Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: AZFS file system proposal | Date | Tue, 8 Jul 2008 16:42:18 +0200 |
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On Monday 07 July 2008, Maxim Shchetynin wrote: > > > + if (copy_to_user(target, (void*) pin, size)) { > > > + rc = -EFAULT; > > > + goto out; > > > + } > > > > Question to the powerpc folks: is copy_to_user safe for an __iomem source? > > Should there be two copies (memcpy_fromio and copy_to_user) instead? > > I leave this question open. >
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 <>< -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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