From ade7956396d0e821097393bc4fe5773525f2634c Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 1 Aug 2022 18:56:35 +0200 Subject: [PATCH] ALSA: control-led: Replace sprintf() with sysfs_emit() For sysfs outputs, it's safer to use a new helper, sysfs_emit(), instead of the raw sprintf() & co. This patch replaces such sprintf() calls with sysfs_emit() while simplifying the open code in list_show(). Link: https://lore.kernel.org/r/20220801165639.26030-4-tiwai@suse.de Signed-off-by: Takashi Iwai --- sound/core/control_led.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) diff --git a/sound/core/control_led.c b/sound/core/control_led.c index 207828f30983..f975cc85772b 100644 --- a/sound/core/control_led.c +++ b/sound/core/control_led.c @@ -405,7 +405,7 @@ static ssize_t mode_show(struct device *dev, case MODE_ON: str = "on"; break; case MODE_OFF: str = "off"; break; } - return sprintf(buf, "%s\n", str); + return sysfs_emit(buf, "%s\n", str); } static ssize_t mode_store(struct device *dev, @@ -443,7 +443,7 @@ static ssize_t brightness_show(struct device *dev, { struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev); - return sprintf(buf, "%u\n", ledtrig_audio_get(led->trigger_type)); + return sysfs_emit(buf, "%u\n", ledtrig_audio_get(led->trigger_type)); } static DEVICE_ATTR_RW(mode); @@ -618,8 +618,7 @@ static ssize_t list_show(struct device *dev, struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev); struct snd_card *card; struct snd_ctl_led_ctl *lctl; - char *buf2 = buf; - size_t l; + size_t l = 0; card = snd_card_ref(led_card->number); if (!card) @@ -627,23 +626,19 @@ static ssize_t list_show(struct device *dev, down_read(&card->controls_rwsem); mutex_lock(&snd_ctl_led_mutex); if (snd_ctl_led_card_valid[led_card->number]) { - list_for_each_entry(lctl, &led_card->led->controls, list) - if (lctl->card == card) { - if (buf2 - buf > PAGE_SIZE - 16) - break; - if (buf2 != buf) - *buf2++ = ' '; - l = scnprintf(buf2, 15, "%u", - lctl->kctl->id.numid + - lctl->index_offset); - buf2[l] = '\0'; - buf2 += l + 1; - } + list_for_each_entry(lctl, &led_card->led->controls, list) { + if (lctl->card != card) + continue; + if (l) + l += sysfs_emit_at(buf, l, " "); + l += sysfs_emit_at(buf, l, "%u", + lctl->kctl->id.numid + lctl->index_offset); + } } mutex_unlock(&snd_ctl_led_mutex); up_read(&card->controls_rwsem); snd_card_unref(card); - return buf2 - buf; + return l; } static DEVICE_ATTR_WO(attach);