[PATCH] workqueue: fix -Wformat-truncation in create_worker

[PATCH] workqueue: fix -Wformat-truncation in create_worker

[Lucy Mielke]

Compiling with W=1 emitted the following warning
(Compiler: gcc (x86-64, ver. 13.2.1, .config: result of make allyesconfig,
"Treat warnings as errors" turned off):

kernel/workqueue.c:2188:54: warning: ‘%d’ directive output may be
	truncated writing between 1 and 10 bytes into a region of size
	between 5 and 14 [-Wformat-truncation=]
kernel/workqueue.c:2188:50: note: directive argument in the range
	[0, 2147483647]
kernel/workqueue.c:2188:17: note: ‘snprintf’ output between 4 and 23 bytes
	into a destination of size 16

setting "id_buf" to size 23 will silence the warning, since GCC
determines snprintf's output to be max. 23 bytes in line 2188.

Please let me know if there are any mistakes in my patch!

Signed-off-by: Lucy Mielke <lucymielke@icloud.com>
---
 kernel/workqueue.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ebe24a5e1435..d14fddd76f49 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2166,7 +2166,7 @@ static struct worker *create_worker(struct worker_pool *pool)
 {
 	struct worker *worker;
 	int id;
-	char id_buf[16];
+	char id_buf[23];
 
 	/* ID is needed to determine kthread name */
 	id = ida_alloc(&pool->worker_ida, GFP_KERNEL);
-- 
2.41.0

Re: [PATCH] workqueue: fix -Wformat-truncation in create_worker

[Tejun Heo]

On Mon, Oct 09, 2023 at 07:09:46PM +0200, Lucy Mielke wrote:
> Compiling with W=1 emitted the following warning
> (Compiler: gcc (x86-64, ver. 13.2.1, .config: result of make allyesconfig,
> "Treat warnings as errors" turned off):
> 
> kernel/workqueue.c:2188:54: warning: ‘%d’ directive output may be
> 	truncated writing between 1 and 10 bytes into a region of size
> 	between 5 and 14 [-Wformat-truncation=]
> kernel/workqueue.c:2188:50: note: directive argument in the range
> 	[0, 2147483647]
> kernel/workqueue.c:2188:17: note: ‘snprintf’ output between 4 and 23 bytes
> 	into a destination of size 16
> 
> setting "id_buf" to size 23 will silence the warning, since GCC
> determines snprintf's output to be max. 23 bytes in line 2188.
> 
> Please let me know if there are any mistakes in my patch!
> 
> Signed-off-by: Lucy Mielke <lucymielke@icloud.com>

Applied to wq/for-6.6-fixes.

Thanks.

-- 
tejun