linux-kernel - Re: [PATCHv3 1/5] efi/runtime-wrappers: detect FW irq flag corruption

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Date:	Mon, 25 Apr 2016 16:59:22 +0100
From:	Matt Fleming <matt@...eblueprint.co.uk>
To:	Mark Rutland <mark.rutland@....com>
Cc:	Ard Biesheuvel <ard.biesheuvel@...aro.org>,
	Robin Murphy <robin.murphy@....com>,
	"linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
	Russell King - ARM Linux <linux@....linux.org.uk>,
	Catalin Marinas <catalin.marinas@....com>,
	Will Deacon <will.deacon@....com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Leif Lindholm <leif.lindholm@...aro.org>,
	"mingo@...hat.com" <mingo@...hat.com>,
	"hpa@...or.com" <hpa@...or.com>,
	"tglx@...utronix.de" <tglx@...utronix.de>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCHv3 1/5] efi/runtime-wrappers: detect FW irq flag corruption

On Mon, 25 Apr, at 03:27:35PM, Mark Rutland wrote:
> 
> I have no strong preference so long as the code is correct.
> 
> Another option is to get rid of the bool entirely:
> 
> 	flags ^= cur_flags;
> 	if (!WARN_ON(flags & ARCH_EFI_IRQ_FLAGS_MASK))
> 		return;

OK, let's do the following because we need flags to be preserved for
printing,

---

	unsigned long cur_flags, mismatch;

	local_save_flags(cur_flags);

	mismatch = flags ^ cur_flags;
	if (!WARN_ON_ONCE(mismatch & ARCH_EFI_IRQ_FLAGS_MASK))
		return;