Commit a1565aa4 authored Feb 26, 2021 by Davidlohr Bueso Committed by Thomas Gleixner Mar 11, 2021

kernel/futex: Make futex_wait_requeue_pi() only call fixup_owner()



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

parent 9a4b99fc

kernel/futex.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -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. */
		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.
		* Check if the requeue code acquired the second futex for us and do
		* any pertinent fixup.
		*/
		if (!q.rt_waiter) {
		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.