From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753345AbaGJMSH (ORCPT ); Thu, 10 Jul 2014 08:18:07 -0400 Received: from mailout2.w1.samsung.com ([210.118.77.12]:44273 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752484AbaGJMSE (ORCPT ); Thu, 10 Jul 2014 08:18:04 -0400 X-AuditID: cbfec7f4-b7fac6d000006cfe-f0-53be84785f79 Message-id: <53BE8333.6060404@samsung.com> Date: Thu, 10 Jul 2014 16:12:35 +0400 From: Andrey Ryabinin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-version: 1.0 To: Dave Hansen , linux-kernel@vger.kernel.org Cc: Dmitry Vyukov , Konstantin Serebryany , Alexey Preobrazhensky , Andrey Konovalov , Yuri Gribov , Konstantin Khlebnikov , Sasha Levin , Michal Marek , Russell King , Thomas Gleixner , Ingo Molnar , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , linux-kbuild@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, linux-mm@kvack.org Subject: Re: [RFC/PATCH RESEND -next 01/21] Add kernel address sanitizer infrastructure. References: <1404905415-9046-1-git-send-email-a.ryabinin@samsung.com> <1404905415-9046-2-git-send-email-a.ryabinin@samsung.com> <53BDA568.5030607@intel.com> In-reply-to: <53BDA568.5030607@intel.com> Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrFIsWRmVeSWpSXmKPExsVy+t/xa7oVLfuCDU62K1j83juT1WLO+jVs Fte/vWG0+PTyAaPFhIdt7BYru5vZLLY/e8tksbLzAavFpsfXWC3+7NrBZHF51xw2i3tr/rNa 3L7Ma3HpwAImi5Z9F5gs2j7/Y7XYt/I8kLVkI5PF4iO3mS3ePZvMbLF501Rmix8bHrM6iHm0 NPeweeycdZfdY8GmUo/Fe14yeWxa1cnmsenTJHaPrrdXmDzenTvH7nFixm8WjydXpjN5bF5S 7/Hx6S0Wj/f7rrJ5nFlwhN3j8ya5AP4oLpuU1JzMstQifbsEroz1LcuYCv6zV/ze3cTcwNjE 1sXIySEhYCIx9e19dghbTOLCvfVAcS4OIYGljBIL1txggXCamSRunpgBVsUroCUx7/tTRhCb RUBV4te9X2BxNgE9iX+ztoNNFRWIkDjQ94wVol5Q4sfkeywgtoiAq8SK7lawocwC11kl2i8f BhskLBAl0fP8DCPEtgWMEm82LWEGSXAKaErs2vsUrJtZQEdif+s0NghbXmLzmrfMExgFZiFZ MgtJ2SwkZQsYmVcxiqaWJhcUJ6XnGuoVJ+YWl+al6yXn525ihMT3lx2Mi49ZHWIU4GBU4uHV qN0dLMSaWFZcmXuIUYKDWUmEN6tuX7AQb0piZVVqUX58UWlOavEhRiYOTqkGxqnKX907vssl vHTR372twGjvk68V4Twb5vUIvNp03kNo4YuVS/cHvRAX35Rld33lDLdfEYVbPOTTUnWPBEd+ uh5XeEaXXcc9izNSc3lHlyZDbkh4W6SB6sGDSdoO65Qdw5SXNisuzXvW5Fy3aZHgqlm582ex 9ik83rhiR/pTiXkNZ9pcp504oMRSnJFoqMVcVJwIAPcdevfNAgAA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/10/14 00:26, Dave Hansen wrote: > On 07/09/2014 04:29 AM, Andrey Ryabinin wrote: >> Address sanitizer dedicates 1/8 of the low memory to the shadow memory and uses direct >> mapping with a scale and offset to translate a memory address to its corresponding >> shadow address. >> >> Here is function to translate address to corresponding shadow address: >> >> unsigned long kasan_mem_to_shadow(unsigned long addr) >> { >> return ((addr - PAGE_OFFSET) >> KASAN_SHADOW_SCALE_SHIFT) >> + kasan_shadow_start; >> } > > How does this interact with vmalloc() addresses or those from a kmap()? > It's used only for lowmem: static inline bool addr_is_in_mem(unsigned long addr) { return likely(addr >= PAGE_OFFSET && addr < (unsigned long)high_memory); } static __always_inline void check_memory_region(unsigned long addr, size_t size, bool write) { .... if (!addr_is_in_mem(addr)) return; // check shadow here From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f47.google.com (mail-pa0-f47.google.com [209.85.220.47]) by kanga.kvack.org (Postfix) with ESMTP id 922026B0031 for ; Thu, 10 Jul 2014 08:18:04 -0400 (EDT) Received: by mail-pa0-f47.google.com with SMTP id kq14so10875219pab.6 for ; Thu, 10 Jul 2014 05:18:04 -0700 (PDT) Received: from mailout2.w1.samsung.com (mailout2.w1.samsung.com. [210.118.77.12]) by mx.google.com with ESMTPS id bo1si48413018pbc.7.2014.07.10.05.18.02 for (version=TLSv1 cipher=RC4-MD5 bits=128/128); Thu, 10 Jul 2014 05:18:03 -0700 (PDT) Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout2.