This is a note to let you know that I've just added the patch titled
workqueue: Don't call cpumask_test_cpu() with -1 CPU in wq_update_node_max_active()
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
workqueue-don-t-call-cpumask_test_cpu-with-1-cpu-in-.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e7538d7f19aafa6680f69cfe66b8dbc9990d853f
Author: Tejun Heo <tj@xxxxxxxxxx>
Date: Tue Jan 30 18:55:55 2024 -1000
workqueue: Don't call cpumask_test_cpu() with -1 CPU in wq_update_node_max_active()
[ Upstream commit 15930da42f8981dc42c19038042947b475b19f47 ]
For wq_update_node_max_active(), @off_cpu of -1 indicates that no CPU is
going down. The function was incorrectly calling cpumask_test_cpu() with -1
CPU leading to oopses like the following on some archs:
Unable to handle kernel paging request at virtual address ffff0002100296e0
..
pc : wq_update_node_max_active+0x50/0x1fc
lr : wq_update_node_max_active+0x1f0/0x1fc
...
Call trace:
wq_update_node_max_active+0x50/0x1fc
apply_wqattrs_commit+0xf0/0x114
apply_workqueue_attrs_locked+0x58/0xa0
alloc_workqueue+0x5ac/0x774
workqueue_init_early+0x460/0x540
start_kernel+0x258/0x684
__primary_switched+0xb8/0xc0
Code: 9100a273 35000d01 53067f00 d0016dc1 (f8607a60)
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Attempted to kill the idle task!
---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---
Fix it.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Tested-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/91eacde0-df99-4d5c-a980-91046f66e612@xxxxxxxxxxx
Fixes: 5797b1c18919 ("workqueue: Implement system-wide nr_active enforcement for unbound workqueues")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index b2975e44dffa9..7d231bbd16593 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1500,7 +1500,7 @@ static void wq_update_node_max_active(struct workqueue_struct *wq, int off_cpu)
lockdep_assert_held(&wq->mutex);
- if (!cpumask_test_cpu(off_cpu, effective))
+ if (off_cpu >= 0 && !cpumask_test_cpu(off_cpu, effective))
off_cpu = -1;
total_cpus = cpumask_weight_and(effective, cpu_online_mask);
