blob: d52eec268b4746a006ef3badf6805b8acae5d7e1 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/arm/kernel/traps.c
3 *
Russell Kingab72b002009-10-25 15:39:37 +00004 * Copyright (C) 1995-2009 Russell King
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 * Fragments that appear the same as linux/arch/i386/kernel/traps.c (C) Linus Torvalds
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * 'traps.c' handles hardware exceptions after we have saved some state in
12 * 'linux/arch/arm/lib/traps.S'. Mostly a debugging aid, but will probably
13 * kill the offending process.
14 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/signal.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/personality.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/kallsyms.h>
Russell Kinga9221de2010-01-20 17:02:54 +000018#include <linux/spinlock.h>
Russell King33fa9b12008-09-06 11:35:55 +010019#include <linux/uaccess.h>
Russell Kinga9221de2010-01-20 17:02:54 +000020#include <linux/hardirq.h>
21#include <linux/kdebug.h>
22#include <linux/module.h>
23#include <linux/kexec.h>
24#include <linux/delay.h>
25#include <linux/init.h>
Will Deacon425fc472011-02-14 14:31:09 +010026#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
28#include <asm/atomic.h>
29#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <asm/system.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <asm/unistd.h>
32#include <asm/traps.h>
Catalin Marinasbff595c2009-02-16 11:41:36 +010033#include <asm/unwind.h>
Tony Lindgrenf159f4e2010-07-05 14:53:10 +010034#include <asm/tls.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
Russell Kinge00d3492005-06-22 20:26:05 +010036#include "signal.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
Linus Torvalds1da177e2005-04-16 15:20:36 -070038static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" };
39
Catalin Marinas247055a2010-09-13 16:03:21 +010040void *vectors_page;
41
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#ifdef CONFIG_DEBUG_USER
43unsigned int user_debug;
44
45static int __init user_debug_setup(char *str)
46{
47 get_option(&str, &user_debug);
48 return 1;
49}
50__setup("user_debug=", user_debug_setup);
51#endif
52
Russell Kinge40c2ec2009-10-11 15:17:53 +010053static void dump_mem(const char *, const char *, unsigned long, unsigned long);
Russell King7ab3f8d2007-03-02 15:01:36 +000054
Russell King7ab3f8d2007-03-02 15:01:36 +000055void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)
Linus Torvalds1da177e2005-04-16 15:20:36 -070056{
57#ifdef CONFIG_KALLSYMS
Joe Perches69448c22010-11-05 16:12:34 -070058 printk("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059#else
60 printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
61#endif
Russell King7ab3f8d2007-03-02 15:01:36 +000062
63 if (in_exception_text(where))
Russell Kinge40c2ec2009-10-11 15:17:53 +010064 dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs));
Linus Torvalds1da177e2005-04-16 15:20:36 -070065}
66
Catalin Marinasbff595c2009-02-16 11:41:36 +010067#ifndef CONFIG_ARM_UNWIND
Linus Torvalds1da177e2005-04-16 15:20:36 -070068/*
69 * Stack pointers should always be within the kernels view of
70 * physical memory. If it is not there, then we can't dump
71 * out any information relating to the stack.
72 */
73static int verify_stack(unsigned long sp)
74{
Russell King09d9bae2008-09-05 14:08:44 +010075 if (sp < PAGE_OFFSET ||
76 (sp > (unsigned long)high_memory && high_memory != NULL))
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 return -EFAULT;
78
79 return 0;
80}
Catalin Marinasbff595c2009-02-16 11:41:36 +010081#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83/*
84 * Dump out the contents of some memory nicely...
85 */
Russell Kinge40c2ec2009-10-11 15:17:53 +010086static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
87 unsigned long top)
Linus Torvalds1da177e2005-04-16 15:20:36 -070088{
Russell Kingd191fe02009-10-11 15:03:11 +010089 unsigned long first;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 mm_segment_t fs;
91 int i;
92
93 /*
94 * We need to switch to kernel mode so that we can use __get_user
95 * to safely read from kernel space. Note that we now dump the
96 * code first, just in case the backtrace kills us.
