From: Paul Brook <paul@codesourcery.com>
To: Alexander Graf <agraf@suse.de>
Cc: blauwirbel@gmail.com, Alexander Graf <alex@csgraf.de>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 7/7] PPC64: Don't fault at lwsync
Date: Thu, 5 Mar 2009 16:29:13 +0000 [thread overview]
Message-ID: <200903051629.14664.paul@codesourcery.com> (raw)
In-Reply-To: <49AFF942.6000708@suse.de>
> > 0xc0000000000ba524: lwsync
> > 0xc0000000000ba528: lwarx r0,0,r3
> > 0xc0000000000ba52c: cmpw r0,r4
> > 0xc0000000000ba530: bne- 0xc0000000000ba540
> >
> >
> > And I seriously have trouble understanding how a data storage exception
> > could happen on the lwsync opcode. It looks like R3 became 0 from the
> > guest's point of view after lwsync though - hum.
>
> Ah I remember that one now :-). The futex_init function tests if cmpxchg
> works with NULL values and that's why R3 is 0. It's actually _supposed_
> to fault here. But something gets messed up when the fault happens on
> IP=lwsync instead of IP=lwarx and I haven't really researched into why.
That's what you need to fix then :-)
I'm pretty sure that terminating the TB after the lwsync is not the correct
solution, and is just hiding the real bug.
Paul
next prev parent reply other threads:[~2009-03-05 16:29 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-05 14:14 [Qemu-devel] [PATCH 0/7] PPC64 Linux bringup patches v2 Alexander Graf
2009-03-05 14:14 ` [Qemu-devel] [PATCH 1/7] PPC64: Implement slbmte Alexander Graf
2009-03-05 14:14 ` [Qemu-devel] [PATCH 2/7] PPC64: Implement large pages Alexander Graf
2009-03-05 14:14 ` [Qemu-devel] [PATCH 3/7] PPC64: Implment tlbiel Alexander Graf
2009-03-05 14:14 ` [Qemu-devel] [PATCH 4/7] Activate uninorth AGP bridge Alexander Graf
2009-03-05 14:14 ` [Qemu-devel] [PATCH 5/7] PPC64: Nop some SPRs on 970fx Alexander Graf
2009-03-05 14:14 ` [Qemu-devel] [PATCH 6/7] PPC64: Enable 64bit mode on interrupts Alexander Graf
2009-03-05 14:14 ` [Qemu-devel] [PATCH 7/7] PPC64: Don't fault at lwsync Alexander Graf
2009-03-05 15:07 ` Paul Brook
2009-03-05 15:57 ` Alexander Graf
2009-03-05 16:09 ` Alexander Graf
2009-03-05 16:29 ` Paul Brook [this message]
2009-03-05 16:44 ` Paul Brook
2009-03-05 19:42 ` Daniel Jacobowitz
2009-03-06 0:53 ` Paul Brook
2009-03-05 21:21 ` Alexander Graf
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