blob: 079f1d39a8b84a9105852864cbc8ceaf8875d5ac [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * kallsyms.c: in-kernel printing of symbolic oopses and stack traces.
3 *
4 * Rewritten and vastly simplified by Rusty Russell for in-kernel
5 * module loader:
6 * Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
7 *
8 * ChangeLog:
9 *
10 * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com>
11 * Changed the compression method from stem compression to "table lookup"
12 * compression (see scripts/kallsyms.c for a more complete description)
13 */
14#include <linux/kallsyms.h>
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/seq_file.h>
18#include <linux/fs.h>
Jason Wessel67fc4e02010-05-20 21:04:21 -050019#include <linux/kdb.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/err.h>
21#include <linux/proc_fs.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -080022#include <linux/sched.h> /* for cond_resched */
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/mm.h>
Adam B. Jerome07354a02006-12-06 20:35:30 -080024#include <linux/ctype.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090025#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
27#include <asm/sections.h>
28
29#ifdef CONFIG_KALLSYMS_ALL
30#define all_var 1
31#else
32#define all_var 0
33#endif
34
Manish Katiyarad6ccfa2009-05-12 13:43:35 -070035/*
36 * These will be re-linked against their real values
37 * during the second link stage.
38 */
Sam Ravnborg2ea03892009-01-14 21:38:20 +010039extern const unsigned long kallsyms_addresses[] __attribute__((weak));
40extern const u8 kallsyms_names[] __attribute__((weak));
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
Manish Katiyarad6ccfa2009-05-12 13:43:35 -070042/*
43 * Tell the compiler that the count isn't in the small data section if the arch
44 * has one (eg: FRV).
David Howells9e6c1e62007-11-28 16:22:04 -080045 */
46extern const unsigned long kallsyms_num_syms
Sam Ravnborg2ea03892009-01-14 21:38:20 +010047__attribute__((weak, section(".rodata")));
David Howells9e6c1e62007-11-28 16:22:04 -080048
Sam Ravnborg2ea03892009-01-14 21:38:20 +010049extern const u8 kallsyms_token_table[] __attribute__((weak));
50extern const u16 kallsyms_token_index[] __attribute__((weak));
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Sam Ravnborg2ea03892009-01-14 21:38:20 +010052extern const unsigned long kallsyms_markers[] __attribute__((weak));
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54static inline int is_kernel_inittext(unsigned long addr)
55{
56 if (addr >= (unsigned long)_sinittext
57 && addr <= (unsigned long)_einittext)
58 return 1;
59 return 0;
60}
61
62static inline int is_kernel_text(unsigned long addr)
63{
Mike Frysinger128e8db2009-09-22 16:44:15 -070064 if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) ||
65 arch_is_kernel_text(addr))
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 return 1;
Stephen Wilsoncae5d392011-03-13 15:49:17 -040067 return in_gate_area_no_mm(addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068}
69
70static inline int is_kernel(unsigned long addr)
71{
72 if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
73 return 1;
Stephen Wilsoncae5d392011-03-13 15:49:17 -040074 return in_gate_area_no_mm(addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075}
76
Franck Bui-Huuffc50892006-10-03 01:13:48 -070077static int is_ksym_addr(unsigned long addr)
78{
79 if (all_var)
80 return is_kernel(addr);
81
Robin Getza3b81112008-02-06 01:36:26 -080082 return is_kernel_text(addr) || is_kernel_inittext(addr);
Franck Bui-Huuffc50892006-10-03 01:13:48 -070083}
84
Manish Katiyarad6ccfa2009-05-12 13:43:35 -070085/*
86 * Expand a compressed symbol data into the resulting uncompressed string,
87 * given the offset to where the symbol is in the compressed stream.
88 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070089static unsigned int kallsyms_expand_symbol(unsigned int off, char *result)
90{
91 int len, skipped_first = 0;
Jan Beulichaad09472006-12-08 02:35:57 -080092 const u8 *tptr, *data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
Manish Katiyarad6ccfa2009-05-12 13:43:35 -070094 /* Get the compressed symbol length from the first symbol byte. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 data = &kallsyms_names[off];
96 len = *data;
97 data++;
98
Manish Katiyarad6ccfa2009-05-12 13:43:35 -070099 /*
100 * Update the offset to return the offset for the next symbol on
101 * the compressed stream.
102 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 off += len + 1;
104
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700105 /*
106 * For every byte on the compressed symbol data, copy the table
107 * entry for that byte.
108 */
109 while (len) {
110 tptr = &kallsyms_token_table[kallsyms_token_index[*data]];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 data++;
112 len--;
113
114 while (*tptr) {
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700115 if (skipped_first) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 *result = *tptr;
117 result++;
118 } else
119 skipped_first = 1;
120 tptr++;
121 }
122 }
123
124 *result = '\0';
125
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700126 /* Return to offset to the next symbol. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 return off;
128}
129
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700130/*
131 * Get symbol type information. This is encoded as a single char at the
132 * beginning of the symbol name.
133 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134static char kallsyms_get_symbol_type(unsigned int off)
135{
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700136 /*
137 * Get just the first code, look it up in the token table,
138 * and return the first char from this token.
139 */
140 return kallsyms_token_table[kallsyms_token_index[kallsyms_names[off + 1]]];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141}
142
143
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700144/*
145 * Find the offset on the compressed stream given and index in the
146 * kallsyms array.
147 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148static unsigned int get_symbol_offset(unsigned long pos)
149{
Jan Beulichaad09472006-12-08 02:35:57 -0800150 const u8 *name;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 int i;
152
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700153 /*
154 * Use the closest marker we have. We have markers every 256 positions,
155 * so that should be close enough.
156 */
157 name = &kallsyms_names[kallsyms_markers[pos >> 8]];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700159 /*
160 * Sequentially scan all the symbols up to the point we're searching
161 * for. Every symbol is stored in a [<len>][<len> bytes of data] format,
162 * so we just need to add the len to the current pointer for every
163 * symbol we wish to skip.
164 */
165 for (i = 0; i < (pos & 0xFF); i++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 name = name + (*name) + 1;
167
168 return name - kallsyms_names;
169}
170
171/* Lookup the address for this symbol. Returns 0 if not found. */
172unsigned long kallsyms_lookup_name(const char *name)
173{
Tejun Heo9281ace2007-07-17 04:03:51 -0700174 char namebuf[KSYM_NAME_LEN];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 unsigned long i;
176 unsigned int off;
177
178 for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
179 off = kallsyms_expand_symbol(off, namebuf);
180
181 if (strcmp(namebuf, name) == 0)
182 return kallsyms_addresses[i];
183 }
184 return module_kallsyms_lookup_name(name);
185}
Frederic Weisbeckerf60d24d2009-11-10 10:17:07 +0100186EXPORT_SYMBOL_GPL(kallsyms_lookup_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
Anders Kaseorg75a66612008-12-05 19:03:58 -0500188int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
189 unsigned long),
190 void *data)
191{
192 char namebuf[KSYM_NAME_LEN];
193 unsigned long i;
194 unsigned int off;
195 int ret;
196
197 for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
198 off = kallsyms_expand_symbol(off, namebuf);
199 ret = fn(data, namebuf, NULL, kallsyms_addresses[i]);
200 if (ret != 0)
201 return ret;
202 }
203 return module_kallsyms_on_each_symbol(fn, data);
204}
205EXPORT_SYMBOL_GPL(kallsyms_on_each_symbol);
206
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700207static unsigned long get_symbol_pos(unsigned long addr,
208 unsigned long *symbolsize,
209 unsigned long *offset)
210{
211 unsigned long symbol_start = 0, symbol_end = 0;
212 unsigned long i, low, high, mid;
213
Sam Ravnborg2ea03892009-01-14 21:38:20 +0100214 /* This kernel should never had been booted. */
215 BUG_ON(!kallsyms_addresses);
216
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700217 /* Do a binary search on the sorted kallsyms_addresses array. */
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700218 low = 0;
219 high = kallsyms_num_syms;
220
221 while (high - low > 1) {
Vegard Nossum2fc9c4e2008-07-25 01:45:34 -0700222 mid = low + (high - low) / 2;
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700223 if (kallsyms_addresses[mid] <= addr)
224 low = mid;
225 else
226 high = mid;
227 }
228
229 /*
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700230 * Search for the first aliased symbol. Aliased
231 * symbols are symbols with the same address.
