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From: Nathan Lynch <nathan_lynch@mentor.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Nicolas Pitre <nico@fluxnic.net>,
	Mark Rutland <mark.rutland@arm.com>,
	Arnd Bergmann <arnd@arndb.de>, Will Deacon <will.deacon@arm.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	Russell King <linux@armlinux.org.uk>
Subject: Re: [PATCH v2] ARM: vdso: Define vdso_{start,end} as array
Date: Wed, 23 Aug 2017 12:46:28 -0500	[thread overview]
Message-ID: <87tw0ytbwr.fsf@mentor.com> (raw)
In-Reply-To: <20170823142419.1811665-1-arnd@arndb.de>

Arnd Bergmann <arnd@arndb.de> writes:

> gcc-8 correctly points out that reading four bytes from a pointer to a
> 'char' variable is wrong
>
> arch/arm/kernel/vdso.c: In function 'vdso_init':
> arch/arm/kernel/vdso.c:200:6: error: '__builtin_memcmp_eq' reading 4 bytes from a region of size 1 [-Werror=stringop-overflow=]
>
> However, in this case the variable just stands for the beginning of the
> vdso and is not actually a 'char', so the code is doing what it is meant
> to do.
>
> This uses the same approach as arm64 and x86, declaring the addresses
> as char arrays.
>
> See also: dbbb08f500d6 ("arm64, vdso: Define vdso_{start,end} as array")
>
> Suggested-by: Mark Rutland <mark.rutland@arm.com>
> Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Acked-by: Nathan Lynch <nathan_lynch@mentor.com>

Thanks!

      reply	other threads:[~2017-08-23 17:47 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-23 14:23 [PATCH v2] ARM: vdso: Define vdso_{start,end} as array Arnd Bergmann
2017-08-23 17:46 ` Nathan Lynch [this message]

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