This is a note to let you know that I've just added the patch titled
padata: Disable BH when taking works lock on MT path
to the 6.9-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:
padata-disable-bh-when-taking-works-lock-on-mt-path.patch
and it can be found in the queue-6.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 244ea3a2bc70e57915195bb3947503f0eca4a3e2
Author: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Date: Wed Apr 3 17:36:18 2024 +0800
padata: Disable BH when taking works lock on MT path
[ Upstream commit 58329c4312031603bb1786b44265c26d5065fe72 ]
As the old padata code can execute in softirq context, disable
softirqs for the new padata_do_mutithreaded code too as otherwise
lockdep will get antsy.
Reported-by: syzbot+0cb5bb0f4bf9e79db3b3@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Acked-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/padata.c b/kernel/padata.c
index e3f639ff16707..53f4bc9127127 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -106,7 +106,7 @@ static int __init padata_work_alloc_mt(int nworks, void *data,
{
int i;
- spin_lock(&padata_works_lock);
+ spin_lock_bh(&padata_works_lock);
/* Start at 1 because the current task participates in the job. */
for (i = 1; i < nworks; ++i) {
struct padata_work *pw = padata_work_alloc();
@@ -116,7 +116,7 @@ static int __init padata_work_alloc_mt(int nworks, void *data,
padata_work_init(pw, padata_mt_helper, data, 0);
list_add(&pw->pw_list, head);
}
- spin_unlock(&padata_works_lock);
+ spin_unlock_bh(&padata_works_lock);
return i;
}
@@ -134,12 +134,12 @@ static void __init padata_works_free(struct list_head *works)
if (list_empty(works))
return;
- spin_lock(&padata_works_lock);
+ spin_lock_bh(&padata_works_lock);
list_for_each_entry_safe(cur, next, works, pw_list) {
list_del(&cur->pw_list);
padata_work_free(cur);
}
- spin_unlock(&padata_works_lock);
+ spin_unlock_bh(&padata_works_lock);
}
static void padata_parallel_worker(struct work_struct *parallel_work)
