From 1128ed7e1dd0f3d9eec6a9ae41ca903b150ef454 Mon Sep 17 00:00:00 2001 From: Scott Wood Date: Wed, 17 Jun 2020 14:17:42 +0200 Subject: [PATCH] sched/core: Check cpus_mask, not cpus_ptr in __set_cpus_allowed_ptr(), to fix mask corruption [ Upstream commit fd844ba9ae59b51e34e77105d79f8eca780b3bd6 ] This function is concerned with the long-term CPU mask, not the transitory mask the task might have while migrate disabled. Before this patch, if a task was migrate-disabled at the time __set_cpus_allowed_ptr() was called, and the new mask happened to be equal to the CPU that the task was running on, then the mask update would be lost. Signed-off-by: Scott Wood Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lkml.kernel.org/r/20200617121742.cpxppyi7twxmpin7@linutronix.de Signed-off-by: Sasha Levin --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 7238ef445daf..8b3e99d095ae 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1649,7 +1649,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, goto out; } - if (cpumask_equal(p->cpus_ptr, new_mask)) + if (cpumask_equal(&p->cpus_mask, new_mask)) goto out; dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask);