[PATCH] workqueue: Remove duplicate worqueue attributes allocation

From: Catalin Marinas
Date: Wed Sep 06 2023 - 13:40:17 EST


Commit 84193c07105c ("workqueue: Generalize unbound CPU pods")
inadvertently introduced another call to alloc_workqueue_attrs()
overriding the pointer returned by a previous alloc_workqueue_attrs() a
few lines up in workqueue_init_early(). This leads to a kmemleak report:

unreferenced object 0xffff000040015000 (size 96):
comm "swapper/0", pid 0, jiffies 4294892296 (age 163.956s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 03 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<000000004cec0d50>] __kmem_cache_alloc_node+0x1c4/0x288
[<0000000083361c2a>] kmalloc_trace+0x20/0x2c
[<000000005ca61f11>] workqueue_init_early+0xe4/0x538
[<000000004e6ea358>] start_kernel+0x23c/0x5ec
[<00000000aea9761e>] __primary_switched+0xbc/0xc4

Remove the first allocation.

Fixes: 84193c07105c ("workqueue: Generalize unbound CPU pods")
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
---

I've seen this mentioned by Sandeep as well but I couldn't find a patch,
so here it is.

https://lore.kernel.org/r/CAB=BE-S=cxewXu7nqJY1DC5w9Bapar_C0cTjpZOQ-Qd5GGwYyw@xxxxxxxxxxxxxx/

kernel/workqueue.c | 3 ---
1 file changed, 3 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index c85825e17df8..43ab8399b72b 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -6524,9 +6524,6 @@ void __init workqueue_init_early(void)

pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);

- wq_update_pod_attrs_buf = alloc_workqueue_attrs();
- BUG_ON(!wq_update_pod_attrs_buf);
-
/* initialize WQ_AFFN_SYSTEM pods */
pt->pod_cpus = kcalloc(1, sizeof(pt->pod_cpus[0]), GFP_KERNEL);
pt->pod_node = kcalloc(1, sizeof(pt->pod_node[0]), GFP_KERNEL);