kernel/linux.git/include/sound/pcm.h, branch v6.12.91

ALSA: pcm: Improve the fix for race of buffer access at PCM OSS layer

2026-01-23T10:18:43+00:00

commit 47c27c9c9c720bc93fdc69605d0ecd9382e99047 upstream. Handle the error code from snd_pcm_buffer_access_lock() in snd_pcm_runtime_buffer_set_silence() function. Found by Alexandros Panagiotou Fixes: 93a81ca06577 ("ALSA: pcm: Fix race of buffer access at PCM OSS layer") Cc: stable@vger.kernel.org # 6.15 Signed-off-by: Jaroslav Kysela Link: https://patch.msgid.link/20260107213642.332954-1-perex@perex.cz Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

ALSA: pcm: Fix race of buffer access at PCM OSS layer

2025-05-29T09:03:20+00:00

commit 93a81ca0657758b607c3f4ba889ae806be9beb73 upstream. The PCM OSS layer tries to clear the buffer with the silence data at initialization (or reconfiguration) of a stream with the explicit call of snd_pcm_format_set_silence() with runtime->dma_area. But this may lead to a UAF because the accessed runtime->dma_area might be freed concurrently, as it's performed outside the PCM ops. For avoiding it, move the code into the PCM core and perform it inside the buffer access lock, so that it won't be changed during the operation. Reported-by: syzbot+32d4647f551007595173@syzkaller.appspotmail.com Closes: https://lore.kernel.org/68164d8e.050a0220.11da1b.0019.GAE@google.com Cc: Link: https://patch.msgid.link/20250516080817.20068-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

ALSA: pcm: Fix breakage of PCM rates used for topology

2024-09-11T14:17:44+00:00

It turned out that the topology ABI takes the standard PCM rate bits as is, and it means that the recent change of the PCM rate bits would lead to the inconsistent rate values used for topology. This patch reverts the original PCM rate bit definitions while adding the new rates to the extended bits instead. This needed the change of snd_pcm_known_rates, too. And this also required to fix the handling in snd_pcm_hw_limit_rates() that blindly assumed that the list is sorted while it became unsorted now. Fixes: 090624b7dc83 ("ALSA: pcm: add more sample rate definitions") Reported-by: Pierre-Louis Bossart Closes: https://lore.kernel.org/1ab3efaa-863c-4dd0-8f81-b50fd9775fad@linux.intel.com Reviewed-by: Jaroslav Kysela Tested-by: Jerome Brunet Tested-by: Bard Liao Link: https://patch.msgid.link/20240911135756.24434-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: pcm: add more sample rate definitions

2024-09-06T07:23:54+00:00

This adds a sample rate definition for 12kHz, 24kHz and 128kHz. Admittedly, just a few drivers are currently using these sample rates but there is enough of a recurrence to justify adding a definition for them and remove some custom rate constraint code while at it. The new definitions are not added to the interval definitions, such as SNDRV_PCM_RATE_8000_44100, because it would silently add new supported rates to drivers that may or may not support them. For sure the drivers have not been tested for these new rates so it is better to leave them out of interval definitions. That being said, the added rates are multiples of well know rates families, it is very likely that a lot of devices out there actually supports them. Signed-off-by: Jerome Brunet Reviewed-by: David Rhodes Acked-by: Mark Brown Reviewed-by: Jaroslav Kysela Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20240905-alsa-12-24-128-v1-1-8371948d3921@baylibre.com

ALSA: pcm: Drop PCM vmalloc buffer helpers

2024-08-27T06:44:58+00:00

As the last-standing user of PCM vmalloc buffer helper API took its own buffer management, we can finally drop those API functions, which were leftover after reorganization of ALSA memalloc code. Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20240807152725.18948-3-tiwai@suse.de

ALSA: pcm: Add xrun counter for snd_pcm_substream

2024-08-10T08:40:58+00:00

This patch adds an xrun counter to snd_pcm_substream as an alternative to using logs from XRUN_DEBUG_BASIC. The counter provides a way to track the number of xrun occurences, accessible through the /proc interface. The counter is enabled when CONFIG_SND_PCM_XRUN_DEBUG is set. Example output: $ cat /proc/asound/card0/pcm9p/sub0/status owner_pid : 1425 trigger_time: 235.248957291 tstamp : 0.000000000 delay : 1912 avail : 480 avail_max : 1920 ----- hw_ptr : 672000 appl_ptr : 673440 xrun_counter: 3 # (new row) Signed-off-by: Norman Bintang Reviewed-by: Chih-Yang Hsia Tested-by: Chih-Yang Hsia Reviewed-by: David Riley Link: https://patch.msgid.link/20240809140648.3414349-1-normanbt@chromium.org Signed-off-by: Takashi Iwai

ALSA: pcm: optimize and clarify stream synchronization ID API

2024-07-02T07:53:21+00:00

Optimize the memory usage in struct snd_pcm_runtime - use boolean value for the standard sync ID scheme. Introduce snd_pcm_set_sync_per_card function to build synchronization IDs. Signed-off-by: Jaroslav Kysela Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20240625172836.589380-3-perex@perex.cz

ALSA: pcm: reinvent the stream synchronization ID API

2024-07-02T07:53:21+00:00

Until the commit e11f0f90a626 ("ALSA: pcm: remove SNDRV_PCM_IOCTL1_INFO internal command"), there was a possibility to pass information about the synchronized streams to the user space. The mentioned commit removed blindly the appropriate code with an irrelevant comment. The revert may be appropriate, but since this API was lost for several years without any complains, it's time to improve it. The hardware parameters may change the used stream clock source (e.g. USB hardware) so move this synchronization ID to hw_params as read-only field. It seems that pipewire can benefit from this API (disable adaptive resampling for perfectly synchronized PCM streams) now. Note that the contents of ID is not supposed to be used for direct comparison with a specific byte sequence. The "empty" case is when all bytes are zero (driver does not offer this information) and all other cases must be only used for equal comparison among PCM streams (including different sound cards) if they are using identical hardware clock. Cc: Takashi Sakamoto Signed-off-by: Jaroslav Kysela Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20240625172836.589380-2-perex@perex.cz

ALSA: pcm: fix typo in comment

2024-05-29T08:40:36+00:00

Fix the typo in the comment for SNDRV_PCM_RATE_KNOT Signed-off-by: Alexandre Belloni Link: https://lore.kernel.org/r/20240528191850.63314-1-alexandre.belloni@bootlin.com Signed-off-by: Takashi Iwai

ALSA: pcm: add support for 705.6kHz and 768kHz sample rates

2024-04-18T07:30:34+00:00

Many modern codecs support 705.6kHz and 768kHz sample rates. Current HW params fail to set 705.6kHz and 768kHz sample rates as these are not in the known-rates list. Add these new rates to the known-rates list to allow them. Also add defines in pcm.h so that drivers can use it. Signed-off-by: Pavel Hofman Reviewed-by: Jaroslav Kysela Signed-off-by: Takashi Iwai Message-ID: <20240416121726.628679-3-pavel.hofman@ivitera.com>