From df14b7f9efcda35e59bb6f50351aac25c50f6e24 Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Fri, 3 Feb 2023 13:18:49 -0500 Subject: [PATCH] sched/core: Fix a missed update of user_cpus_ptr Since commit 8f9ea86fdf99 ("sched: Always preserve the user requested cpumask"), a successful call to sched_setaffinity() should always save the user requested cpu affinity mask in a task's user_cpus_ptr. However, when the given cpu mask is the same as the current one, user_cpus_ptr is not updated. Fix this by saving the user mask in this case too. Fixes: 8f9ea86fdf99 ("sched: Always preserve the user requested cpumask") Signed-off-by: Waiman Long Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20230203181849.221943-1-longman@redhat.com --- kernel/sched/core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e838feb6adc5..2a4918a1faa9 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2951,8 +2951,11 @@ static int __set_cpus_allowed_ptr_locked(struct task_struct *p, } if (!(ctx->flags & SCA_MIGRATE_ENABLE)) { - if (cpumask_equal(&p->cpus_mask, ctx->new_mask)) + if (cpumask_equal(&p->cpus_mask, ctx->new_mask)) { + if (ctx->flags & SCA_USER) + swap(p->user_cpus_ptr, ctx->user_mask); goto out; + } if (WARN_ON_ONCE(p == current && is_migration_disabled(p) &&