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700232 */
233 while (low && kallsyms_addresses[low-1] == kallsyms_addresses[low])
234 --low;
235
236 symbol_start = kallsyms_addresses[low];
237
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700238 /* Search for next non-aliased symbol. */
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700239 for (i = low + 1; i < kallsyms_num_syms; i++) {
240 if (kallsyms_addresses[i] > symbol_start) {
241 symbol_end = kallsyms_addresses[i];
242 break;
243 }
244 }
245
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700246 /* If we found no next symbol, we use the end of the section. */
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700247 if (!symbol_end) {
248 if (is_kernel_inittext(addr))
249 symbol_end = (unsigned long)_einittext;
250 else if (all_var)
251 symbol_end = (unsigned long)_end;
252 else
253 symbol_end = (unsigned long)_etext;
254 }
255
Alexey Dobriyanffb45122007-05-08 00:28:41 -0700256 if (symbolsize)
257 *symbolsize = symbol_end - symbol_start;
258 if (offset)
259 *offset = addr - symbol_start;
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700260
261 return low;
262}
263
264/*
265 * Lookup an address but don't bother to find any names.
266 */
267int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize,
268 unsigned long *offset)
269{
Rusty Russell6dd06c92008-01-29 17:13:22 -0500270 char namebuf[KSYM_NAME_LEN];
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700271 if (is_ksym_addr(addr))
272 return !!get_symbol_pos(addr, symbolsize, offset);
273
Rusty Russell6dd06c92008-01-29 17:13:22 -0500274 return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf);
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700275}
276
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277/*
278 * Lookup an address
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700279 * - modname is set to NULL if it's in the kernel.
280 * - We guarantee that the returned name is valid until we reschedule even if.
281 * It resides in a module.
282 * - We also guarantee that modname will be valid until rescheduled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 */
284const char *kallsyms_lookup(unsigned long addr,
285 unsigned long *symbolsize,
286 unsigned long *offset,
287 char **modname, char *namebuf)
288{
Tejun Heo9281ace2007-07-17 04:03:51 -0700289 namebuf[KSYM_NAME_LEN - 1] = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 namebuf[0] = 0;
291
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700292 if (is_ksym_addr(addr)) {
293 unsigned long pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700295 pos = get_symbol_pos(addr, symbolsize, offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 /* Grab name */
Franck Bui-Huuffc50892006-10-03 01:13:48 -0700297 kallsyms_expand_symbol(get_symbol_offset(pos), namebuf);
Kyle McMartin7a74fc42007-05-30 02:43:16 -0400298 if (modname)
299 *modname = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 return namebuf;
301 }
302
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700303 /* See if it's in a module. */
Rusty Russell6dd06c92008-01-29 17:13:22 -0500304 return module_address_lookup(addr, symbolsize, offset, modname,
305 namebuf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306}
307
Alexey Dobriyan9d65cb42007-05-08 00:28:43 -0700308int lookup_symbol_name(unsigned long addr, char *symname)
309{
310 symname[0] = '\0';
Tejun Heo9281ace2007-07-17 04:03:51 -0700311 symname[KSYM_NAME_LEN - 1] = '\0';
Alexey Dobriyan9d65cb42007-05-08 00:28:43 -0700312
313 if (is_ksym_addr(addr)) {
314 unsigned long pos;
315
316 pos = get_symbol_pos(addr, NULL, NULL);
317 /* Grab name */
318 kallsyms_expand_symbol(get_symbol_offset(pos), symname);
319 return 0;
320 }
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700321 /* See if it's in a module. */
Alexey Dobriyan9d65cb42007-05-08 00:28:43 -0700322 return lookup_module_symbol_name(addr, symname);
323}
324
Alexey Dobriyana5c43da2007-05-08 00:28:47 -0700325int lookup_symbol_attrs(unsigned long addr, unsigned long *size,
326 unsigned long *offset, char *modname, char *name)
327{
328 name[0] = '\0';
Tejun Heo9281ace2007-07-17 04:03:51 -0700329 name[KSYM_NAME_LEN - 1] = '\0';
Alexey Dobriyana5c43da2007-05-08 00:28:47 -0700330
331 if (is_ksym_addr(addr)) {
332 unsigned long pos;
333
334 pos = get_symbol_pos(addr, size, offset);
335 /* Grab name */
336 kallsyms_expand_symbol(get_symbol_offset(pos), name);
337 modname[0] = '\0';
338 return 0;
339 }
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700340 /* See if it's in a module. */
Alexey Dobriyana5c43da2007-05-08 00:28:47 -0700341 return lookup_module_symbol_attrs(addr, size, offset, modname, name);
342}
343
Robert Peterson42e38082007-04-30 15:09:48 -0700344/* Look up a kernel symbol and return it in a text buffer. */
Namhyung Kim0f77a8d2011-03-24 11:42:29 +0900345static int __sprint_symbol(char *buffer, unsigned long address,
346 int symbol_offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347{
348 char *modname;
349 const char *name;
350 unsigned long offset, size;
Hugh Dickins966c8c12008-11-19 15:36:36 -0800351 int len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352
Namhyung Kim0f77a8d2011-03-24 11:42:29 +0900353 address += symbol_offset;
Hugh Dickins966c8c12008-11-19 15:36:36 -0800354 name = kallsyms_lookup(address, &size, &offset, &modname, buffer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 if (!name)
Robert Peterson42e38082007-04-30 15:09:48 -0700356 return sprintf(buffer, "0x%lx", address);
Andrew Morton19769b72007-07-15 23:41:24 -0700357
Hugh Dickins966c8c12008-11-19 15:36:36 -0800358 if (name != buffer)
359 strcpy(buffer, name);
360 len = strlen(buffer);
361 buffer += len;
Namhyung Kim0f77a8d2011-03-24 11:42:29 +0900362 offset -= symbol_offset;
Hugh Dickins966c8c12008-11-19 15:36:36 -0800363
Andrew Morton19769b72007-07-15 23:41:24 -0700364 if (modname)
Namhyung Kim0f77a8d2011-03-24 11:42:29 +0900365 len += sprintf(buffer, "+%#lx/%#lx [%s]", offset, size, modname);
Andrew Morton19769b72007-07-15 23:41:24 -0700366 else
Hugh Dickins966c8c12008-11-19 15:36:36 -0800367 len += sprintf(buffer, "+%#lx/%#lx", offset, size);
368
369 return len;
Robert Peterson42e38082007-04-30 15:09:48 -0700370}
Namhyung Kim0f77a8d2011-03-24 11:42:29 +0900371
372/**
373 * sprint_symbol - Look up a kernel symbol and return it in a text buffer
374 * @buffer: buffer to be stored
375 * @address: address to lookup
376 *
377 * This function looks up a kernel symbol with @address and stores its name,
378 * offset, size and module name to @buffer if possible. If no symbol was found,
379 * just saves its @address as is.
380 *
381 * This function returns the number of bytes stored in @buffer.
382 */
383int sprint_symbol(char *buffer, unsigned long address)
384{
385 return __sprint_symbol(buffer, address, 0);
386}
387
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700388EXPORT_SYMBOL_GPL(sprint_symbol);
Robert Peterson42e38082007-04-30 15:09:48 -0700389
Namhyung Kim0f77a8d2011-03-24 11:42:29 +0900390/**
391 * sprint_backtrace - Look up a backtrace symbol and return it in a text buffer
392 * @buffer: buffer to be stored
393 * @address: address to lookup
394 *
395 * This function is for stack backtrace and does the same thing as
396 * sprint_symbol() but with modified/decreased @address. If there is a
397 * tail-call to the function marked "noreturn", gcc optimized out code after
398 * the call so that the stack-saved return address could point outside of the
399 * caller. This function ensures that kallsyms will find the original caller
400 * by decreasing @address.
401 *
402 * This function returns the number of bytes stored in @buffer.
403 */
404int sprint_backtrace(char *buffer, unsigned long address)
405{
406 return __sprint_symbol(buffer, address, -1);
407}
408
Robert Peterson42e38082007-04-30 15:09:48 -0700409/* Look up a kernel symbol and print it to the kernel messages. */
410void __print_symbol(const char *fmt, unsigned long address)
411{
412 char buffer[KSYM_SYMBOL_LEN];
413
414 sprint_symbol(buffer, address);
415
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 printk(fmt, buffer);
417}
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700418EXPORT_SYMBOL(__print_symbol);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
420/* To avoid using get_symbol_offset for every symbol, we carry prefix along. */
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700421struct kallsym_iter {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 loff_t pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 unsigned long value;
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700424 unsigned int nameoff; /* If iterating in core kernel symbols. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 char type;
Tejun Heo9281ace2007-07-17 04:03:51 -0700426 char name[KSYM_NAME_LEN];
427 char module_name[MODULE_NAME_LEN];
Alexey Dobriyanea078902007-05-08 00:28:39 -0700428 int exported;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429};
430
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431static int get_ksymbol_mod(struct kallsym_iter *iter)
432{
Alexey Dobriyanea078902007-05-08 00:28:39 -0700433 if (module_get_kallsym(iter->pos - kallsyms_num_syms, &iter->value,
434 &iter->type, iter->name, iter->module_name,
435 &iter->exported) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 return 1;
438}
439
440/* Returns space to next name. */
441static unsigned long get_ksymbol_core(struct kallsym_iter *iter)
442{
443 unsigned off = iter->nameoff;
444
Alexey Dobriyanea078902007-05-08 00:28:39 -0700445 iter->module_name[0] = '\0';
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 iter->value = kallsyms_addresses[iter->pos];
447
448 iter->type = kallsyms_get_symbol_type(off);
449
450 off = kallsyms_expand_symbol(off, iter->name);
451
452 return off - iter->nameoff;
453}
454
455static void reset_iter(struct kallsym_iter *iter, loff_t new_pos)
456{
457 iter->name[0] = '\0';
458 iter->nameoff = get_symbol_offset(new_pos);
459 iter->pos = new_pos;
460}
461
462/* Returns false if pos at or past end of file. */
463static int update_iter(struct kallsym_iter *iter, loff_t pos)
464{
465 /* Module symbols can be accessed randomly. */
466 if (pos >= kallsyms_num_syms) {
467 iter->pos = pos;
468 return get_ksymbol_mod(iter);
469 }
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700470
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 /* If we're not on the desired position, reset to new position. */
472 if (pos != iter->pos)
473 reset_iter(iter, pos);
474
475 iter->nameoff += get_ksymbol_core(iter);
476 iter->pos++;
477
478 return 1;
479}
480
481static void *s_next(struct seq_file *m, void *p, loff_t *pos)
482{
483 (*pos)++;
484
485 if (!update_iter(m->private, *pos))
486 return NULL;
487 return p;
488}
489
490static void *s_start(struct seq_file *m, loff_t *pos)
491{
492 if (!update_iter(m->private, *pos))
493 return NULL;
494 return m->private;
495}
496
497static void s_stop(struct seq_file *m, void *p)
498{
499}
500
501static int s_show(struct seq_file *m, void *p)
502{
503 struct kallsym_iter *iter = m->private;
504
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700505 /* Some debugging symbols have no name. Ignore them. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 if (!iter->name[0])
507 return 0;
508
Alexey Dobriyanea078902007-05-08 00:28:39 -0700509 if (iter->module_name[0]) {
510 char type;
511
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700512 /*
513 * Label it "global" if it is exported,
514 * "local" if not exported.
515 */
Alexey Dobriyanea078902007-05-08 00:28:39 -0700516 type = iter->exported ? toupper(iter->type) :
517 tolower(iter->type);
Kees Cook9f36e2c2011-03-22 16:34:22 -0700518 seq_printf(m, "%pK %c %s\t[%s]\n", (void *)iter->value,
519 type, iter->name, iter->module_name);
Alexey Dobriyanea078902007-05-08 00:28:39 -0700520 } else
Kees Cook9f36e2c2011-03-22 16:34:22 -0700521 seq_printf(m, "%pK %c %s\n", (void *)iter->value,
522 iter->type, iter->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 return 0;
524}
525
Helge Deller15ad7cd2006-12-06 20:40:36 -0800526static const struct seq_operations kallsyms_op = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 .start = s_start,
528 .next = s_next,
529 .stop = s_stop,
530 .show = s_show
531};
532
533static int kallsyms_open(struct inode *inode, struct file *file)
534{
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700535 /*
536 * We keep iterator in m->private, since normal case is to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 * s_start from where we left off, so we avoid doing
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700538 * using get_symbol_offset for every symbol.
539 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 struct kallsym_iter *iter;
541 int ret;
542
543 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
544 if (!iter)
545 return -ENOMEM;
546 reset_iter(iter, 0);
547
548 ret = seq_open(file, &kallsyms_op);
549 if (ret == 0)
550 ((struct seq_file *)file->private_data)->private = iter;
551 else
552 kfree(iter);
553 return ret;
554}
555
Jason Wessel67fc4e02010-05-20 21:04:21 -0500556#ifdef CONFIG_KGDB_KDB
557const char *kdb_walk_kallsyms(loff_t *pos)
558{
559 static struct kallsym_iter kdb_walk_kallsyms_iter;
560 if (*pos == 0) {
561 memset(&kdb_walk_kallsyms_iter, 0,
562 sizeof(kdb_walk_kallsyms_iter));
563 reset_iter(&kdb_walk_kallsyms_iter, 0);
564 }
565 while (1) {
566 if (!update_iter(&kdb_walk_kallsyms_iter, *pos))
567 return NULL;
568 ++*pos;
569 /* Some debugging symbols have no name. Ignore them. */
570 if (kdb_walk_kallsyms_iter.name[0])
571 return kdb_walk_kallsyms_iter.name;
572 }
573}
574#endif /* CONFIG_KGDB_KDB */
575
Helge Deller15ad7cd2006-12-06 20:40:36 -0800576static const struct file_operations kallsyms_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 .open = kallsyms_open,
578 .read = seq_read,
579 .llseek = seq_lseek,
Martin Peschke5a0c6a02007-05-08 00:29:25 -0700580 .release = seq_release_private,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581};
582
583static int __init kallsyms_init(void)
584{
Linus Torvalds33e0d572010-11-19 11:54:40 -0800585 proc_create("kallsyms", 0444, NULL, &kallsyms_operations);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 return 0;
587}
Manish Katiyarad6ccfa2009-05-12 13:43:35 -0700588device_initcall(kallsyms_init);