Messages in this thread | | | Date | Thu, 17 Dec 2020 10:55:42 +0100 | From | Takashi Iwai <> | Subject | Re: [PATCH v1 ] ALSA: core: memalloc: add page alignment for iram |
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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
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