Re: [PATCH v7 0/4] KASAN for arm64

From: Andrey Ryabinin <aryabinin@virtuozzo.com>
To: Mark Rutland <mark.rutland@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>
Cc: "Suzuki K. Poulose" <Suzuki.Poulose@arm.com>,
	Yury <yury.norov@gmail.com>, Arnd Bergmann <arnd@arndb.de>,
	linux-mm@kvack.org, Linus Walleij <linus.walleij@linaro.org>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Will Deacon <will.deacon@arm.com>,
	linux-kernel@vger.kernel.org,
	kasan-dev <kasan-dev@googlegroups.com>,
	Alexey Klimov <klimov.linux@gmail.com>,
	Alexander Potapenko <glider@google.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	David Keitel <dkeitel@codeaurora.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v7 0/4] KASAN for arm64
Date: Thu, 26 Nov 2015 15:22:41 +0300	[thread overview]
Message-ID: <5656F991.8090108@virtuozzo.com> (raw)
In-Reply-To: <20151126121007.GC32343@leverpostej>

On 11/26/2015 03:10 PM, Mark Rutland wrote:
> Hi Catalin,
> 
> Can you pick up Andrey's patch below for v4.4, until we have a better
> solution?
> 

FYI, better solution is almost ready, I'm going to send it today.
However, I don't know for sure whether it works or not :)
I'm not able to test as I don't have any setup working with 16k pages.

> I stumbled across this myself and was about to post a similar patch.
> 
> FWIW:
> 
> Acked-by: Mark Rutland <mark.rutland@arm.com>
> 
> Thanks,
> Mark.
> 
> On Tue, Nov 17, 2015 at 06:47:08PM +0300, Andrey Ryabinin wrote:
>> We should either add proper Kconfig dependency for now, or just make it work.
>>
>>
>> From: Andrey Ryabinin <aryabinin@virtuozzo.com>
>> Subject: [PATCH] arm64: KASAN depends on !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
>>
>> On KASAN + 16K_PAGES + 48BIT_VA
>>  arch/arm64/mm/kasan_init.c: In function a??kasan_early_inita??:
>>  include/linux/compiler.h:484:38: error: call to a??__compiletime_assert_95a?? declared with attribute error: BUILD_BUG_ON failed: !IS_ALIGNED(KASAN_SHADOW_END, PGDIR_SIZE)
>>     _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
>>
>> Currently KASAN will not work on 16K_PAGES and 48BIT_VA, so
>> forbid such configuration to avoid above build failure.
>>
>> Reported-by: Suzuki K. Poulose <Suzuki.Poulose@arm.com>
>> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
>> ---
>>  arch/arm64/Kconfig | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index 9ac16a4..bf7de69 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -49,7 +49,7 @@ config ARM64
>>  	select HAVE_ARCH_AUDITSYSCALL
>>  	select HAVE_ARCH_BITREVERSE
>>  	select HAVE_ARCH_JUMP_LABEL
>> -	select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP
>> +	select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP && !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
>>  	select HAVE_ARCH_KGDB
>>  	select HAVE_ARCH_SECCOMP_FILTER
>>  	select HAVE_ARCH_TRACEHOOK
>> -- 
>> 2.4.10
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>

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