From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1521828378; cv=none; d=google.com; s=arc-20160816; b=bjthdQRLmksAjhtwUpOUVTGBB0Fug9bmN9gRhFGvD22NTs+SGus+tyTUqkSkKrCUL0 8hI6rFvn705k+e84G2C/nmh/bbZ9orXp5KrhlsM/mYW2YOXf4CS73AaFAoLjmDi5AaIW tR3wSVqNPw/1UZWo4QgNHasoCVPepuIiOeLD/APZYdFhX0mUJatLpaWMjqGPwiw2kgOZ 3H7t4tFCzU61e9mqGXfhO+UnJsFq4lkxPypd9+xPZ0siUiO3whReh7cQH3qkoWLLR67H vaz85BZG8lV0MS0K+6Hf0CZ7cvjNV094LeuG3h+l2LC2iKwH4l8mYimjCgfnWe2/LYLj wUdA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:arc-authentication-results; bh=h7UAM4u0ltxxy6L178zyCoaH+JXfuyTZuKiCHYRMeXU=; b=waAxpVsrqv43odkId6FRqpfRjQvVVAzC8jujAM8UpOXFARFaZJx2sf+Ro1B1UDEa/J spgIWcaN16Vl4xH4WWP2EcvaWMDd1xECaihJWHYTvX44zkPrFSm3jjiQvy5qV8nRu1l8 j+jZoGVCgExuDyGKhuNfnEZI4UbAnhFij/jjGkNxrWwDdWiSN/za0Z9SkqigHb5C64oI 332K7aRCqeO6Um3GQGxyS4k1NEsKeqrro4ZZScmhzngg4hlU9Mme9KDT4aD5JgiVyVr+ voPNePl99uWE1zWBJEeGnlpsaVLPPzuF1vOKseJonPdQuOM0cwEwTtcfttu8K/FImrDE fUrw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=Fs4ONDnJ; spf=pass (google.com: domain of andreyknvl@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=andreyknvl@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=Fs4ONDnJ; spf=pass (google.com: domain of andreyknvl@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=andreyknvl@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com X-Google-Smtp-Source: AG47ELsuAzh6p7g7ra2+h+UClcAzKG/37YUeQ/5K9N+hkqo0hMa6Hv2Ylc89BIENdayTIbOX5w6V0Q== From: Andrey Konovalov 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 Subject: [RFC PATCH v2 10/15] khwasan, arm64: enable top byte ignore for the kernel Date: Fri, 23 Mar 2018 19:05:46 +0100 Message-Id: <1dcf5f0ef52a08581f453e05101cd2193575249c.1521828274.git.andreyknvl@google.com> X-Mailer: git-send-email 2.17.0.rc0.231.g781580f067-goog In-Reply-To: References: In-Reply-To: References: X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1595752713986341704?= X-GMAIL-MSGID: =?utf-8?q?1595752713986341704?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: KHWASAN uses the Top Byte Ignore feature of arm64 CPUs to store a pointer tag in the top byte of each pointer. This commit enables the TCR_TBI1 bit, which enables Top Byte Ignore for the kernel, when KHWASAN is used. Signed-off-by: Andrey Konovalov --- arch/arm64/include/asm/pgtable-hwdef.h | 1 + arch/arm64/mm/proc.S | 9 ++++++++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index cdfe3e657a9e..ae6b6405eacc 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -289,6 +289,7 @@ #define TCR_A1 (UL(1) << 22) #define TCR_ASID16 (UL(1) << 36) #define TCR_TBI0 (UL(1) << 37) +#define TCR_TBI1 (UL(1) << 38) #define TCR_HA (UL(1) << 39) #define TCR_HD (UL(1) << 40) diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index c0af47617299..d64ce2ea40ec 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -41,6 +41,12 @@ /* PTWs cacheable, inner/outer WBWA */ #define TCR_CACHE_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA +#ifdef CONFIG_KASAN_TAGS +#define KASAN_TCR_FLAGS TCR_TBI1 +#else +#define KASAN_TCR_FLAGS 0 +#endif + #define MAIR(attr, mt) ((attr) << ((mt) * 8)) /* @@ -432,7 +438,8 @@ ENTRY(__cpu_setup) * both user and kernel. */ ldr x10, =TCR_TxSZ(VA_BITS) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \ - TCR_TG_FLAGS | TCR_ASID16 | TCR_TBI0 | TCR_A1 + TCR_TG_FLAGS | TCR_ASID16 | TCR_TBI0 | TCR_A1 | \ + KASAN_TCR_FLAGS tcr_set_idmap_t0sz x10, x9 /* -- 2.17.0.rc0.231.g781580f067-goog