From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C76DC64ED6 for ; Sun, 26 Feb 2023 05:03:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229590AbjBZFDu (ORCPT ); Sun, 26 Feb 2023 00:03:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229445AbjBZFDp (ORCPT ); Sun, 26 Feb 2023 00:03:45 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60C4712857 for ; Sat, 25 Feb 2023 21:03:44 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EF06060BE9 for ; Sun, 26 Feb 2023 05:03:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4DF8BC433D2; Sun, 26 Feb 2023 05:03:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1677387823; bh=0liWfwISLrMxPiQkUeEb9N0/1YQI9wDCzOmljFQBJWw=; h=Date:To:From:Subject:From; b=mwq4BhhQZf1zF83v2iw4cMVrG+P54GJfkhpAjYoTLrZGQeWXZlyFQEJFhJHZRX9Ae Iy57tWYK5tGFV0IXrn7mVCa3tZjqXFHK0FxM4IADt5FZKvG5HG1GtCd2xxCyEMYl/U bqoinY12gjkqh7SWWeVrNLeHfVlf24+h6vKcD9gU= Date: Sat, 25 Feb 2023 21:03:42 -0800 To: mm-commits@vger.kernel.org, vincenzo.frascino@arm.com, tglx@linutronix.de, ryabinin.a.a@gmail.com, peterz@infradead.org, nicolas@fjasle.eu, ndesaulniers@google.com, nathan@kernel.org, naresh.kamboju@linaro.org, mingo@redhat.com, lkft@linaro.org, keescook@chromium.org, jakub@redhat.com, glider@google.com, dvyukov@google.com, dave.hansen@linux.intel.com, bp@alien8.de, andreyknvl@gmail.com, elver@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: + kasan-treat-meminstrinsic-as-builtins-in-uninstrumented-files.patch added to mm-hotfixes-unstable branch Message-Id: <20230226050343.4DF8BC433D2@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: kasan: treat meminstrinsic as builtins in uninstrumented files has been added to the -mm mm-hotfixes-unstable branch. Its filename is kasan-treat-meminstrinsic-as-builtins-in-uninstrumented-files.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kasan-treat-meminstrinsic-as-builtins-in-uninstrumented-files.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Marco Elver Subject: kasan: treat meminstrinsic as builtins in uninstrumented files Date: Fri, 24 Feb 2023 09:59:40 +0100 Where the compiler instruments meminstrinsics by generating calls to __asan/__hwasan_ prefixed functions, let the compiler consider memintrinsics as builtin again. To do so, never override memset/memmove/memcpy if the compiler does the correct instrumentation - even on !GENERIC_ENTRY architectures. Link: https://lkml.kernel.org/r/20230224085942.1791837-2-elver@google.com Fixes: 69d4c0d32186 ("entry, kasan, x86: Disallow overriding mem*() functions") Signed-off-by: Marco Elver Reviewed-by: Andrey Konovalov Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Borislav Petkov (AMD) Cc: Dave Hansen Cc: Dmitry Vyukov Cc: Ingo Molnar Cc: Jakub Jelinek Cc: Kees Cook Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Nicolas Schier Cc: Peter Zijlstra (Intel) Cc: Thomas Gleixner Cc: Vincenzo Frascino Signed-off-by: Andrew Morton --- --- a/lib/Kconfig.kasan~kasan-treat-meminstrinsic-as-builtins-in-uninstrumented-files +++ b/lib/Kconfig.kasan @@ -49,6 +49,15 @@ menuconfig KASAN if KASAN +config CC_HAS_KASAN_MEMINTRINSIC_PREFIX + def_bool (CC_IS_CLANG && $(cc-option,-fsanitize=kernel-address -mllvm -asan-kernel-mem-intrinsic-prefix=1)) || \ + (CC_IS_GCC && $(cc-option,-fsanitize=kernel-address --param asan-kernel-mem-intrinsic-prefix=1)) + # Don't define it if we don't need it: compilation of the test uses + # this variable to decide how the compiler should treat builtins. + depends on !KASAN_HW_TAGS + help + The compiler is able to prefix memintrinsics with __asan or __hwasan. + choice prompt "KASAN mode" default KASAN_GENERIC --- a/mm/kasan/shadow.c~kasan-treat-meminstrinsic-as-builtins-in-uninstrumented-files +++ b/mm/kasan/shadow.c @@ -38,11 +38,14 @@ bool __kasan_check_write(const volatile void *p, unsigned int size) } EXPORT_SYMBOL(__kasan_check_write); -#ifndef CONFIG_GENERIC_ENTRY +#if !defined(CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX) && !defined(CONFIG_GENERIC_ENTRY) /* * CONFIG_GENERIC_ENTRY relies on compiler emitted mem*() calls to not be * instrumented. KASAN enabled toolchains should emit __asan_mem*() functions * for the sites they want to instrument. + * + * If we have a compiler that can instrument meminstrinsics, never override + * these, so that non-instrumented files can safely consider them as builtins. */ #undef memset void *memset(void *addr, int c, size_t len) --- a/scripts/Makefile.kasan~kasan-treat-meminstrinsic-as-builtins-in-uninstrumented-files +++ b/scripts/Makefile.kasan @@ -1,5 +1,14 @@ # SPDX-License-Identifier: GPL-2.0 + +ifdef CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX +# Safe for compiler to generate meminstrinsic calls in uninstrumented files. +CFLAGS_KASAN_NOSANITIZE := +else +# Don't let compiler generate memintrinsic calls in uninstrumented files +# because they are instrumented. CFLAGS_KASAN_NOSANITIZE := -fno-builtin +endif + KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET) cc-param = $(call cc-option, -mllvm -$(1), $(call cc-option, --param $(1))) _ Patches currently in -mm which might be from elver@google.com are kasan-emit-different-calls-for-instrumentable-memintrinsics.patch kasan-treat-meminstrinsic-as-builtins-in-uninstrumented-files.patch kasan-test-fix-test-for-new-meminstrinsic-instrumentation.patch kasan-x86-dont-rename-memintrinsics-in-uninstrumented-files.patch