From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: [PATCH] ALSA: core: fix 64-bit SNDRV_PCM_IOCTL_STATUS ABI breakage Date: Sat, 27 Oct 2012 21:55:27 +0200 Message-ID: <508C3C2F.7070009@ladisch.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) by alsa0.perex.cz (Postfix) with ESMTP id 4F55E26522A for ; Sat, 27 Oct 2012 21:56:52 +0200 (CEST) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Takashi Iwai Cc: alsa-devel@alsa-project.org, Pierre-Louis Bossart List-Id: alsa-devel@alsa-project.org Commit 4eeaaeaea (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: Clemens Ladisch --- include/uapi/sound/asound.h | 3 ++- sound/core/pcm_compat.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) --- a/include/uapi/sound/asound.h +++ b/include/uapi/sound/asound.h @@ -408,8 +408,9 @@ 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 { --- a/sound/core/pcm_compat.c +++ b/sound/core/pcm_compat.c @@ -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));