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

[Takashi Iwai]

At Thu, 19 Jun 2014 14:41:00 +0530,
Vinod Koul wrote:
> 
> 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>

Applied with slight coding-style fixes.
I didn't put Cc to stable for this patch as this shouldn't change
anything for x86.  If you think it better being to be merged to
stable, feel free to submit it after merged to Linus tree.


thanks,

Takashi


> ---
>  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
>