINVAL;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003664 if (ret < 0)
3665 return ret;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003666 return 0;
Steven Rostedtf6180772009-02-14 00:40:25 -05003667}
3668
3669static struct ftrace_func_command ftrace_mod_cmd = {
3670 .name = "mod",
3671 .func = ftrace_mod_callback,
3672};
3673
3674static int __init ftrace_mod_cmd_init(void)
3675{
3676 return register_ftrace_command(&ftrace_mod_cmd);
3677}
Steven Rostedt6f415672012-10-05 12:13:07 -04003678core_initcall(ftrace_mod_cmd_init);
Steven Rostedtf6180772009-02-14 00:40:25 -05003679
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04003680static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -04003681 struct ftrace_ops *op, struct pt_regs *pt_regs)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003682{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003683 struct ftrace_func_probe *entry;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003684 struct hlist_head *hhd;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003685 unsigned long key;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003686
3687 key = hash_long(ip, FTRACE_HASH_BITS);
3688
3689 hhd = &ftrace_func_hash[key];
3690
3691 if (hlist_empty(hhd))
3692 return;
3693
3694 /*
3695 * Disable preemption for these calls to prevent a RCU grace
3696 * period. This syncs the hash iteration and freeing of items
3697 * on the hash. rcu_read_lock is too dangerous here.
3698 */
Steven Rostedt5168ae52010-06-03 09:36:50 -04003699 preempt_disable_notrace();
Steven Rostedt1bb539c2013-05-28 14:38:43 -04003700 hlist_for_each_entry_rcu_notrace(entry, hhd, node) {
Steven Rostedt59df055f2009-02-14 15:29:06 -05003701 if (entry->ip == ip)
3702 entry->ops->func(ip, parent_ip, &entry->data);
3703 }
Steven Rostedt5168ae52010-06-03 09:36:50 -04003704 preempt_enable_notrace();
Steven Rostedt59df055f2009-02-14 15:29:06 -05003705}
3706
Steven Rostedtb6887d72009-02-17 12:32:04 -05003707static struct ftrace_ops trace_probe_ops __read_mostly =
Steven Rostedt59df055f2009-02-14 15:29:06 -05003708{
Steven Rostedtfb9fb012009-03-25 13:26:41 -04003709 .func = function_trace_probe_call,
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09003710 .flags = FTRACE_OPS_FL_INITIALIZED,
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003711 INIT_OPS_HASH(trace_probe_ops)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003712};
3713
Steven Rostedtb6887d72009-02-17 12:32:04 -05003714static int ftrace_probe_registered;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003715
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05003716static void __enable_ftrace_function_probe(struct ftrace_ops_hash *old_hash)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003717{
Steven Rostedtb8489142011-05-04 09:27:52 -04003718 int ret;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003719 int i;
3720
Steven Rostedt (Red Hat)19dd6032013-05-09 19:37:36 -04003721 if (ftrace_probe_registered) {
3722 /* still need to update the function call sites */
3723 if (ftrace_enabled)
Steven Rostedt (Red Hat)8252ecf2014-10-24 14:56:01 -04003724 ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS,
3725 old_hash);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003726 return;
Steven Rostedt (Red Hat)19dd6032013-05-09 19:37:36 -04003727 }
Steven Rostedt59df055f2009-02-14 15:29:06 -05003728
3729 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3730 struct hlist_head *hhd = &ftrace_func_hash[i];
3731 if (hhd->first)
3732 break;
3733 }
3734 /* Nothing registered? */
3735 if (i == FTRACE_FUNC_HASHSIZE)
3736 return;
3737
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05003738 ret = ftrace_startup(&trace_probe_ops, 0);
Steven Rostedtb8489142011-05-04 09:27:52 -04003739
Steven Rostedtb6887d72009-02-17 12:32:04 -05003740 ftrace_probe_registered = 1;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003741}
3742
Steven Rostedtb6887d72009-02-17 12:32:04 -05003743static void __disable_ftrace_function_probe(void)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003744{
3745 int i;
3746
Steven Rostedtb6887d72009-02-17 12:32:04 -05003747 if (!ftrace_probe_registered)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003748 return;
3749
3750 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3751 struct hlist_head *hhd = &ftrace_func_hash[i];
3752 if (hhd->first)
3753 return;
3754 }
3755
3756 /* no more funcs left */
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05003757 ftrace_shutdown(&trace_probe_ops, 0);
Steven Rostedtb8489142011-05-04 09:27:52 -04003758
Steven Rostedtb6887d72009-02-17 12:32:04 -05003759 ftrace_probe_registered = 0;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003760}
3761
3762
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003763static void ftrace_free_entry(struct ftrace_func_probe *entry)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003764{
Steven Rostedt59df055f2009-02-14 15:29:06 -05003765 if (entry->ops->free)
Steven Rostedt (Red Hat)e67efb92013-03-12 15:07:59 -04003766 entry->ops->free(entry->ops, entry->ip, &entry->data);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003767 kfree(entry);
3768}
3769
Steven Rostedt59df055f2009-02-14 15:29:06 -05003770int
Steven Rostedtb6887d72009-02-17 12:32:04 -05003771register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
Steven Rostedt59df055f2009-02-14 15:29:06 -05003772 void *data)
3773{
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05003774 struct ftrace_ops_hash old_hash_ops;
Steven Rostedtb6887d72009-02-17 12:32:04 -05003775 struct ftrace_func_probe *entry;
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003776 struct ftrace_glob func_g;
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003777 struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04003778 struct ftrace_hash *old_hash = *orig_hash;
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003779 struct ftrace_hash *hash;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003780 struct ftrace_page *pg;
3781 struct dyn_ftrace *rec;
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003782 int not;
Steven Rostedt6a24a242009-02-17 11:20:26 -05003783 unsigned long key;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003784 int count = 0;
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003785 int ret;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003786
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003787 func_g.type = filter_parse_regex(glob, strlen(glob),
3788 &func_g.search, &not);
3789 func_g.len = strlen(func_g.search);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003790
Steven Rostedtb6887d72009-02-17 12:32:04 -05003791 /* we do not support '!' for function probes */
Steven Rostedt59df055f2009-02-14 15:29:06 -05003792 if (WARN_ON(not))
3793 return -EINVAL;
3794
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003795 mutex_lock(&trace_probe_ops.func_hash->regex_lock);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003796
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05003797 old_hash_ops.filter_hash = old_hash;
3798 /* Probes only have filters */
3799 old_hash_ops.notrace_hash = NULL;
3800
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04003801 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003802 if (!hash) {
3803 count = -ENOMEM;
Steven Rostedt (Red Hat)5ae0bf52013-05-09 18:20:37 -04003804 goto out;
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003805 }
3806
3807 if (unlikely(ftrace_disabled)) {
3808 count = -ENODEV;
Steven Rostedt (Red Hat)5ae0bf52013-05-09 18:20:37 -04003809 goto out;
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003810 }
Steven Rostedt45a4a232011-04-21 23:16:46 -04003811
Steven Rostedt (Red Hat)5ae0bf52013-05-09 18:20:37 -04003812 mutex_lock(&ftrace_lock);
3813
Steven Rostedt59df055f2009-02-14 15:29:06 -05003814 do_for_each_ftrace_rec(pg, rec) {
3815
Steven Rostedt (Red Hat)546fece2016-11-14 16:31:49 -05003816 if (rec->flags & FTRACE_FL_DISABLED)
3817 continue;
3818
Dmitry Safonov0b507e12015-09-29 19:46:15 +03003819 if (!ftrace_match_record(rec, &func_g, NULL, 0))
Steven Rostedt59df055f2009-02-14 15:29:06 -05003820 continue;
3821
3822 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
3823 if (!entry) {
Steven Rostedtb6887d72009-02-17 12:32:04 -05003824 /* If we did not process any, then return error */
Steven Rostedt59df055f2009-02-14 15:29:06 -05003825 if (!count)
3826 count = -ENOMEM;
3827 goto out_unlock;
3828 }
3829
3830 count++;
3831
3832 entry->data = data;
3833
3834 /*
3835 * The caller might want to do something special
3836 * for each function we find. We call the callback
3837 * to give the caller an opportunity to do so.
3838 */
Steven Rostedt (Red Hat)e67efb92013-03-12 15:07:59 -04003839 if (ops->init) {
3840 if (ops->init(ops, rec->ip, &entry->data) < 0) {
Steven Rostedt59df055f2009-02-14 15:29:06 -05003841 /* caller does not like this func */
3842 kfree(entry);
3843 continue;
3844 }
3845 }
3846
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003847 ret = enter_record(hash, rec, 0);
3848 if (ret < 0) {
3849 kfree(entry);
3850 count = ret;
3851 goto out_unlock;
3852 }
3853
Steven Rostedt59df055f2009-02-14 15:29:06 -05003854 entry->ops = ops;
3855 entry->ip = rec->ip;
3856
3857 key = hash_long(entry->ip, FTRACE_HASH_BITS);
3858 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
3859
3860 } while_for_each_ftrace_rec();
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003861
3862 ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
Steven Rostedt (Red Hat)8252ecf2014-10-24 14:56:01 -04003863
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05003864 __enable_ftrace_function_probe(&old_hash_ops);
Steven Rostedt (Red Hat)8252ecf2014-10-24 14:56:01 -04003865
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04003866 if (!ret)
3867 free_ftrace_hash_rcu(old_hash);
3868 else
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003869 count = ret;
3870
Steven Rostedt59df055f2009-02-14 15:29:06 -05003871 out_unlock:
Steven Rostedt (Red Hat)5ae0bf52013-05-09 18:20:37 -04003872 mutex_unlock(&ftrace_lock);
3873 out:
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003874 mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003875 free_ftrace_hash(hash);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003876
3877 return count;
3878}
3879
3880enum {
Steven Rostedtb6887d72009-02-17 12:32:04 -05003881 PROBE_TEST_FUNC = 1,
3882 PROBE_TEST_DATA = 2
Steven Rostedt59df055f2009-02-14 15:29:06 -05003883};
3884
3885static void
Steven Rostedtb6887d72009-02-17 12:32:04 -05003886__unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
Steven Rostedt59df055f2009-02-14 15:29:06 -05003887 void *data, int flags)
3888{
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003889 struct ftrace_func_entry *rec_entry;
Steven Rostedtb6887d72009-02-17 12:32:04 -05003890 struct ftrace_func_probe *entry;
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003891 struct ftrace_func_probe *p;
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003892 struct ftrace_glob func_g;
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003893 struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04003894 struct ftrace_hash *old_hash = *orig_hash;
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003895 struct list_head free_list;
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003896 struct ftrace_hash *hash;
Sasha Levinb67bfe02013-02-27 17:06:00 -08003897 struct hlist_node *tmp;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003898 char str[KSYM_SYMBOL_LEN];
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003899 int i, ret;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003900
Atsushi Tsujib36461d2009-09-15 19:06:30 +09003901 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003902 func_g.search = NULL;
Atsushi Tsujib36461d2009-09-15 19:06:30 +09003903 else if (glob) {
Steven Rostedt59df055f2009-02-14 15:29:06 -05003904 int not;
3905
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003906 func_g.type = filter_parse_regex(glob, strlen(glob),
3907 &func_g.search, &not);
3908 func_g.len = strlen(func_g.search);
3909 func_g.search = glob;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003910
Steven Rostedtb6887d72009-02-17 12:32:04 -05003911 /* we do not support '!' for function probes */
Steven Rostedt59df055f2009-02-14 15:29:06 -05003912 if (WARN_ON(not))
3913 return;
3914 }
3915
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003916 mutex_lock(&trace_probe_ops.func_hash->regex_lock);
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003917
3918 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3919 if (!hash)
3920 /* Hmm, should report this somehow */
3921 goto out_unlock;
3922
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003923 INIT_LIST_HEAD(&free_list);
3924
Steven Rostedt59df055f2009-02-14 15:29:06 -05003925 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3926 struct hlist_head *hhd = &ftrace_func_hash[i];
3927
Sasha Levinb67bfe02013-02-27 17:06:00 -08003928 hlist_for_each_entry_safe(entry, tmp, hhd, node) {
Steven Rostedt59df055f2009-02-14 15:29:06 -05003929
3930 /* break up if statements for readability */
Steven Rostedtb6887d72009-02-17 12:32:04 -05003931 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003932 continue;
3933
Steven Rostedtb6887d72009-02-17 12:32:04 -05003934 if ((flags & PROBE_TEST_DATA) && entry->data != data)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003935 continue;
3936
3937 /* do this last, since it is the most expensive */
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003938 if (func_g.search) {
Steven Rostedt59df055f2009-02-14 15:29:06 -05003939 kallsyms_lookup(entry->ip, NULL, NULL,
3940 NULL, str);
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003941 if (!ftrace_match(str, &func_g))
Steven Rostedt59df055f2009-02-14 15:29:06 -05003942 continue;
3943 }
3944
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003945 rec_entry = ftrace_lookup_ip(hash, entry->ip);
3946 /* It is possible more than one entry had this ip */
3947 if (rec_entry)
3948 free_hash_entry(hash, rec_entry);
3949
Steven Rostedt (Red Hat)740466b2013-03-13 11:15:19 -04003950 hlist_del_rcu(&entry->node);
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003951 list_add(&entry->free_list, &free_list);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003952 }
3953 }
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003954 mutex_lock(&ftrace_lock);
Steven Rostedtb6887d72009-02-17 12:32:04 -05003955 __disable_ftrace_function_probe();
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003956 /*
3957 * Remove after the disable is called. Otherwise, if the last
3958 * probe is removed, a null hash means *all enabled*.
3959 */
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04003960 ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003961 synchronize_sched();
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04003962 if (!ret)
3963 free_ftrace_hash_rcu(old_hash);
3964
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003965 list_for_each_entry_safe(entry, p, &free_list, free_list) {
3966 list_del(&entry->free_list);
3967 ftrace_free_entry(entry);
3968 }
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003969 mutex_unlock(&ftrace_lock);
Dmitry Safonov3ba00922015-09-29 19:46:14 +03003970
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003971 out_unlock:
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003972 mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003973 free_ftrace_hash(hash);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003974}
3975
3976void
Steven Rostedtb6887d72009-02-17 12:32:04 -05003977unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
Steven Rostedt59df055f2009-02-14 15:29:06 -05003978 void *data)
3979{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003980 __unregister_ftrace_function_probe(glob, ops, data,
3981 PROBE_TEST_FUNC | PROBE_TEST_DATA);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003982}
3983
3984void
Steven Rostedtb6887d72009-02-17 12:32:04 -05003985unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003986{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003987 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003988}
3989
Steven Rostedtb6887d72009-02-17 12:32:04 -05003990void unregister_ftrace_function_probe_all(char *glob)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003991{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003992 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003993}
3994
Steven Rostedtf6180772009-02-14 00:40:25 -05003995static LIST_HEAD(ftrace_commands);
3996static DEFINE_MUTEX(ftrace_cmd_mutex);
3997
Tom Zanussi38de93a2013-10-24 08:34:18 -05003998/*
3999 * Currently we only register ftrace commands from __init, so mark this
4000 * __init too.
4001 */
4002__init int register_ftrace_command(struct ftrace_func_command *cmd)
Steven Rostedtf6180772009-02-14 00:40:25 -05004003{
4004 struct ftrace_func_command *p;
4005 int ret = 0;
4006
4007 mutex_lock(&ftrace_cmd_mutex);
4008 list_for_each_entry(p, &ftrace_commands, list) {
4009 if (strcmp(cmd->name, p->name) == 0) {
4010 ret = -EBUSY;
4011 goto out_unlock;
4012 }
4013 }
4014 list_add(&cmd->list, &ftrace_commands);
4015 out_unlock:
4016 mutex_unlock(&ftrace_cmd_mutex);
4017
4018 return ret;
4019}
4020
Tom Zanussi38de93a2013-10-24 08:34:18 -05004021/*
4022 * Currently we only unregister ftrace commands from __init, so mark
4023 * this __init too.
4024 */
4025__init int unregister_ftrace_command(struct ftrace_func_command *cmd)
Steven Rostedtf6180772009-02-14 00:40:25 -05004026{
4027 struct ftrace_func_command *p, *n;
4028 int ret = -ENODEV;
4029
4030 mutex_lock(&ftrace_cmd_mutex);
4031 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
4032 if (strcmp(cmd->name, p->name) == 0) {
4033 ret = 0;
4034 list_del_init(&p->list);
4035 goto out_unlock;
4036 }
4037 }
4038 out_unlock:
4039 mutex_unlock(&ftrace_cmd_mutex);
4040
4041 return ret;
4042}
4043
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004044static int ftrace_process_regex(struct ftrace_hash *hash,
4045 char *buff, int len, int enable)
Steven Rostedt64e7c442009-02-13 17:08:48 -05004046{
Steven Rostedtf6180772009-02-14 00:40:25 -05004047 char *func, *command, *next = buff;
Steven Rostedt6a24a242009-02-17 11:20:26 -05004048 struct ftrace_func_command *p;
GuoWen Li0aff1c02011-06-01 19:18:47 +08004049 int ret = -EINVAL;
Steven Rostedt64e7c442009-02-13 17:08:48 -05004050
4051 func = strsep(&next, ":");
4052
4053 if (!next) {
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04004054 ret = ftrace_match_records(hash, func, len);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04004055 if (!ret)
4056 ret = -EINVAL;
4057 if (ret < 0)
4058 return ret;
4059 return 0;
Steven Rostedt64e7c442009-02-13 17:08:48 -05004060 }
4061
Steven Rostedtf6180772009-02-14 00:40:25 -05004062 /* command found */
Steven Rostedt64e7c442009-02-13 17:08:48 -05004063
4064 command = strsep(&next, ":");
4065
Steven Rostedtf6180772009-02-14 00:40:25 -05004066 mutex_lock(&ftrace_cmd_mutex);
4067 list_for_each_entry(p, &ftrace_commands, list) {
4068 if (strcmp(p->name, command) == 0) {
Steven Rostedt43dd61c2011-07-07 11:09:22 -04004069 ret = p->func(hash, func, command, next, enable);
Steven Rostedtf6180772009-02-14 00:40:25 -05004070 goto out_unlock;
4071 }
Steven Rostedt64e7c442009-02-13 17:08:48 -05004072 }
Steven Rostedtf6180772009-02-14 00:40:25 -05004073 out_unlock:
4074 mutex_unlock(&ftrace_cmd_mutex);
Steven Rostedt64e7c442009-02-13 17:08:48 -05004075
Steven Rostedtf6180772009-02-14 00:40:25 -05004076 return ret;
Steven Rostedt64e7c442009-02-13 17:08:48 -05004077}
4078
Ingo Molnare309b412008-05-12 21:20:51 +02004079static ssize_t
Steven Rostedt41c52c02008-05-22 11:46:33 -04004080ftrace_regex_write(struct file *file, const char __user *ubuf,
4081 size_t cnt, loff_t *ppos, int enable)
Steven Rostedt5072c592008-05-12 21:20:43 +02004082{
4083 struct ftrace_iterator *iter;
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004084 struct trace_parser *parser;
4085 ssize_t ret, read;
Steven Rostedt5072c592008-05-12 21:20:43 +02004086
Li Zefan4ba79782009-09-22 13:52:20 +08004087 if (!cnt)
Steven Rostedt5072c592008-05-12 21:20:43 +02004088 return 0;
4089
Steven Rostedt5072c592008-05-12 21:20:43 +02004090 if (file->f_mode & FMODE_READ) {
4091 struct seq_file *m = file->private_data;
4092 iter = m->private;
4093 } else
4094 iter = file->private_data;
4095
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09004096 if (unlikely(ftrace_disabled))
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09004097 return -ENODEV;
4098
4099 /* iter->hash is a local copy, so we don't need regex_lock */
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09004100
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004101 parser = &iter->parser;
4102 read = trace_get_user(parser, ubuf, cnt, ppos);
Steven Rostedt5072c592008-05-12 21:20:43 +02004103
Li Zefan4ba79782009-09-22 13:52:20 +08004104 if (read >= 0 && trace_parser_loaded(parser) &&
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004105 !trace_parser_cont(parser)) {
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004106 ret = ftrace_process_regex(iter->hash, parser->buffer,
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004107 parser->idx, enable);
Li Zefan313254a2009-12-08 11:15:30 +08004108 trace_parser_clear(parser);
Steven Rostedt (Red Hat)7c088b52013-05-09 11:35:12 -04004109 if (ret < 0)
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09004110 goto out;
Steven Rostedt5072c592008-05-12 21:20:43 +02004111 }
4112
Steven Rostedt5072c592008-05-12 21:20:43 +02004113 ret = read;
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09004114 out:
Steven Rostedt5072c592008-05-12 21:20:43 +02004115 return ret;
4116}
4117
Steven Rostedtfc13cb02011-12-19 14:41:25 -05004118ssize_t
Steven Rostedt41c52c02008-05-22 11:46:33 -04004119ftrace_filter_write(struct file *file, const char __user *ubuf,
4120 size_t cnt, loff_t *ppos)
4121{
4122 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
4123}
4124
Steven Rostedtfc13cb02011-12-19 14:41:25 -05004125ssize_t
Steven Rostedt41c52c02008-05-22 11:46:33 -04004126ftrace_notrace_write(struct file *file, const char __user *ubuf,
4127 size_t cnt, loff_t *ppos)
4128{
4129 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
4130}
4131
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004132static int
Masami Hiramatsu647664e2012-06-05 19:28:08 +09004133ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
4134{
4135 struct ftrace_func_entry *entry;
4136
4137 if (!ftrace_location(ip))
4138 return -EINVAL;
4139
4140 if (remove) {
4141 entry = ftrace_lookup_ip(hash, ip);
4142 if (!entry)
4143 return -ENOENT;
4144 free_hash_entry(hash, entry);
4145 return 0;
4146 }
4147
4148 return add_hash_entry(hash, ip);
4149}
4150
Steven Rostedt (Red Hat)8252ecf2014-10-24 14:56:01 -04004151static void ftrace_ops_update_code(struct ftrace_ops *ops,
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05004152 struct ftrace_ops_hash *old_hash)
Steven Rostedt (Red Hat)1c80c432013-07-25 20:22:00 -04004153{
Steven Rostedt (Red Hat)8f86f832015-01-13 11:20:43 -05004154 struct ftrace_ops *op;
4155
4156 if (!ftrace_enabled)
4157 return;
4158
4159 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
Steven Rostedt (Red Hat)8252ecf2014-10-24 14:56:01 -04004160 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
Steven Rostedt (Red Hat)8f86f832015-01-13 11:20:43 -05004161 return;
4162 }
4163
4164 /*
4165 * If this is the shared global_ops filter, then we need to
4166 * check if there is another ops that shares it, is enabled.
4167 * If so, we still need to run the modify code.
4168 */
4169 if (ops->func_hash != &global_ops.local_hash)
4170 return;
4171
4172 do_for_each_ftrace_op(op, ftrace_ops_list) {
4173 if (op->func_hash == &global_ops.local_hash &&
4174 op->flags & FTRACE_OPS_FL_ENABLED) {
4175 ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
4176 /* Only need to do this once */
4177 return;
4178 }
4179 } while_for_each_ftrace_op(op);
Steven Rostedt (Red Hat)1c80c432013-07-25 20:22:00 -04004180}
4181
Masami Hiramatsu647664e2012-06-05 19:28:08 +09004182static int
4183ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
4184 unsigned long ip, int remove, int reset, int enable)
Steven Rostedt41c52c02008-05-22 11:46:33 -04004185{
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004186 struct ftrace_hash **orig_hash;
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05004187 struct ftrace_ops_hash old_hash_ops;
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04004188 struct ftrace_hash *old_hash;
Steven Rostedtf45948e2011-05-02 12:29:25 -04004189 struct ftrace_hash *hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004190 int ret;
Steven Rostedtf45948e2011-05-02 12:29:25 -04004191
Steven Rostedt41c52c02008-05-22 11:46:33 -04004192 if (unlikely(ftrace_disabled))
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004193 return -ENODEV;
Steven Rostedt41c52c02008-05-22 11:46:33 -04004194
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004195 mutex_lock(&ops->func_hash->regex_lock);
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09004196
Steven Rostedtf45948e2011-05-02 12:29:25 -04004197 if (enable)
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004198 orig_hash = &ops->func_hash->filter_hash;
Steven Rostedtf45948e2011-05-02 12:29:25 -04004199 else
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004200 orig_hash = &ops->func_hash->notrace_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004201
Wang Nanb972cc52014-07-15 08:40:20 +08004202 if (reset)
4203 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4204 else
4205 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
4206
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09004207 if (!hash) {
4208 ret = -ENOMEM;
4209 goto out_regex_unlock;
4210 }
Steven Rostedtf45948e2011-05-02 12:29:25 -04004211
Jiri Olsaac483c42012-01-02 10:04:14 +01004212 if (buf && !ftrace_match_records(hash, buf, len)) {
4213 ret = -EINVAL;
4214 goto out_regex_unlock;
4215 }
Masami Hiramatsu647664e2012-06-05 19:28:08 +09004216 if (ip) {
4217 ret = ftrace_match_addr(hash, ip, remove);
4218 if (ret < 0)
4219 goto out_regex_unlock;
4220 }
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004221
4222 mutex_lock(&ftrace_lock);
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04004223 old_hash = *orig_hash;
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05004224 old_hash_ops.filter_hash = ops->func_hash->filter_hash;
4225 old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
Steven Rostedt41fb61c2011-07-13 15:03:44 -04004226 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04004227 if (!ret) {
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05004228 ftrace_ops_update_code(ops, &old_hash_ops);
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04004229 free_ftrace_hash_rcu(old_hash);
4230 }
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004231 mutex_unlock(&ftrace_lock);
4232
Jiri Olsaac483c42012-01-02 10:04:14 +01004233 out_regex_unlock:
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004234 mutex_unlock(&ops->func_hash->regex_lock);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004235
4236 free_ftrace_hash(hash);
4237 return ret;
Steven Rostedt41c52c02008-05-22 11:46:33 -04004238}
4239
Masami Hiramatsu647664e2012-06-05 19:28:08 +09004240static int
4241ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
4242 int reset, int enable)
4243{
4244 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
4245}
4246
4247/**
4248 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4249 * @ops - the ops to set the filter with
4250 * @ip - the address to add to or remove from the filter.
4251 * @remove - non zero to remove the ip from the filter
4252 * @reset - non zero to reset all filters before applying this filter.
4253 *
4254 * Filters denote which functions should be enabled when tracing is enabled
4255 * If @ip is NULL, it failes to update filter.
4256 */
4257int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
4258 int remove, int reset)
4259{
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09004260 ftrace_ops_init(ops);
Masami Hiramatsu647664e2012-06-05 19:28:08 +09004261 return ftrace_set_addr(ops, ip, remove, reset, 1);
4262}
4263EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
4264
Joel Fernandesd032ae82016-11-15 12:31:20 -08004265/**
4266 * ftrace_ops_set_global_filter - setup ops to use global filters
4267 * @ops - the ops which will use the global filters
4268 *
4269 * ftrace users who need global function trace filtering should call this.
4270 * It can set the global filter only if ops were not initialized before.
4271 */
4272void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
4273{
4274 if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
4275 return;
4276
4277 ftrace_ops_init(ops);
4278 ops->func_hash = &global_ops.local_hash;
4279}
4280EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
4281
Masami Hiramatsu647664e2012-06-05 19:28:08 +09004282static int
4283ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4284 int reset, int enable)
4285{
4286 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
4287}
4288
Steven Rostedt77a2b372008-05-12 21:20:45 +02004289/**
4290 * ftrace_set_filter - set a function to filter on in ftrace
Steven Rostedt936e0742011-05-05 22:54:01 -04004291 * @ops - the ops to set the filter with
Steven Rostedt77a2b372008-05-12 21:20:45 +02004292 * @buf - the string that holds the function filter text.
4293 * @len - the length of the string.
4294 * @reset - non zero to reset all filters before applying this filter.
4295 *
4296 * Filters denote which functions should be enabled when tracing is enabled.
4297 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4298 */
Jiri Olsaac483c42012-01-02 10:04:14 +01004299int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
Steven Rostedt936e0742011-05-05 22:54:01 -04004300 int len, int reset)
Steven Rostedt77a2b372008-05-12 21:20:45 +02004301{
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09004302 ftrace_ops_init(ops);
Jiri Olsaac483c42012-01-02 10:04:14 +01004303 return ftrace_set_regex(ops, buf, len, reset, 1);
Steven Rostedt41c52c02008-05-22 11:46:33 -04004304}
Steven Rostedt936e0742011-05-05 22:54:01 -04004305EXPORT_SYMBOL_GPL(ftrace_set_filter);
Steven Rostedt4eebcc82008-05-12 21:20:48 +02004306
Steven Rostedt41c52c02008-05-22 11:46:33 -04004307/**
4308 * ftrace_set_notrace - set a function to not trace in ftrace
Steven Rostedt936e0742011-05-05 22:54:01 -04004309 * @ops - the ops to set the notrace filter with
Steven Rostedt41c52c02008-05-22 11:46:33 -04004310 * @buf - the string that holds the function notrace text.
4311 * @len - the length of the string.
4312 * @reset - non zero to reset all filters before applying this filter.
4313 *
4314 * Notrace Filters denote which functions should not be enabled when tracing
4315 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4316 * for tracing.
4317 */
Jiri Olsaac483c42012-01-02 10:04:14 +01004318int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
Steven Rostedt936e0742011-05-05 22:54:01 -04004319 int len, int reset)
4320{
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09004321 ftrace_ops_init(ops);
Jiri Olsaac483c42012-01-02 10:04:14 +01004322 return ftrace_set_regex(ops, buf, len, reset, 0);
Steven Rostedt936e0742011-05-05 22:54:01 -04004323}
4324EXPORT_SYMBOL_GPL(ftrace_set_notrace);
4325/**
Jiaxing Wang8d1b0652014-04-20 23:10:44 +08004326 * ftrace_set_global_filter - set a function to filter on with global tracers
Steven Rostedt936e0742011-05-05 22:54:01 -04004327 * @buf - the string that holds the function filter text.
4328 * @len - the length of the string.
4329 * @reset - non zero to reset all filters before applying this filter.
4330 *
4331 * Filters denote which functions should be enabled when tracing is enabled.
4332 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4333 */
4334void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
4335{
4336 ftrace_set_regex(&global_ops, buf, len, reset, 1);
4337}
4338EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
4339
4340/**
Jiaxing Wang8d1b0652014-04-20 23:10:44 +08004341 * ftrace_set_global_notrace - set a function to not trace with global tracers
Steven Rostedt936e0742011-05-05 22:54:01 -04004342 * @buf - the string that holds the function notrace text.
4343 * @len - the length of the string.
4344 * @reset - non zero to reset all filters before applying this filter.
4345 *
4346 * Notrace Filters denote which functions should not be enabled when tracing
4347 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4348 * for tracing.
4349 */
4350void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
Steven Rostedt41c52c02008-05-22 11:46:33 -04004351{
Steven Rostedtf45948e2011-05-02 12:29:25 -04004352 ftrace_set_regex(&global_ops, buf, len, reset, 0);
Steven Rostedt77a2b372008-05-12 21:20:45 +02004353}
Steven Rostedt936e0742011-05-05 22:54:01 -04004354EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
Steven Rostedt77a2b372008-05-12 21:20:45 +02004355
Steven Rostedt2af15d62009-05-28 13:37:24 -04004356/*
4357 * command line interface to allow users to set filters on boot up.
4358 */
4359#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4360static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4361static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
4362
Steven Rostedt (Red Hat)f1ed7c72013-06-27 22:18:06 -04004363/* Used by function selftest to not test if filter is set */
4364bool ftrace_filter_param __initdata;
4365
Steven Rostedt2af15d62009-05-28 13:37:24 -04004366static int __init set_ftrace_notrace(char *str)
4367{
Steven Rostedt (Red Hat)f1ed7c72013-06-27 22:18:06 -04004368 ftrace_filter_param = true;
Chen Gang75761cc2013-04-08 12:12:39 +08004369 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
Steven Rostedt2af15d62009-05-28 13:37:24 -04004370 return 1;
4371}
4372__setup("ftrace_notrace=", set_ftrace_notrace);
4373
4374static int __init set_ftrace_filter(char *str)
4375{
Steven Rostedt (Red Hat)f1ed7c72013-06-27 22:18:06 -04004376 ftrace_filter_param = true;
Chen Gang75761cc2013-04-08 12:12:39 +08004377 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
Steven Rostedt2af15d62009-05-28 13:37:24 -04004378 return 1;
4379}
4380__setup("ftrace_filter=", set_ftrace_filter);
4381
Stefan Assmann369bc182009-10-12 22:17:21 +02004382#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Lai Jiangshanf6060f42009-11-05 11:16:17 +08004383static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
Namhyung Kim0d7d9a12014-06-13 01:23:50 +09004384static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004385static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer);
Steven Rostedt801c29f2010-03-05 20:02:19 -05004386
Steven Rostedt (Red Hat)f3bea492014-07-02 23:23:31 -04004387static unsigned long save_global_trampoline;
4388static unsigned long save_global_flags;
4389
Stefan Assmann369bc182009-10-12 22:17:21 +02004390static int __init set_graph_function(char *str)
4391{
Frederic Weisbecker06f43d62009-10-14 20:43:39 +02004392 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
Stefan Assmann369bc182009-10-12 22:17:21 +02004393 return 1;
4394}
4395__setup("ftrace_graph_filter=", set_graph_function);
4396
Namhyung Kim0d7d9a12014-06-13 01:23:50 +09004397static int __init set_graph_notrace_function(char *str)
4398{
4399 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
4400 return 1;
4401}
4402__setup("ftrace_graph_notrace=", set_graph_notrace_function);
4403
4404static void __init set_ftrace_early_graph(char *buf, int enable)
Stefan Assmann369bc182009-10-12 22:17:21 +02004405{
4406 int ret;
4407 char *func;
Namhyung Kim0d7d9a12014-06-13 01:23:50 +09004408 unsigned long *table = ftrace_graph_funcs;
4409 int *count = &ftrace_graph_count;
4410
4411 if (!enable) {
4412 table = ftrace_graph_notrace_funcs;
4413 count = &ftrace_graph_notrace_count;
4414 }
Stefan Assmann369bc182009-10-12 22:17:21 +02004415
4416 while (buf) {
4417 func = strsep(&buf, ",");
4418 /* we allow only one expression at a time */
Namhyung Kim0d7d9a12014-06-13 01:23:50 +09004419 ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func);
Stefan Assmann369bc182009-10-12 22:17:21 +02004420 if (ret)
4421 printk(KERN_DEBUG "ftrace: function %s not "
4422 "traceable\n", func);
4423 }
4424}
4425#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4426
Steven Rostedt2a85a372011-12-19 21:57:44 -05004427void __init
4428ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
Steven Rostedt2af15d62009-05-28 13:37:24 -04004429{
4430 char *func;
4431
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09004432 ftrace_ops_init(ops);
4433
Steven Rostedt2af15d62009-05-28 13:37:24 -04004434 while (buf) {
4435 func = strsep(&buf, ",");
Steven Rostedtf45948e2011-05-02 12:29:25 -04004436 ftrace_set_regex(ops, func, strlen(func), 0, enable);
Steven Rostedt2af15d62009-05-28 13:37:24 -04004437 }
4438}
4439
4440static void __init set_ftrace_early_filters(void)
4441{
4442 if (ftrace_filter_buf[0])
Steven Rostedt2a85a372011-12-19 21:57:44 -05004443 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
Steven Rostedt2af15d62009-05-28 13:37:24 -04004444 if (ftrace_notrace_buf[0])
Steven Rostedt2a85a372011-12-19 21:57:44 -05004445 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
Stefan Assmann369bc182009-10-12 22:17:21 +02004446#ifdef CONFIG_FUNCTION_GRAPH_TRACER
4447 if (ftrace_graph_buf[0])
Namhyung Kim0d7d9a12014-06-13 01:23:50 +09004448 set_ftrace_early_graph(ftrace_graph_buf, 1);
4449 if (ftrace_graph_notrace_buf[0])
4450 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
Stefan Assmann369bc182009-10-12 22:17:21 +02004451#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
Steven Rostedt2af15d62009-05-28 13:37:24 -04004452}
4453
Steven Rostedtfc13cb02011-12-19 14:41:25 -05004454int ftrace_regex_release(struct inode *inode, struct file *file)
Steven Rostedt5072c592008-05-12 21:20:43 +02004455{
4456 struct seq_file *m = (struct seq_file *)file->private_data;
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05004457 struct ftrace_ops_hash old_hash_ops;
Steven Rostedt5072c592008-05-12 21:20:43 +02004458 struct ftrace_iterator *iter;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004459 struct ftrace_hash **orig_hash;
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04004460 struct ftrace_hash *old_hash;
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004461 struct trace_parser *parser;
Steven Rostedted926f92011-05-03 13:25:24 -04004462 int filter_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004463 int ret;
Steven Rostedt5072c592008-05-12 21:20:43 +02004464
Steven Rostedt5072c592008-05-12 21:20:43 +02004465 if (file->f_mode & FMODE_READ) {
4466 iter = m->private;
Steven Rostedt5072c592008-05-12 21:20:43 +02004467 seq_release(inode, file);
4468 } else
4469 iter = file->private_data;
4470
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004471 parser = &iter->parser;
4472 if (trace_parser_loaded(parser)) {
4473 parser->buffer[parser->idx] = 0;
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04004474 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
Steven Rostedt5072c592008-05-12 21:20:43 +02004475 }
4476
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004477 trace_parser_put(parser);
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004478
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004479 mutex_lock(&iter->ops->func_hash->regex_lock);
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09004480
Steven Rostedt058e2972011-04-29 22:35:33 -04004481 if (file->f_mode & FMODE_WRITE) {
Steven Rostedted926f92011-05-03 13:25:24 -04004482 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
4483
4484 if (filter_hash)
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004485 orig_hash = &iter->ops->func_hash->filter_hash;
Steven Rostedted926f92011-05-03 13:25:24 -04004486 else
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004487 orig_hash = &iter->ops->func_hash->notrace_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004488
Steven Rostedt058e2972011-04-29 22:35:33 -04004489 mutex_lock(&ftrace_lock);
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04004490 old_hash = *orig_hash;
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05004491 old_hash_ops.filter_hash = iter->ops->func_hash->filter_hash;
4492 old_hash_ops.notrace_hash = iter->ops->func_hash->notrace_hash;
Steven Rostedt41fb61c2011-07-13 15:03:44 -04004493 ret = ftrace_hash_move(iter->ops, filter_hash,
4494 orig_hash, iter->hash);
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04004495 if (!ret) {
Steven Rostedt (Red Hat)7485058e2015-01-13 14:03:38 -05004496 ftrace_ops_update_code(iter->ops, &old_hash_ops);
Steven Rostedt (Red Hat)3296fc42014-07-24 15:33:41 -04004497 free_ftrace_hash_rcu(old_hash);
4498 }
Steven Rostedt058e2972011-04-29 22:35:33 -04004499 mutex_unlock(&ftrace_lock);
4500 }
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09004501
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004502 mutex_unlock(&iter->ops->func_hash->regex_lock);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004503 free_ftrace_hash(iter->hash);
4504 kfree(iter);
Steven Rostedt058e2972011-04-29 22:35:33 -04004505
Steven Rostedt5072c592008-05-12 21:20:43 +02004506 return 0;
4507}
4508
Steven Rostedt5e2336a2009-03-05 21:44:55 -05004509static const struct file_operations ftrace_avail_fops = {
Steven Rostedt5072c592008-05-12 21:20:43 +02004510 .open = ftrace_avail_open,
4511 .read = seq_read,
4512 .llseek = seq_lseek,
Li Zefan3be04b42009-08-17 16:54:03 +08004513 .release = seq_release_private,
Steven Rostedt5072c592008-05-12 21:20:43 +02004514};
4515
Steven Rostedt647bcd02011-05-03 14:39:21 -04004516static const struct file_operations ftrace_enabled_fops = {
4517 .open = ftrace_enabled_open,
4518 .read = seq_read,
4519 .llseek = seq_lseek,
4520 .release = seq_release_private,
4521};
4522
Steven Rostedt5e2336a2009-03-05 21:44:55 -05004523static const struct file_operations ftrace_filter_fops = {
