futex: remove the pointer math from double_unlock_hb, fix
Impact: fix double unlock crash
Thomas Gleixner noticed that the simplified double_unlock_hb()
became ... too unsophisticated: in the hb1 == hb2 case it will
do a double unlock.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Darren Hart <dvhltc@us.ibm.com>
LKML-Reference: <20090312221118.11146.68610.stgit@Aeon>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/futex.c b/kernel/futex.c
index 2331b73..6b50a02 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -659,7 +659,8 @@
double_unlock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2)
{
spin_unlock(&hb1->lock);
- spin_unlock(&hb2->lock);
+ if (hb1 != hb2)
+ spin_unlock(&hb2->lock);
}
/*