lkml.org 
[lkml]   [2019]   [Aug]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: "arm64/for-next/core" causes boot panic
Date
On Tue, Aug 13, 2019 at 03:04:52PM +0100, Steve Capper wrote:
> Hi Will,
>
> On Tue, Aug 13, 2019 at 01:06:44PM +0100, Will Deacon wrote:
> > [+Steve]
> >
> > On Tue, Aug 13, 2019 at 11:58:52AM +0100, Will Deacon wrote:
> > > On Tue, Aug 13, 2019 at 10:02:01AM +0100, Will Deacon wrote:
> > > > On Mon, Aug 12, 2019 at 05:51:35PM -0400, Qian Cai wrote:
> > > > > Booting today's linux-next on an arm64 server triggers a panic with
> > > > > CONFIG_KASAN_SW_TAGS=y pointing to this line,
> > > >
> > > > Is this the only change on top of defconfig? If not, please can you share
> > > > your full .config?
> > > >
> > > > > kfree()->virt_to_head_page()->compound_head()
> > > > >
> > > > > unsigned long head = READ_ONCE(page->compound_head);
> > > > >
> > > > > The bisect so far indicates one of those could be bad,
> > > >
> > > > I guess that means the issue is reproducible on the arm64 for-next/core
> > > > branch. Once I have your .config, I'll give it a go.
> > >
> > > FWIW, I've managed to reproduce this using defconfig + SW_TAGS on
> > > for-next/core, so I'll keep investigating.
>
> I've installed clang-8 and enabled CONFIG_KASAN_SW_TAGS and was able to
> reproduce the problem quite rapidly. Many apologies for missing this
> before in my testing.
>
> >
> > Right, hacky diff below seems to resolve this, so I'll split this up into
> > some proper patches as there is more than one bug here.
> >
> > Thanks,
> >
> > Will
> >
> > --->8
> >
> > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> FWIW, this fixed the crashes I experienced, I'll run some additional
> tests.
>

This works for me with 52-bit VAs + CONFIG_KASAN_SW_TAGS +
CONFIG_DEBUG_VIRTUAL + CONFIG_DEBUG_VM

FWIW:
Tested-by: Steve Capper <steve.capper@arm.com>

Cheers,
--
Steve

\
 
 \ /
  Last update: 2019-08-13 16:41    [W:0.037 / U:49.488 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site