Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754129AbbKQPrL (ORCPT ); Tue, 17 Nov 2015 10:47:11 -0500 Received: from relay.parallels.com ([195.214.232.42]:55903 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753931AbbKQPrI (ORCPT ); Tue, 17 Nov 2015 10:47:08 -0500 Subject: Re: [PATCH v7 0/4] KASAN for arm64 To: "Suzuki K. Poulose" References: <1444665180-301-1-git-send-email-ryabinin.a.a@gmail.com> <20151013083432.GG6320@e104818-lin.cambridge.arm.com> <5649BAFD.6030005@arm.com> <5649F783.40109@gmail.com> <564B40A7.1000206@arm.com> CC: Catalin Marinas , Will Deacon , , Yury , Alexey Klimov , Arnd Bergmann , , Andrey Konovalov , Linus Walleij , Ard Biesheuvel , , kasan-dev , David Keitel , Alexander Potapenko , Dmitry Vyukov From: Andrey Ryabinin Message-ID: <564B4BFC.1020905@virtuozzo.com> Date: Tue, 17 Nov 2015 18:47:08 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <564B40A7.1000206@arm.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: US-EXCH.sw.swsoft.com (10.255.249.47) To MSK-EXCH1.sw.swsoft.com (10.67.48.55) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2807 Lines: 71 On 11/17/2015 05:58 PM, Suzuki K. Poulose wrote: > On 16/11/15 15:34, Andrey Ryabinin wrote: >> On 11/16/2015 02:16 PM, Suzuki K. Poulose wrote: >>> On 13/10/15 09:34, Catalin Marinas wrote: >>>> On Mon, Oct 12, 2015 at 06:52:56PM +0300, Andrey Ryabinin wrote: > >>> Hi, >>> >>> I get the following failure with KASAN + 16K_PAGES + 48BIT_VA, with 4.4-rc1: >>> >>> >>> arch/arm64/mm/kasan_init.c: In function ?kasan_early_init?: >>> include/linux/compiler.h:484:38: error: call to ?__compiletime_assert_95? declared with attribute error: BUILD_BUG_ON failed: !IS_ALIGNED(KASAN_SHADOW_END, PGDIR_SIZE) >>> _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) >>> ^ > > ... > >> >> Yes, it's really needed, because some code relies on this (e.g. clear_pgs() and kasan_init()). >> But it should be possible to get rid of this requirement. > > And the other important point I missed mentioning was that, my tool chain doesn't > support KASAN. But still the KASAN support files are still compiled and generates > the above error. Shouldn't we disable it at build time if we detect that compiler > doesn't support it ? Something like we do for LSE_ATOMICS. > We should either add proper Kconfig dependency for now, or just make it work. From: Andrey Ryabinin 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 ?kasan_early_init?: include/linux/compiler.h:484:38: error: call to ?__compiletime_assert_95? 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 Signed-off-by: Andrey Ryabinin --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/