Re: next-0519 on thinkpad x60: sound related? window manager crash

[Takashi Iwai]

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);