97 */
98 fs = get_fs();
99 set_fs(KERNEL_DS);
100
Russell Kinge40c2ec2009-10-11 15:17:53 +0100101 printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
Russell Kingd191fe02009-10-11 15:03:11 +0100103 for (first = bottom & ~31; first < top; first += 32) {
104 unsigned long p;
105 char str[sizeof(" 12345678") * 8 + 1];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
Russell Kingd191fe02009-10-11 15:03:11 +0100107 memset(str, ' ', sizeof(str));
108 str[sizeof(str) - 1] = '\0';
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109
Russell Kingd191fe02009-10-11 15:03:11 +0100110 for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
111 if (p >= bottom && p < top) {
112 unsigned long val;
113 if (__get_user(val, (unsigned long *)p) == 0)
114 sprintf(str + i * 9, " %08lx", val);
115 else
116 sprintf(str + i * 9, " ????????");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 }
118 }
Russell Kinge40c2ec2009-10-11 15:17:53 +0100119 printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 }
121
122 set_fs(fs);
123}
124
Russell Kinge40c2ec2009-10-11 15:17:53 +0100125static void dump_instr(const char *lvl, struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126{
127 unsigned long addr = instruction_pointer(regs);
128 const int thumb = thumb_mode(regs);
129 const int width = thumb ? 4 : 8;
130 mm_segment_t fs;
Russell Kingd191fe02009-10-11 15:03:11 +0100131 char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 int i;
133
134 /*
135 * We need to switch to kernel mode so that we can use __get_user
136 * to safely read from kernel space. Note that we now dump the
137 * code first, just in case the backtrace kills us.
138 */
139 fs = get_fs();
140 set_fs(KERNEL_DS);
141
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 for (i = -4; i < 1; i++) {
143 unsigned int val, bad;
144
145 if (thumb)
146 bad = __get_user(val, &((u16 *)addr)[i]);
147 else
148 bad = __get_user(val, &((u32 *)addr)[i]);
149
150 if (!bad)
Russell Kingd191fe02009-10-11 15:03:11 +0100151 p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ",
152 width, val);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 else {
Russell Kingd191fe02009-10-11 15:03:11 +0100154 p += sprintf(p, "bad PC value");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 break;
156 }
157 }
Russell Kinge40c2ec2009-10-11 15:17:53 +0100158 printk("%sCode: %s\n", lvl, str);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
160 set_fs(fs);
161}
162
Catalin Marinasbff595c2009-02-16 11:41:36 +0100163#ifdef CONFIG_ARM_UNWIND
164static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
165{
166 unwind_backtrace(regs, tsk);
167}
168#else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
170{
Catalin Marinas67a94c22009-02-11 13:06:53 +0100171 unsigned int fp, mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 int ok = 1;
173
174 printk("Backtrace: ");
Catalin Marinas67a94c22009-02-11 13:06:53 +0100175
176 if (!tsk)
177 tsk = current;
178
179 if (regs) {
180 fp = regs->ARM_fp;
181 mode = processor_mode(regs);
182 } else if (tsk != current) {
183 fp = thread_saved_fp(tsk);
184 mode = 0x10;
185 } else {
186 asm("mov %0, fp" : "=r" (fp) : : "cc");
187 mode = 0x10;
188 }
189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 if (!fp) {
191 printk("no frame pointer");
192 ok = 0;
193 } else if (verify_stack(fp)) {
194 printk("invalid frame pointer 0x%08x", fp);
195 ok = 0;
Al Viro55205822006-01-12 01:05:57 -0800196 } else if (fp < (unsigned long)end_of_stack(tsk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 printk("frame pointer underflow");
198 printk("\n");
199
200 if (ok)
Catalin Marinas67a94c22009-02-11 13:06:53 +0100201 c_backtrace(fp, mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202}
Catalin Marinasbff595c2009-02-16 11:41:36 +0100203#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
205void dump_stack(void)
206{
Catalin Marinas67a94c22009-02-11 13:06:53 +0100207 dump_backtrace(NULL, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208}
