diff options
| author | Alexey Dobriyan <adobriyan@sw.ru> | 2007-05-08 09:28:43 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 20:15:08 +0200 |
| commit | 9d65cb4a1718a072898c7a57a3bc61b2dc4bcd4d (patch) | |
| tree | 9e3fd1c9e61e8ed16959d115a9a3f6f7eb0bbf21 /include | |
| parent | Simplify kallsyms_lookup() (diff) | |
| download | linux-9d65cb4a1718a072898c7a57a3bc61b2dc4bcd4d.tar.xz linux-9d65cb4a1718a072898c7a57a3bc61b2dc4bcd4d.zip | |
Fix race between cat /proc/*/wchan and rmmod et al
kallsyms_lookup() can go iterating over modules list unprotected which is OK
for emergency situations (oops), but not OK for regular stuff like
/proc/*/wchan.
Introduce lookup_symbol_name()/lookup_module_symbol_name() which copy symbol
name into caller-supplied buffer or return -ERANGE. All copying is done with
module_mutex held, so...
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/kallsyms.h | 7 | ||||
| -rw-r--r-- | include/linux/module.h | 6 |
2 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h index 3e3b92dabe3b..ae0117a95cfd 100644 --- a/include/linux/kallsyms.h +++ b/include/linux/kallsyms.h @@ -30,6 +30,8 @@ extern int sprint_symbol(char *buffer, unsigned long address); /* Look up a kernel symbol and print it to the kernel messages. */ extern void __print_symbol(const char *fmt, unsigned long address); +int lookup_symbol_name(unsigned long addr, char *symname); + #else /* !CONFIG_KALLSYMS */ static inline unsigned long kallsyms_lookup_name(const char *name) @@ -58,6 +60,11 @@ static inline int sprint_symbol(char *buffer, unsigned long addr) return 0; } +static inline int lookup_symbol_name(unsigned long addr, char *symname) +{ + return -ERANGE; +} + /* Stupid that this does nothing, but I didn't create this mess. */ #define __print_symbol(fmt, addr) #endif /*CONFIG_KALLSYMS*/ diff --git a/include/linux/module.h b/include/linux/module.h index 58d5a10cdf0d..099ae5932c68 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -454,6 +454,7 @@ const char *module_address_lookup(unsigned long addr, unsigned long *symbolsize, unsigned long *offset, char **modname); +int lookup_module_symbol_name(unsigned long addr, char *symname); /* For extable.c to search modules' exception tables. */ const struct exception_table_entry *search_module_extables(unsigned long addr); @@ -525,6 +526,11 @@ static inline const char *module_address_lookup(unsigned long addr, return NULL; } +static inline int lookup_module_symbol_name(unsigned long addr, char *symname) +{ + return -ERANGE; +} + static inline int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, char *name, char *module_name, int *exported) |