From d21255321c6af2fa14dc3c940f2da153d911a4f7 Mon Sep 17 00:00:00 2001
Message-Id: <d21255321c6af2fa14dc3c940f2da153d911a4f7.1594742967.git.zanussi@kernel.org>
In-Reply-To: <832f7d97d6b989a5b4860dd2dbec58ad6ad5ab81.1594742966.git.zanussi@kernel.org>
References: <832f7d97d6b989a5b4860dd2dbec58ad6ad5ab81.1594742966.git.zanussi@kernel.org>
From: Scott Wood <swood@redhat.com>
Date: Sat, 27 Jul 2019 00:56:32 -0500
Subject: [PATCH 299/329] sched: __set_cpus_allowed_ptr: Check cpus_mask, not
 cpus_ptr
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.132-rt59.tar.xz

[ 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 <swood@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 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 593aa5c2f394..c2aebfab8556 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);
-- 
2.17.1

