kernel/futex: Make futex_wait_requeue_pi() only call fixup_owner()
authorDavidlohr Bueso <dave@stgolabs.net>
Fri, 26 Feb 2021 17:50:27 +0000 (09:50 -0800)
committerThomas Gleixner <tglx@linutronix.de>
Thu, 11 Mar 2021 18:19:17 +0000 (19:19 +0100)
A small cleanup that allows for fixup_pi_state_owner() only to be called
from fixup_owner(), and make requeue_pi uniformly call fixup_owner()
regardless of the state in which the fixup is actually needed. Of course
this makes the caller's first pi_state->owner != current check redundant,
but that should't really matter.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210226175029.50335-2-dave@stgolabs.net
kernel/futex.c

index db8002d..ee09995 100644 (file)
@@ -3241,15 +3241,14 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
         * reference count.
         */
 
-       /* Check if the requeue code acquired the second futex for us. */
+       /*
+        * Check if the requeue code acquired the second futex for us and do
+        * any pertinent fixup.
+        */
        if (!q.rt_waiter) {
-               /*
-                * Got the lock. We might not be the anticipated owner if we
-                * did a lock-steal - fix up the PI-state in that case.
-                */
                if (q.pi_state && (q.pi_state->owner != current)) {
                        spin_lock(q.lock_ptr);
-                       ret = fixup_pi_state_owner(uaddr2, &q, current);
+                       ret = fixup_owner(uaddr2, &q, true);
                        /*
                         * Drop the reference to the pi state which
                         * the requeue_pi() code acquired for us.