futex: catch certain assymetric (get|put)_futex_key calls

Impact: add debug check

Following up on my previous key reference accounting patches, this patch
will catch puts on keys that haven't been "got".  This won't catch nested
get/put mismatches though.

Build and boot tested, with minimal desktop activity and a run of the
open_posix_testsuite in LTP for testing.  No warnings logged.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Darren Hart 2008-12-29 19:43:21 -08:00 committed by Ingo Molnar
parent 42d35d48ce
commit 90621c40cc

View file

@ -170,8 +170,11 @@ static void get_futex_key_refs(union futex_key *key)
*/
static void drop_futex_key_refs(union futex_key *key)
{
if (!key->both.ptr)
if (!key->both.ptr) {
/* If we're here then we tried to put a key we failed to get */
WARN_ON_ONCE(1);
return;
}
switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
case FUT_OFF_INODE: