[PATCH] workqueue: Fix incorrect error return value in apply_workqueue_attrs_locked

[Ye Liu <ye.liu@linux.dev>]

From: Ye Liu <liuye@kylinos.cn>

Commit 84193c07105c ("workqueue: Generalize unbound CPU pods") introduced
a change that caused apply_workqueue_attrs_locked() to return error
pointers using PTR_ERR() on failure instead of a negative error code.
This caused unexpected behavior in functions that rely on the return value
of apply_workqueue_attrs_locked, such as alloc_and_link_pwqs().

Specifically, alloc_and_link_pwqs() expects apply_workqueue_attrs_locked()
to return 0 on success and a negative error code on failure. However,
returning PTR_ERR(ctx) instead of -ENOMEM led to incorrect error handling
in __alloc_workqueue, potentially causing system instability or crashes.

This patch ensures apply_workqueue_attrs_locked() returns a proper negative
error code (-ENOMEM) in case of failure, restoring expected behavior.

Fixes: 84193c07105c ("workqueue: Generalize unbound CPU pods")
Signed-off-by: Ye Liu <liuye@kylinos.cn>
---
 kernel/workqueue.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index bfe030b443e2..8ba679d9b566 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -5363,7 +5363,7 @@ static int apply_workqueue_attrs_locked(struct workqueue_struct *wq,
 
 	ctx = apply_wqattrs_prepare(wq, attrs, wq_unbound_cpumask);
 	if (IS_ERR(ctx))
-		return PTR_ERR(ctx);
+		return -ENOMEM;
 
 	/* the ctx has been prepared successfully, let's commit it */
 	apply_wqattrs_commit(ctx);
-- 
2.25.1