209
210EXPORT_SYMBOL(dump_stack);
211
212void show_stack(struct task_struct *tsk, unsigned long *sp)
213{
Catalin Marinas67a94c22009-02-11 13:06:53 +0100214 dump_backtrace(NULL, tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 barrier();
216}
217
Russell Kingd9202422007-06-17 13:38:27 +0100218#ifdef CONFIG_PREEMPT
219#define S_PREEMPT " PREEMPT"
220#else
221#define S_PREEMPT ""
222#endif
223#ifdef CONFIG_SMP
224#define S_SMP " SMP"
225#else
226#define S_SMP ""
227#endif
228
Russell Kinga9221de2010-01-20 17:02:54 +0000229static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230{
Russell Kingd3629792005-10-30 19:01:43 +0000231 struct task_struct *tsk = thread->task;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 static int die_counter;
Russell Kinga9221de2010-01-20 17:02:54 +0000233 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Russell Kinge40c2ec2009-10-11 15:17:53 +0100235 printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
Russell Kingd9202422007-06-17 13:38:27 +0100236 str, err, ++die_counter);
Russell Kinga9221de2010-01-20 17:02:54 +0000237
238 /* trap and error numbers are mostly meaningless on ARM */
239 ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV);
240 if (ret == NOTIFY_STOP)
241 return ret;
242
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 print_modules();
Russell King652a12e2005-04-17 15:50:36 +0100244 __show_regs(regs);
Russell Kinge40c2ec2009-10-11 15:17:53 +0100245 printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n",
246 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
248 if (!user_mode(regs) || in_interrupt()) {
Russell Kinge40c2ec2009-10-11 15:17:53 +0100249 dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp,
Al Viro32d39a92006-01-12 01:05:58 -0800250 THREAD_SIZE + (unsigned long)task_stack_page(tsk));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 dump_backtrace(regs, tsk);
Russell Kinge40c2ec2009-10-11 15:17:53 +0100252 dump_instr(KERN_EMERG, regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 }
Russell Kinga9221de2010-01-20 17:02:54 +0000254
255 return ret;
Russell Kingd3629792005-10-30 19:01:43 +0000256}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
Russell King2bbd7e92011-01-08 12:05:09 +0000258static DEFINE_SPINLOCK(die_lock);
Russell Kingd3629792005-10-30 19:01:43 +0000259
260/*
261 * This function is protected against re-entrancy.
262 */
Russell Kinga9221de2010-01-20 17:02:54 +0000263void die(const char *str, struct pt_regs *regs, int err)
Russell Kingd3629792005-10-30 19:01:43 +0000264{
265 struct thread_info *thread = current_thread_info();
Russell Kinga9221de2010-01-20 17:02:54 +0000266 int ret;
Russell Kingd3629792005-10-30 19:01:43 +0000267
Russell Kingd9202422007-06-17 13:38:27 +0100268 oops_enter();
269
Russell Kingd3629792005-10-30 19:01:43 +0000270 spin_lock_irq(&die_lock);
Russell King03a6e5b2009-10-11 15:25:05 +0100271 console_verbose();
Russell Kingd3629792005-10-30 19:01:43 +0000272 bust_spinlocks(1);
Russell Kinga9221de2010-01-20 17:02:54 +0000273 ret = __die(str, err, thread, regs);
274
275 if (regs && kexec_should_crash(thread->task))
276 crash_kexec(regs);
277
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 bust_spinlocks(0);
Pavel Emelianovbcdcd8e2007-07-17 04:03:42 -0700279 add_taint(TAINT_DIE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 spin_unlock_irq(&die_lock);
Russell King03a6e5b2009-10-11 15:25:05 +0100281 oops_exit();
Russell King31867492006-02-19 19:53:56 +0000282
Russell Kingd9202422007-06-17 13:38:27 +0100283 if (in_interrupt())
284 panic("Fatal exception in interrupt");
Hormscea6a4b2006-07-30 03:03:34 -0700285 if (panic_on_oops)
Horms012c4372006-08-13 23:24:22 -0700286 panic("Fatal exception");
Russell Kinga9221de2010-01-20 17:02:54 +0000287 if (ret != NOTIFY_STOP)
288 do_exit(SIGSEGV);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289}
290
