From: Arnd Bergmann <arnd@arndb•de>
To: linuxppc-dev@ozlabs•org
Cc: Paul Mackerras <paulus@samba•org>,
Jan Kratochvil <jan.kratochvil@redhat•com>,
Roland McGrath <roland@redhat•com>
Subject: Re: PPC upstream kernel ignored DABR bug
Date: Tue, 27 Nov 2007 23:35:36 +0100 [thread overview]
Message-ID: <200711272335.36981.arnd@arndb.de> (raw)
In-Reply-To: <20071126220224.GA5606@host0.dyn.jankratochvil.net>
On Monday 26 November 2007, Jan Kratochvil wrote:
> Hi,
>=20
> this testcase:
> =A0=A0=A0=A0=A0=A0=A0=A0http://people.redhat.com/jkratoch/dabr-lost.c
>=20
> reproduces a PPC DABR kernel bug. =A0The variable `variable' should not g=
et
> modified as the thread modifying it should be caught by its DABR:
>=20
> $ ./dabr-lost
> TID 30914: DABR 0x10012a77 NIP 0x80f6ebb318
> TID 30915: DABR 0x10012a77 NIP 0x80f6ebb318
> TID 30916: DABR 0x10012a77 NIP 0x80f6ebb318
> TID 30914: hitting the variable
> TID 30915: hitting the variable
> TID 30916: hitting the variable
> variable found =3D 30916, caught TID =3D 30914
> TID 30916: DABR 0x10012a77
> Variable got modified by a thread which has DABR still set!
>=20
This sounds like a bug recently reported by Uli Weigand. BenH
said he'd take a look, but it probably fell under the table.
The problem found by Uli is that on certain processors (Cell/B.E.
in his case), the DABRX register needs to be set in order for
the DABR to take effect.
Arnd <><
next prev parent reply other threads:[~2007-11-27 22:36 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-26 22:02 PPC upstream kernel ignored DABR bug Jan Kratochvil
2007-11-27 22:35 ` Arnd Bergmann [this message]
2007-11-28 8:59 ` Jan Kratochvil
2007-11-28 12:28 ` Arnd Bergmann
2007-11-28 12:45 ` Jan Kratochvil
2007-11-28 22:59 ` Geoff Levand
2007-11-29 0:13 ` Arnd Bergmann
2008-03-10 0:53 ` Luis Machado
2008-03-10 14:01 ` Jens Osterkamp
2008-03-10 15:13 ` Luis Machado
2008-03-10 19:19 ` Roland McGrath
2008-03-10 19:36 ` Luis Machado
2008-03-10 19:50 ` Olof Johansson
2008-03-10 19:54 ` Roland McGrath
2008-03-10 22:06 ` Segher Boessenkool
2008-03-12 17:51 ` Luis Machado
2008-03-12 22:30 ` Jens Osterkamp
2008-03-13 1:47 ` Roland McGrath
2008-03-13 22:20 ` Segher Boessenkool
2008-03-13 22:42 ` Roland McGrath
2008-03-14 2:11 ` Segher Boessenkool
2008-03-14 7:45 ` Roland McGrath
2008-03-14 8:42 ` Segher Boessenkool
2008-03-16 20:38 ` Benjamin Herrenschmidt
2008-03-16 20:37 ` Benjamin Herrenschmidt
2008-03-26 20:57 ` Josh Boyer
2008-03-27 1:47 ` Josh Boyer
2008-03-13 13:13 ` Luis Machado
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