kernel/linux.git/sound/core/pcm_lib.c, branch linux-7.1.y

ALSA: pcm: Don't setup bogus iov_iter for silencing

2026-05-17T19:49:47+00:00

At transition to the iov_iter for PCM data transfer, we blindly applied the iov_iter setup also for silencing (i.e. data = NULL), and it leads to a calculation of bogus iov_iter. Fortunately this didn't cause troubles on most of architectures but it goes wrong on RISC-V now, causing a NULL dereference. Handle the NULL data case to treat the silencing in interleaved_copy() for addressing the bug above. noninterleaved_copy() has already the NULL data handling, so it doesn't need changes. Reported-by: Jiakai Xu Closes: https://lore.kernel.org/20260515051516.3103036-1-xujiakai24@mails.ucas.ac.cn Fixes: cf393babb37a ("ALSA: pcm: Add copy ops with iov_iter") Cc: Link: https://patch.msgid.link/20260517165121.31399-1-tiwai@suse.de Signed-off-by: Takashi Iwai

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

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: Fix id copying in snd_pcm_set_sync_per_card()

2024-07-05T08:02:07+00:00

Avoid to use strncpy and do proper length limiting (12 bytes) to avoid out of array access. Fixes: d712c58c55d9 ("ALSA: pcm: optimize and clarify stream synchronization ID API") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202407050501.o5Z3bibi-lkp@intel.com/ Signed-off-by: Jaroslav Kysela Link: https://patch.msgid.link/20240705075828.19746-1-perex@perex.cz Signed-off-by: Takashi Iwai

ALSA: pcm: Fix missing export of snd_pcm_set_sync_per-card()

2024-07-05T07:47:40+00:00

The recent change for the PCM sync API forgot to export a new API function that is currently used in emu10k1 driver. This patch adds the missing export. Fixes: d712c58c55d9 ("ALSA: pcm: optimize and clarify stream synchronization ID API") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202407051343.1Sz8AKFt-lkp@intel.com/ Reviewed-by: Jaroslav Kysela Link: https://patch.msgid.link/20240705063555.17220-1-tiwai@suse.de 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: chmap: Mark Channel Map controls as volatile

2024-06-18T10:00:19+00:00

The values returned from Playback Channel Map and Capture Channel Map controls may vary dynamically depending on the corresponding PCM stream. Mark those as volatile to indicate the values are unstable and not suitable for testing. Note that we may change the driver to return -EINVAL, but this would bring other side effects, such as "alsactl restore" would start receiving unexpected errors. So we still keep returning 0 for those invalid inputs. Reported-by: Paul Menzel Closes: https://lore.kernel.org/r/1d44be36-9bb9-4d82-8953-5ae2a4f09405@molgen.mpg.de Reviewed-by: Jaroslav Kysela Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/20240616073454.16512-6-tiwai@suse.de

ALSA: pcm: Use guard() for PCM stream locks

2024-02-28T14:01:22+00:00

Define guard() usage for PCM stream locking and use it in appropriate places. The pair of snd_pcm_stream_lock() and snd_pcm_stream_unlock() can be presented with guard(pcm_stream_lock) now. Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/r/20240227085306.9764-23-tiwai@suse.de