Christoph Hellwig1eeb66a2007-05-08 00:27:03 -0700291void arm_notify_die(const char *str, struct pt_regs *regs,
292 struct siginfo *info, unsigned long err, unsigned long trap)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293{
294 if (user_mode(regs)) {
295 current->thread.error_code = err;
296 current->thread.trap_no = trap;
297
298 force_sig_info(info->si_signo, info, current);
299 } else {
300 die(str, regs, err);
301 }
302}
303
304static LIST_HEAD(undef_hook);
305static DEFINE_SPINLOCK(undef_lock);
306
307void register_undef_hook(struct undef_hook *hook)
308{
Russell King109d89c2005-07-16 16:43:33 +0100309 unsigned long flags;
310
311 spin_lock_irqsave(&undef_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 list_add(&hook->node, &undef_hook);
Russell King109d89c2005-07-16 16:43:33 +0100313 spin_unlock_irqrestore(&undef_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314}
315
316void unregister_undef_hook(struct undef_hook *hook)
317{
Russell King109d89c2005-07-16 16:43:33 +0100318 unsigned long flags;
319
320 spin_lock_irqsave(&undef_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 list_del(&hook->node);
Russell King109d89c2005-07-16 16:43:33 +0100322 spin_unlock_irqrestore(&undef_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323}
324
Russell Kingb03a5b72008-08-11 12:27:16 +0100325static int call_undef_hook(struct pt_regs *regs, unsigned int instr)
326{
327 struct undef_hook *hook;
328 unsigned long flags;
329 int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL;
330
331 spin_lock_irqsave(&undef_lock, flags);
332 list_for_each_entry(hook, &undef_hook, node)
333 if ((instr & hook->instr_mask) == hook->instr_val &&
334 (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val)
335 fn = hook->fn;
336 spin_unlock_irqrestore(&undef_lock, flags);
337
338 return fn ? fn(regs, instr) : 1;
339}
340
Russell King7ab3f8d2007-03-02 15:01:36 +0000341asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342{
343 unsigned int correction = thumb_mode(regs) ? 2 : 4;
344 unsigned int instr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 siginfo_t info;
346 void __user *pc;
347
348 /*
349 * According to the ARM ARM, PC is 2 or 4 bytes ahead,
350 * depending whether we're in Thumb mode or not.
351 * Correct this offset.
352 */
353 regs->ARM_pc -= correction;
354
355 pc = (void __user *)instruction_pointer(regs);
Dan Williamsdfc544c2007-02-13 17:11:34 +0100356
357 if (processor_mode(regs) == SVC_MODE) {
358 instr = *(u32 *) pc;
359 } else if (thumb_mode(regs)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 get_user(instr, (u16 __user *)pc);
361 } else {
362 get_user(instr, (u32 __user *)pc);
363 }
364
Russell Kingb03a5b72008-08-11 12:27:16 +0100365 if (call_undef_hook(regs, instr) == 0)
366 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367
368#ifdef CONFIG_DEBUG_USER
369 if (user_debug & UDBG_UNDEFINED) {
370 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
Alexey Dobriyan19c58702007-10-18 23:40:41 -0700371 current->comm, task_pid_nr(current), pc);
Russell Kinge40c2ec2009-10-11 15:17:53 +0100372 dump_instr(KERN_INFO, regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 }
374#endif
375
376 info.si_signo = SIGILL;
377 info.si_errno = 0;
378 info.si_code = ILL_ILLOPC;
379 info.si_addr = pc;
380
Christoph Hellwig1eeb66a2007-05-08 00:27:03 -0700381 arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382}
383
384asmlinkage void do_unexp_fiq (struct pt_regs *regs)
385{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 printk("Hmm. Unexpected FIQ received, but trying to continue\n");
387 printk("You may have a hardware problem...\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388}
389
390/*
391 * bad_mode handles the impossible case in the vectors. If you see one of
392 * these, then it's extremely serious, and could mean you have buggy hardware.
393 * It never returns, and never tries to sync. We hope that we can at least
394 * dump out some state information...
