Re: AZFS file system proposal

On Monday 07 July 2008, Maxim Shchetynin wrote:

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 (copy_to_user(target, (void*) pin, size)) {

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=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0rc =3D -EFAULT;

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=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0goto out;

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+=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0}

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Question to the powerpc folks: is copy_to_user safe for an __iomem sour=

ce?

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Should there be two copies (memcpy_fromio and copy_to_user) instead?

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I leave this question open.
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Cc:'ing some more people that might have more of a clue on this question.
_memcpy_fromio does a "sync" at the start and an "eieio" at the end.
IFAICT, neither are needed here because the source is always memory.

It also handles unaligned memory accesses, which copy_to_user should
also do correctly, so it *looks* like it should work with just a
copy_to_user, but it still feels wrong to use an __iomem pointer
as the source for a copy_to_user.

Any ideas?

	Arnd <><