Messages in this thread |  | | | Date | Tue, 17 Jun 2008 23:15:09 +0200 | | From | Andi Kleen <> | | Subject | Re: BUG: mmapfile/writev spurious zero bytes (x86_64/not i386, bisected, reproducable) | |
Linus Torvalds wrote:
>
> On Tue, 17 Jun 2008, Linus Torvalds wrote:
>> I actually am starting to think that the bug is in
>> __copy_to_user_inatomic_nocache().
>
> Confirmed.
>
> The uncached user copies are totally broken. The number of bytes left
> uncopied is simply wrong, because of how it does that unrolled loop and
> doesn't account for the fact that just doing loads does not actually
> increase the number of bytes copied at all.
How can a load fault legitimately in copy_to_user?
-Andi
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