395 */
Russell Kingae0a8462007-01-09 12:57:37 +0000396asmlinkage void bad_mode(struct pt_regs *regs, int reason)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397{
398 console_verbose();
399
Russell Kingae0a8462007-01-09 12:57:37 +0000400 printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401
402 die("Oops - bad mode", regs, 0);
403 local_irq_disable();
404 panic("bad mode");
405}
406
407static int bad_syscall(int n, struct pt_regs *regs)
408{
409 struct thread_info *thread = current_thread_info();
410 siginfo_t info;
411
Nicolas Pitre88b9ef42011-04-13 05:01:52 +0100412 if ((current->personality & PER_MASK) != PER_LINUX &&
Nicolas Pitrea999cb02005-10-28 16:35:46 +0100413 thread->exec_domain->handler) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 thread->exec_domain->handler(n, regs);
415 return regs->ARM_r0;
416 }
417
418#ifdef CONFIG_DEBUG_USER
419 if (user_debug & UDBG_SYSCALL) {
420 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",
Alexey Dobriyan19c58702007-10-18 23:40:41 -0700421 task_pid_nr(current), current->comm, n);
Russell Kinge40c2ec2009-10-11 15:17:53 +0100422 dump_instr(KERN_ERR, regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 }
424#endif
425
426 info.si_signo = SIGILL;
427 info.si_errno = 0;
428 info.si_code = ILL_ILLTRP;
429 info.si_addr = (void __user *)instruction_pointer(regs) -
430 (thumb_mode(regs) ? 2 : 4);
431
Christoph Hellwig1eeb66a2007-05-08 00:27:03 -0700432 arm_notify_die("Oops - bad syscall", regs, &info, n, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433
434 return regs->ARM_r0;
435}
436
437static inline void
438do_cache_op(unsigned long start, unsigned long end, int flags)
439{
Russell Kingaa45ee82009-09-28 11:41:51 +0100440 struct mm_struct *mm = current->active_mm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 struct vm_area_struct *vma;
442
443 if (end < start || flags)
444 return;
445
Russell Kingaa45ee82009-09-28 11:41:51 +0100446 down_read(&mm->mmap_sem);
447 vma = find_vma(mm, start);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 if (vma && vma->vm_start < end) {
449 if (start < vma->vm_start)
450 start = vma->vm_start;
451 if (end > vma->vm_end)
452 end = vma->vm_end;
453
454 flush_cache_user_range(vma, start, end);
455 }
Russell Kingaa45ee82009-09-28 11:41:51 +0100456 up_read(&mm->mmap_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457}
458
459/*
460 * Handle all unrecognised system calls.
461 * 0x9f0000 - 0x9fffff are some more esoteric system calls
462 */
463#define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
464asmlinkage int arm_syscall(int no, struct pt_regs *regs)
465{
466 struct thread_info *thread = current_thread_info();
467 siginfo_t info;
468
Nicolas Pitre3f2829a2006-01-14 16:31:29 +0000469 if ((no >> 16) != (__ARM_NR_BASE>> 16))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 return bad_syscall(no, regs);
471
472 switch (no & 0xffff) {
473 case 0: /* branch through 0 */
474 info.si_signo = SIGSEGV;
475 info.si_errno = 0;
476 info.si_code = SEGV_MAPERR;
477 info.si_addr = NULL;
478
Christoph Hellwig1eeb66a2007-05-08 00:27:03 -0700479 arm_notify_die("branch through zero", regs, &info, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 return 0;
481
482 case NR(breakpoint): /* SWI BREAK_POINT */
483 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
484 ptrace_break(current, regs);
485 return regs->ARM_r0;
486
487 /*
488 * Flush a region from virtual address 'r0' to virtual address 'r1'
489 * _exclusive_. There is no alignment requirement on either address;
490 * user space does not need to know the hardware cache layout.
491 *
492 * r2 contains flags. It should ALWAYS be passed as ZERO until it
493 * is defined to be something else. For now we ignore it, but may
494 * the fires of hell burn in your belly if you break this rule. ;)
495 *
496 * (at a later date, we may want to allow this call to not flush
497 * various aspects of the cache. Passing '0' will guarantee that
498 * everything necessary gets flushed to maintain consistency in
499 * the specified region).
500 */
501 case NR(cacheflush):
502 do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
503 return 0;
504
505 case NR(usr26):
506 if (!(elf_hwcap & HWCAP_26BIT))
507 break;
508 regs->ARM_cpsr &= ~MODE32_BIT;
509 return regs->ARM_r0;
510
511 case NR(usr32):
512 if (!(elf_hwcap & HWCAP_26BIT))
513 break;
514 regs->ARM_cpsr |= MODE32_BIT;
515 return regs->ARM_r0;
516
517 case NR(set_tls):
518 thread->tp_value = regs->ARM_r0;
Tony Lindgrenf159f4e2010-07-05 14:53:10 +0100519 if (tls_emu)
520 return 0;
521 if (has_tls_reg) {
522 asm ("mcr p15, 0, %0, c13, c0, 3"
523 : : "r" (regs->ARM_r0));
524 } else {
525 /*
526 * User space must never try to access this directly.
