From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id B75AD6B0253 for ; Fri, 23 Mar 2018 14:06:12 -0400 (EDT) Received: by mail-wm0-f70.google.com with SMTP id j25so1239579wmh.1 for ; Fri, 23 Mar 2018 11:06:12 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id q13sor4637602wrg.76.2018.03.23.11.06.11 for (Google Transport Security); Fri, 23 Mar 2018 11:06:11 -0700 (PDT) From: Andrey Konovalov Subject: [RFC PATCH v2 06/15] khwasan, arm64: untag virt address in __kimg_to_phys Date: Fri, 23 Mar 2018 19:05:42 +0100 Message-Id: <81963b1be20e0d661aa626d18d245be653bdc150.1521828274.git.andreyknvl@google.com> In-Reply-To: References: In-Reply-To: References: Sender: owner-linux-mm@kvack.org List-ID: To: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Jonathan Corbet , Catalin Marinas , Will Deacon , Christoffer Dall , Marc Zyngier , Christopher Li , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Masahiro Yamada , Michal Marek , "GitAuthor : Andrey Konovalov" , Mark Rutland , Ard Biesheuvel , Yury Norov , Nick Desaulniers , Suzuki K Poulose , Kristina Martsenko , Punit Agrawal , Dave Martin , Michael Weiser , James Morse , Julien Thierry , Steve Capper , Tyler Baicar , "Eric W . Biederman" , Stephen Boyd , Thomas Gleixner , Ingo Molnar , Paul Lawrence , Greg Kroah-Hartman , David Woodhouse , Sandipan Das , Kees Cook , Herbert Xu , Geert Uytterhoeven , Josh Poimboeuf , Arnd Bergmann , kasan-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-sparse@vger.kernel.org, linux-mm@kvack.org, linux-kbuild@vger.kernel.org Cc: Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Kees Cook , Jann Horn , Mark Brand __kimg_to_phys (which is used by virt_to_phys) assumes that the top byte of the address is 0xff, which isn't always the case with KHWASAN enabled. The solution is to reset the tag in __kimg_to_phys. __lm_to_phys doesn't require any fixups, as it zeroes out the top byte with the current implementation. Signed-off-by: Andrey Konovalov --- arch/arm64/include/asm/memory.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index febd54ff3354..c13b89257352 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -98,6 +98,10 @@ #define KASAN_THREAD_SHIFT 0 #endif +#ifdef CONFIG_KASAN_TAGS +#define KASAN_PTR_TAG_MASK (UL(0xff) << 56) +#endif + #define MIN_THREAD_SHIFT (14 + KASAN_THREAD_SHIFT) /* @@ -231,7 +235,12 @@ static inline unsigned long kaslr_offset(void) #define __is_lm_address(addr) (!!((addr) & BIT(VA_BITS - 1))) #define __lm_to_phys(addr) (((addr) & ~PAGE_OFFSET) + PHYS_OFFSET) + +#ifdef CONFIG_KASAN_TAGS +#define __kimg_to_phys(addr) (((addr) | KASAN_PTR_TAG_MASK) - kimage_voffset) +#else #define __kimg_to_phys(addr) ((addr) - kimage_voffset) +#endif #define __virt_to_phys_nodebug(x) ({ \ phys_addr_t __x = (phys_addr_t)(x); \ -- 2.17.0.rc0.231.g781580f067-goog