From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it1-f197.google.com (mail-it1-f197.google.com [209.85.166.197]) by kanga.kvack.org (Postfix) with ESMTP id 058E86B0003 for ; Mon, 12 Nov 2018 13:21:57 -0500 (EST) Received: by mail-it1-f197.google.com with SMTP id h126-v6so1208337ita.1 for ; Mon, 12 Nov 2018 10:21:56 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id 71-v6sor35462081jay.9.2018.11.12.10.21.55 for (Google Transport Security); Mon, 12 Nov 2018 10:21:55 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20181107170458.jirk2b3tszrcagbt@lakrids.cambridge.arm.com> References: <20181107170458.jirk2b3tszrcagbt@lakrids.cambridge.arm.com> From: Andrey Konovalov Date: Mon, 12 Nov 2018 19:21:54 +0100 Message-ID: Subject: Re: [PATCH v10 05/22] kasan: add CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Mark Rutland Cc: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Catalin Marinas , Will Deacon , Christoph Lameter , Andrew Morton , Nick Desaulniers , Marc Zyngier , Dave Martin , Ard Biesheuvel , "Eric W . Biederman" , Ingo Molnar , Paul Lawrence , Geert Uytterhoeven , Arnd Bergmann , "Kirill A . Shutemov" , Greg Kroah-Hartman , Kate Stewart , Mike Rapoport , kasan-dev@googlegroups.com, "open list:DOCUMENTATION" , LKML , Linux ARM , linux-sparse@vger.kernel.org, Linux Memory Management List , Linux Kbuild mailing list , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Jann Horn , Mark Brand , Chintan Pandya , Vishwath Mohan On Wed, Nov 7, 2018 at 6:04 PM, Mark Rutland wrote: > On Tue, Nov 06, 2018 at 06:30:20PM +0100, Andrey Konovalov wrote: >> This commit splits the current CONFIG_KASAN config option into two: >> 1. CONFIG_KASAN_GENERIC, that enables the generic KASAN mode (the one >> that exists now); >> 2. CONFIG_KASAN_SW_TAGS, that enables the software tag-based KASAN mode. >> >> The name CONFIG_KASAN_SW_TAGS is chosen as in the future we will have >> another hardware tag-based KASAN mode, that will rely on hardware memory >> tagging support in arm64. >> >> With CONFIG_KASAN_SW_TAGS enabled, compiler options are changed to >> instrument kernel files with -fsantize=kernel-hwaddress (except the ones >> for which KASAN_SANITIZE := n is set). >> >> Both CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS support both >> CONFIG_KASAN_INLINE and CONFIG_KASAN_OUTLINE instrumentation modes. >> >> This commit also adds empty placeholder (for now) implementation of >> tag-based KASAN specific hooks inserted by the compiler and adjusts >> common hooks implementation to compile correctly with each of the >> config options. >> >> Reviewed-by: Andrey Ryabinin >> Reviewed-by: Dmitry Vyukov >> Signed-off-by: Andrey Konovalov >> --- >> arch/arm64/Kconfig | 1 + >> include/linux/compiler-clang.h | 5 +- >> include/linux/compiler-gcc.h | 6 ++ >> include/linux/compiler_attributes.h | 13 ----- >> include/linux/kasan.h | 16 ++++-- >> lib/Kconfig.kasan | 87 +++++++++++++++++++++++------ >> mm/kasan/Makefile | 6 +- >> mm/kasan/generic.c | 2 +- >> mm/kasan/kasan.h | 3 +- >> mm/kasan/tags.c | 75 +++++++++++++++++++++++++ >> mm/slub.c | 2 +- >> scripts/Makefile.kasan | 27 ++++++++- >> 12 files changed, 201 insertions(+), 42 deletions(-) >> create mode 100644 mm/kasan/tags.c >> >> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >> index 787d7850e064..8b331dcfb48e 100644 >> --- a/arch/arm64/Kconfig >> +++ b/arch/arm64/Kconfig >> @@ -111,6 +111,7 @@ config ARM64 >> select HAVE_ARCH_JUMP_LABEL >> select HAVE_ARCH_JUMP_LABEL_RELATIVE >> select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) >> + select HAVE_ARCH_KASAN_SW_TAGS if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) > > Given this relies on a compiler feature, can we please gate this on > compiler feature detection? e.g. in some common Kconfig have: > > select CC_HAS_ASAN_HWADDRESS if $(cc-option -fsanitize=kernel-hwaddress) > > ... and on arm64 we can do: > > select HAVE_ARCH_KASAN_SW_TAGS if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) > > ... and core KASAN Kconfig can have: > > config KASAN_SW_TAGS > depends on HAVE_ARCH_KASAN_SW_TAGS > depends on CC_HAS_ASAN_HWADDRESS > > [...] > >> +ifeq ($(call cc-option, $(CFLAGS_KASAN) -Werror),) >> + ifneq ($(CONFIG_COMPILE_TEST),y) >> + $(warning Cannot use CONFIG_KASAN_SW_TAGS: \ >> + -fsanitize=hwaddress is not supported by compiler) >> + endif >> +endif > > ... and then this warning shouldn't be possible, and can go. Will do in v11, thanks!