527 * Expect your app to break eventually if you do so.
528 * The user helper at 0xffff0fe0 must be used instead.
529 * (see entry-armv.S for details)
530 */
531 *((unsigned int *)0xffff0ff0) = regs->ARM_r0;
532 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 return 0;
534
Nicolas Pitredcef1f62005-06-08 19:00:47 +0100535#ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG
536 /*
537 * Atomically store r1 in *r2 if *r2 is equal to r0 for user space.
538 * Return zero in r0 if *MEM was changed or non-zero if no exchange
539 * happened. Also set the user C flag accordingly.
540 * If access permissions have to be fixed up then non-zero is
541 * returned and the operation has to be re-attempted.
542 *
543 * *NOTE*: This is a ghost syscall private to the kernel. Only the
544 * __kuser_cmpxchg code in entry-armv.S should be aware of its
545 * existence. Don't ever use this from user code.
546 */
Russell Kingcc20d422009-11-09 23:53:29 +0000547 case NR(cmpxchg):
Nicolas Pitreb49c0f22007-11-20 17:20:29 +0100548 for (;;) {
Nicolas Pitredcef1f62005-06-08 19:00:47 +0100549 extern void do_DataAbort(unsigned long addr, unsigned int fsr,
550 struct pt_regs *regs);
551 unsigned long val;
552 unsigned long addr = regs->ARM_r2;
553 struct mm_struct *mm = current->mm;
554 pgd_t *pgd; pmd_t *pmd; pte_t *pte;
Hugh Dickins69b04752005-10-29 18:16:36 -0700555 spinlock_t *ptl;
Nicolas Pitredcef1f62005-06-08 19:00:47 +0100556
557 regs->ARM_cpsr &= ~PSR_C_BIT;
Hugh Dickins69b04752005-10-29 18:16:36 -0700558 down_read(&mm->mmap_sem);
Nicolas Pitredcef1f62005-06-08 19:00:47 +0100559 pgd = pgd_offset(mm, addr);
560 if (!pgd_present(*pgd))
561 goto bad_access;
562 pmd = pmd_offset(pgd, addr);
563 if (!pmd_present(*pmd))
564 goto bad_access;
Hugh Dickins69b04752005-10-29 18:16:36 -0700565 pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
Nicolas Pitre2ce98042006-03-25 22:44:05 +0000566 if (!pte_present(*pte) || !pte_dirty(*pte)) {
Hugh Dickins69b04752005-10-29 18:16:36 -0700567 pte_unmap_unlock(pte, ptl);
Nicolas Pitredcef1f62005-06-08 19:00:47 +0100568 goto bad_access;
Hugh Dickins69b04752005-10-29 18:16:36 -0700569 }
Nicolas Pitredcef1f62005-06-08 19:00:47 +0100570 val = *(unsigned long *)addr;
571 val -= regs->ARM_r0;
572 if (val == 0) {
573 *(unsigned long *)addr = regs->ARM_r1;
574 regs->ARM_cpsr |= PSR_C_BIT;
575 }
Hugh Dickins69b04752005-10-29 18:16:36 -0700576 pte_unmap_unlock(pte, ptl);
577 up_read(&mm->mmap_sem);
Nicolas Pitredcef1f62005-06-08 19:00:47 +0100578 return val;
579
580 bad_access:
Hugh Dickins69b04752005-10-29 18:16:36 -0700581 up_read(&mm->mmap_sem);
Nicolas Pitre74f88492005-10-04 23:17:52 +0100582 /* simulate a write access fault */
Nicolas Pitredcef1f62005-06-08 19:00:47 +0100583 do_DataAbort(addr, 15 + (1 << 11), regs);
Nicolas Pitredcef1f62005-06-08 19:00:47 +0100584 }
585#endif
586
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 default:
588 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS
589 if not implemented, rather than raising SIGILL. This
590 way the calling program can gracefully determine whether
591 a feature is supported. */
Russell Kingbfd2e292009-11-08 20:05:28 +0000592 if ((no & 0xffff) <= 0x7ff)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 return -ENOSYS;
594 break;
595 }
596#ifdef CONFIG_DEBUG_USER
597 /*
598 * experience shows that these seem to indicate that
599 * something catastrophic has happened
600 */
601 if (user_debug & UDBG_SYSCALL) {
602 printk("[%d] %s: arm syscall %d\n",
Alexey Dobriyan19c58702007-10-18 23:40:41 -0700603 task_pid_nr(current), current->comm, no);
Russell Kinge40c2ec2009-10-11 15:17:53 +0100604 dump_instr("", regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 if (user_mode(regs)) {
