From: Takashi Iwai <tiwai@suse.de>
To: Lars-Peter Clausen <lars@metafoo.de>
Cc: Robin Gong <yibin.gong@nxp.com>,
perex@perex.cz, tiwai@suse.com, akpm@linux-foundation.org,
xiang@kernel.org, pierre-louis.bossart@linux.intel.com,
gustavoars@kernel.org, shengjiu.wang@nxp.com,
alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 ] ALSA: core: memalloc: add page alignment for iram
Date: Thu, 17 Dec 2020 10:55:42 +0100 [thread overview]
Message-ID: <s5h5z50n4dd.wl-tiwai@suse.de> (raw)
In-Reply-To: <05c824e5-0c33-4182-26fa-b116a42b10d6@metafoo.de>
On Thu, 17 Dec 2020 10:43:45 +0100,
Lars-Peter Clausen wrote:
>
> On 12/17/20 5:15 PM, Robin Gong wrote:
> > Since mmap for userspace is based on page alignment, add page alignment
> > for iram alloc from pool, otherwise, some good data located in the same
> > page of dmab->area maybe touched wrongly by userspace like pulseaudio.
> >
> I wonder, do we also have to align size to be a multiple of PAGE_SIZE
> to avoid leaking unrelated data?
Hm, a good question. Basically the PCM buffer size itself shouldn't
be influenced by that (i.e. no hw-constraint or such is needed), but
the padding should be cleared indeed. I somehow left those to the
allocator side, but maybe it's safer to clear the whole buffer in
sound/core/memalloc.c commonly.
thanks,
Takashi
next prev parent reply other threads:[~2020-12-17 9:56 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-17 16:15 [PATCH v1 ] ALSA: core: memalloc: add page alignment for iram Robin Gong
2020-12-17 9:38 ` Takashi Iwai
2020-12-17 9:43 ` Lars-Peter Clausen
2020-12-17 9:55 ` Takashi Iwai [this message]
2020-12-17 10:14 ` Takashi Iwai
2020-12-17 10:44 ` Lars-Peter Clausen
2020-12-17 10:59 ` Lars-Peter Clausen
2020-12-17 11:06 ` Takashi Iwai
2020-12-17 13:16 ` Lars-Peter Clausen
2020-12-17 14:24 ` Takashi Iwai
2020-12-17 14:57 ` Lars-Peter Clausen
2020-12-17 15:18 ` Takashi Iwai
2020-12-17 15:38 ` Lars-Peter Clausen
2020-12-17 16:28 ` Takashi Iwai
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