alsa/0029-topology-fix-the-unaligned-access.patch

From ab73253924ad8d46f94ab1212e0f05ebc2e3dcc5 Mon Sep 17 00:00:00 2001
From: Jaroslav Kysela <perex@perex.cz>
Date: Mon, 31 Aug 2020 14:27:26 +0200
Subject: [PATCH 29/32] topology: fix the unaligned access

Introduce unaligned_get32/put32 helpers to deal with the
packed structures.

Use the gcc __BYTE_ORDER__ defines for the endian checks.
It may be improved to support other compilation environment.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 src/topology/parser.c     |  6 ++----
 src/topology/pcm.c        | 26 ++++++++++++++------------
 src/topology/tplg_local.h | 13 +++++++++++++
 3 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/src/topology/parser.c b/src/topology/parser.c
index 436e48416a43..f34de01bdc53 100644
--- a/src/topology/parser.c
+++ b/src/topology/parser.c
@@ -427,10 +427,8 @@ void snd_tplg_verbose(snd_tplg_t *tplg, int verbose)
 
 static bool is_little_endian(void)
 {
-#ifdef __BYTE_ORDER
-	#if __BYTE_ORDER == __LITTLE_ENDIAN
-		return true;
-	#endif
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ && __SIZEOF_INT__ == 4
+	return true;
 #endif
 	return false;
 }
diff --git a/src/topology/pcm.c b/src/topology/pcm.c
index 5a54e1534c95..a60ba00d979a 100644
--- a/src/topology/pcm.c
+++ b/src/topology/pcm.c
@@ -376,19 +376,19 @@ static int split_rate(struct snd_soc_tplg_stream_caps *caps, char *str)
 	return 0;
 }
 
-static int parse_unsigned(snd_config_t *n, unsigned int *dst)
+static int parse_unsigned(snd_config_t *n, void *dst)
 {
 	int ival;
 
 	if (tplg_get_integer(n, &ival, 0) < 0)
 		return -EINVAL;
 
-	*dst = ival;
+	unaligned_put32(dst, ival);
 #if TPLG_DEBUG
 	{
 		const char *id;
 		if (snd_config_get_id(n, &id) >= 0)
-			tplg_dbg("\t\t%s: %d", id, *dst);
+			tplg_dbg("\t\t%s: %d", id, ival);
 	}
 #endif
 	return 0;
@@ -621,7 +621,7 @@ static int tplg_parse_streams(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
 	struct tplg_elem *elem = private;
 	struct snd_soc_tplg_pcm *pcm;
 	struct snd_soc_tplg_dai *dai;
-	unsigned int *playback, *capture;
+	void *playback, *capture;
 	struct snd_soc_tplg_stream_caps *caps;
 	const char *id, *value;
 	int stream;
@@ -651,10 +651,10 @@ static int tplg_parse_streams(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
 
 	if (strcmp(id, "playback") == 0) {
 		stream = SND_SOC_TPLG_STREAM_PLAYBACK;
-		*playback = 1;
+		unaligned_put32(playback, 1);
 	} else if (strcmp(id, "capture") == 0) {
 		stream = SND_SOC_TPLG_STREAM_CAPTURE;
-		*capture = 1;
+		unaligned_put32(capture, 1);
 	} else
 		return -EINVAL;
 
@@ -747,6 +747,7 @@ static int tplg_parse_fe_dai(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
 	snd_config_iterator_t i, next;
 	snd_config_t *n;
 	const char *id;
+	unsigned int dai_id;
 
 	snd_config_get_id(cfg, &id);
 	tplg_dbg("\t\tFE DAI %s:", id);
@@ -761,12 +762,13 @@ static int tplg_parse_fe_dai(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
 			continue;
 
 		if (strcmp(id, "id") == 0) {
-			if (tplg_get_unsigned(n, &pcm->dai_id, 0)) {
+			if (tplg_get_unsigned(n, &dai_id, 0)) {
 				SNDERR("invalid fe dai ID");
 				return -EINVAL;
 			}
 
-			tplg_dbg("\t\t\tindex: %d", pcm->dai_id);
+			unaligned_put32(&pcm->dai_id, dai_id);
+			tplg_dbg("\t\t\tindex: %d", dai_id);
 		}
 	}
 
@@ -790,7 +792,7 @@ int tplg_save_fe_dai(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
 
 /* parse a flag bit of the given mask */
 static int parse_flag(snd_config_t *n, unsigned int mask_in,
-		      unsigned int *mask, unsigned int *flags)
+		      void *mask, void *flags)
 {
 	int ret;
 
@@ -798,11 +800,11 @@ static int parse_flag(snd_config_t *n, unsigned int mask_in,
 	if (ret < 0)
 		return ret;
 
-	*mask |= mask_in;
+	unaligned_put32(mask, unaligned_get32(mask) | mask_in);
 	if (ret)
-		*flags |= mask_in;
+		unaligned_put32(flags, unaligned_get32(flags) | mask_in);
 	else
-		*flags &= ~mask_in;
+		unaligned_put32(flags, unaligned_get32(flags) & (~mask_in));
 
 	return 0;
 }
diff --git a/src/topology/tplg_local.h b/src/topology/tplg_local.h
index acb01a831f30..0c7be2001a63 100644
--- a/src/topology/tplg_local.h
+++ b/src/topology/tplg_local.h
@@ -225,6 +225,19 @@ struct tplg_table {
 extern struct tplg_table tplg_table[];
 extern unsigned int tplg_table_items;
 
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ && __SIZEOF_INT__ == 4
+static inline unsigned int unaligned_get32(void *src)
+{
+	unsigned int ret;
+	memcpy(&ret, src, sizeof(ret));
+	return ret;
+}
+static inline void unaligned_put32(void *dst, unsigned int val)
+{
+	memcpy(dst, &val, sizeof(val));
+}
+#endif
+
 #define tplg_log(tplg, type, pos, fmt, args...) do { \
 	if ((tplg)->verbose) \
 		tplg_log_((tplg), (type), (pos), (fmt), ##args); \
-- 
2.16.4