All of lore.kernel.org
 help / color / mirror / Atom feed
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



  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4858295D.8000904@firstfloor.org \
    --to=andi@firstfloor.org \
    --cc=akpm@linux-foundation.org \
    --cc=brong@fastmail.fm \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=npiggin@suse.de \
    --cc=robm@fastmail.fm \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.