Russell King652a12e2005-04-17 15:50:36 +0100606 __show_regs(regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 c_backtrace(regs->ARM_fp, processor_mode(regs));
608 }
609 }
610#endif
611 info.si_signo = SIGILL;
612 info.si_errno = 0;
613 info.si_code = ILL_ILLTRP;
614 info.si_addr = (void __user *)instruction_pointer(regs) -
615 (thumb_mode(regs) ? 2 : 4);
616
Christoph Hellwig1eeb66a2007-05-08 00:27:03 -0700617 arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 return 0;
619}
620
Nicolas Pitre4b0e07a2005-05-05 23:24:45 +0100621#ifdef CONFIG_TLS_REG_EMUL
Nicolas Pitre2d2669b2005-04-29 22:08:33 +0100622
623/*
624 * We might be running on an ARMv6+ processor which should have the TLS
Nicolas Pitre4b0e07a2005-05-05 23:24:45 +0100625 * register but for some reason we can't use it, or maybe an SMP system
626 * using a pre-ARMv6 processor (there are apparently a few prototypes like
627 * that in existence) and therefore access to that register must be
628 * emulated.
Nicolas Pitre2d2669b2005-04-29 22:08:33 +0100629 */
630
631static int get_tp_trap(struct pt_regs *regs, unsigned int instr)
632{
633 int reg = (instr >> 12) & 15;
634 if (reg == 15)
635 return 1;
636 regs->uregs[reg] = current_thread_info()->tp_value;
637 regs->ARM_pc += 4;
638 return 0;
639}
640
641static struct undef_hook arm_mrc_hook = {
642 .instr_mask = 0x0fff0fff,
643 .instr_val = 0x0e1d0f70,
644 .cpsr_mask = PSR_T_BIT,
645 .cpsr_val = 0,
646 .fn = get_tp_trap,
647};
648
649static int __init arm_mrc_hook_init(void)
650{
651 register_undef_hook(&arm_mrc_hook);
652 return 0;
653}
654
655late_initcall(arm_mrc_hook_init);
656
657#endif
658
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659void __bad_xchg(volatile void *ptr, int size)
660{
661 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
662 __builtin_return_address(0), ptr, size);
663 BUG();
664}
665EXPORT_SYMBOL(__bad_xchg);
666
667/*
668 * A data abort trap was taken, but we did not handle the instruction.
669 * Try to abort the user program, or panic if it was the kernel.
670 */
671asmlinkage void
672baddataabort(int code, unsigned long instr, struct pt_regs *regs)
673{
674 unsigned long addr = instruction_pointer(regs);
675 siginfo_t info;
676
677#ifdef CONFIG_DEBUG_USER
678 if (user_debug & UDBG_BADABORT) {
679 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",
Alexey Dobriyan19c58702007-10-18 23:40:41 -0700680 task_pid_nr(current), current->comm, code, instr);
Russell Kinge40c2ec2009-10-11 15:17:53 +0100681 dump_instr(KERN_ERR, regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 show_pte(current->mm, addr);
683 }
684#endif
685
686 info.si_signo = SIGILL;
687 info.si_errno = 0;
688 info.si_code = ILL_ILLOPC;
689 info.si_addr = (void __user *)addr;
690
Christoph Hellwig1eeb66a2007-05-08 00:27:03 -0700691 arm_notify_die("unknown data abort code", regs, &info, instr, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692}
693
Nicolas Pitre7174d852006-12-07 19:09:20 +0100694void __attribute__((noreturn)) __bug(const char *file, int line)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695{
Nicolas Pitre7174d852006-12-07 19:09:20 +0100696 printk(KERN_CRIT"kernel BUG at %s:%d!\n", file, line);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 *(int *)0 = 0;
Catalin Marinas6a1ced52005-09-21 22:14:05 +0100698
699 /* Avoid "noreturn function does return" */
700 for (;;);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701}
702EXPORT_SYMBOL(__bug);
703
704void __readwrite_bug(const char *fn)
705{
706 printk("%s called, but not implemented\n", fn);
707 BUG();
708}
709EXPORT_SYMBOL(__readwrite_bug);
710
