From: Andi Kleen <andi@firstfloor.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Bron Gondwana <brong@fastmail.fm>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Nick Piggin <npiggin@suse.de>,
Andrew Morton <akpm@linux-foundation.org>,
Rob Mueller <robm@fastmail.fm>, Ingo Molnar <mingo@elte.hu>
Subject: Re: BUG: mmapfile/writev spurious zero bytes (x86_64/not i386, bisected, reproducable)
Date: Tue, 17 Jun 2008 23:15:09 +0200 [thread overview]
Message-ID: <4858295D.8000904@firstfloor.org> (raw)
In-Reply-To: <alpine.LFD.1.10.0806171331460.2908@woody.linux-foundation.org>
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
next prev parent reply other threads:[~2008-06-17 21:15 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-17 6:00 BUG: mmapfile/writev spurious zero bytes (x86_64/not i386, bisected, reproducable) Bron Gondwana
2008-06-17 6:02 ` Bron Gondwana
2008-06-17 17:08 ` Linus Torvalds
2008-06-17 17:45 ` Linus Torvalds
2008-06-17 20:16 ` Linus Torvalds
2008-06-17 20:41 ` Linus Torvalds
2008-06-17 21:06 ` Linus Torvalds
2008-06-17 21:16 ` Andi Kleen
2008-06-17 21:24 ` Linus Torvalds
2008-06-17 21:30 ` Andi Kleen
2008-06-17 21:37 ` Linus Torvalds
2008-06-17 21:36 ` Al Viro
2008-06-17 21:42 ` Andi Kleen
2008-06-17 21:49 ` Linus Torvalds
2008-06-17 22:11 ` Al Viro
2008-06-17 22:21 ` Andi Kleen
2008-06-18 6:22 ` Nick Piggin
2008-06-17 21:20 ` Linus Torvalds
2008-06-18 2:27 ` Bron Gondwana
2008-06-18 3:14 ` Bron Gondwana
2008-06-18 4:03 ` Linus Torvalds
2008-06-18 5:11 ` Cyrus mmap vs lseek/write usage - (WAS: BUG: mmapfile/writev spurious zero bytes (x86_64/not i386, bisected, reproducable)) Bron Gondwana
2008-06-18 16:22 ` Linus Torvalds
2008-06-18 23:45 ` Robert Mueller
2008-06-19 0:20 ` Linus Torvalds
2008-10-03 11:44 ` BUG: mmapfile/writev spurious zero bytes still in the wild Bron Gondwana
2008-10-03 13:07 ` Andrew Morton
2008-10-04 0:13 ` Bron Gondwana
2008-06-17 21:15 ` Andi Kleen [this message]
2008-06-17 20:58 ` BUG: mmapfile/writev spurious zero bytes (x86_64/not i386, bisected, reproducable) Andi Kleen
2008-06-17 21:14 ` Linus Torvalds
2008-06-17 21:26 ` Andi Kleen
2008-06-17 21:31 ` Linus Torvalds
2008-06-17 21:34 ` Linus Torvalds
2008-06-17 21:34 ` Andi Kleen
2008-06-17 21:46 ` Linus Torvalds
2008-06-18 6:10 ` Nick Piggin
2008-06-18 2:21 ` Bron Gondwana
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