Commit 90621c40 authored Dec 29, 2008 by Darren Hart Committed by Ingo Molnar Jan 02, 2009

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>

parent 42d35d48

kernel/futex.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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: