From b0809d42d151925c4cff666379ae27eeaf7e554c Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@tuebingen.mpg.de>
Date: Fri, 2 Jan 2015 20:10:56 +0000
Subject: [PATCH] alsa: Avoid alloca().

It is not in POSIX.1-2001, and its use is discouraged. Fortunately,
the alsa library provides also variants which call ordinary malloc(),
so use these instead.
---
 alsa_mix.c   | 22 ++++++++++++++++------
 alsa_write.c | 19 +++++++++++++------
 2 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/alsa_mix.c b/alsa_mix.c
index 5a46963e..cad58af0 100644
--- a/alsa_mix.c
+++ b/alsa_mix.c
@@ -100,11 +100,13 @@ static bool channel_has_playback(snd_mixer_selem_channel_id_t chn,
 
 static char *alsa_mix_get_channels(struct mixer_handle *handle)
 {
+	int ret;
 	char *list = NULL;
 	snd_mixer_selem_id_t *sid;
 	snd_mixer_elem_t *elem;
 
-	snd_mixer_selem_id_alloca(&sid);
+	ret = snd_mixer_selem_id_malloc(&sid);
+	assert(ret >= 0);
 	elem = snd_mixer_first_elem(handle->mixer);
 	for (; elem; elem = snd_mixer_elem_next(elem)) {
 		char *tmp = list;
@@ -122,6 +124,7 @@ static char *alsa_mix_get_channels(struct mixer_handle *handle)
 			name);
 		free(tmp);
 	}
+	snd_mixer_selem_id_free(sid);
 	return list;
 }
 
@@ -133,7 +136,8 @@ static int alsa_mix_set_channel(struct mixer_handle *h,
 
 	if (!mixer_channel)
 		mixer_channel = "Master";
-	snd_mixer_selem_id_alloca(&sid);
+	ret = snd_mixer_selem_id_malloc(&sid);
+	assert(ret >= 0);
 	snd_mixer_selem_id_set_index(sid, selem_id);
 	snd_mixer_selem_id_set_name(sid, mixer_channel);
 	h->elem = snd_mixer_find_selem(h->mixer, sid);
@@ -141,21 +145,27 @@ static int alsa_mix_set_channel(struct mixer_handle *h,
 		PARA_NOTICE_LOG("unable to find simple control '%s',%i\n",
 			snd_mixer_selem_id_get_name(sid),
 			snd_mixer_selem_id_get_index(sid));
-		return -E_BAD_CHANNEL;
+		ret = -E_BAD_CHANNEL;
+		goto out;
 	}
 	ret = snd_mixer_selem_get_playback_volume_range(h->elem,
 		&h->pmin, &h->pmax);
 	if (ret < 0) {
 		PARA_NOTICE_LOG("unable to get %s range (%s): %s\n",
 			mixer_channel, h->card, snd_strerror(ret));
-		return -E_ALSA_MIX_RANGE;
+		ret = -E_ALSA_MIX_RANGE;
+		goto out;
 	}
 	if (h->pmin >= h->pmax) {
 		PARA_NOTICE_LOG("alsa reported %s range %ld-%ld (%s)\n",
 			mixer_channel, h->pmin, h->pmax, h->card);
-		return -E_ALSA_MIX_RANGE;
+		ret = -E_ALSA_MIX_RANGE;
+		goto out;
 	}
-	return 1;
+	ret = 1;
+out:
+	snd_mixer_selem_id_free(sid);
+	return ret;
 }
 
 static int alsa_mix_get(struct mixer_handle *h)
diff --git a/alsa_write.c b/alsa_write.c
index b0b21f2b..63a7055b 100644
--- a/alsa_write.c
+++ b/alsa_write.c
@@ -74,8 +74,8 @@ static snd_pcm_format_t get_alsa_pcm_format(enum sample_format sf)
 static int alsa_init(struct private_alsa_write_data *pad,
 		struct alsa_write_args_info *conf)
 {
-	snd_pcm_hw_params_t *hwparams;
-	snd_pcm_sw_params_t *swparams;
+	snd_pcm_hw_params_t *hwparams = NULL;
+	snd_pcm_sw_params_t *swparams = NULL;
 	snd_pcm_uframes_t start_threshold, stop_threshold;
 	snd_pcm_uframes_t buffer_size, period_size;
 	snd_output_t *output_log;
@@ -89,7 +89,8 @@ static int alsa_init(struct private_alsa_write_data *pad,
 		SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
 	if (ret < 0)
 		goto fail;
-	snd_pcm_hw_params_alloca(&hwparams);
+	ret = snd_pcm_hw_params_malloc(&hwparams);
+	assert(ret >= 0);
 	msg = "Broken alsa configuration";
 	ret = snd_pcm_hw_params_any(pad->handle, hwparams);
 	if (ret < 0)
@@ -140,7 +141,8 @@ static int alsa_init(struct private_alsa_write_data *pad,
 		goto fail;
 
 	/* software parameter setup */
-	snd_pcm_sw_params_alloca(&swparams);
+	ret = snd_pcm_sw_params_malloc(&swparams);
+	assert(ret >= 0);
 	snd_pcm_sw_params_current(pad->handle, swparams);
 	snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
 	if (buffer_size < 1)
@@ -190,13 +192,18 @@ static int alsa_init(struct private_alsa_write_data *pad,
 		}
 		snd_output_close(output_log);
 	}
-	return 1;
+	ret = 1;
+	goto out;
 fail:
 	if (ret < 0)
 		PARA_ERROR_LOG("%s: %s\n", msg, snd_strerror(-ret));
 	else
 		PARA_ERROR_LOG("%s\n", msg);
-	return -E_ALSA;
+	ret = -E_ALSA;
+out:
+	snd_pcm_hw_params_free(hwparams);
+	snd_pcm_sw_params_free(swparams);
+	return ret;
 }
 
 static void alsa_write_pre_select(struct sched *s, void *context)
-- 
2.30.2