linux-kernel - Re: [PATCHv2 5/5] efi/runtime-wrappers: detect FW irq flag corruption

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Message-ID: <20160421171814.GB3078@leverpostej>
Date:	Thu, 21 Apr 2016 18:18:14 +0100
From:	Mark Rutland <mark.rutland@....com>
To:	Ard Biesheuvel <ard.biesheuvel@...aro.org>
Cc:	"linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
	Catalin Marinas <catalin.marinas@....com>,
	"hpa@...or.com" <hpa@...or.com>,
	Leif Lindholm <leif.lindholm@...aro.org>,
	Russell King - ARM Linux <linux@....linux.org.uk>,
	Matt Fleming <matt@...eblueprint.co.uk>,
	"mingo@...hat.com" <mingo@...hat.com>,
	"tglx@...utronix.de" <tglx@...utronix.de>,
	Will Deacon <will.deacon@....com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCHv2 5/5] efi/runtime-wrappers: detect FW irq flag corruption

On Thu, Apr 21, 2016 at 07:05:32PM +0200, Ard Biesheuvel wrote:
> On 21 April 2016 at 13:35, Mark Rutland <mark.rutland@....com> wrote:
> > @@ -25,8 +27,11 @@
> >  #define efi_call_virt(f, args...)                                      \
> >  ({                                                                     \
> >         efi_status_t __s;                                               \
> > +       unsigned long flags;                                            \
> >         arch_efi_call_virt_setup();                                     \
> > +       local_save_flags(flags);                                        \
> >         __s = arch_efi_call_virt(f, args);                              \
> > +       efi_call_virt_check_flags(flags, __stringify(f));               \
> >         arch_efi_call_virt_teardown();                                  \
> >         __s;                                                            \
> >  })
> > @@ -35,12 +40,29 @@
> >  #ifndef __efi_call_virt
> >  #define __efi_call_virt(f, args...)                                    \
> >  ({                                                                     \
> > +       unsigned long flags;                                            \
> >         arch_efi_call_virt_setup();                                     \
> > +       local_irq_save(flags);                                          \
> 
> We shouldn't disable interrupts here. I assume this is a typo, and you
> intended to use local_save_flags() as above?

Oh, yes. That's an impressive mistake on my behalf; thanks for spotting
that!

I've been seeing issues with GetVariable and GetNextVariable, which
happen to only exercise the correct macro above.

> Other than that, this series looks fine to me.
> 
> With the above fixed:
> 
> For the series (except the x86 patch)
> 
> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>

Cheers!

Mark.