Steven Rostedt5072c592008-05-12 21:20:43 +02004524 .open = ftrace_filter_open,
Lai Jiangshan850a80c2009-03-13 17:47:23 +08004525 .read = seq_read,
Steven Rostedt5072c592008-05-12 21:20:43 +02004526 .write = ftrace_filter_write,
Steven Rostedt (Red Hat)098c8792013-12-21 17:39:40 -05004527 .llseek = tracing_lseek,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04004528 .release = ftrace_regex_release,
Steven Rostedt5072c592008-05-12 21:20:43 +02004529};
4530
Steven Rostedt5e2336a2009-03-05 21:44:55 -05004531static const struct file_operations ftrace_notrace_fops = {
Steven Rostedt41c52c02008-05-22 11:46:33 -04004532 .open = ftrace_notrace_open,
Lai Jiangshan850a80c2009-03-13 17:47:23 +08004533 .read = seq_read,
Steven Rostedt41c52c02008-05-22 11:46:33 -04004534 .write = ftrace_notrace_write,
Steven Rostedt (Red Hat)098c8792013-12-21 17:39:40 -05004535 .llseek = tracing_lseek,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04004536 .release = ftrace_regex_release,
Steven Rostedt41c52c02008-05-22 11:46:33 -04004537};
4538
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004539#ifdef CONFIG_FUNCTION_GRAPH_TRACER
4540
4541static DEFINE_MUTEX(graph_lock);
4542
4543int ftrace_graph_count;
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004544int ftrace_graph_notrace_count;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004545unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004546unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004547
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004548struct ftrace_graph_data {
4549 unsigned long *table;
4550 size_t size;
4551 int *count;
4552 const struct seq_operations *seq_ops;
4553};
4554
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004555static void *
Li Zefan85951842009-06-24 09:54:00 +08004556__g_next(struct seq_file *m, loff_t *pos)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004557{
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004558 struct ftrace_graph_data *fgd = m->private;
4559
4560 if (*pos >= *fgd->count)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004561 return NULL;
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004562 return &fgd->table[*pos];
Li Zefan85951842009-06-24 09:54:00 +08004563}
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004564
Li Zefan85951842009-06-24 09:54:00 +08004565static void *
4566g_next(struct seq_file *m, void *v, loff_t *pos)
4567{
4568 (*pos)++;
4569 return __g_next(m, pos);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004570}
4571
4572static void *g_start(struct seq_file *m, loff_t *pos)
4573{
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004574 struct ftrace_graph_data *fgd = m->private;
4575
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004576 mutex_lock(&graph_lock);
4577
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004578 /* Nothing, tell g_show to print all functions are enabled */
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004579 if (!*fgd->count && !*pos)
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004580 return (void *)1;
4581
Li Zefan85951842009-06-24 09:54:00 +08004582 return __g_next(m, pos);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004583}
4584
4585static void g_stop(struct seq_file *m, void *p)
4586{
4587 mutex_unlock(&graph_lock);
4588}
4589
4590static int g_show(struct seq_file *m, void *v)
4591{
4592 unsigned long *ptr = v;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004593
4594 if (!ptr)
4595 return 0;
4596
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004597 if (ptr == (unsigned long *)1) {
Namhyung Kim280d1422014-06-13 01:23:51 +09004598 struct ftrace_graph_data *fgd = m->private;
4599
4600 if (fgd->table == ftrace_graph_funcs)
Rasmus Villemoesfa6f0cc2014-11-08 21:42:10 +01004601 seq_puts(m, "#### all functions enabled ####\n");
Namhyung Kim280d1422014-06-13 01:23:51 +09004602 else
Rasmus Villemoesfa6f0cc2014-11-08 21:42:10 +01004603 seq_puts(m, "#### no functions disabled ####\n");
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004604 return 0;
4605 }
4606
Steven Rostedtb375a112009-09-17 00:05:58 -04004607 seq_printf(m, "%ps\n", (void *)*ptr);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004608
4609 return 0;
4610}
4611
James Morris88e9d342009-09-22 16:43:43 -07004612static const struct seq_operations ftrace_graph_seq_ops = {
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004613 .start = g_start,
4614 .next = g_next,
4615 .stop = g_stop,
4616 .show = g_show,
4617};
4618
4619static int
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004620__ftrace_graph_open(struct inode *inode, struct file *file,
4621 struct ftrace_graph_data *fgd)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004622{
4623 int ret = 0;
4624
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004625 mutex_lock(&graph_lock);
4626 if ((file->f_mode & FMODE_WRITE) &&
Steven Rostedt8650ae32009-07-22 23:29:30 -04004627 (file->f_flags & O_TRUNC)) {
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004628 *fgd->count = 0;
4629 memset(fgd->table, 0, fgd->size * sizeof(*fgd->table));
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004630 }
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004631 mutex_unlock(&graph_lock);
4632
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004633 if (file->f_mode & FMODE_READ) {
4634 ret = seq_open(file, fgd->seq_ops);
4635 if (!ret) {
4636 struct seq_file *m = file->private_data;
4637 m->private = fgd;
4638 }
4639 } else
4640 file->private_data = fgd;
Li Zefana4ec5e02009-09-18 14:06:28 +08004641
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004642 return ret;
4643}
4644
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004645static int
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004646ftrace_graph_open(struct inode *inode, struct file *file)
4647{
4648 struct ftrace_graph_data *fgd;
4649
4650 if (unlikely(ftrace_disabled))
4651 return -ENODEV;
4652
4653 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
4654 if (fgd == NULL)
4655 return -ENOMEM;
4656
4657 fgd->table = ftrace_graph_funcs;
4658 fgd->size = FTRACE_GRAPH_MAX_FUNCS;
4659 fgd->count = &ftrace_graph_count;
4660 fgd->seq_ops = &ftrace_graph_seq_ops;
4661
4662 return __ftrace_graph_open(inode, file, fgd);
4663}
4664
4665static int
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004666ftrace_graph_notrace_open(struct inode *inode, struct file *file)
4667{
4668 struct ftrace_graph_data *fgd;
4669
4670 if (unlikely(ftrace_disabled))
4671 return -ENODEV;
4672
4673 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
4674 if (fgd == NULL)
4675 return -ENOMEM;
4676
4677 fgd->table = ftrace_graph_notrace_funcs;
4678 fgd->size = FTRACE_GRAPH_MAX_FUNCS;
4679 fgd->count = &ftrace_graph_notrace_count;
4680 fgd->seq_ops = &ftrace_graph_seq_ops;
4681
4682 return __ftrace_graph_open(inode, file, fgd);
4683}
4684
4685static int
Li Zefan87827112009-07-23 11:29:11 +08004686ftrace_graph_release(struct inode *inode, struct file *file)
4687{
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004688 if (file->f_mode & FMODE_READ) {
4689 struct seq_file *m = file->private_data;
4690
4691 kfree(m->private);
Li Zefan87827112009-07-23 11:29:11 +08004692 seq_release(inode, file);
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004693 } else {
4694 kfree(file->private_data);
4695 }
4696
Li Zefan87827112009-07-23 11:29:11 +08004697 return 0;
4698}
4699
4700static int
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004701ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004702{
Dmitry Safonov3ba00922015-09-29 19:46:14 +03004703 struct ftrace_glob func_g;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004704 struct dyn_ftrace *rec;
4705 struct ftrace_page *pg;
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004706 int fail = 1;
Dmitry Safonov3ba00922015-09-29 19:46:14 +03004707 int not;
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004708 bool exists;
4709 int i;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004710
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004711 /* decode regex */
Dmitry Safonov3ba00922015-09-29 19:46:14 +03004712 func_g.type = filter_parse_regex(buffer, strlen(buffer),
4713 &func_g.search, &not);
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004714 if (!not && *idx >= size)
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004715 return -EBUSY;
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004716
Dmitry Safonov3ba00922015-09-29 19:46:14 +03004717 func_g.len = strlen(func_g.search);
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004718
Steven Rostedt52baf112009-02-14 01:15:39 -05004719 mutex_lock(&ftrace_lock);
Steven Rostedt45a4a232011-04-21 23:16:46 -04004720
4721 if (unlikely(ftrace_disabled)) {
4722 mutex_unlock(&ftrace_lock);
4723 return -ENODEV;
4724 }
4725
Steven Rostedt265c8312009-02-13 12:43:56 -05004726 do_for_each_ftrace_rec(pg, rec) {
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004727
Steven Rostedt (Red Hat)546fece2016-11-14 16:31:49 -05004728 if (rec->flags & FTRACE_FL_DISABLED)
4729 continue;
4730
Dmitry Safonov0b507e12015-09-29 19:46:15 +03004731 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004732 /* if it is in the array */
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004733 exists = false;
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004734 for (i = 0; i < *idx; i++) {
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004735 if (array[i] == rec->ip) {
4736 exists = true;
Steven Rostedt265c8312009-02-13 12:43:56 -05004737 break;
4738 }
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004739 }
4740
4741 if (!not) {
4742 fail = 0;
4743 if (!exists) {
4744 array[(*idx)++] = rec->ip;
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004745 if (*idx >= size)
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004746 goto out;
4747 }
4748 } else {
4749 if (exists) {
4750 array[i] = array[--(*idx)];
4751 array[*idx] = 0;
4752 fail = 0;
4753 }
4754 }
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004755 }
Steven Rostedt265c8312009-02-13 12:43:56 -05004756 } while_for_each_ftrace_rec();
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004757out:
Steven Rostedt52baf112009-02-14 01:15:39 -05004758 mutex_unlock(&ftrace_lock);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004759
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004760 if (fail)
4761 return -EINVAL;
4762
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004763 return 0;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004764}
4765
4766static ssize_t
4767ftrace_graph_write(struct file *file, const char __user *ubuf,
4768 size_t cnt, loff_t *ppos)
4769{
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004770 struct trace_parser parser;
Namhyung Kim6a101082013-10-14 17:24:25 +09004771 ssize_t read, ret = 0;
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004772 struct ftrace_graph_data *fgd = file->private_data;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004773
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004774 if (!cnt)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004775 return 0;
4776
Namhyung Kim6a101082013-10-14 17:24:25 +09004777 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX))
4778 return -ENOMEM;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004779
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004780 read = trace_get_user(&parser, ubuf, cnt, ppos);
4781
Li Zefan4ba79782009-09-22 13:52:20 +08004782 if (read >= 0 && trace_parser_loaded((&parser))) {
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004783 parser.buffer[parser.idx] = 0;
4784
Namhyung Kim6a101082013-10-14 17:24:25 +09004785 mutex_lock(&graph_lock);
4786
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004787 /* we allow only one expression at a time */
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004788 ret = ftrace_set_func(fgd->table, fgd->count, fgd->size,
4789 parser.buffer);
Namhyung Kim6a101082013-10-14 17:24:25 +09004790
4791 mutex_unlock(&graph_lock);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004792 }
4793
Namhyung Kim6a101082013-10-14 17:24:25 +09004794 if (!ret)
4795 ret = read;
Li Zefan1eb90f12009-09-22 13:52:57 +08004796
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004797 trace_parser_put(&parser);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004798
4799 return ret;
4800}
4801
4802static const struct file_operations ftrace_graph_fops = {
Li Zefan87827112009-07-23 11:29:11 +08004803 .open = ftrace_graph_open,
4804 .read = seq_read,
4805 .write = ftrace_graph_write,
Steven Rostedt (Red Hat)098c8792013-12-21 17:39:40 -05004806 .llseek = tracing_lseek,
Li Zefan87827112009-07-23 11:29:11 +08004807 .release = ftrace_graph_release,
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004808};
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004809
4810static const struct file_operations ftrace_graph_notrace_fops = {
4811 .open = ftrace_graph_notrace_open,
4812 .read = seq_read,
4813 .write = ftrace_graph_write,
Steven Rostedt (Red Hat)098c8792013-12-21 17:39:40 -05004814 .llseek = tracing_lseek,
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004815 .release = ftrace_graph_release,
4816};
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004817#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4818
Steven Rostedt (Red Hat)591dffd2014-01-10 16:17:45 -05004819void ftrace_create_filter_files(struct ftrace_ops *ops,
4820 struct dentry *parent)
4821{
4822
4823 trace_create_file("set_ftrace_filter", 0644, parent,
4824 ops, &ftrace_filter_fops);
4825
4826 trace_create_file("set_ftrace_notrace", 0644, parent,
4827 ops, &ftrace_notrace_fops);
4828}
4829
4830/*
4831 * The name "destroy_filter_files" is really a misnomer. Although
4832 * in the future, it may actualy delete the files, but this is
4833 * really intended to make sure the ops passed in are disabled
4834 * and that when this function returns, the caller is free to
4835 * free the ops.
4836 *
4837 * The "destroy" name is only to match the "create" name that this
4838 * should be paired with.
4839 */
4840void ftrace_destroy_filter_files(struct ftrace_ops *ops)
4841{
4842 mutex_lock(&ftrace_lock);
4843 if (ops->flags & FTRACE_OPS_FL_ENABLED)
4844 ftrace_shutdown(ops, 0);
4845 ops->flags |= FTRACE_OPS_FL_DELETED;
4846 mutex_unlock(&ftrace_lock);
4847}
4848
Steven Rostedt (Red Hat)8434dc92015-01-20 12:13:40 -05004849static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
Steven Rostedt5072c592008-05-12 21:20:43 +02004850{
Steven Rostedt5072c592008-05-12 21:20:43 +02004851
Frederic Weisbecker5452af62009-03-27 00:25:38 +01004852 trace_create_file("available_filter_functions", 0444,
4853 d_tracer, NULL, &ftrace_avail_fops);
Steven Rostedt5072c592008-05-12 21:20:43 +02004854
Steven Rostedt647bcd02011-05-03 14:39:21 -04004855 trace_create_file("enabled_functions", 0444,
4856 d_tracer, NULL, &ftrace_enabled_fops);
4857
Steven Rostedt (Red Hat)591dffd2014-01-10 16:17:45 -05004858 ftrace_create_filter_files(&global_ops, d_tracer);
Steven Rostedtad90c0e2008-05-27 20:48:37 -04004859
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004860#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Frederic Weisbecker5452af62009-03-27 00:25:38 +01004861 trace_create_file("set_graph_function", 0444, d_tracer,
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004862 NULL,
4863 &ftrace_graph_fops);
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004864 trace_create_file("set_graph_notrace", 0444, d_tracer,
4865 NULL,
4866 &ftrace_graph_notrace_fops);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004867#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4868
Steven Rostedt5072c592008-05-12 21:20:43 +02004869 return 0;
4870}
4871
Steven Rostedt9fd49322012-04-24 22:32:06 -04004872static int ftrace_cmp_ips(const void *a, const void *b)
Steven Rostedt68950612011-12-16 17:06:45 -05004873{
Steven Rostedt9fd49322012-04-24 22:32:06 -04004874 const unsigned long *ipa = a;
4875 const unsigned long *ipb = b;
Steven Rostedt68950612011-12-16 17:06:45 -05004876
Steven Rostedt9fd49322012-04-24 22:32:06 -04004877 if (*ipa > *ipb)
4878 return 1;
4879 if (*ipa < *ipb)
4880 return -1;
4881 return 0;
4882}
4883
Jiri Olsa5cb084b2009-10-13 16:33:53 -04004884static int ftrace_process_locs(struct module *mod,
Steven Rostedt31e88902008-11-14 16:21:19 -08004885 unsigned long *start,
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004886 unsigned long *end)
4887{
Steven Rostedt706c81f2012-04-24 23:45:26 -04004888 struct ftrace_page *start_pg;
Steven Rostedta7900872011-12-16 16:23:44 -05004889 struct ftrace_page *pg;
Steven Rostedt706c81f2012-04-24 23:45:26 -04004890 struct dyn_ftrace *rec;
Steven Rostedta7900872011-12-16 16:23:44 -05004891 unsigned long count;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004892 unsigned long *p;
4893 unsigned long addr;
Steven Rostedt4376cac2011-06-24 23:28:13 -04004894 unsigned long flags = 0; /* Shut up gcc */
Steven Rostedta7900872011-12-16 16:23:44 -05004895 int ret = -ENOMEM;
4896
4897 count = end - start;
4898
4899 if (!count)
4900 return 0;
4901
Steven Rostedt9fd49322012-04-24 22:32:06 -04004902 sort(start, count, sizeof(*start),
Rasmus Villemoes6db02902015-09-09 23:27:02 +02004903 ftrace_cmp_ips, NULL);
Steven Rostedt9fd49322012-04-24 22:32:06 -04004904
Steven Rostedt706c81f2012-04-24 23:45:26 -04004905 start_pg = ftrace_allocate_pages(count);
4906 if (!start_pg)
Steven Rostedta7900872011-12-16 16:23:44 -05004907 return -ENOMEM;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004908
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004909 mutex_lock(&ftrace_lock);
Steven Rostedta7900872011-12-16 16:23:44 -05004910
Steven Rostedt32082302011-12-16 14:42:37 -05004911 /*
4912 * Core and each module needs their own pages, as
4913 * modules will free them when they are removed.
4914 * Force a new page to be allocated for modules.
4915 */
Steven Rostedta7900872011-12-16 16:23:44 -05004916 if (!mod) {
4917 WARN_ON(ftrace_pages || ftrace_pages_start);
4918 /* First initialization */
Steven Rostedt706c81f2012-04-24 23:45:26 -04004919 ftrace_pages = ftrace_pages_start = start_pg;
Steven Rostedta7900872011-12-16 16:23:44 -05004920 } else {
Steven Rostedt32082302011-12-16 14:42:37 -05004921 if (!ftrace_pages)
Steven Rostedta7900872011-12-16 16:23:44 -05004922 goto out;
Steven Rostedt32082302011-12-16 14:42:37 -05004923
Steven Rostedta7900872011-12-16 16:23:44 -05004924 if (WARN_ON(ftrace_pages->next)) {
4925 /* Hmm, we have free pages? */
4926 while (ftrace_pages->next)
4927 ftrace_pages = ftrace_pages->next;
Steven Rostedt32082302011-12-16 14:42:37 -05004928 }
Steven Rostedta7900872011-12-16 16:23:44 -05004929
Steven Rostedt706c81f2012-04-24 23:45:26 -04004930 ftrace_pages->next = start_pg;
Steven Rostedt32082302011-12-16 14:42:37 -05004931 }
4932
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004933 p = start;
Steven Rostedt706c81f2012-04-24 23:45:26 -04004934 pg = start_pg;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004935 while (p < end) {
4936 addr = ftrace_call_adjust(*p++);
Steven Rostedt20e52272008-11-14 16:21:19 -08004937 /*
4938 * Some architecture linkers will pad between
4939 * the different mcount_loc sections of different
4940 * object files to satisfy alignments.
4941 * Skip any NULL pointers.
4942 */
4943 if (!addr)
4944 continue;
Steven Rostedt706c81f2012-04-24 23:45:26 -04004945
4946 if (pg->index == pg->size) {
4947 /* We should have allocated enough */
4948 if (WARN_ON(!pg->next))
4949 break;
4950 pg = pg->next;
4951 }
4952
4953 rec = &pg->records[pg->index++];
4954 rec->ip = addr;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004955 }
4956
Steven Rostedt706c81f2012-04-24 23:45:26 -04004957 /* We should have used all pages */
4958 WARN_ON(pg->next);
4959
4960 /* Assign the last page to ftrace_pages */
4961 ftrace_pages = pg;
4962
Steven Rostedta4f18ed2011-06-07 09:26:46 -04004963 /*
Steven Rostedt4376cac2011-06-24 23:28:13 -04004964 * We only need to disable interrupts on start up
4965 * because we are modifying code that an interrupt
4966 * may execute, and the modification is not atomic.
4967 * But for modules, nothing runs the code we modify
4968 * until we are finished with it, and there's no
4969 * reason to cause large interrupt latencies while we do it.
Steven Rostedta4f18ed2011-06-07 09:26:46 -04004970 */
Steven Rostedt4376cac2011-06-24 23:28:13 -04004971 if (!mod)
4972 local_irq_save(flags);
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01004973 ftrace_update_code(mod, start_pg);
Steven Rostedt4376cac2011-06-24 23:28:13 -04004974 if (!mod)
4975 local_irq_restore(flags);
Steven Rostedta7900872011-12-16 16:23:44 -05004976 ret = 0;
4977 out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004978 mutex_unlock(&ftrace_lock);
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004979
Steven Rostedta7900872011-12-16 16:23:44 -05004980 return ret;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004981}
4982
Steven Rostedt93eb6772009-04-15 13:24:06 -04004983#ifdef CONFIG_MODULES
Steven Rostedt32082302011-12-16 14:42:37 -05004984
4985#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4986
Steven Rostedt (Red Hat)b7ffffb2016-01-07 15:40:01 -05004987static int referenced_filters(struct dyn_ftrace *rec)
4988{
4989 struct ftrace_ops *ops;
4990 int cnt = 0;
4991
4992 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
4993 if (ops_references_rec(ops, rec))
4994 cnt++;
4995 }
4996
4997 return cnt;
4998}
4999
jolsa@redhat.come7247a12009-10-07 19:00:35 +02005000void ftrace_release_mod(struct module *mod)
Steven Rostedt93eb6772009-04-15 13:24:06 -04005001{
5002 struct dyn_ftrace *rec;
Steven Rostedt32082302011-12-16 14:42:37 -05005003 struct ftrace_page **last_pg;
Steven Rostedt93eb6772009-04-15 13:24:06 -04005004 struct ftrace_page *pg;
Steven Rostedta7900872011-12-16 16:23:44 -05005005 int order;
Steven Rostedt93eb6772009-04-15 13:24:06 -04005006
Steven Rostedt93eb6772009-04-15 13:24:06 -04005007 mutex_lock(&ftrace_lock);
Steven Rostedt45a4a232011-04-21 23:16:46 -04005008
5009 if (ftrace_disabled)
5010 goto out_unlock;
5011
Steven Rostedt32082302011-12-16 14:42:37 -05005012 /*
5013 * Each module has its own ftrace_pages, remove
5014 * them from the list.
5015 */
5016 last_pg = &ftrace_pages_start;
5017 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
5018 rec = &pg->records[0];
jolsa@redhat.come7247a12009-10-07 19:00:35 +02005019 if (within_module_core(rec->ip, mod)) {
Steven Rostedt93eb6772009-04-15 13:24:06 -04005020 /*
Steven Rostedt32082302011-12-16 14:42:37 -05005021 * As core pages are first, the first
5022 * page should never be a module page.
Steven Rostedt93eb6772009-04-15 13:24:06 -04005023 */
Steven Rostedt32082302011-12-16 14:42:37 -05005024 if (WARN_ON(pg == ftrace_pages_start))
5025 goto out_unlock;
5026
5027 /* Check if we are deleting the last page */
5028 if (pg == ftrace_pages)
5029 ftrace_pages = next_to_ftrace_page(last_pg);
5030
5031 *last_pg = pg->next;
Steven Rostedta7900872011-12-16 16:23:44 -05005032 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5033 free_pages((unsigned long)pg->records, order);
5034 kfree(pg);
Steven Rostedt32082302011-12-16 14:42:37 -05005035 } else
5036 last_pg = &pg->next;
5037 }
Steven Rostedt45a4a232011-04-21 23:16:46 -04005038 out_unlock:
Steven Rostedt93eb6772009-04-15 13:24:06 -04005039 mutex_unlock(&ftrace_lock);
5040}
5041
Jessica Yu7dcd1822016-02-16 17:32:33 -05005042void ftrace_module_enable(struct module *mod)
Steven Rostedt (Red Hat)b7ffffb2016-01-07 15:40:01 -05005043{
5044 struct dyn_ftrace *rec;
5045 struct ftrace_page *pg;
5046
5047 mutex_lock(&ftrace_lock);
5048
5049 if (ftrace_disabled)
5050 goto out_unlock;
5051
5052 /*
5053 * If the tracing is enabled, go ahead and enable the record.
5054 *
5055 * The reason not to enable the record immediatelly is the
5056 * inherent check of ftrace_make_nop/ftrace_make_call for
5057 * correct previous instructions. Making first the NOP
5058 * conversion puts the module to the correct state, thus
5059 * passing the ftrace_make_call check.
5060 *
5061 * We also delay this to after the module code already set the
5062 * text to read-only, as we now need to set it back to read-write
5063 * so that we can modify the text.
5064 */
5065 if (ftrace_start_up)
5066 ftrace_arch_code_modify_prepare();
5067
5068 do_for_each_ftrace_rec(pg, rec) {
5069 int cnt;
5070 /*
5071 * do_for_each_ftrace_rec() is a double loop.
5072 * module text shares the pg. If a record is
5073 * not part of this module, then skip this pg,
5074 * which the "break" will do.
5075 */
5076 if (!within_module_core(rec->ip, mod))
5077 break;
5078
5079 cnt = 0;
5080
5081 /*
5082 * When adding a module, we need to check if tracers are
5083 * currently enabled and if they are, and can trace this record,
5084 * we need to enable the module functions as well as update the
5085 * reference counts for those function records.
