[PATCH] ALSA: synth: Save a few bytes of memory when registering a 'snd_emux'

[PATCH] ALSA: synth: Save a few bytes of memory when registering a 'snd_emux'

[Christophe JAILLET]

snd_emux_register() calls pass a string literal as the 'name' parameter.

So kstrdup_const() can be used instead of kfree() to avoid a memory
allocation in such cases.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 include/sound/emux_synth.h | 2 +-
 sound/synth/emux/emux.c    | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/sound/emux_synth.h b/include/sound/emux_synth.h
index 1cc530434b97..3f7f365ed248 100644
--- a/include/sound/emux_synth.h
+++ b/include/sound/emux_synth.h
@@ -103,7 +103,7 @@ struct snd_emux {
 	int ports[SNDRV_EMUX_MAX_PORTS];	/* The ports for this device */
 	struct snd_emux_port *portptrs[SNDRV_EMUX_MAX_PORTS];
 	int used;	/* use counter */
-	char *name;	/* name of the device (internal) */
+	const char *name;	/* name of the device (internal) */
 	struct snd_rawmidi **vmidi;
 	struct timer_list tlist;	/* for pending note-offs */
 	int timer_active;
diff --git a/sound/synth/emux/emux.c b/sound/synth/emux/emux.c
index 0006c3ddb51d..a82af9374852 100644
--- a/sound/synth/emux/emux.c
+++ b/sound/synth/emux/emux.c
@@ -85,7 +85,7 @@ int snd_emux_register(struct snd_emux *emu, struct snd_card *card, int index, ch
 		return -EINVAL;
 
 	emu->card = card;
-	emu->name = kstrdup(name, GFP_KERNEL);
+	emu->name = kstrdup_const(name, GFP_KERNEL);
 	emu->voices = kcalloc(emu->max_voices, sizeof(struct snd_emux_voice),
 			      GFP_KERNEL);
 	if (emu->name == NULL || emu->voices == NULL)
@@ -140,7 +140,7 @@ int snd_emux_free(struct snd_emux *emu)
 	snd_emux_delete_hwdep(emu);
 	snd_sf_free(emu->sflist);
 	kfree(emu->voices);
-	kfree(emu->name);
+	kfree_const(emu->name);
 	kfree(emu);
 	return 0;
 }
-- 
2.43.0

Re: [PATCH] ALSA: synth: Save a few bytes of memory when registering a 'snd_emux'

[Takashi Iwai]

On Sat, 20 Jan 2024 10:42:12 +0100,
Christophe JAILLET wrote:
> 
> snd_emux_register() calls pass a string literal as the 'name' parameter.
> 
> So kstrdup_const() can be used instead of kfree() to avoid a memory
> allocation in such cases.
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Thanks, applied now.


Takashi