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From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm64: fix warning about swapper_pg_dir overflow
Date: Wed, 15 Feb 2017 11:33:59 +0000	[thread overview]
Message-ID: <20170215113358.GC9630@arm.com> (raw)
In-Reply-To: <20170214212718.2792194-1-arnd@arndb.de>

On Tue, Feb 14, 2017 at 10:27:01PM +0100, Arnd Bergmann wrote:
> With 4 levels of 16KB pages, we get this warning about the fact that we are
> copying a whole page into an array that is declared as having only two pointers
> for the top level of the page table:
> 
> arch/arm64/mm/mmu.c: In function 'paging_init':
> arch/arm64/mm/mmu.c:528:2: error: 'memcpy' writing 16384 bytes into a region of size 16 overflows the destination [-Werror=stringop-overflow=]
> 
> This is harmless since we actually reserve a whole page in the definition of the
> array that comes from, and just the extern declaration is short. The pgdir
> is initialized to zero either way, so copying the actual entries here seems
> like the best solution.

Thanks, I'll queue this up for 4.11 with the acks.

Will

WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will.deacon@arm.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Laura Abbott <labbott@redhat.com>,
	Kefeng Wang <wangkefeng.wang@huawei.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arm64: fix warning about swapper_pg_dir overflow
Date: Wed, 15 Feb 2017 11:33:59 +0000	[thread overview]
Message-ID: <20170215113358.GC9630@arm.com> (raw)
In-Reply-To: <20170214212718.2792194-1-arnd@arndb.de>

On Tue, Feb 14, 2017 at 10:27:01PM +0100, Arnd Bergmann wrote:
> With 4 levels of 16KB pages, we get this warning about the fact that we are
> copying a whole page into an array that is declared as having only two pointers
> for the top level of the page table:
> 
> arch/arm64/mm/mmu.c: In function 'paging_init':
> arch/arm64/mm/mmu.c:528:2: error: 'memcpy' writing 16384 bytes into a region of size 16 overflows the destination [-Werror=stringop-overflow=]
> 
> This is harmless since we actually reserve a whole page in the definition of the
> array that comes from, and just the extern declaration is short. The pgdir
> is initialized to zero either way, so copying the actual entries here seems
> like the best solution.

Thanks, I'll queue this up for 4.11 with the acks.

Will

  parent reply	other threads:[~2017-02-15 11:33 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-14 21:27 [PATCH] arm64: fix warning about swapper_pg_dir overflow Arnd Bergmann
2017-02-14 21:27 ` Arnd Bergmann
2017-02-14 21:33 ` Ard Biesheuvel
2017-02-14 21:33   ` Ard Biesheuvel
2017-02-14 22:06   ` Arnd Bergmann
2017-02-14 22:06     ` Arnd Bergmann
2017-02-15 10:56 ` Mark Rutland
2017-02-15 10:56   ` Mark Rutland
2017-02-15 11:33 ` Will Deacon [this message]
2017-02-15 11:33   ` Will Deacon

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