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 X-Spam-Level: X-Spam-Status: No, score=-20.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9AD9FC55ABD for ; Tue, 10 Nov 2020 22:12:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4EB37208CA for ; Tue, 10 Nov 2020 22:12:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="UOKpUFeF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732798AbgKJWMQ (ORCPT ); Tue, 10 Nov 2020 17:12:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732720AbgKJWMK (ORCPT ); Tue, 10 Nov 2020 17:12:10 -0500 Received: from mail-wm1-x34a.google.com (mail-wm1-x34a.google.com [IPv6:2a00:1450:4864:20::34a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DEE4C0613D3 for ; Tue, 10 Nov 2020 14:12:08 -0800 (PST) Received: by mail-wm1-x34a.google.com with SMTP id z62so1668524wmb.1 for ; Tue, 10 Nov 2020 14:12:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=b+EvmbcrIzXMPo/m/7VxFCc4Xq4JWsmqnUpW/yxxI4A=; b=UOKpUFeF+RKfDxdKeAuqH9Ep38E/IibnknrTVPrxW/xuGNx4sl82/JZzPEnLv1hzqy G9yy7gxZ/ZrOB7KxawXhoQPEIwatw+uhVfwNQWVUbmRBFgRo7kV+lwQ3BN+f6ivtYrMZ LKHrk4gliZQ+k+BejsDXu5LK90ppf/Ith+jVDKO/6ZGZHlDLz9vl1VyRJ6JSTcGDpF+1 5PzQZyELkg3sW2GepOg/s3VN/CtDNSQqwAPocz/FnHX0B0W0S72qyqFdt3aXH0099yKm xUouqMd/NMiJVSE2QLOwpwcfVsCv0A2+3aTh7+ZE1UnAJPqHdTzHvjKsgouegj7kgDlS OPjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=b+EvmbcrIzXMPo/m/7VxFCc4Xq4JWsmqnUpW/yxxI4A=; b=klAdHXOJeXOLUT1tFoVDyt1mP7131x6diahh9hA0/fSbMgwNqBauehJH/83Vyo72kt +kEpTGQR9QcCZ3sQ5r9SxDBOrihjNlJOniGW7pB4J7EJwGwg4UkbvlNeYXnE6z0PT2fM 329LWSRSrFi0I4KTmXsFfOrzSpF4chdSxZ58p6PKth3GoFPghSePgX+oJGXEbaFLA+bP aLrlEH9VQgwBtCiuh58wAiKwaUDpdSesqK/zpAijl2/QVAvbM6Hgga4+qqHVdAGjDuBu mgPhxzvfWdKaYSk99ztwfKt86WP+PX6JdFn0IBfsLsUqPq6MGsbkKW/yJfKQHNNtR/OE Mbxw== X-Gm-Message-State: AOAM5304idu4Rkc/YLfnhz6er7lsSttkbudYmO660j72ktg4LFuyI4x0 RCDdZUovBpKub1FJgVg3YlJG7Io+MeQQ9ONj X-Google-Smtp-Source: ABdhPJyv/1EGGeUZviATC/5X9dTB0m7XMbtCtTViI9SEPTGVaeOF1dXVHorUMP/w+/Tkg+7Cb62gZVmjl0n7ugkb Sender: "andreyknvl via sendgmr" X-Received: from andreyknvl3.muc.corp.google.com ([2a00:79e0:15:13:7220:84ff:fe09:7e9d]) (user=andreyknvl job=sendgmr) by 2002:a7b:cf1a:: with SMTP id l26mr287557wmg.18.1605046327072; Tue, 10 Nov 2020 14:12:07 -0800 (PST) Date: Tue, 10 Nov 2020 23:10:22 +0100 In-Reply-To: Message-Id: <55d90be0a5815917f0e1bd468ea0a257f72e7e46.1605046192.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.29.2.222.g5d2a92d10f8-goog Subject: [PATCH v9 25/44] kasan: introduce CONFIG_KASAN_HW_TAGS From: Andrey Konovalov To: Catalin Marinas Cc: Will Deacon , Vincenzo Frascino , Dmitry Vyukov , Andrey Ryabinin , Alexander Potapenko , Marco Elver , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , Andrew Morton , kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds a configuration option for a new KASAN mode called hardware tag-based KASAN. This mode uses the memory tagging approach like the software tag-based mode, but relies on arm64 Memory Tagging Extension feature for tag management and access checking. Signed-off-by: Andrey Konovalov Co-developed-by: Vincenzo Frascino Signed-off-by: Vincenzo Frascino Reviewed-by: Marco Elver --- Change-Id: I246c2def9fffa6563278db1bddfbe742ca7bdefe --- lib/Kconfig.kasan | 58 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 41 insertions(+), 17 deletions(-) diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index ec59a0e26d09..e5f27ec8b254 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -6,7 +6,10 @@ config HAVE_ARCH_KASAN config HAVE_ARCH_KASAN_SW_TAGS bool -config HAVE_ARCH_KASAN_VMALLOC +config HAVE_ARCH_KASAN_HW_TAGS + bool + +config HAVE_ARCH_KASAN_VMALLOC bool config CC_HAS_KASAN_GENERIC @@ -20,11 +23,11 @@ config