diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2017-04-07 09:04:07 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-04-14 10:30:07 +0200 |
| commit | 94ffac5d847cfd790bb37b7cef1cad803743985e (patch) | |
| tree | 5d2af8a51d49a4d4a33f967ddd2cdf29e936294d | |
| parent | futex: Avoid freeing an active timer (diff) | |
| download | linux-94ffac5d847cfd790bb37b7cef1cad803743985e.tar.xz linux-94ffac5d847cfd790bb37b7cef1cad803743985e.zip | |
futex: Fix small (and harmless looking) inconsistencies
During (post-commit) review Darren spotted a few minor things. One
(harmless AFAICT) type inconsistency and a comment that wasn't as
clear as hoped.
Reported-by: Darren Hart (VMWare) <dvhart@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | kernel/futex.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 7ac167683c9f..ede2f1ef8511 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1025,7 +1025,8 @@ static int attach_to_pi_state(u32 __user *uaddr, u32 uval, struct futex_pi_state **ps) { pid_t pid = uval & FUTEX_TID_MASK; - int ret, uval2; + u32 uval2; + int ret; /* * Userspace might have messed up non-PI and PI futexes [3] @@ -1441,6 +1442,11 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_ if (ret) goto out_unlock; + /* + * This is a point of no return; once we modify the uval there is no + * going back and subsequent operations must not fail. + */ + raw_spin_lock(&pi_state->owner->pi_lock); WARN_ON(list_empty(&pi_state->list)); list_del_init(&pi_state->list); @@ -1452,9 +1458,6 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_ pi_state->owner = new_owner; raw_spin_unlock(&new_owner->pi_lock); - /* - * We've updated the uservalue, this unlock cannot fail. - */ postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q); out_unlock: |