diff options
author | Alexey Dobriyan <adobriyan@sw.ru> | 2007-05-08 03:28:43 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 14:15:08 -0400 |
commit | 9d65cb4a1718a072898c7a57a3bc61b2dc4bcd4d (patch) | |
tree | 9e3fd1c9e61e8ed16959d115a9a3f6f7eb0bbf21 /kernel/module.c | |
parent | ffb45122766db220d0bf3d01848d575fbbcb6430 (diff) |
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 bf4dccadf7b..3da76ad32d7 100644 --- a/kernel/module.c +++ b/kernel/module.c | |||
@@ -2126,6 +2126,29 @@ const char *module_address_lookup(unsigned long addr, | |||
2126 | return NULL; | 2126 | return NULL; |
2127 | } | 2127 | } |
2128 | 2128 | ||
2129 | int lookup_module_symbol_name(unsigned long addr, char *symname) | ||
2130 | { | ||
2131 | struct module *mod; | ||
2132 | |||
2133 | mutex_lock(&module_mutex); | ||
2134 | list_for_each_entry(mod, &modules, list) { | ||
2135 | if (within(addr, mod->module_init, mod->init_size) || | ||
2136 | within(addr, mod->module_core, mod->core_size)) { | ||
2137 | const char *sym; | ||
2138 | |||
2139 | sym = get_ksymbol(mod, addr, NULL, NULL); | ||
2140 | if (!sym) | ||
2141 | goto out; | ||
2142 | strlcpy(symname, sym, KSYM_NAME_LEN + 1); | ||
2143 | mutex_unlock(&module_mutex); | ||
2144 | return 0; | ||
2145 | } | ||
2146 | } | ||
2147 | out: | ||
2148 | mutex_unlock(&module_mutex); | ||
2149 | return -ERANGE; | ||
2150 | } | ||
2151 | |||
2129 | int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, | 2152 | int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, |
2130 | char *name, char *module_name, int *exported) | 2153 | char *name, char *module_name, int *exported) |
2131 | { | 2154 | { |