From: Andi Kleen <andi@firstfloor.org>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
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: Wed, 18 Jun 2008 00:21:45 +0200 [thread overview]
Message-ID: <485838F9.8010001@firstfloor.org> (raw)
In-Reply-To: <20080617221118.GM28946@ZenIV.linux.org.uk>
> AFAICS, what happened is that b0rken copy_*FROM*_user() had been discussed
> with references to copy_*TO*_user(). With proposed patch indeed not affecting
> any legitimate calls of the latter. Does affect the former and that, from
> my reading of the code in question, correctly.
>
> IOW, s/copy_to_user/copy_from_user/ in Linus' postings upthread and they
> make sense.
Yes, it makes some more sense, but I'm not completely happy with the fix
because it makes the fault point reporting very unreliable (maximum error
will be 63 instead of 7 now). iirc especially mount was sensitive to that.
Unfortunately fixing the accuracy is a little tricky.
-Andi
next prev parent reply other threads:[~2008-06-17 22:22 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 [this message]
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 ` BUG: mmapfile/writev spurious zero bytes (x86_64/not i386, bisected, reproducable) Andi Kleen
2008-06-17 20:58 ` 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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