From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f198.google.com (mail-wr0-f198.google.com [209.85.128.198]) by kanga.kvack.org (Postfix) with ESMTP id DAF9F6B0008 for ; Fri, 20 Apr 2018 10:47:06 -0400 (EDT) Received: by mail-wr0-f198.google.com with SMTP id u13-v6so9093971wre.1 for ; Fri, 20 Apr 2018 07:47:06 -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 s9-v6sor2940539wra.62.2018.04.20.07.47.05 for (Google Transport Security); Fri, 20 Apr 2018 07:47:05 -0700 (PDT) From: Andrey Konovalov Subject: [RFC PATCH v3 03/15] khwasan, arm64: adjust shadow size for CONFIG_KASAN_HW Date: Fri, 20 Apr 2018 16:46:41 +0200 Message-Id: <12a1cdde7c35ccb62c71f9f3e8847fc782d2e8bf.1524235387.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 , 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" , 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 KWHASAN uses 1 shadow byte for 16 bytes of kernel memory, so it requires 1/16th of the kernel virtual address space for the shadow memory. This commit sets KASAN_SHADOW_SCALE_SHIFT to 4 when KHWASAN is enabled. Signed-off-by: Andrey Konovalov --- arch/arm64/Makefile | 2 +- arch/arm64/include/asm/memory.h | 13 +++++++++---- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 15402861bb59..49092d763673 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -95,7 +95,7 @@ endif # KASAN_SHADOW_OFFSET = VA_START + (1 << (VA_BITS - KASAN_SHADOW_SCALE_SHIFT)) # - (1 << (64 - KASAN_SHADOW_SCALE_SHIFT)) # in 32-bit arithmetic -KASAN_SHADOW_SCALE_SHIFT := 3 +KASAN_SHADOW_SCALE_SHIFT := $(if $(CONFIG_KASAN_HW), 4, 3) KASAN_SHADOW_OFFSET := $(shell printf "0x%08x00000000\n" $$(( \ (0xffffffff & (-1 << ($(CONFIG_ARM64_VA_BITS) - 32))) \ + (1 << ($(CONFIG_ARM64_VA_BITS) - 32 - $(KASAN_SHADOW_SCALE_SHIFT))) \ diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 49d99214f43c..6d084431b7f7 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -74,12 +74,17 @@ #define KERNEL_END _end /* - * KASAN requires 1/8th of the kernel virtual address space for the shadow - * region. KASAN can bloat the stack significantly, so double the (minimum) - * stack size when KASAN is in use. + * KASAN and KHWASAN require 1/8th and 1/16th of the kernel virtual address + * space for the shadow region respectively. They can bloat the stack + * significantly, so double the (minimum) stack size when they are in use. */ -#ifdef CONFIG_KASAN +#ifdef CONFIG_KASAN_GENERIC #define KASAN_SHADOW_SCALE_SHIFT 3 +#endif +#ifdef CONFIG_KASAN_HW +#define KASAN_SHADOW_SCALE_SHIFT 4 +#endif +#ifdef CONFIG_KASAN #define KASAN_SHADOW_SIZE (UL(1) << (VA_BITS - KASAN_SHADOW_SCALE_SHIFT)) #define KASAN_THREAD_SHIFT 1 #else -- 2.17.0.484.g0c8726318c-goog