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>
This commit is contained in:
Peter Zijlstra 2017-04-07 09:04:07 +02:00 committed by Ingo Molnar
parent 97181f9bd5
commit 94ffac5d84
1 changed files with 7 additions and 4 deletions

View File

@ -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: