Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Thu, 11 Jun 2020 10:51:55 -0400
From:   "Alex Xu (Hello71)" <alex_y_xu@yahoo.ca>
Subject: Re: next-0519 on thinkpad x60: sound related? window manager crash
To:     Takashi Iwai <tiwai@suse.de>
Cc:     alsa-devel@alsa-project.org, bp@alien8.de, hch@infradead.org,
        Christoph Hellwig <hch@lst.de>, hpa@zytor.com,
        linux-kernel@vger.kernel.org, mingo@redhat.com,
        Pavel Machek <pavel@ucw.cz>, perex@perex.cz,
        rientjes@google.com, tglx@linutronix.de, tiwai@suse.com,
        x86@kernel.org
References: <20200520111136.GA3802@amd>
        <1591545088.74ii116nf2.none@localhost> <20200608061950.GA17476@lst.de>
        <1591624340.z01ejtod28.none@localhost> <20200609114733.GA1621@lst.de>
        <s5hr1uogtna.wl-tiwai@suse.de>
In-Reply-To: <<s5hr1uogtna.wl-tiwai@suse.de>
MIME-Version: 1.0
Message-Id: <1591885264.uk6f214o4o.none@localhost>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Content-Length: 1246
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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:
>>=20
>> Alex, can you try this patch?
>=20
> 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.
>=20
> If this works more or less, I'll cook a more comprehensive fix.
>=20
>=20
> thanks,
>=20
> Takashi
>=20
> --- 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_substrea=
m *substream,
>  	while (runtime->boundary * 2 <=3D LONG_MAX - runtime->buffer_size)
>  		runtime->boundary *=3D 2;
> =20
> +#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
> =20
>  	snd_pcm_timer_resolution_change(substream);
>  	snd_pcm_set_state(substream, SNDRV_PCM_STATE_SETUP);
>=20

Sorry, this patch doesn't work for me with SME off using abfbb29297c2.=20
David's newest submitted patch works for me, which I already replied to=20
separately.

Thanks,
Alex.