Russell King69529c02010-11-16 00:19:55 +0000711void __pte_error(const char *file, int line, pte_t pte)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712{
Will Deacon29a38192011-02-15 14:31:37 +0100713 printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714}
715
Russell King69529c02010-11-16 00:19:55 +0000716void __pmd_error(const char *file, int line, pmd_t pmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717{
Will Deacon29a38192011-02-15 14:31:37 +0100718 printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719}
720
Russell King69529c02010-11-16 00:19:55 +0000721void __pgd_error(const char *file, int line, pgd_t pgd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722{
Will Deacon29a38192011-02-15 14:31:37 +0100723 printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724}
725
726asmlinkage void __div0(void)
727{
728 printk("Division by zero in kernel.\n");
729 dump_stack();
730}
731EXPORT_SYMBOL(__div0);
732
733void abort(void)
734{
735 BUG();
736
737 /* if that doesn't kill us, halt */
738 panic("Oops failed to kill thread");
739}
740EXPORT_SYMBOL(abort);
741
742void __init trap_init(void)
743{
Jason Wessel5cbad0e2008-02-20 13:33:40 -0600744 return;
745}
746
Tony Lindgrenf159f4e2010-07-05 14:53:10 +0100747static void __init kuser_get_tls_init(unsigned long vectors)
748{
749 /*
750 * vectors + 0xfe0 = __kuser_get_tls
751 * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8
752 */
753 if (tls_emu || has_tls_reg)
754 memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4);
755}
756
Jason Wessel5cbad0e2008-02-20 13:33:40 -0600757void __init early_trap_init(void)
758{
Catalin Marinas247055a2010-09-13 16:03:21 +0100759#if defined(CONFIG_CPU_USE_DOMAINS)
Hyok S. Choic760fc12006-03-27 15:18:50 +0100760 unsigned long vectors = CONFIG_VECTORS_BASE;
Catalin Marinas247055a2010-09-13 16:03:21 +0100761#else
762 unsigned long vectors = (unsigned long)vectors_page;
763#endif
Russell King79335232005-04-26 15:17:42 +0100764 extern char __stubs_start[], __stubs_end[];
765 extern char __vectors_start[], __vectors_end[];
Nicolas Pitre2d2669b2005-04-29 22:08:33 +0100766 extern char __kuser_helper_start[], __kuser_helper_end[];
767 int kuser_sz = __kuser_helper_end - __kuser_helper_start;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768
Russell King79335232005-04-26 15:17:42 +0100769 /*
Nicolas Pitre2d2669b2005-04-29 22:08:33 +0100770 * Copy the vectors, stubs and kuser helpers (in entry-armv.S)
771 * into the vector page, mapped at 0xffff0000, and ensure these
772 * are visible to the instruction stream.
Russell King79335232005-04-26 15:17:42 +0100773 */
Hyok S. Choic760fc12006-03-27 15:18:50 +0100774 memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start);
775 memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start);
776 memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz);
Russell Kinge00d3492005-06-22 20:26:05 +0100777
778 /*
Tony Lindgrenf159f4e2010-07-05 14:53:10 +0100779 * Do processor specific fixups for the kuser helpers
780 */
781 kuser_get_tls_init(vectors);
782
783 /*
Russell Kinge00d3492005-06-22 20:26:05 +0100784 * Copy signal return handlers into the vector page, and
785 * set sigreturn to be a pointer to these.
786 */
Catalin Marinas247055a2010-09-13 16:03:21 +0100787 memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE),
788 sigreturn_codes, sizeof(sigreturn_codes));
789 memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE),
790 syscall_restart_code, sizeof(syscall_restart_code));
Russell Kinge00d3492005-06-22 20:26:05 +0100791
Hyok S. Choic760fc12006-03-27 15:18:50 +0100792 flush_icache_range(vectors, vectors + PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
794}