[PATCH 4.14 074/242] sched: Reenable interrupts in do_sched_yield()

From: Greg Kroah-Hartman
Date: Mon Dec 28 2020 - 11:23:32 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

[ Upstream commit 345a957fcc95630bf5535d7668a59ed983eb49a7 ]

do_sched_yield() invokes schedule() with interrupts disabled which is
not allowed. This goes back to the pre git era to commit a6efb709806c
("[PATCH] irqlock patch 2.5.27-H6") in the history tree.

Reenable interrupts and remove the misleading comment which "explains" it.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/87r1pt7y5c.fsf@xxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
kernel/sched/core.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c5599174e7450..7cedada731c1b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4826,12 +4826,8 @@ SYSCALL_DEFINE0(sched_yield)
schedstat_inc(rq->yld_count);
current->sched_class->yield_task(rq);

- /*
- * Since we are going to call schedule() anyway, there's
- * no need to preempt or enable interrupts:
- */
preempt_disable();
- rq_unlock(rq, &rf);
+ rq_unlock_irq(rq, &rf);
sched_preempt_enable_no_resched();

schedule();
--
2.27.0