[RFC PATCH 03/10] sched: snapshot thread flags

[Mark Rutland]

Some thread flags can be set remotely, and so even when IRQs are
disabled, the flags can change under our feet. Generally this is
unlikely to cause a problem in practice, but it is somewhat unsound, and
KCSAN will legitimately warn that there is a data race.

To avoid such issues, we should snapshot the flags prior to using them.
Let's use the new helpers to do so in the common sched code.

Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Juri Lelli <juri.lelli@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
---
 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 5226cc26a095..7183c2f8abac 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7364,7 +7364,7 @@ void sched_show_task(struct task_struct *p)
 	rcu_read_unlock();
 	pr_cont(" stack:%5lu pid:%5d ppid:%6d flags:0x%08lx\n",
 		free, task_pid_nr(p), ppid,
-		(unsigned long)task_thread_info(p)->flags);
+		read_task_thread_flags(p));
 
 	print_worker_info(KERN_INFO, p);
 	print_stop_info(KERN_INFO, p);
-- 
2.11.0