5086 */
5087 if (ftrace_start_up)
5088 cnt += referenced_filters(rec);
5089
5090 /* This clears FTRACE_FL_DISABLED */
5091 rec->flags = cnt;
5092
5093 if (ftrace_start_up && cnt) {
5094 int failed = __ftrace_replace_code(rec, 1);
5095 if (failed) {
5096 ftrace_bug(failed, rec);
5097 goto out_loop;
5098 }
5099 }
5100
5101 } while_for_each_ftrace_rec();
5102
5103 out_loop:
5104 if (ftrace_start_up)
5105 ftrace_arch_code_modify_post_process();
5106
5107 out_unlock:
5108 mutex_unlock(&ftrace_lock);
5109}
5110
Steven Rostedt (Red Hat)a949ae52014-04-24 10:40:12 -04005111void ftrace_module_init(struct module *mod)
Steven Rostedt93eb6772009-04-15 13:24:06 -04005112{
Steven Rostedt (Red Hat)97e9b4f2015-12-23 12:12:22 -05005113 if (ftrace_disabled || !mod->num_ftrace_callsites)
Abel Vesab6b71f62015-12-02 15:39:57 +01005114 return;
5115
Steven Rostedt (Red Hat)97e9b4f2015-12-23 12:12:22 -05005116 ftrace_process_locs(mod, mod->ftrace_callsites,
5117 mod->ftrace_callsites + mod->num_ftrace_callsites);
Steven Rostedt (Red Hat)8c189ea2013-02-13 15:18:38 -05005118}
Steven Rostedt93eb6772009-04-15 13:24:06 -04005119#endif /* CONFIG_MODULES */
5120
Steven Rostedt68bf21a2008-08-14 15:45:08 -04005121void __init ftrace_init(void)
5122{
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01005123 extern unsigned long __start_mcount_loc[];
5124 extern unsigned long __stop_mcount_loc[];
Jiri Slaby3a36cb12014-02-24 19:59:59 +01005125 unsigned long count, flags;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04005126 int ret;
5127
Steven Rostedt68bf21a2008-08-14 15:45:08 -04005128 local_irq_save(flags);
Jiri Slaby3a36cb12014-02-24 19:59:59 +01005129 ret = ftrace_dyn_arch_init();
Steven Rostedt68bf21a2008-08-14 15:45:08 -04005130 local_irq_restore(flags);
Jiri Slabyaf64a7c2014-02-24 19:59:58 +01005131 if (ret)
Steven Rostedt68bf21a2008-08-14 15:45:08 -04005132 goto failed;
5133
5134 count = __stop_mcount_loc - __start_mcount_loc;
Jiri Slabyc867ccd2014-02-24 19:59:57 +01005135 if (!count) {
5136 pr_info("ftrace: No functions to be traced?\n");
Steven Rostedt68bf21a2008-08-14 15:45:08 -04005137 goto failed;
Jiri Slabyc867ccd2014-02-24 19:59:57 +01005138 }
5139
5140 pr_info("ftrace: allocating %ld entries in %ld pages\n",
5141 count, count / ENTRIES_PER_PAGE + 1);
Steven Rostedt68bf21a2008-08-14 15:45:08 -04005142
5143 last_ftrace_enabled = ftrace_enabled = 1;
5144
Jiri Olsa5cb084b2009-10-13 16:33:53 -04005145 ret = ftrace_process_locs(NULL,
Steven Rostedt31e88902008-11-14 16:21:19 -08005146 __start_mcount_loc,
Steven Rostedt68bf21a2008-08-14 15:45:08 -04005147 __stop_mcount_loc);
5148
Steven Rostedt2af15d62009-05-28 13:37:24 -04005149 set_ftrace_early_filters();
5150
Steven Rostedt68bf21a2008-08-14 15:45:08 -04005151 return;
5152 failed:
5153 ftrace_disabled = 1;
5154}
Steven Rostedt68bf21a2008-08-14 15:45:08 -04005155
Steven Rostedt (Red Hat)f3bea492014-07-02 23:23:31 -04005156/* Do nothing if arch does not support this */
5157void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
5158{
5159}
5160
5161static void ftrace_update_trampoline(struct ftrace_ops *ops)
5162{
Steven Rostedt (Red Hat)12cce592014-07-03 15:48:16 -04005163
5164/*
5165 * Currently there's no safe way to free a trampoline when the kernel
5166 * is configured with PREEMPT. That is because a task could be preempted
5167 * when it jumped to the trampoline, it may be preempted for a long time
5168 * depending on the system load, and currently there's no way to know
5169 * when it will be off the trampoline. If the trampoline is freed
5170 * too early, when the task runs again, it will be executing on freed
5171 * memory and crash.
5172 */
5173#ifdef CONFIG_PREEMPT
Steven Rostedt (Red Hat)f3bea492014-07-02 23:23:31 -04005174 /* Currently, only non dynamic ops can have a trampoline */
5175 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
5176 return;
Steven Rostedt (Red Hat)12cce592014-07-03 15:48:16 -04005177#endif
Steven Rostedt (Red Hat)f3bea492014-07-02 23:23:31 -04005178
5179 arch_ftrace_update_trampoline(ops);
5180}
5181
Steven Rostedt3d083392008-05-12 21:20:42 +02005182#else
Frederic Weisbecker0b6e4d52008-10-28 20:17:38 +01005183
Steven Rostedt2b499382011-05-03 22:49:52 -04005184static struct ftrace_ops global_ops = {
Steven Rostedtbd69c302011-05-03 21:55:54 -04005185 .func = ftrace_stub,
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -04005186 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
5187 FTRACE_OPS_FL_INITIALIZED |
5188 FTRACE_OPS_FL_PID,
Steven Rostedtbd69c302011-05-03 21:55:54 -04005189};
5190
Frederic Weisbecker0b6e4d52008-10-28 20:17:38 +01005191static int __init ftrace_nodyn_init(void)
5192{
5193 ftrace_enabled = 1;
5194 return 0;
5195}
Steven Rostedt6f415672012-10-05 12:13:07 -04005196core_initcall(ftrace_nodyn_init);
Frederic Weisbecker0b6e4d52008-10-28 20:17:38 +01005197
Steven Rostedt (Red Hat)8434dc92015-01-20 12:13:40 -05005198static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005199static inline void ftrace_startup_enable(int command) { }
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04005200static inline void ftrace_startup_all(int command) { }
Steven Rostedt5a45cfe2008-11-26 00:16:24 -05005201/* Keep as macros so we do not need to define the commands */
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05005202# define ftrace_startup(ops, command) \
5203 ({ \
5204 int ___ret = __register_ftrace_function(ops); \
5205 if (!___ret) \
5206 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
5207 ___ret; \
Steven Rostedt3b6cfdb2011-05-23 15:33:49 -04005208 })
Steven Rostedt (Red Hat)1fcc1552014-02-19 15:12:18 -05005209# define ftrace_shutdown(ops, command) \
5210 ({ \
5211 int ___ret = __unregister_ftrace_function(ops); \
5212 if (!___ret) \
5213 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
5214 ___ret; \
5215 })
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05005216
Ingo Molnarc7aafc52008-05-12 21:20:45 +02005217# define ftrace_startup_sysctl() do { } while (0)
5218# define ftrace_shutdown_sysctl() do { } while (0)
Steven Rostedtb8489142011-05-04 09:27:52 -04005219
5220static inline int
Steven Rostedt (Red Hat)195a8af2013-07-23 22:06:15 -04005221ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
Steven Rostedtb8489142011-05-04 09:27:52 -04005222{
5223 return 1;
5224}
5225
Steven Rostedt (Red Hat)f3bea492014-07-02 23:23:31 -04005226static void ftrace_update_trampoline(struct ftrace_ops *ops)
5227{
5228}
5229
Steven Rostedt3d083392008-05-12 21:20:42 +02005230#endif /* CONFIG_DYNAMIC_FTRACE */
5231
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -05005232__init void ftrace_init_global_array_ops(struct trace_array *tr)
5233{
5234 tr->ops = &global_ops;
5235 tr->ops->private = tr;
5236}
5237
5238void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
5239{
5240 /* If we filter on pids, update to use the pid function */
5241 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
5242 if (WARN_ON(tr->ops->func != ftrace_stub))
5243 printk("ftrace ops had %pS for function\n",
5244 tr->ops->func);
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -05005245 }
5246 tr->ops->func = func;
5247 tr->ops->private = tr;
5248}
5249
5250void ftrace_reset_array_ops(struct trace_array *tr)
5251{
5252 tr->ops->func = ftrace_stub;
5253}
5254
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04005255static inline void
5256__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -04005257 struct ftrace_ops *ignored, struct pt_regs *regs)
Steven Rostedtb8489142011-05-04 09:27:52 -04005258{
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04005259 struct ftrace_ops *op;
Steven Rostedtedc15ca2012-11-02 17:47:21 -04005260 int bit;
Steven Rostedtb8489142011-05-04 09:27:52 -04005261
Steven Rostedtedc15ca2012-11-02 17:47:21 -04005262 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
5263 if (bit < 0)
5264 return;
Steven Rostedtc29f1222012-11-02 17:17:59 -04005265
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04005266 /*
5267 * Some of the ops may be dynamically allocated,
5268 * they must be freed after a synchronize_sched().
5269 */
5270 preempt_disable_notrace();
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -05005271
Steven Rostedt0a016402012-11-02 17:03:03 -04005272 do_for_each_ftrace_op(op, ftrace_ops_list) {
Steven Rostedt (Red Hat)ba27f2b2015-11-30 17:23:39 -05005273 /*
5274 * Check the following for each ops before calling their func:
5275 * if RCU flag is set, then rcu_is_watching() must be true
5276 * if PER_CPU is set, then ftrace_function_local_disable()
5277 * must be false
5278 * Otherwise test if the ip matches the ops filter
5279 *
5280 * If any of the above fails then the op->func() is not executed.
5281 */
5282 if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
5283 (!(op->flags & FTRACE_OPS_FL_PER_CPU) ||
5284 !ftrace_function_local_disabled(op)) &&
5285 ftrace_ops_test(op, ip, regs)) {
5286
Steven Rostedt (Red Hat)1d48d592014-06-25 11:54:03 -04005287 if (FTRACE_WARN_ON(!op->func)) {
5288 pr_warn("op=%p %pS\n", op, op);
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -05005289 goto out;
5290 }
Steven Rostedta1e2e312011-08-09 12:50:46 -04005291 op->func(ip, parent_ip, op, regs);
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -05005292 }
Steven Rostedt0a016402012-11-02 17:03:03 -04005293 } while_for_each_ftrace_op(op);
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -05005294out:
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04005295 preempt_enable_notrace();
Steven Rostedtedc15ca2012-11-02 17:47:21 -04005296 trace_clear_recursion(bit);
Steven Rostedtb8489142011-05-04 09:27:52 -04005297}
5298
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04005299/*
5300 * Some archs only support passing ip and parent_ip. Even though
5301 * the list function ignores the op parameter, we do not want any
5302 * C side effects, where a function is called without the caller
5303 * sending a third parameter.
Steven Rostedta1e2e312011-08-09 12:50:46 -04005304 * Archs are to support both the regs and ftrace_ops at the same time.
5305 * If they support ftrace_ops, it is assumed they support regs.
5306 * If call backs want to use regs, they must either check for regs
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +09005307 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
5308 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
Steven Rostedta1e2e312011-08-09 12:50:46 -04005309 * An architecture can pass partial regs with ftrace_ops and still
Li Binb8ec3302015-11-30 18:23:36 +08005310 * set the ARCH_SUPPORTS_FTRACE_OPS.
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04005311 */
5312#if ARCH_SUPPORTS_FTRACE_OPS
5313static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -04005314 struct ftrace_ops *op, struct pt_regs *regs)
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04005315{
Steven Rostedta1e2e312011-08-09 12:50:46 -04005316 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04005317}
5318#else
5319static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
5320{
Steven Rostedta1e2e312011-08-09 12:50:46 -04005321 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04005322}
5323#endif
5324
Steven Rostedt (Red Hat)f1ff6342014-07-22 20:16:57 -04005325/*
5326 * If there's only one function registered but it does not support
Steven Rostedt (Red Hat)c68c0fa2015-12-01 13:28:16 -05005327 * recursion, needs RCU protection and/or requires per cpu handling, then
5328 * this function will be called by the mcount trampoline.
Steven Rostedt (Red Hat)f1ff6342014-07-22 20:16:57 -04005329 */
Steven Rostedt (Red Hat)c68c0fa2015-12-01 13:28:16 -05005330static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
Steven Rostedt (Red Hat)f1ff6342014-07-22 20:16:57 -04005331 struct ftrace_ops *op, struct pt_regs *regs)
5332{
5333 int bit;
5334
Steven Rostedt (Red Hat)c68c0fa2015-12-01 13:28:16 -05005335 if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
5336 return;
5337
Steven Rostedt (Red Hat)f1ff6342014-07-22 20:16:57 -04005338 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
5339 if (bit < 0)
5340 return;
5341
Steven Rostedt (Red Hat)c68c0fa2015-12-01 13:28:16 -05005342 preempt_disable_notrace();
Steven Rostedt (Red Hat)f1ff6342014-07-22 20:16:57 -04005343
Steven Rostedt (Red Hat)c68c0fa2015-12-01 13:28:16 -05005344 if (!(op->flags & FTRACE_OPS_FL_PER_CPU) ||
5345 !ftrace_function_local_disabled(op)) {
5346 op->func(ip, parent_ip, op, regs);
5347 }
5348
5349 preempt_enable_notrace();
Steven Rostedt (Red Hat)f1ff6342014-07-22 20:16:57 -04005350 trace_clear_recursion(bit);
5351}
5352
Steven Rostedt (Red Hat)87354052014-07-22 20:41:42 -04005353/**
5354 * ftrace_ops_get_func - get the function a trampoline should call
5355 * @ops: the ops to get the function for
5356 *
5357 * Normally the mcount trampoline will call the ops->func, but there
5358 * are times that it should not. For example, if the ops does not
5359 * have its own recursion protection, then it should call the
5360 * ftrace_ops_recurs_func() instead.
5361 *
5362 * Returns the function that the trampoline should call for @ops.
5363 */
5364ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
5365{
5366 /*
Steven Rostedt (Red Hat)c68c0fa2015-12-01 13:28:16 -05005367 * If the function does not handle recursion, needs to be RCU safe,
5368 * or does per cpu logic, then we need to call the assist handler.
Steven Rostedt (Red Hat)87354052014-07-22 20:41:42 -04005369 */
Steven Rostedt (Red Hat)c68c0fa2015-12-01 13:28:16 -05005370 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
5371 ops->flags & (FTRACE_OPS_FL_RCU | FTRACE_OPS_FL_PER_CPU))
5372 return ftrace_ops_assist_func;
Steven Rostedt (Red Hat)87354052014-07-22 20:41:42 -04005373
5374 return ops->func;
5375}
5376
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005377static void
5378ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
5379 struct task_struct *prev, struct task_struct *next)
Steven Rostedte32d8952008-12-04 00:26:41 -05005380{
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005381 struct trace_array *tr = data;
5382 struct trace_pid_list *pid_list;
5383
5384 pid_list = rcu_dereference_sched(tr->function_pids);
5385
5386 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
5387 trace_ignore_this_task(pid_list, next));
5388}
5389
5390static void clear_ftrace_pids(struct trace_array *tr)
5391{
5392 struct trace_pid_list *pid_list;
Steven Rostedte32d8952008-12-04 00:26:41 -05005393 int cpu;
5394
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005395 pid_list = rcu_dereference_protected(tr->function_pids,
5396 lockdep_is_held(&ftrace_lock));
5397 if (!pid_list)
5398 return;
5399
5400 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
5401
5402 for_each_possible_cpu(cpu)
5403 per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
5404
5405 rcu_assign_pointer(tr->function_pids, NULL);
5406
5407 /* Wait till all users are no longer using pid filtering */
5408 synchronize_sched();
5409
5410 trace_free_pid_list(pid_list);
Steven Rostedte32d8952008-12-04 00:26:41 -05005411}
5412
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005413static void ftrace_pid_reset(struct trace_array *tr)
Steven Rostedte32d8952008-12-04 00:26:41 -05005414{
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005415 mutex_lock(&ftrace_lock);
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005416 clear_ftrace_pids(tr);
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005417
5418 ftrace_update_pid_func();
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04005419 ftrace_startup_all(0);
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005420
5421 mutex_unlock(&ftrace_lock);
5422}
5423
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005424/* Greater than any max PID */
5425#define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
5426
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005427static void *fpid_start(struct seq_file *m, loff_t *pos)
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005428 __acquires(RCU)
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005429{
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005430 struct trace_pid_list *pid_list;
5431 struct trace_array *tr = m->private;
5432
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005433 mutex_lock(&ftrace_lock);
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005434 rcu_read_lock_sched();
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005435
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005436 pid_list = rcu_dereference_sched(tr->function_pids);
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005437
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005438 if (!pid_list)
5439 return !(*pos) ? FTRACE_NO_PIDS : NULL;
5440
5441 return trace_pid_start(pid_list, pos);
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005442}
5443
5444static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
5445{
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005446 struct trace_array *tr = m->private;
5447 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
5448
5449 if (v == FTRACE_NO_PIDS)
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005450 return NULL;
5451
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005452 return trace_pid_next(pid_list, v, pos);
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005453}
5454
5455static void fpid_stop(struct seq_file *m, void *p)
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005456 __releases(RCU)
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005457{
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005458 rcu_read_unlock_sched();
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005459 mutex_unlock(&ftrace_lock);
5460}
5461
5462static int fpid_show(struct seq_file *m, void *v)
5463{
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005464 if (v == FTRACE_NO_PIDS) {
Rasmus Villemoesfa6f0cc2014-11-08 21:42:10 +01005465 seq_puts(m, "no pid\n");
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005466 return 0;
5467 }
5468
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005469 return trace_pid_show(m, v);
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005470}
5471
5472static const struct seq_operations ftrace_pid_sops = {
5473 .start = fpid_start,
5474 .next = fpid_next,
5475 .stop = fpid_stop,
5476 .show = fpid_show,
5477};
5478
5479static int
5480ftrace_pid_open(struct inode *inode, struct file *file)
5481{
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005482 struct trace_array *tr = inode->i_private;
5483 struct seq_file *m;
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005484 int ret = 0;
5485
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005486 if (trace_array_get(tr) < 0)
5487 return -ENODEV;
5488
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005489 if ((file->f_mode & FMODE_WRITE) &&
5490 (file->f_flags & O_TRUNC))
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005491 ftrace_pid_reset(tr);
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005492
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005493 ret = seq_open(file, &ftrace_pid_sops);
5494 if (ret < 0) {
5495 trace_array_put(tr);
5496 } else {
5497 m = file->private_data;
5498 /* copy tr over to seq ops */
5499 m->private = tr;
5500 }
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005501
5502 return ret;
5503}
5504
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005505static void ignore_task_cpu(void *data)
5506{
5507 struct trace_array *tr = data;
5508 struct trace_pid_list *pid_list;
5509
5510 /*
5511 * This function is called by on_each_cpu() while the
5512 * event_mutex is held.
5513 */
5514 pid_list = rcu_dereference_protected(tr->function_pids,
5515 mutex_is_locked(&ftrace_lock));
5516
5517 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
5518 trace_ignore_this_task(pid_list, current));
5519}
5520
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005521static ssize_t
5522ftrace_pid_write(struct file *filp, const char __user *ubuf,
5523 size_t cnt, loff_t *ppos)
5524{
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005525 struct seq_file *m = filp->private_data;
5526 struct trace_array *tr = m->private;
5527 struct trace_pid_list *filtered_pids = NULL;
5528 struct trace_pid_list *pid_list;
5529 ssize_t ret;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005530
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005531 if (!cnt)
5532 return 0;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005533
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005534 mutex_lock(&ftrace_lock);
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005535
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005536 filtered_pids = rcu_dereference_protected(tr->function_pids,
5537 lockdep_is_held(&ftrace_lock));
5538
5539 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
5540 if (ret < 0)
5541 goto out;
5542
5543 rcu_assign_pointer(tr->function_pids, pid_list);
5544
5545 if (filtered_pids) {
5546 synchronize_sched();
5547 trace_free_pid_list(filtered_pids);
5548 } else if (pid_list) {
5549 /* Register a probe to set whether to ignore the tracing of a task */
5550 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
5551 }
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005552
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005553 /*
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005554 * Ignoring of pids is done at task switch. But we have to
5555 * check for those tasks that are currently running.
5556 * Always do this in case a pid was appended or removed.
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005557 */
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005558 on_each_cpu(ignore_task_cpu, tr, 1);
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005559
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005560 ftrace_update_pid_func();
5561 ftrace_startup_all(0);
5562 out:
5563 mutex_unlock(&ftrace_lock);
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005564
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005565 if (ret > 0)
5566 *ppos += ret;
Steven Rostedt978f3a42008-12-04 00:26:40 -05005567
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005568 return ret;
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005569}
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005570
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005571static int
5572ftrace_pid_release(struct inode *inode, struct file *file)
5573{
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005574 struct trace_array *tr = inode->i_private;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005575
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005576 trace_array_put(tr);
5577
5578 return seq_release(inode, file);
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005579}
5580
Steven Rostedt5e2336a2009-03-05 21:44:55 -05005581static const struct file_operations ftrace_pid_fops = {
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005582 .open = ftrace_pid_open,
5583 .write = ftrace_pid_write,
5584 .read = seq_read,
Steven Rostedt (Red Hat)098c8792013-12-21 17:39:40 -05005585 .llseek = tracing_lseek,
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005586 .release = ftrace_pid_release,
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005587};
5588
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005589void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005590{
Frederic Weisbecker5452af62009-03-27 00:25:38 +01005591 trace_create_file("set_ftrace_pid", 0644, d_tracer,
Steven Rostedt (Red Hat)345ddcc2016-04-22 18:11:33 -04005592 tr, &ftrace_pid_fops);
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005593}
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005594
Steven Rostedt (Red Hat)501c2372016-07-05 10:04:34 -04005595void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
5596 struct dentry *d_tracer)
5597{
5598 /* Only the top level directory has the dyn_tracefs and profile */
5599 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
5600
5601 ftrace_init_dyn_tracefs(d_tracer);
5602 ftrace_profile_tracefs(d_tracer);
5603}
5604
Steven Rostedt3d083392008-05-12 21:20:42 +02005605/**
Steven Rostedt81adbdc2008-10-23 09:33:02 -04005606 * ftrace_kill - kill ftrace
Steven Rostedta2bb6a32008-07-10 20:58:15 -04005607 *
5608 * This function should be used by panic code. It stops ftrace
5609 * but in a not so nice way. If you need to simply kill ftrace
5610 * from a non-atomic section, use ftrace_kill.
5611 */
Steven Rostedt81adbdc2008-10-23 09:33:02 -04005612void ftrace_kill(void)
Steven Rostedta2bb6a32008-07-10 20:58:15 -04005613{
5614 ftrace_disabled = 1;
5615 ftrace_enabled = 0;
Steven Rostedta2bb6a32008-07-10 20:58:15 -04005616 clear_ftrace_function();
5617}
5618
5619/**
Steven Rostedte0a413f2011-09-29 21:26:16 -04005620 * Test if ftrace is dead or not.
5621 */
5622int ftrace_is_dead(void)
5623{
5624 return ftrace_disabled;
5625}
5626
5627/**
Steven Rostedt3d083392008-05-12 21:20:42 +02005628 * register_ftrace_function - register a function for profiling
5629 * @ops - ops structure that holds the function for profiling.
5630 *
5631 * Register a function to be called by all functions in the
5632 * kernel.
5633 *
5634 * Note: @ops->func and all the functions it calls must be labeled
5635 * with "notrace", otherwise it will go into a
5636 * recursive loop.
5637 */
5638int register_ftrace_function(struct ftrace_ops *ops)
5639{
Steven Rostedt45a4a232011-04-21 23:16:46 -04005640 int ret = -1;
Steven Rostedt4eebcc82008-05-12 21:20:48 +02005641
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09005642 ftrace_ops_init(ops);
5643
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005644 mutex_lock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005645
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05005646 ret = ftrace_startup(ops, 0);
Steven Rostedtb8489142011-05-04 09:27:52 -04005647
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005648 mutex_unlock(&ftrace_lock);
Borislav Petkov8d240dd2012-03-29 19:11:40 +02005649
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005650 return ret;
Steven Rostedt3d083392008-05-12 21:20:42 +02005651}
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04005652EXPORT_SYMBOL_GPL(register_ftrace_function);
Steven Rostedt3d083392008-05-12 21:20:42 +02005653
5654/**
Uwe Kleine-Koenig32632922009-01-12 23:35:50 +01005655 * unregister_ftrace_function - unregister a function for profiling.
Steven Rostedt3d083392008-05-12 21:20:42 +02005656 * @ops - ops structure that holds the function to unregister
5657 *
5658 * Unregister a function that was added to be called by ftrace profiling.
5659 */
5660int unregister_ftrace_function(struct ftrace_ops *ops)
5661{
5662 int ret;
5663
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005664 mutex_lock(&ftrace_lock);
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05005665 ret = ftrace_shutdown(ops, 0);
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005666 mutex_unlock(&ftrace_lock);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005667
5668 return ret;
5669}
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04005670EXPORT_SYMBOL_GPL(unregister_ftrace_function);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005671
Ingo Molnare309b412008-05-12 21:20:51 +02005672int
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005673ftrace_enable_sysctl(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -07005674 void __user *buffer, size_t *lenp,
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005675 loff_t *ppos)
5676{
Steven Rostedt45a4a232011-04-21 23:16:46 -04005677 int ret = -ENODEV;
Steven Rostedt4eebcc82008-05-12 21:20:48 +02005678
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005679 mutex_lock(&ftrace_lock);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005680
Steven Rostedt45a4a232011-04-21 23:16:46 -04005681 if (unlikely(ftrace_disabled))
5682 goto out;
5683
5684 ret = proc_dointvec(table, write, buffer, lenp, ppos);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005685
Li Zefana32c7762009-06-26 16:55:51 +08005686 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005687 goto out;
5688
Li Zefana32c7762009-06-26 16:55:51 +08005689 last_ftrace_enabled = !!ftrace_enabled;
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005690
5691 if (ftrace_enabled) {
5692
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005693 /* we are starting ftrace again */
Jan Kiszka5000c412013-03-26 17:53:03 +01005694 if (ftrace_ops_list != &ftrace_list_end)
5695 update_ftrace_function();
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005696
Steven Rostedt (Red Hat)524a3862015-03-06 19:55:13 -05005697 ftrace_startup_sysctl();
5698
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005699 } else {
5700 /* stopping ftrace calls (just send to ftrace_stub) */
5701 ftrace_trace_function = ftrace_stub;
5702
5703 ftrace_shutdown_sysctl();
5704 }
5705
5706 out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005707 mutex_unlock(&ftrace_lock);
Steven Rostedt3d083392008-05-12 21:20:42 +02005708 return ret;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02005709}
Ingo Molnarf17845e2008-10-24 12:47:10 +02005710
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01005711#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005712
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005713static struct ftrace_ops graph_ops = {
5714 .func = ftrace_stub,
5715 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
5716 FTRACE_OPS_FL_INITIALIZED |
Steven Rostedt (Red Hat)e3eea142015-07-24 10:38:12 -04005717 FTRACE_OPS_FL_PID |
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005718 FTRACE_OPS_FL_STUB,
5719#ifdef FTRACE_GRAPH_TRAMP_ADDR
5720 .trampoline = FTRACE_GRAPH_TRAMP_ADDR,
Steven Rostedt (Red Hat)aec0be22014-11-18 21:14:11 -05005721 /* trampoline_size is only needed for dynamically allocated tramps */
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005722#endif
5723 ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
5724};
5725
Steven Rostedt (Red Hat)55577202015-09-29 19:06:50 -04005726void ftrace_graph_sleep_time_control(bool enable)
5727{
5728 fgraph_sleep_time = enable;
5729}
5730
5731void ftrace_graph_graph_time_control(bool enable)
5732{
5733 fgraph_graph_time = enable;
5734}
5735
Steven Rostedte49dc192008-12-02 23:50:05 -05005736int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
5737{
5738 return 0;
5739}
5740
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01005741/* The callbacks that hook a function */
5742trace_func_graph_ret_t ftrace_graph_return =
5743 (trace_func_graph_ret_t)ftrace_stub;
Steven Rostedte49dc192008-12-02 23:50:05 -05005744trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005745static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005746
5747/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
5748static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
5749{
5750 int i;
5751 int ret = 0;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005752 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
5753 struct task_struct *g, *t;
5754
5755 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
5756 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
5757 * sizeof(struct ftrace_ret_stack),
5758 GFP_KERNEL);
5759 if (!ret_stack_list[i]) {
5760 start = 0;
5761 end = i;
5762 ret = -ENOMEM;
5763 goto free;
5764 }
5765 }
5766
Soumya PN6112a302016-05-17 21:31:14 +05305767 read_lock(&tasklist_lock);
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005768 do_each_thread(g, t) {
5769 if (start == end) {
5770 ret = -EAGAIN;
5771 goto unlock;
5772 }
5773
5774 if (t->ret_stack == NULL) {
Frederic Weisbecker380c4b12008-12-06 03:43:41 +01005775 atomic_set(&t->tracing_graph_pause, 0);
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005776 atomic_set(&t->trace_overrun, 0);
Steven Rostedt26c01622009-06-02 14:01:19 -04005777 t->curr_ret_stack = -1;
5778 /* Make sure the tasks see the -1 first: */
5779 smp_wmb();
5780 t->ret_stack = ret_stack_list[start++];
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005781 }
5782 } while_each_thread(g, t);
5783
5784unlock:
Soumya PN6112a302016-05-17 21:31:14 +05305785 read_unlock(&tasklist_lock);
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005786free:
5787 for (i = start; i < end; i++)
5788 kfree(ret_stack_list[i]);
5789 return ret;
5790}
5791
Steven Rostedt8aef2d22009-03-24 01:10:15 -04005792static void
Peter Zijlstrac73464b2015-09-28 18:06:56 +02005793ftrace_graph_probe_sched_switch(void *ignore, bool preempt,
Steven Rostedt38516ab2010-04-20 17:04:50 -04005794 struct task_struct *prev, struct task_struct *next)
Steven Rostedt8aef2d22009-03-24 01:10:15 -04005795{
5796 unsigned long long timestamp;
5797 int index;
5798
Steven Rostedtbe6f1642009-03-24 11:06:24 -04005799 /*
5800 * Does the user want to count the time a function was asleep.
5801 * If so, do not update the time stamps.
5802 */
Steven Rostedt (Red Hat)55577202015-09-29 19:06:50 -04005803 if (fgraph_sleep_time)
Steven Rostedtbe6f1642009-03-24 11:06:24 -04005804 return;
5805
Steven Rostedt8aef2d22009-03-24 01:10:15 -04005806 timestamp = trace_clock_local();
5807
5808 prev->ftrace_timestamp = timestamp;
5809
5810 /* only process tasks that we timestamped */
5811 if (!next->ftrace_timestamp)
5812 return;
5813
5814 /*
5815 * Update all the counters in next to make up for the
5816 * time next was sleeping.
5817 */
5818 timestamp -= next->ftrace_timestamp;
5819
5820 for (index = next->curr_ret_stack; index >= 0; index--)
5821 next->ret_stack[index].calltime += timestamp;
5822}
5823
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005824/* Allocate a return stack for each task */
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01005825static int start_graph_tracing(void)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005826{
5827 struct ftrace_ret_stack **ret_stack_list;
Frederic Weisbecker5b058bc2009-02-17 18:35:34 +01005828 int ret, cpu;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005829
5830 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
5831 sizeof(struct ftrace_ret_stack *),
5832 GFP_KERNEL);
5833
5834 if (!ret_stack_list)
5835 return -ENOMEM;
5836
Frederic Weisbecker5b058bc2009-02-17 18:35:34 +01005837 /* The cpu_boot init_task->ret_stack will never be freed */
Steven Rostedt179c4982009-06-02 12:03:19 -04005838 for_each_online_cpu(cpu) {
5839 if (!idle_task(cpu)->ret_stack)
Steven Rostedt868baf02011-02-10 21:26:13 -05005840 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
Steven Rostedt179c4982009-06-02 12:03:19 -04005841 }
Frederic Weisbecker5b058bc2009-02-17 18:35:34 +01005842
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005843 do {
5844 ret = alloc_retstack_tasklist(ret_stack_list);
5845 } while (ret == -EAGAIN);
5846
Steven Rostedt8aef2d22009-03-24 01:10:15 -04005847 if (!ret) {
Steven Rostedt38516ab2010-04-20 17:04:50 -04005848 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
Steven Rostedt8aef2d22009-03-24 01:10:15 -04005849 if (ret)
5850 pr_info("ftrace_graph: Couldn't activate tracepoint"
5851 " probe to kernel_sched_switch\n");
5852 }
5853
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005854 kfree(ret_stack_list);
5855 return ret;
5856}
5857
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -08005858/*
5859 * Hibernation protection.
5860 * The state of the current task is too much unstable during
5861 * suspend/restore to disk. We want to protect against that.
5862 */
5863static int
5864ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
5865 void *unused)
5866{
5867 switch (state) {
5868 case PM_HIBERNATION_PREPARE:
5869 pause_graph_tracing();
5870 break;
5871
5872 case PM_POST_HIBERNATION:
5873 unpause_graph_tracing();
5874 break;
5875 }
5876 return NOTIFY_DONE;
5877}
5878
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005879static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
5880{
5881 if (!ftrace_ops_test(&global_ops, trace->func, NULL))
5882 return 0;
5883 return __ftrace_graph_entry(trace);
5884}
5885
5886/*
5887 * The function graph tracer should only trace the functions defined
5888 * by set_ftrace_filter and set_ftrace_notrace. If another function
5889 * tracer ops is registered, the graph tracer requires testing the
5890 * function against the global ops, and not just trace any function
5891 * that any ftrace_ops registered.
5892 */
5893static void update_function_graph_func(void)
5894{
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005895 struct ftrace_ops *op;
5896 bool do_test = false;
5897
5898 /*
5899 * The graph and global ops share the same set of functions
5900 * to test. If any other ops is on the list, then
5901 * the graph tracing needs to test if its the function
5902 * it should call.
5903 */
5904 do_for_each_ftrace_op(op, ftrace_ops_list) {
5905 if (op != &global_ops && op != &graph_ops &&
5906 op != &ftrace_list_end) {
5907 do_test = true;
5908 /* in double loop, break out with goto */
5909 goto out;
5910 }
5911 } while_for_each_ftrace_op(op);
5912 out:
5913 if (do_test)
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005914 ftrace_graph_entry = ftrace_graph_entry_test;
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005915 else
5916 ftrace_graph_entry = __ftrace_graph_entry;
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005917}
5918
Mathias Krause8275f692014-03-30 15:31:50 +02005919static struct notifier_block ftrace_suspend_notifier = {
5920 .notifier_call = ftrace_suspend_notifier_call,
5921};
5922
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01005923int register_ftrace_graph(trace_func_graph_ret_t retfunc,
5924 trace_func_graph_ent_t entryfunc)
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01005925{
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005926 int ret = 0;
5927
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005928 mutex_lock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005929
Steven Rostedt05ce5812009-03-24 00:18:31 -04005930 /* we currently allow only one tracer registered at a time */
Steven Rostedt597af812009-04-03 15:24:12 -04005931 if (ftrace_graph_active) {
Steven Rostedt05ce5812009-03-24 00:18:31 -04005932 ret = -EBUSY;
5933 goto out;
5934 }
5935
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -08005936 register_pm_notifier(&ftrace_suspend_notifier);
5937
Steven Rostedt597af812009-04-03 15:24:12 -04005938 ftrace_graph_active++;
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01005939 ret = start_graph_tracing();
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005940 if (ret) {
Steven Rostedt597af812009-04-03 15:24:12 -04005941 ftrace_graph_active--;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005942 goto out;
5943 }
Steven Rostedte53a6312008-11-26 00:16:25 -05005944
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01005945 ftrace_graph_return = retfunc;
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005946
5947 /*
5948 * Update the indirect function to the entryfunc, and the
5949 * function that gets called to the entry_test first. Then
5950 * call the update fgraph entry function to determine if
5951 * the entryfunc should be called directly or not.
5952 */
5953 __ftrace_graph_entry = entryfunc;
5954 ftrace_graph_entry = ftrace_graph_entry_test;
5955 update_function_graph_func();
Steven Rostedte53a6312008-11-26 00:16:25 -05005956
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005957 ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005958out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005959 mutex_unlock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005960 return ret;
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01005961}
5962
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01005963void unregister_ftrace_graph(void)
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01005964{
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005965 mutex_lock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005966
Steven Rostedt597af812009-04-03 15:24:12 -04005967 if (unlikely(!ftrace_graph_active))
Steven Rostedt2aad1b72009-03-30 11:11:28 -04005968 goto out;
5969
Steven Rostedt597af812009-04-03 15:24:12 -04005970 ftrace_graph_active--;
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01005971 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
Steven Rostedte49dc192008-12-02 23:50:05 -05005972 ftrace_graph_entry = ftrace_graph_entry_stub;
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005973 __ftrace_graph_entry = ftrace_graph_entry_stub;
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005974 ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -08005975 unregister_pm_notifier(&ftrace_suspend_notifier);
Steven Rostedt38516ab2010-04-20 17:04:50 -04005976 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005977
Steven Rostedt (Red Hat)f3bea492014-07-02 23:23:31 -04005978#ifdef CONFIG_DYNAMIC_FTRACE
5979 /*
5980 * Function graph does not allocate the trampoline, but
5981 * other global_ops do. We need to reset the ALLOC_TRAMP flag
5982 * if one was used.
5983 */
5984 global_ops.trampoline = save_global_trampoline;
5985 if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP)
5986 global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
5987#endif
5988
Steven Rostedt2aad1b72009-03-30 11:11:28 -04005989 out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005990 mutex_unlock(&ftrace_lock);
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01005991}
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005992
Steven Rostedt868baf02011-02-10 21:26:13 -05005993static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
5994
5995static void
5996graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
5997{
5998 atomic_set(&t->tracing_graph_pause, 0);
5999 atomic_set(&t->trace_overrun, 0);
6000 t->ftrace_timestamp = 0;
Lucas De Marchi25985ed2011-03-30 22:57:33 -03006001 /* make curr_ret_stack visible before we add the ret_stack */
Steven Rostedt868baf02011-02-10 21:26:13 -05006002 smp_wmb();
6003 t->ret_stack = ret_stack;
6004}
6005
6006/*
6007 * Allocate a return stack for the idle task. May be the first
6008 * time through, or it may be done by CPU hotplug online.
6009 */
6010void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
6011{
6012 t->curr_ret_stack = -1;
6013 /*
6014 * The idle task has no parent, it either has its own
6015 * stack or no stack at all.
6016 */
6017 if (t->ret_stack)
6018 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
6019
6020 if (ftrace_graph_active) {
6021 struct ftrace_ret_stack *ret_stack;
6022
6023 ret_stack = per_cpu(idle_ret_stack, cpu);
6024 if (!ret_stack) {
6025 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
6026 * sizeof(struct ftrace_ret_stack),
6027 GFP_KERNEL);
6028 if (!ret_stack)
6029 return;
6030 per_cpu(idle_ret_stack, cpu) = ret_stack;
6031 }
6032 graph_init_task(t, ret_stack);
6033 }
6034}
6035
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01006036/* Allocate a return stack for newly created task */
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01006037void ftrace_graph_init_task(struct task_struct *t)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01006038{
Steven Rostedt84047e32009-06-02 16:51:55 -04006039 /* Make sure we do not use the parent ret_stack */
6040 t->ret_stack = NULL;
Steven Rostedtea14eb72010-03-12 19:41:23 -05006041 t->curr_ret_stack = -1;
Steven Rostedt84047e32009-06-02 16:51:55 -04006042
Steven Rostedt597af812009-04-03 15:24:12 -04006043 if (ftrace_graph_active) {
Steven Rostedt82310a32009-06-02 12:26:07 -04006044 struct ftrace_ret_stack *ret_stack;
6045
6046 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01006047 * sizeof(struct ftrace_ret_stack),
6048 GFP_KERNEL);
Steven Rostedt82310a32009-06-02 12:26:07 -04006049 if (!ret_stack)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01006050 return;
Steven Rostedt868baf02011-02-10 21:26:13 -05006051 graph_init_task(t, ret_stack);
Steven Rostedt84047e32009-06-02 16:51:55 -04006052 }
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01006053}
6054
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01006055void ftrace_graph_exit_task(struct task_struct *t)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01006056{
Frederic Weisbeckereae849c2008-11-23 17:33:12 +01006057 struct ftrace_ret_stack *ret_stack = t->ret_stack;
6058
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01006059 t->ret_stack = NULL;
Frederic Weisbeckereae849c2008-11-23 17:33:12 +01006060 /* NULL must become visible to IRQs before we free it: */
6061 barrier();
6062
6063 kfree(ret_stack);
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01006064}
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01006065#endif