From: Jean-Philippe Brucker jean-philippe.brucker@arm.com
[ Upstream commit 92e074acf6f7694e96204265eb18ac113f546e80 ]
Since commit 85f1abe0019f ("kthread, sched/wait: Fix kthread_parkme() completion issue"), kthreads that are bound to a CPU must be parked before being stopped. At the moment the PSCI checker calls kthread_stop() directly on the suspend kthread, which triggers the following warning:
[ 6.068288] WARNING: CPU: 1 PID: 1 at kernel/kthread.c:398 __kthread_bind_mask+0x20/0x78 ... [ 6.190151] Call trace: [ 6.192566] __kthread_bind_mask+0x20/0x78 [ 6.196615] kthread_unpark+0x74/0x80 [ 6.200235] kthread_stop+0x44/0x1d8 [ 6.203769] psci_checker+0x3bc/0x484 [ 6.207389] do_one_initcall+0x48/0x260 [ 6.211180] kernel_init_freeable+0x2c8/0x368 [ 6.215488] kernel_init+0x10/0x100 [ 6.218935] ret_from_fork+0x10/0x1c [ 6.222467] ---[ end trace e05e22863d043cd3 ]---
kthread_unpark() tries to bind the thread to its CPU and aborts with a WARN() if the thread wasn't in TASK_PARKED state. Park the kthreads before stopping them.
Fixes: 85f1abe0019f ("kthread, sched/wait: Fix kthread_parkme() completion issue") Signed-off-by: Jean-Philippe Brucker jean-philippe.brucker@arm.com Reviewed-by: Sudeep Holla sudeep.holla@arm.com Acked-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Signed-off-by: Olof Johansson olof@lixom.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/firmware/psci_checker.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/firmware/psci_checker.c b/drivers/firmware/psci_checker.c index 346943657962..cbd53cb1b2d4 100644 --- a/drivers/firmware/psci_checker.c +++ b/drivers/firmware/psci_checker.c @@ -366,16 +366,16 @@ static int suspend_test_thread(void *arg) for (;;) { /* Needs to be set first to avoid missing a wakeup. */ set_current_state(TASK_INTERRUPTIBLE); - if (kthread_should_stop()) { - __set_current_state(TASK_RUNNING); + if (kthread_should_park()) break; - } schedule(); }
pr_info("CPU %d suspend test results: success %d, shallow states %d, errors %d\n", cpu, nb_suspend, nb_shallow_sleep, nb_err);
+ kthread_parkme(); + return nb_err; }
@@ -440,8 +440,10 @@ static int suspend_tests(void)
/* Stop and destroy all threads, get return status. */ - for (i = 0; i < nb_threads; ++i) + for (i = 0; i < nb_threads; ++i) { + err += kthread_park(threads[i]); err += kthread_stop(threads[i]); + } out: cpuidle_resume_and_unlock(); kfree(threads);