Commit 9c7066ae authored by Clemens Ladisch's avatar Clemens Ladisch Committed by Takashi Iwai
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ALSA: core: fix 64-bit SNDRV_PCM_IOCTL_STATUS ABI breakage 



Commit 4eeaaeae (ALSA: core: add hooks for audio timestamps) added the
new audio_tstamp field to struct snd_pcm_status.  However, struct
timespec requires 64-bit alignment, so the 64-bit compiler would insert
32 bits of padding before this field, which broke SNDRV_PCM_IOCTL_STATUS
with error messages like this:

  kernel: unknown ioctl = 0x80984120

To solve this, insert the padding explicitly so that it can be taken
into account when calculating the ABI structure size.

Signed-off-by: default avatarClemens Ladisch <clemens@ladisch.de>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 7dd7a2fd

include/uapi/sound/asound.h

+2 −1
Original line number Diff line number Diff line
@@ -407,8 +407,9 @@ struct snd_pcm_status { 
	snd_pcm_uframes_t avail_max;	/* max frames available on hw since last status */

	snd_pcm_uframes_t overrange;	/* count of ADC (capture) overrange detections from last status */

	snd_pcm_state_t suspended_state; /* suspended stream state */

	__u32 reserved_alignment;	/* must be filled with zero */

	struct timespec audio_tstamp;	/* from sample counter or wall clock */

	unsigned char reserved[60-sizeof(struct timespec)]; /* must be filled with zero */

	unsigned char reserved[56-sizeof(struct timespec)]; /* must be filled with zero */

};



struct snd_pcm_mmap_status {

sound/core/pcm_compat.c

+2 −1
Original line number Diff line number Diff line
@@ -190,8 +190,9 @@ struct snd_pcm_status32 { 
	u32 avail_max;

	u32 overrange;

	s32 suspended_state;

	u32 reserved_alignment;

	struct compat_timespec audio_tstamp;

	unsigned char reserved[60-sizeof(struct compat_timespec)];

	unsigned char reserved[56-sizeof(struct compat_timespec)];

} __attribute__((packed));

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