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| 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 /kernel/module.c | |
| 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 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/kernel/module.c b/kernel/module.c index bf4dccadf7b8..3da76ad32d78 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2126,6 +2126,29 @@ const char *module_address_lookup(unsigned long addr, return NULL; } +int lookup_module_symbol_name(unsigned long addr, char *symname) +{ + struct module *mod; + + mutex_lock(&module_mutex); + list_for_each_entry(mod, &modules, list) { + if (within(addr, mod->module_init, mod->init_size) || + within(addr, mod->module_core, mod->core_size)) { + const char *sym; + + sym = get_ksymbol(mod, addr, NULL, NULL); + if (!sym) + goto out; + strlcpy(symname, sym, KSYM_NAME_LEN + 1); + mutex_unlock(&module_mutex); + return 0; + } + } +out: + mutex_unlock(&module_mutex); + return -ERANGE; +} + int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, char *name, char *module_name, int *exported) { |