On Thu, 11 Jun 2020 16:51:55 +0200, Alex Xu (Hello71) wrote: > > Excerpts from Takashi Iwai's message of June 9, 2020 11:12 am: > > On Tue, 09 Jun 2020 13:47:33 +0200, > > Christoph Hellwig wrote: > >> > >> Alex, can you try this patch? > > > > Also could you check whether just papering over the memset() call > > alone avoids the crash like below? For PulseAudio and dmix/dsnoop, > > it's the only code path that accesses the vmapped buffer, I believe. > > > > If this works more or less, I'll cook a more comprehensive fix. > > > > > > thanks, > > > > Takashi > > > > --- a/sound/core/pcm_native.c > > +++ b/sound/core/pcm_native.c > > @@ -754,9 +754,11 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream, > > while (runtime->boundary * 2 <= LONG_MAX - runtime->buffer_size) > > runtime->boundary *= 2; > > > > +#if 0 > > /* clear the buffer for avoiding possible kernel info leaks */ > > if (runtime->dma_area && !substream->ops->copy_user) > > memset(runtime->dma_area, 0, runtime->dma_bytes); > > +#endif > > > > snd_pcm_timer_resolution_change(substream); > > snd_pcm_set_state(substream, SNDRV_PCM_STATE_SETUP); > > > > Sorry, this patch doesn't work for me with SME off using abfbb29297c2. > David's newest submitted patch works for me, which I already replied to > separately. Thanks, so something still missing in the mmap handling, I guess. I've worked on two different branches for potential fixes of your problems. Could you test topic/dma-fix and topic/dma-fix2 branches? git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git Just pull one of them onto Linus' git HEAD. I guess we'll go with David's new patch, but still it's interesting whether my changes do anything good actually. Takashi
