From 59263b513c11398cd66a52d4c5b2b118ce1e0359 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 15 Feb 2012 12:08:34 +0100 Subject: [PATCH] futex: Cover all PI opcodes with cmpxchg enabled check Some of the newer futex PI opcodes do not check the cmpxchg enabled variable and call unconditionally into the handling functions. Cover all PI opcodes in a separate check. Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Cc: Peter Zijlstra Cc: Darren Hart --- kernel/futex.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/kernel/futex.c b/kernel/futex.c index ea87f4d2f455..4b1c4b6a339c 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2628,6 +2628,16 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, return -ENOSYS; } + switch (cmd) { + case FUTEX_LOCK_PI: + case FUTEX_UNLOCK_PI: + case FUTEX_TRYLOCK_PI: + case FUTEX_WAIT_REQUEUE_PI: + case FUTEX_CMP_REQUEUE_PI: + if (!futex_cmpxchg_enabled) + return -ENOSYS; + } + switch (cmd) { case FUTEX_WAIT: val3 = FUTEX_BITSET_MATCH_ANY; @@ -2649,16 +2659,13 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, ret = futex_wake_op(uaddr, flags, uaddr2, val, val2, val3); break; case FUTEX_LOCK_PI: - if (futex_cmpxchg_enabled) - ret = futex_lock_pi(uaddr, flags, val, timeout, 0); + ret = futex_lock_pi(uaddr, flags, val, timeout, 0); break; case FUTEX_UNLOCK_PI: - if (futex_cmpxchg_enabled) - ret = futex_unlock_pi(uaddr, flags); + ret = futex_unlock_pi(uaddr, flags); break; case FUTEX_TRYLOCK_PI: - if (futex_cmpxchg_enabled) - ret = futex_lock_pi(uaddr, flags, 0, timeout, 1); + ret = futex_lock_pi(uaddr, flags, 0, timeout, 1); break; case FUTEX_WAIT_REQUEUE_PI: val3 = FUTEX_BITSET_MATCH_ANY;