diff options
| author | Alexey Dobriyan <adobriyan@sw.ru> | 2007-05-08 00:28:43 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 11:15:08 -0700 |
| commit | 9d65cb4a1718a072898c7a57a3bc61b2dc4bcd4d (patch) | |
| tree | 9e3fd1c9e61e8ed16959d115a9a3f6f7eb0bbf21 /kernel/kallsyms.c | |
| parent | ffb45122766db220d0bf3d01848d575fbbcb6430 (diff) | |
| download | lwn-9d65cb4a1718a072898c7a57a3bc61b2dc4bcd4d.tar.gz lwn-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/kallsyms.c')
| -rw-r--r-- | kernel/kallsyms.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index f66da025cb7f..4e2ec191a127 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -269,6 +269,23 @@ const char *kallsyms_lookup(unsigned long addr, return NULL; } +int lookup_symbol_name(unsigned long addr, char *symname) +{ + symname[0] = '\0'; + symname[KSYM_NAME_LEN] = '\0'; + + if (is_ksym_addr(addr)) { + unsigned long pos; + + pos = get_symbol_pos(addr, NULL, NULL); + /* Grab name */ + kallsyms_expand_symbol(get_symbol_offset(pos), symname); + return 0; + } + /* see if it's in a module */ + return lookup_module_symbol_name(addr, symname); +} + /* Look up a kernel symbol and return it in a text buffer. */ int sprint_symbol(char *buffer, unsigned long address) { |