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032322b44c
__snd_pcm_set_state() writes runtime->state under the PCM stream lock. However, the OSS I/O functions snd_pcm_oss_write3(), snd_pcm_oss_read3(), snd_pcm_oss_writev3() and snd_pcm_oss_readv3() read runtime->state without holding the stream lock, only holding oss.params_lock (a different mutex that does not synchronize with the stream lock). Since __snd_pcm_set_state() is called from IRQ context (e.g., snd_pcm_period_elapsed -> snd_pcm_update_state -> __snd_pcm_xrun -> snd_pcm_stop -> snd_pcm_post_stop) while the OSS read/write paths run in process context, these are concurrent accesses that constitute a data race. Rather than using READ_ONCE()/WRITE_ONCE() barriers, introduce a snd_pcm_get_state() helper that reads runtime->state under the stream lock, matching the locking discipline used elsewhere in the PCM layer. Also export snd_pcm_set_state() for completeness. Use snd_pcm_get_state() in all four OSS I/O functions, caching the result in a local variable where the same snapshot is used for multiple comparisons to avoid taking the lock repeatedly. Signed-off-by: Cen Zhang <zzzccc427@gmail.com> Link: https://patch.msgid.link/20260316085047.2876451-1-zzzccc427@gmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de>