sched/core: Fix a missed update of user_cpus_ptr

Since commit 8f9ea86 ("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: 8f9ea86 ("sched: Always preserve the user requested cpumask") Signed-off-by: Waiman Long <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
frank-w · Feb 13, 2023 · df14b7f · df14b7f
1 parent eedeb78
commit df14b7f
Showing 1 changed file with 4 additions and 1 deletion.
diff --git 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) &&