1 // SPDX-License-Identifier: GPL-2.0-only
3 * kallsyms.c: in-kernel printing of symbolic oopses and stack traces.
5 * Rewritten and vastly simplified by Rusty Russell for in-kernel
7 * Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
11 * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com>
12 * Changed the compression method from stem compression to "table lookup"
13 * compression (see scripts/kallsyms.c for a more complete description)
15 #include <linux/kallsyms.h>
16 #include <linux/init.h>
17 #include <linux/seq_file.h>
19 #include <linux/kdb.h>
20 #include <linux/err.h>
21 #include <linux/proc_fs.h>
22 #include <linux/sched.h> /* for cond_resched */
23 #include <linux/ctype.h>
24 #include <linux/slab.h>
25 #include <linux/filter.h>
26 #include <linux/ftrace.h>
27 #include <linux/kprobes.h>
28 #include <linux/build_bug.h>
29 #include <linux/compiler.h>
30 #include <linux/module.h>
31 #include <linux/kernel.h>
32 #include <linux/bsearch.h>
33 #include <linux/btf_ids.h>
35 #include "kallsyms_internal.h"
38 * Expand a compressed symbol data into the resulting uncompressed string,
39 * if uncompressed string is too long (>= maxlen), it will be truncated,
40 * given the offset to where the symbol is in the compressed stream.
42 static unsigned int kallsyms_expand_symbol(unsigned int off
,
43 char *result
, size_t maxlen
)
45 int len
, skipped_first
= 0;
49 /* Get the compressed symbol length from the first symbol byte. */
50 data
= &kallsyms_names
[off
];
55 /* If MSB is 1, it is a "big" symbol, so needs an additional byte. */
56 if ((len
& 0x80) != 0) {
57 len
= (len
& 0x7F) | (*data
<< 7);
63 * Update the offset to return the offset for the next symbol on
64 * the compressed stream.
69 * For every byte on the compressed symbol data, copy the table
70 * entry for that byte.
73 tptr
= &kallsyms_token_table
[kallsyms_token_index
[*data
]];
94 /* Return to offset to the next symbol. */
99 * Get symbol type information. This is encoded as a single char at the
100 * beginning of the symbol name.
102 static char kallsyms_get_symbol_type(unsigned int off
)
105 * Get just the first code, look it up in the token table,
106 * and return the first char from this token.
108 return kallsyms_token_table
[kallsyms_token_index
[kallsyms_names
[off
+ 1]]];
113 * Find the offset on the compressed stream given and index in the
116 static unsigned int get_symbol_offset(unsigned long pos
)
122 * Use the closest marker we have. We have markers every 256 positions,
123 * so that should be close enough.
125 name
= &kallsyms_names
[kallsyms_markers
[pos
>> 8]];
128 * Sequentially scan all the symbols up to the point we're searching
129 * for. Every symbol is stored in a [<len>][<len> bytes of data] format,
130 * so we just need to add the len to the current pointer for every
131 * symbol we wish to skip.
133 for (i
= 0; i
< (pos
& 0xFF); i
++) {
137 * If MSB is 1, it is a "big" symbol, so we need to look into
138 * the next byte (and skip it, too).
140 if ((len
& 0x80) != 0)
141 len
= ((len
& 0x7F) | (name
[1] << 7)) + 1;
143 name
= name
+ len
+ 1;
146 return name
- kallsyms_names
;
149 unsigned long kallsyms_sym_address(int idx
)
151 if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE
))
152 return kallsyms_addresses
[idx
];
154 /* values are unsigned offsets if --absolute-percpu is not in effect */
155 if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLUTE_PERCPU
))
156 return kallsyms_relative_base
+ (u32
)kallsyms_offsets
[idx
];
158 /* ...otherwise, positive offsets are absolute values */
159 if (kallsyms_offsets
[idx
] >= 0)
160 return kallsyms_offsets
[idx
];
162 /* ...and negative offsets are relative to kallsyms_relative_base - 1 */
163 return kallsyms_relative_base
- 1 - kallsyms_offsets
[idx
];
166 static bool cleanup_symbol_name(char *s
)
170 if (!IS_ENABLED(CONFIG_LTO_CLANG
))
174 * LLVM appends various suffixes for local functions and variables that
175 * must be promoted to global scope as part of LTO. This can break
176 * hooking of static functions with kprobes. '.' is not a valid
177 * character in an identifier in C. Suffixes observed:
178 * - foo.llvm.[0-9a-f]+
181 res
= strchr(s
, '.');
190 static int compare_symbol_name(const char *name
, char *namebuf
)
194 ret
= strcmp(name
, namebuf
);
198 if (cleanup_symbol_name(namebuf
) && !strcmp(name
, namebuf
))
204 static unsigned int get_symbol_seq(int index
)
206 unsigned int i
, seq
= 0;
208 for (i
= 0; i
< 3; i
++)
209 seq
= (seq
<< 8) | kallsyms_seqs_of_names
[3 * index
+ i
];
214 static int kallsyms_lookup_names(const char *name
,
220 unsigned int seq
, off
;
221 char namebuf
[KSYM_NAME_LEN
];
224 high
= kallsyms_num_syms
- 1;
226 while (low
<= high
) {
227 mid
= low
+ (high
- low
) / 2;
228 seq
= get_symbol_seq(mid
);
229 off
= get_symbol_offset(seq
);
230 kallsyms_expand_symbol(off
, namebuf
, ARRAY_SIZE(namebuf
));
231 ret
= compare_symbol_name(name
, namebuf
);
245 seq
= get_symbol_seq(low
- 1);
246 off
= get_symbol_offset(seq
);
247 kallsyms_expand_symbol(off
, namebuf
, ARRAY_SIZE(namebuf
));
248 if (compare_symbol_name(name
, namebuf
))
256 while (high
< kallsyms_num_syms
- 1) {
257 seq
= get_symbol_seq(high
+ 1);
258 off
= get_symbol_offset(seq
);
259 kallsyms_expand_symbol(off
, namebuf
, ARRAY_SIZE(namebuf
));
260 if (compare_symbol_name(name
, namebuf
))
270 /* Lookup the address for this symbol. Returns 0 if not found. */
271 unsigned long kallsyms_lookup_name(const char *name
)
276 /* Skip the search for empty string. */
280 ret
= kallsyms_lookup_names(name
, &i
, NULL
);
282 return kallsyms_sym_address(get_symbol_seq(i
));
284 return module_kallsyms_lookup_name(name
);
288 * Iterate over all symbols in vmlinux. For symbols from modules use
289 * module_kallsyms_on_each_symbol instead.
291 int kallsyms_on_each_symbol(int (*fn
)(void *, const char *, unsigned long),
294 char namebuf
[KSYM_NAME_LEN
];
299 for (i
= 0, off
= 0; i
< kallsyms_num_syms
; i
++) {
300 off
= kallsyms_expand_symbol(off
, namebuf
, ARRAY_SIZE(namebuf
));
301 ret
= fn(data
, namebuf
, kallsyms_sym_address(i
));
309 int kallsyms_on_each_match_symbol(int (*fn
)(void *, unsigned long),
310 const char *name
, void *data
)
313 unsigned int i
, start
, end
;
315 ret
= kallsyms_lookup_names(name
, &start
, &end
);
319 for (i
= start
; !ret
&& i
<= end
; i
++) {
320 ret
= fn(data
, kallsyms_sym_address(get_symbol_seq(i
)));
327 static unsigned long get_symbol_pos(unsigned long addr
,
328 unsigned long *symbolsize
,
329 unsigned long *offset
)
331 unsigned long symbol_start
= 0, symbol_end
= 0;
332 unsigned long i
, low
, high
, mid
;
334 /* This kernel should never had been booted. */
335 if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE
))
336 BUG_ON(!kallsyms_addresses
);
338 BUG_ON(!kallsyms_offsets
);
340 /* Do a binary search on the sorted kallsyms_addresses array. */
342 high
= kallsyms_num_syms
;
344 while (high
- low
> 1) {
345 mid
= low
+ (high
- low
) / 2;
346 if (kallsyms_sym_address(mid
) <= addr
)
353 * Search for the first aliased symbol. Aliased
354 * symbols are symbols with the same address.
356 while (low
&& kallsyms_sym_address(low
-1) == kallsyms_sym_address(low
))
359 symbol_start
= kallsyms_sym_address(low
);
361 /* Search for next non-aliased symbol. */
362 for (i
= low
+ 1; i
< kallsyms_num_syms
; i
++) {
363 if (kallsyms_sym_address(i
) > symbol_start
) {
364 symbol_end
= kallsyms_sym_address(i
);
369 /* If we found no next symbol, we use the end of the section. */
371 if (is_kernel_inittext(addr
))
372 symbol_end
= (unsigned long)_einittext
;
373 else if (IS_ENABLED(CONFIG_KALLSYMS_ALL
))
374 symbol_end
= (unsigned long)_end
;
376 symbol_end
= (unsigned long)_etext
;
380 *symbolsize
= symbol_end
- symbol_start
;
382 *offset
= addr
- symbol_start
;
388 * Lookup an address but don't bother to find any names.
390 int kallsyms_lookup_size_offset(unsigned long addr
, unsigned long *symbolsize
,
391 unsigned long *offset
)
393 char namebuf
[KSYM_NAME_LEN
];
395 if (is_ksym_addr(addr
)) {
396 get_symbol_pos(addr
, symbolsize
, offset
);
399 return !!module_address_lookup(addr
, symbolsize
, offset
, NULL
, NULL
, namebuf
) ||
400 !!__bpf_address_lookup(addr
, symbolsize
, offset
, namebuf
);
403 static const char *kallsyms_lookup_buildid(unsigned long addr
,
404 unsigned long *symbolsize
,
405 unsigned long *offset
, char **modname
,
406 const unsigned char **modbuildid
, char *namebuf
)
410 namebuf
[KSYM_NAME_LEN
- 1] = 0;
413 if (is_ksym_addr(addr
)) {
416 pos
= get_symbol_pos(addr
, symbolsize
, offset
);
418 kallsyms_expand_symbol(get_symbol_offset(pos
),
419 namebuf
, KSYM_NAME_LEN
);
429 /* See if it's in a module or a BPF JITed image. */
430 ret
= module_address_lookup(addr
, symbolsize
, offset
,
431 modname
, modbuildid
, namebuf
);
433 ret
= bpf_address_lookup(addr
, symbolsize
,
434 offset
, modname
, namebuf
);
437 ret
= ftrace_mod_address_lookup(addr
, symbolsize
,
438 offset
, modname
, namebuf
);
441 cleanup_symbol_name(namebuf
);
447 * - modname is set to NULL if it's in the kernel.
448 * - We guarantee that the returned name is valid until we reschedule even if.
449 * It resides in a module.
450 * - We also guarantee that modname will be valid until rescheduled.
452 const char *kallsyms_lookup(unsigned long addr
,
453 unsigned long *symbolsize
,
454 unsigned long *offset
,
455 char **modname
, char *namebuf
)
457 return kallsyms_lookup_buildid(addr
, symbolsize
, offset
, modname
,
461 int lookup_symbol_name(unsigned long addr
, char *symname
)
466 symname
[KSYM_NAME_LEN
- 1] = '\0';
468 if (is_ksym_addr(addr
)) {
471 pos
= get_symbol_pos(addr
, NULL
, NULL
);
473 kallsyms_expand_symbol(get_symbol_offset(pos
),
474 symname
, KSYM_NAME_LEN
);
477 /* See if it's in a module. */
478 res
= lookup_module_symbol_name(addr
, symname
);
483 cleanup_symbol_name(symname
);
487 /* Look up a kernel symbol and return it in a text buffer. */
488 static int __sprint_symbol(char *buffer
, unsigned long address
,
489 int symbol_offset
, int add_offset
, int add_buildid
)
492 const unsigned char *buildid
;
494 unsigned long offset
, size
;
497 address
+= symbol_offset
;
498 name
= kallsyms_lookup_buildid(address
, &size
, &offset
, &modname
, &buildid
,
501 return sprintf(buffer
, "0x%lx", address
- symbol_offset
);
504 strcpy(buffer
, name
);
505 len
= strlen(buffer
);
506 offset
-= symbol_offset
;
509 len
+= sprintf(buffer
+ len
, "+%#lx/%#lx", offset
, size
);
512 len
+= sprintf(buffer
+ len
, " [%s", modname
);
513 #if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
514 if (add_buildid
&& buildid
) {
515 /* build ID should match length of sprintf */
516 #if IS_ENABLED(CONFIG_MODULES)
517 static_assert(sizeof(typeof_member(struct module
, build_id
)) == 20);
519 len
+= sprintf(buffer
+ len
, " %20phN", buildid
);
522 len
+= sprintf(buffer
+ len
, "]");
529 * sprint_symbol - Look up a kernel symbol and return it in a text buffer
530 * @buffer: buffer to be stored
531 * @address: address to lookup
533 * This function looks up a kernel symbol with @address and stores its name,
534 * offset, size and module name to @buffer if possible. If no symbol was found,
535 * just saves its @address as is.
537 * This function returns the number of bytes stored in @buffer.
539 int sprint_symbol(char *buffer
, unsigned long address
)
541 return __sprint_symbol(buffer
, address
, 0, 1, 0);
543 EXPORT_SYMBOL_GPL(sprint_symbol
);
546 * sprint_symbol_build_id - Look up a kernel symbol and return it in a text buffer
547 * @buffer: buffer to be stored
548 * @address: address to lookup
550 * This function looks up a kernel symbol with @address and stores its name,
551 * offset, size, module name and module build ID to @buffer if possible. If no
552 * symbol was found, just saves its @address as is.
554 * This function returns the number of bytes stored in @buffer.
556 int sprint_symbol_build_id(char *buffer
, unsigned long address
)
558 return __sprint_symbol(buffer
, address
, 0, 1, 1);
560 EXPORT_SYMBOL_GPL(sprint_symbol_build_id
);
563 * sprint_symbol_no_offset - Look up a kernel symbol and return it in a text buffer
564 * @buffer: buffer to be stored
565 * @address: address to lookup
567 * This function looks up a kernel symbol with @address and stores its name
568 * and module name to @buffer if possible. If no symbol was found, just saves
569 * its @address as is.
571 * This function returns the number of bytes stored in @buffer.
573 int sprint_symbol_no_offset(char *buffer
, unsigned long address
)
575 return __sprint_symbol(buffer
, address
, 0, 0, 0);
577 EXPORT_SYMBOL_GPL(sprint_symbol_no_offset
);
580 * sprint_backtrace - Look up a backtrace symbol and return it in a text buffer
581 * @buffer: buffer to be stored
582 * @address: address to lookup
584 * This function is for stack backtrace and does the same thing as
585 * sprint_symbol() but with modified/decreased @address. If there is a
586 * tail-call to the function marked "noreturn", gcc optimized out code after
587 * the call so that the stack-saved return address could point outside of the
588 * caller. This function ensures that kallsyms will find the original caller
589 * by decreasing @address.
591 * This function returns the number of bytes stored in @buffer.
593 int sprint_backtrace(char *buffer
, unsigned long address
)
595 return __sprint_symbol(buffer
, address
, -1, 1, 0);
599 * sprint_backtrace_build_id - Look up a backtrace symbol and return it in a text buffer
600 * @buffer: buffer to be stored
601 * @address: address to lookup
603 * This function is for stack backtrace and does the same thing as
604 * sprint_symbol() but with modified/decreased @address. If there is a
605 * tail-call to the function marked "noreturn", gcc optimized out code after
606 * the call so that the stack-saved return address could point outside of the
607 * caller. This function ensures that kallsyms will find the original caller
608 * by decreasing @address. This function also appends the module build ID to
609 * the @buffer if @address is within a kernel module.
611 * This function returns the number of bytes stored in @buffer.
613 int sprint_backtrace_build_id(char *buffer
, unsigned long address
)
615 return __sprint_symbol(buffer
, address
, -1, 1, 1);
618 /* To avoid using get_symbol_offset for every symbol, we carry prefix along. */
619 struct kallsym_iter
{
622 loff_t pos_ftrace_mod_end
;
625 unsigned int nameoff
; /* If iterating in core kernel symbols. */
627 char name
[KSYM_NAME_LEN
];
628 char module_name
[MODULE_NAME_LEN
];
633 static int get_ksymbol_mod(struct kallsym_iter
*iter
)
635 int ret
= module_get_kallsym(iter
->pos
- kallsyms_num_syms
,
636 &iter
->value
, &iter
->type
,
637 iter
->name
, iter
->module_name
,
640 iter
->pos_mod_end
= iter
->pos
;
648 * ftrace_mod_get_kallsym() may also get symbols for pages allocated for ftrace
649 * purposes. In that case "__builtin__ftrace" is used as a module name, even
650 * though "__builtin__ftrace" is not a module.
