Re: [PATCH] ALSA: core: Increase the name array size for debugfs directory name

From: Arnd Bergmann
Date: Tue Sep 12 2023 - 06:18:36 EST


On Tue, Sep 12, 2023, at 10:39, Peter Ujfalusi wrote:

> While the code is correct, we need to silence the compiler somehow.
> It could be done by limiting the range in sprintf like
> sprintf(name, "card%d", idx % SNDRV_CARDS);
> sprintf(name, "card%hhd", idx);
> etc
>
> These are too workaroundish. Increase the name array to 15 instead which
> looks better and only adds 7 bytes on stack.

It looks like we use the same string for kobject_set_name(), so
maybe this would work as well:

--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -278,9 +278,6 @@ static int snd_card_init(struct snd_card *card, struct device *parent,
size_t extra_size)
{
int err;
-#ifdef CONFIG_SND_DEBUG
- char name[8];
-#endif

if (extra_size > 0)
card->private_data = (char *)card + sizeof(struct snd_card);
@@ -364,8 +361,8 @@ static int snd_card_init(struct snd_card *card, struct device *parent,
}

#ifdef CONFIG_SND_DEBUG
- sprintf(name, "card%d", idx);
- card->debugfs_root = debugfs_create_dir(name, sound_debugfs_root);
+ card->debugfs_root = debugfs_create_dir(kobject_name(&card->card_dev.kobj),
+ sound_debugfs_root);
#endif
return 0;


Arnd