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0N8H00GSVWTKFU30@mailout2.w1.samsung.com> for linux-mm@kvack.org; Thu, 10 Jul 2014 13:17:44 +0100 (BST) Message-id: <53BE8333.6060404@samsung.com> Date: Thu, 10 Jul 2014 16:12:35 +0400 From: Andrey Ryabinin MIME-version: 1.0 Subject: Re: [RFC/PATCH RESEND -next 01/21] Add kernel address sanitizer infrastructure. References: <1404905415-9046-1-git-send-email-a.ryabinin@samsung.com> <1404905415-9046-2-git-send-email-a.ryabinin@samsung.com> <53BDA568.5030607@intel.com> In-reply-to: <53BDA568.5030607@intel.com> Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen , linux-kernel@vger.kernel.org Cc: Dmitry Vyukov , Konstantin Serebryany , Alexey Preobrazhensky , Andrey Konovalov , Yuri Gribov , Konstantin Khlebnikov , Sasha Levin , Michal Marek , Russell King , Thomas Gleixner , Ingo Molnar , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , linux-kbuild@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, linux-mm@kvack.org On 07/10/14 00:26, Dave Hansen wrote: > On 07/09/2014 04:29 AM, Andrey Ryabinin wrote: >> Address sanitizer dedicates 1/8 of the low memory to the shadow memory and uses direct >> mapping with a scale and offset to translate a memory address to its corresponding >> shadow address. >> >> Here is function to translate address to corresponding shadow address: >> >> unsigned long kasan_mem_to_shadow(unsigned long addr) >> { >> return ((addr - PAGE_OFFSET) >> KASAN_SHADOW_SCALE_SHIFT) >> + kasan_shadow_start; >> } > > How does this interact with vmalloc() addresses or those from a kmap()? > It's used only for lowmem: static inline bool addr_is_in_mem(unsigned long addr) { return likely(addr >= PAGE_OFFSET && addr < (unsigned long)high_memory); } static __always_inline void check_memory_region(unsigned long addr, size_t size, bool write) { .... if (!addr_is_in_mem(addr)) return; // check shadow here -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: a.ryabinin@samsung.com (Andrey Ryabinin) Date: Thu, 10 Jul 2014 16:12:35 +0400 Subject: [RFC/PATCH RESEND -next 01/21] Add kernel address sanitizer infrastructure. In-Reply-To: <53BDA568.5030607@intel.com> References: <1404905415-9046-1-git-send-email-a.ryabinin@samsung.com> <1404905415-9046-2-git-send-email-a.ryabinin@samsung.com> <53BDA568.5030607@intel.com> Message-ID: <53BE8333.6060404@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/10/14 00:26, Dave Hansen wrote: > On 07/09/2014 04:29 AM, Andrey Ryabinin wrote: >> Address sanitizer dedicates 1/8 of the low memory to the shadow memory and uses direct >> mapping with a scale and offset to translate a memory address to its corresponding >> shadow address. >> >> Here is function to translate address to corresponding shadow address: >> >> unsigned long kasan_mem_to_shadow(unsigned long addr) >> { >> return ((addr - PAGE_OFFSET) >> KASAN_SHADOW_SCALE_SHIFT) >> + kasan_shadow_start; >> } > > How does this interact with vmalloc() addresses or those from a kmap()? > It's used only for lowmem: static inline bool addr_is_in_mem(unsigned long addr) { return likely(addr >= PAGE_OFFSET && addr < (unsigned long)high_memory); } static __always_inline void check_memory_region(unsigned long addr, size_t size, bool write) { .... if (!addr_is_in_mem(addr)) return; // check shadow here