From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB85FC43381 for ; Mon, 1 Apr 2019 11:27:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DF2F2086C for ; Mon, 1 Apr 2019 11:27:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726163AbfDAL1u (ORCPT ); Mon, 1 Apr 2019 07:27:50 -0400 Received: from foss.arm.com ([217.140.101.70]:33068 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725882AbfDAL1u (ORCPT ); Mon, 1 Apr 2019 07:27:50 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 36547A78; Mon, 1 Apr 2019 04:27:49 -0700 (PDT) Received: from [10.1.196.72] (e119884-lin.cambridge.arm.com [10.1.196.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 223F63F557; Mon, 1 Apr 2019 04:27:47 -0700 (PDT) Subject: Re: [PATCH] arm64: compat: Reduce address limit To: Catalin Marinas Cc: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, stable@vger.kernel.org, Will Deacon , Jann Horn References: <20190401103201.9268-1-vincenzo.frascino@arm.com> <20190401105913.GC14874@arrakis.emea.arm.com> From: Vincenzo Frascino Message-ID: <5b732920-b067-219c-ffd7-3ce99f1b4446@arm.com> Date: Mon, 1 Apr 2019 12:27:46 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190401105913.GC14874@arrakis.emea.arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On 01/04/2019 11:59, Catalin Marinas wrote: > On Mon, Apr 01, 2019 at 11:32:01AM +0100, Vincenzo Frascino wrote: >> Currently, compat tasks running on arm64 can allocate memory up to >> TASK_SIZE_32 (UL(0x100000000)). >> >> This means that mmap() allocations, if we treat them as returning an >> array, are not compliant with the sections 6.5.8 of the C standard >> (C99) which states that: "If the expression P points to an element of >> an array object and the expression Q points to the last element of the >> same array object, the pointer expression Q+1 compares greater than P". >> >> Redefine TASK_SIZE_32 to address the issue. >> >> Cc: Catalin Marinas >> Cc: Will Deacon >> Cc: Jann Horn >> Reported-by: Jann Horn >> Signed-off-by: Vincenzo Frascino >> --- >> arch/arm64/include/asm/processor.h | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h >> index 5d9ce62bdebd..f8235f7df29b 100644 >> --- a/arch/arm64/include/asm/processor.h >> +++ b/arch/arm64/include/asm/processor.h >> @@ -57,7 +57,11 @@ >> #define TASK_SIZE_64 (UL(1) << vabits_user) >> >> #ifdef CONFIG_COMPAT >> +#ifdef CONFIG_ARM64_64K_PAGES >> #define TASK_SIZE_32 UL(0x100000000) >> +#else >> +#define TASK_SIZE_32 (UL(0x100000000) - PAGE_SIZE) >> +#endif /* CONFIG_ARM64_64K_PAGES */ > > I'd add a comment above stating that with the 64K page configuration, > the last page is occupied by the compat vectors page. > Ok, I will post v2 shortly. -- Regards, Vincenzo From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 702E8C43381 for ; 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Mon, 1 Apr 2019 04:27:47 -0700 (PDT) Subject: Re: [PATCH] arm64: compat: Reduce address limit To: Catalin Marinas References: <20190401103201.9268-1-vincenzo.frascino@arm.com> <20190401105913.GC14874@arrakis.emea.arm.com> From: Vincenzo Frascino Message-ID: <5b732920-b067-219c-ffd7-3ce99f1b4446@arm.com> Date: Mon, 1 Apr 2019 12:27:46 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190401105913.GC14874@arrakis.emea.arm.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190401_042749_599446_A97EF8DB X-CRM114-Status: GOOD ( 15.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Will Deacon , stable@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jann Horn Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 01/04/2019 11:59, Catalin Marinas wrote: > On Mon, Apr 01, 2019 at 11:32:01AM +0100, Vincenzo Frascino wrote: >> Currently, compat tasks running on arm64 can allocate memory up to >> TASK_SIZE_32 (UL(0x100000000)). >> >> This means that mmap() allocations, if we treat them as returning an >> array, are not compliant with the sections 6.5.8 of the C standard >> (C99) which states that: "If the expression P points to an element of >> an array object and the expression Q points to the last element of the >> same array object, the pointer expression Q+1 compares greater than P". >> >> Redefine TASK_SIZE_32 to address the issue. >> >> Cc: Catalin Marinas >> Cc: Will Deacon >> Cc: Jann Horn >> Reported-by: Jann Horn >> Signed-off-by: Vincenzo Frascino >> --- >> arch/arm64/include/asm/processor.h | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h >> index 5d9ce62bdebd..f8235f7df29b 100644 >> --- a/arch/arm64/include/asm/processor.h >> +++ b/arch/arm64/include/asm/processor.h >> @@ -57,7 +57,11 @@ >> #define TASK_SIZE_64 (UL(1) << vabits_user) >> >> #ifdef CONFIG_COMPAT >> +#ifdef CONFIG_ARM64_64K_PAGES >> #define TASK_SIZE_32 UL(0x100000000) >> +#else >> +#define TASK_SIZE_32 (UL(0x100000000) - PAGE_SIZE) >> +#endif /* CONFIG_ARM64_64K_PAGES */ > > I'd add a comment above stating that with the 64K page configuration, > the last page is occupied by the compat vectors page. > Ok, I will post v2 shortly. -- Regards, Vincenzo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel