linux-kernel - Re: amba-pl08x and 'get_signal' namespace collision/build error

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20130626091325.GA7389@linaro.org>
Date:	Wed, 26 Jun 2013 10:13:26 +0100
From:	Steve Capper <steve.capper@...aro.org>
To:	Russell King - ARM Linux <linux@....linux.org.uk>
Cc:	Jonathan Austin <jonathan.austin@....com>,
	Steve Capper <Steve.Capper@....com>,
	Vinod Koul <vinod.koul@...el.com>,
	Catalin Marinas <catalin.marinas@....com>,
	linus.walleij@...aro.org, Will Deacon <will.deacon@....com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Al Viro <viro@...iv.linux.org.uk>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: amba-pl08x and 'get_signal' namespace collision/build error

On Wed, Jun 26, 2013 at 09:40:25AM +0100, Steve Capper wrote:
> On Tue, Jun 25, 2013 at 07:45:39PM +0100, Russell King - ARM Linux wrote:
> > On Tue, Jun 25, 2013 at 12:30:08PM +0100, Jonathan Austin wrote:
> > > There's a patch making its way to mainline via Russell's tree
> > > (8d96250700: ARM: mm: Transparent huge page support for LPAE systems)
> > > that breaks the build of the amba-pl08x driver (drivers/dma/amba-pl08x.c) 
> > > because the 'get_signal' macro from include/linux/signal.h is now in the
> > > driver's scope and it clobbers a (previously) valid function call.
> > 
> > Well, here's the change to asm/pgtable.h in that patch:
> > 
> > diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
> > index 9bcd262..eaedce7 100644
> > --- a/arch/arm/include/asm/pgtable.h
> > +++ b/arch/arm/include/asm/pgtable.h
> > @@ -24,6 +24,9 @@
> >  #include <asm/memory.h>
> >  #include <asm/pgtable-hwdef.h>
> > 
> > +
> > +#include <asm/tlbflush.h>
> > +
> >  #ifdef CONFIG_ARM_LPAE
> >  #include <asm/pgtable-3level.h>
> >  #else
> > 
> > And the question is - if that's all that is going on in that file, why
> > is asm/tlbflush.h being added to it?  What in _that_ file uses anything
> > from asm/tlbflush.h (nothing apparantly from what I can see)?
> > 
> > So, I'm tempted to kill this change off unless someone can justify why
> > that addition happened - it looks completely inappropriate to me.
> > 
> 
> Hi Russell,
> I needed tlbflush.h for the definition of flush_pmd_entry, called by set_pmd_at
> in pgtable-3level.h.
> 
> It was pulled into pgtable.h as it would also be needed for the equivalent
> set_pmd_at function for 2-levels of paging.
> 

I was a little quick sending this sorry....

I have tried converting set_pmd_at into a macro to allow for delayed expansion.
(As I've noticed that other functions in pgtable-3level.h do this to call
flush_pmd_entry.)

Unfortunately, even with set_pmd_at defined as a macro, I get undefined
references to flush_pmd_entry and clean_pmd_entry (called from
pmdp_test_and_clear_young and pmdp_get_and_clear in asm-generic/pgtable.h).

I'm having a look to see if there's anything else I can do.
Apologies for causing this problem.

Best,
-- 
Steve
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/