Hi,
this is a revised patch set for dropping fasync support from ALSA core.
The async signal itself is very difficult to use properly due to various restrictions (e.g. you cannot perform any I/O in the context), hence it's a feature that has been never used by real applications.
OTOH, the real problem is that there have been quite a few syzcaller reports indicating that fasync code path may lead to some potential deadlocks for long time. Dropping the feature is the easiest solution, obviously.
The corresponding update for alsa-lib will follow once when we agree with this approach.
thanks,
Takashi
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v1: https://lore.kernel.org/r/20220715102935.4695-1-tiwai@suse.de v1->v2: Fix unused variable warning in patch 2
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Takashi Iwai (5): ALSA: timer: Drop async signal support ALSA: pcm: Drop async signal support ALSA: control: Drop async signal support ALSA: core: Drop async signal support ALSA: doc: Drop stale fasync entry
.../kernel-api/writing-an-alsa-driver.rst | 1 - include/sound/control.h | 1 - include/sound/pcm.h | 1 - sound/core/control.c | 11 ----------- sound/core/init.c | 11 +---------- sound/core/pcm_lib.c | 8 +------- sound/core/pcm_native.c | 18 ------------------ sound/core/timer.c | 13 ------------- 8 files changed, 2 insertions(+), 62 deletions(-)