[alsa-devel] [PATCH] ALSA: compress: fix the struct alignment to 4 bytes

[Vinod Koul]

In 64bit systems the compiler can default align to 8bytes causing mis-match with
32bit usermode. Avoid this is future by ensuring all the structures shared with
usermode are packed and aligned to 4 bytes irrespective of arch used

Signed-off-by: Vinod Koul <vinod.koul at intel.com>
---
 include/uapi/sound/compress_offload.h |   14 +++++++-------
 include/uapi/sound/compress_params.h  |   14 +++++++-------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/include/uapi/sound/compress_offload.h b/include/uapi/sound/compress_offload.h
index 21eed48..bd06dd0 100644
--- a/include/uapi/sound/compress_offload.h
+++ b/include/uapi/sound/compress_offload.h
@@ -39,7 +39,7 @@
 struct snd_compressed_buffer {
 	__u32 fragment_size;
 	__u32 fragments;
-};
+}__attribute__((packed, aligned(4)));
 
 /**
  * struct snd_compr_params: compressed stream params
@@ -51,7 +51,7 @@ struct snd_compr_params {
 	struct snd_compressed_buffer buffer;
 	struct snd_codec codec;
 	__u8 no_wake_mode;
-};
+}__attribute__((packed, aligned(4)));
 
 /**
  * struct snd_compr_tstamp: timestamp descriptor
@@ -70,7 +70,7 @@ struct snd_compr_tstamp {
 	__u32 pcm_frames;
 	__u32 pcm_io_frames;
 	__u32 sampling_rate;
-};
+}__attribute__((packed, aligned(4)));
 
 /**
  * struct snd_compr_avail: avail descriptor
@@ -80,7 +80,7 @@ struct snd_compr_tstamp {
 struct snd_compr_avail {
 	__u64 avail;
 	struct snd_compr_tstamp tstamp;
-} __attribute__((packed));
+}__attribute__((packed, aligned(4)));
 
 enum snd_compr_direction {
 	SND_COMPRESS_PLAYBACK = 0,
@@ -107,7 +107,7 @@ struct snd_compr_caps {
 	__u32 max_fragments;
 	__u32 codecs[MAX_NUM_CODECS];
 	__u32 reserved[11];
-};
+}__attribute__((packed, aligned(4)));
 
 /**
  * struct snd_compr_codec_caps: query capability of codec
@@ -119,7 +119,7 @@ struct snd_compr_codec_caps {
 	__u32 codec;
 	__u32 num_descriptors;
 	struct snd_codec_desc descriptor[MAX_NUM_CODEC_DESCRIPTORS];
-};
+}__attribute__((packed, aligned(4)));
 
 /**
  * @SNDRV_COMPRESS_ENCODER_PADDING: no of samples appended by the encoder at the
@@ -140,7 +140,7 @@ enum {
 struct snd_compr_metadata {
 	 __u32 key;
 	 __u32 value[8];
-};
+}__attribute__((packed, aligned(4)));
 
 /**
  * compress path ioctl definitions
diff --git a/include/uapi/sound/compress_params.h b/include/uapi/sound/compress_params.h
index 165e705..54299ba 100644
--- a/include/uapi/sound/compress_params.h
+++ b/include/uapi/sound/compress_params.h
@@ -268,7 +268,7 @@ struct snd_enc_vorbis {
 	__u32 max_bit_rate;
 	__u32 min_bit_rate;
 	__u32 downmix;
-};
+}__attribute__((packed, aligned(4)));
 
 
 /**
@@ -284,7 +284,7 @@ struct snd_enc_real {
 	__u32 quant_bits;
 	__u32 start_region;
 	__u32 num_regions;
-};
+}__attribute__((packed, aligned(4)));
 
 /**
  * struct snd_enc_flac
@@ -308,12 +308,12 @@ struct snd_enc_real {
 struct snd_enc_flac {
 	__u32 num;
 	__u32 gain;
-};
+}__attribute__((packed, aligned(4)));
 
 struct snd_enc_generic {
 	__u32 bw;	/* encoder bandwidth */
 	__s32 reserved[15];
-};
+}__attribute__((packed, aligned(4)));
 
 union snd_codec_options {
 	struct snd_enc_wma wma;
@@ -321,7 +321,7 @@ union snd_codec_options {
 	struct snd_enc_real real;
 	struct snd_enc_flac flac;
 	struct snd_enc_generic generic;
-};
+}__attribute__((packed, aligned(4)));
 
 /** struct snd_codec_desc - description of codec capabilities
  * @max_ch: Maximum number of audio channels
@@ -358,7 +358,7 @@ struct snd_codec_desc {
 	__u32 formats;
 	__u32 min_buffer;
 	__u32 reserved[15];
-};
+}__attribute__((packed, aligned(4)));
 
 /** struct snd_codec
  * @id: Identifies the supported audio encoder/decoder.
@@ -399,6 +399,6 @@ struct snd_codec {
 	__u32 align;
 	union snd_codec_options options;
 	__u32 reserved[3];
-};
+}__attribute__((packed, aligned(4)));
 
 #endif
-- 
1.7.0.4