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) |
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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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