From: Eyal Ben David <bdeyal@gmail.com>
To: "Ewan D. Milne" <emilne@redhat.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>,
dgilbert@interlog.com, Laurence Oberman <loberman@redhat.com>,
linux-scsi@vger.kernel.org
Subject: Re: SG does not ignore dxferp (direct io + mmap)
Date: Tue, 22 Nov 2016 22:55:44 +0200 [thread overview]
Message-ID: <CAPrnrPAFSUL4C+N09-BUUm+7e84oxasaHb7-Ej-+8FuYOddRgA@mail.gmail.com> (raw)
In-Reply-To: <1479839407.28416.21.camel@localhost.localdomain>
On Tue, Nov 22, 2016 at 8:30 PM, Ewan D. Milne <emilne@redhat.com> wrote:
>
> I see the behavior (zero byte) on the 4.4.34, 4.5.7, 4.6.7, and 4.7.10
> -stable kernels. But not (of course) on 4.8.10 -stable.
>
> It doesn't look like the sg driver, might be something in the mmap code?
A kernel guy colleague suggested to look at copy_from_user / copy_to_user code.
It was changed in 4.8
It was OK with 3.13 (Ubuntu 14.04) but from some kernel (prior or equal to 4.4)
until 4.7 we see the bug. It was somehow fixed at 4.8.
In order to fully understand what happened, there are two changes to find.
They might not even be related.
Thanks!
Eyal
next prev parent reply other threads:[~2016-11-22 20:55 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-20 16:02 SG does not ignore dxferp (direct io + mmap) Eyal Ben David
2016-11-21 0:04 ` Laurence Oberman
2016-11-21 9:23 ` Eyal Ben David
2016-11-21 14:24 ` Ewan D. Milne
2016-11-21 14:54 ` Laurence Oberman
2016-11-21 14:55 ` Eyal Ben David
2016-11-21 15:12 ` Laurence Oberman
2016-11-21 15:15 ` Johannes Thumshirn
2016-11-21 15:44 ` Johannes Thumshirn
2016-11-21 16:04 ` Eyal Ben David
2016-11-21 16:25 ` Ewan D. Milne
2016-11-21 17:34 ` Douglas Gilbert
2016-11-21 18:24 ` Ewan D. Milne
2016-11-22 8:37 ` Johannes Thumshirn
2016-11-22 13:48 ` Eyal Ben David
2016-11-22 15:31 ` Laurence Oberman
2016-11-22 16:00 ` Johannes Thumshirn
2016-11-22 16:28 ` Eyal Ben David
2016-11-22 18:30 ` Ewan D. Milne
2016-11-22 18:46 ` Laurence Oberman
2016-11-22 20:55 ` Eyal Ben David [this message]
2016-11-23 18:55 ` Laurence Oberman
2016-11-23 20:22 ` Ewan D. Milne
2016-11-25 8:07 ` Johannes Thumshirn
2016-11-25 11:20 ` Eyal Ben David
2016-11-25 11:53 ` Johannes Thumshirn
2016-11-25 12:28 ` Johannes Thumshirn
2016-11-25 12:36 ` Eyal Ben David
2016-11-25 14:46 ` Laurence Oberman
2016-11-28 10:30 ` Johannes Thumshirn
2016-11-25 17:56 ` Ewan Milne
2016-11-25 18:01 ` Laurence Oberman
2016-11-30 16:26 ` Ewan D. Milne
2016-12-01 13:40 ` Martin K. Petersen
2016-12-02 12:21 ` Christoph Hellwig
2016-12-02 13:29 ` Ewan D. Milne
2016-12-02 14:10 ` Hannes Reinecke
2016-12-02 14:17 ` Laurence Oberman
2016-12-02 19:29 ` Ewan D. Milne
2016-12-02 20:37 ` Ewan D. Milne
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