From: Scott Wood Date: Sat, 27 Jul 2019 00:56:32 -0500 Subject: [PATCH 298/351] sched: __set_cpus_allowed_ptr: Check cpus_mask, not cpus_ptr Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=db7cc169d8ef63ea459c7fde68b248a2789e895a [ Upstream commit e5606fb7b042db634ed62b4dd733d62e050e468f ] 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: Steven Rostedt (VMware) --- 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 b5675306ebed..6fd462e18949 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1157,7 +1157,7 @@ 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);