652 static int get_ksymbol_ftrace_mod(struct kallsym_iter
*iter
)
654 int ret
= ftrace_mod_get_kallsym(iter
->pos
- iter
->pos_mod_end
,
655 &iter
->value
, &iter
->type
,
656 iter
->name
, iter
->module_name
,
659 iter
->pos_ftrace_mod_end
= iter
->pos
;
666 static int get_ksymbol_bpf(struct kallsym_iter
*iter
)
670 strscpy(iter
->module_name
, "bpf", MODULE_NAME_LEN
);
672 ret
= bpf_get_kallsym(iter
->pos
- iter
->pos_ftrace_mod_end
,
673 &iter
->value
, &iter
->type
,
676 iter
->pos_bpf_end
= iter
->pos
;
684 * This uses "__builtin__kprobes" as a module name for symbols for pages
685 * allocated for kprobes' purposes, even though "__builtin__kprobes" is not a
688 static int get_ksymbol_kprobe(struct kallsym_iter
*iter
)
690 strscpy(iter
->module_name
, "__builtin__kprobes", MODULE_NAME_LEN
);
692 return kprobe_get_kallsym(iter
->pos
- iter
->pos_bpf_end
,
693 &iter
->value
, &iter
->type
,
694 iter
->name
) < 0 ? 0 : 1;
697 /* Returns space to next name. */
698 static unsigned long get_ksymbol_core(struct kallsym_iter
*iter
)
700 unsigned off
= iter
->nameoff
;
702 iter
->module_name
[0] = '\0';
703 iter
->value
= kallsyms_sym_address(iter
->pos
);
705 iter
->type
= kallsyms_get_symbol_type(off
);
707 off
= kallsyms_expand_symbol(off
, iter
->name
, ARRAY_SIZE(iter
->name
));
709 return off
- iter
->nameoff
;
712 static void reset_iter(struct kallsym_iter
*iter
, loff_t new_pos
)
714 iter
->name
[0] = '\0';
715 iter
->nameoff
= get_symbol_offset(new_pos
);
718 iter
->pos_mod_end
= 0;
719 iter
->pos_ftrace_mod_end
= 0;
720 iter
->pos_bpf_end
= 0;
725 * The end position (last + 1) of each additional kallsyms section is recorded
726 * in iter->pos_..._end as each section is added, and so can be used to
727 * determine which get_ksymbol_...() function to call next.
729 static int update_iter_mod(struct kallsym_iter
*iter
, loff_t pos
)
733 if ((!iter
->pos_mod_end
|| iter
->pos_mod_end
> pos
) &&
734 get_ksymbol_mod(iter
))
737 if ((!iter
->pos_ftrace_mod_end
|| iter
->pos_ftrace_mod_end
> pos
) &&
738 get_ksymbol_ftrace_mod(iter
))
741 if ((!iter
->pos_bpf_end
|| iter
->pos_bpf_end
> pos
) &&
742 get_ksymbol_bpf(iter
))
745 return get_ksymbol_kprobe(iter
);
748 /* Returns false if pos at or past end of file. */
749 static int update_iter(struct kallsym_iter
*iter
, loff_t pos
)
751 /* Module symbols can be accessed randomly. */
752 if (pos
>= kallsyms_num_syms
)
753 return update_iter_mod(iter
, pos
);
755 /* If we're not on the desired position, reset to new position. */
756 if (pos
!= iter
->pos
)
757 reset_iter(iter
, pos
);
759 iter
->nameoff
+= get_ksymbol_core(iter
);
765 static void *s_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
769 if (!update_iter(m
->private, *pos
))
774 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
776 if (!update_iter(m
->private, *pos
))
781 static void s_stop(struct seq_file
*m
, void *p
)
785 static int s_show(struct seq_file
*m
, void *p
)
788 struct kallsym_iter
*iter
= m
->private;
790 /* Some debugging symbols have no name. Ignore them. */
794 value
= iter
->show_value
? (void *)iter
->value
: NULL
;
796 if (iter
->module_name
[0]) {
800 * Label it "global" if it is exported,
801 * "local" if not exported.
803 type
= iter
->exported
? toupper(iter
->type
) :
805 seq_printf(m
, "%px %c %s\t[%s]\n", value
,
806 type
, iter
->name
, iter
->module_name
);
808 seq_printf(m
, "%px %c %s\n", value
,
809 iter
->type
, iter
->name
);
813 static const struct seq_operations kallsyms_op
= {
820 #ifdef CONFIG_BPF_SYSCALL
822 struct bpf_iter__ksym
{
823 __bpf_md_ptr(struct bpf_iter_meta
*, meta
);
824 __bpf_md_ptr(struct kallsym_iter
*, ksym
);
827 static int ksym_prog_seq_show(struct seq_file
*m
, bool in_stop
)
829 struct bpf_iter__ksym ctx
;
830 struct bpf_iter_meta meta
;
831 struct bpf_prog
*prog
;
834 prog
= bpf_iter_get_info(&meta
, in_stop
);
839 ctx
.ksym
= m
? m
->private : NULL
;
840 return bpf_iter_run_prog(prog
, &ctx
);
843 static int bpf_iter_ksym_seq_show(struct seq_file
*m
, void *p
)
845 return ksym_prog_seq_show(m
, false);
848 static void bpf_iter_ksym_seq_stop(struct seq_file
*m
, void *p
)
851 (void) ksym_prog_seq_show(m
, true);
856 static const struct seq_operations bpf_iter_ksym_ops
= {
859 .stop
= bpf_iter_ksym_seq_stop
,
860 .show
= bpf_iter_ksym_seq_show
,
863 static int bpf_iter_ksym_init(void *priv_data
, struct bpf_iter_aux_info
*aux
)
865 struct kallsym_iter
*iter
= priv_data
;
869 /* cache here as in kallsyms_open() case; use current process
870 * credentials to tell BPF iterators if values should be shown.
872 iter
->show_value
= kallsyms_show_value(current_cred());
877 DEFINE_BPF_ITER_FUNC(ksym
, struct bpf_iter_meta
*meta
, struct kallsym_iter
*ksym
)
879 static const struct bpf_iter_seq_info ksym_iter_seq_info
= {
880 .seq_ops
= &bpf_iter_ksym_ops
,
881 .init_seq_private
= bpf_iter_ksym_init
,
882 .fini_seq_private
= NULL
,
883 .seq_priv_size
= sizeof(struct kallsym_iter
),
886 static struct bpf_iter_reg ksym_iter_reg_info
= {
888 .feature
= BPF_ITER_RESCHED
,
889 .ctx_arg_info_size
= 1,
891 { offsetof(struct bpf_iter__ksym
, ksym
),
892 PTR_TO_BTF_ID_OR_NULL
},
894 .seq_info
= &ksym_iter_seq_info
,
897 BTF_ID_LIST(btf_ksym_iter_id
)
898 BTF_ID(struct, kallsym_iter
)
900 static int __init
bpf_ksym_iter_register(void)
902 ksym_iter_reg_info
.ctx_arg_info
[0].btf_id
= *btf_ksym_iter_id
;
903 return bpf_iter_reg_target(&ksym_iter_reg_info
);
906 late_initcall(bpf_ksym_iter_register
);
908 #endif /* CONFIG_BPF_SYSCALL */
910 static int kallsyms_open(struct inode
*inode
, struct file
*file
)
913 * We keep iterator in m->private, since normal case is to
914 * s_start from where we left off, so we avoid doing
915 * using get_symbol_offset for every symbol.
917 struct kallsym_iter
*iter
;
918 iter
= __seq_open_private(file
, &kallsyms_op
, sizeof(*iter
));
924 * Instead of checking this on every s_show() call, cache
925 * the result here at open time.
927 iter
->show_value
= kallsyms_show_value(file
->f_cred
);
931 #ifdef CONFIG_KGDB_KDB
932 const char *kdb_walk_kallsyms(loff_t
*pos
)
934 static struct kallsym_iter kdb_walk_kallsyms_iter
;
936 memset(&kdb_walk_kallsyms_iter
, 0,
937 sizeof(kdb_walk_kallsyms_iter
));
938 reset_iter(&kdb_walk_kallsyms_iter
, 0);
941 if (!update_iter(&kdb_walk_kallsyms_iter
, *pos
))
944 /* Some debugging symbols have no name. Ignore them. */
945 if (kdb_walk_kallsyms_iter
.name
[0])
946 return kdb_walk_kallsyms_iter
.name
;
949 #endif /* CONFIG_KGDB_KDB */
951 static const struct proc_ops kallsyms_proc_ops
= {
952 .proc_open
= kallsyms_open
,
953 .proc_read
= seq_read
,
954 .proc_lseek
= seq_lseek
,
955 .proc_release
= seq_release_private
,
958 static int __init
kallsyms_init(void)
960 proc_create("kallsyms", 0444, NULL
, &kallsyms_proc_ops
);
963 device_initcall(kallsyms_init
);