CC_HAS_WORKING_NOSANITIZE_ADDRESS menuconfig KASAN bool "KASAN: runtime memory debugger" - depends on (HAVE_ARCH_KASAN && CC_HAS_KASAN_GENERIC) || \ - (HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS) + depends on (((HAVE_ARCH_KASAN && CC_HAS_KASAN_GENERIC) || \ + (HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS)) && \ + CC_HAS_WORKING_NOSANITIZE_ADDRESS) || \ + HAVE_ARCH_KASAN_HW_TAGS depends on (SLUB && SYSFS) || (SLAB && !DEBUG_SLAB) - depends on CC_HAS_WORKING_NOSANITIZE_ADDRESS - select CONSTRUCTORS select STACKDEPOT help Enables KASAN (KernelAddressSANitizer) - runtime memory debugger, @@ -37,18 +40,24 @@ choice prompt "KASAN mode" default KASAN_GENERIC help - KASAN has two modes: generic KASAN (similar to userspace ASan, - x86_64/arm64/xtensa, enabled with CONFIG_KASAN_GENERIC) and - software tag-based KASAN (a version based on software memory - tagging, arm64 only, similar to userspace HWASan, enabled with - CONFIG_KASAN_SW_TAGS). + KASAN has three modes: + 1. generic KASAN (similar to userspace ASan, + x86_64/arm64/xtensa, enabled with CONFIG_KASAN_GENERIC), + 2. software tag-based KASAN (arm64 only, based on software + memory tagging (similar to userspace HWASan), enabled with + CONFIG_KASAN_SW_TAGS), and + 3. hardware tag-based KASAN (arm64 only, based on hardware + memory tagging, enabled with CONFIG_KASAN_HW_TAGS). + + All KASAN modes are strictly debugging features. - Both generic and tag-based KASAN are strictly debugging features. + For better error reports enable CONFIG_STACKTRACE. config KASAN_GENERIC bool "Generic mode" depends on HAVE_ARCH_KASAN && CC_HAS_KASAN_GENERIC select SLUB_DEBUG if SLUB + select CONSTRUCTORS help Enables generic KASAN mode. @@ -61,8 +70,6 @@ config KASAN_GENERIC and introduces an overhead of ~x1.5 for the rest of the allocations. The performance slowdown is ~x3. - For better error detection enable CONFIG_STACKTRACE. - Currently CONFIG_KASAN_GENERIC doesn't work with CONFIG_DEBUG_SLAB (the resulting kernel does not boot). @@ -70,11 +77,15 @@ config KASAN_SW_TAGS bool "Software tag-based mode" depends on HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS select SLUB_DEBUG if SLUB + select CONSTRUCTORS help Enables software tag-based KASAN mode. - This mode requires Top Byte Ignore support by the CPU and therefore - is only supported for arm64. This mode requires Clang. + This mode require software memory tagging support in the form of + HWASan-like compiler instrumentation. + + Currently this mode is only implemented for arm64 CPUs and relies on + Top Byte Ignore. This mode requires Clang. This mode consumes about 1/16th of available memory at kernel start and introduces an overhead of ~20% for the rest of the allocations. @@ -82,15 +93,27 @@ config KASAN_SW_TAGS casting and comparison, as it embeds tags into the top byte of each pointer. - For better error detection enable CONFIG_STACKTRACE. - Currently CONFIG_KASAN_SW_TAGS doesn't work with CONFIG_DEBUG_SLAB (the resulting kernel does not boot). +config KASAN_HW_TAGS + bool "Hardware tag-based mode" + depends on HAVE_ARCH_KASAN_HW_TAGS + depends on SLUB + help + Enables hardware tag-based KASAN mode. + + This mode requires hardware memory tagging support, and can be used + by any architecture that provides it. + + Currently this mode is only implemented for arm64 CPUs starting from + ARMv8.5 and relies on Memory Tagging Extension and Top Byte Ignore. + endchoice choice prompt "Instrumentation type" + depends on KASAN_GENERIC || KASAN_SW_TAGS default KASAN_OUTLINE config KASAN_OUTLINE @@ -114,6 +137,7 @@ endchoice config KASAN_STACK_ENABLE bool "Enable stack instrumentation (unsafe)" if CC_IS_CLANG && !COMPILE_TEST + depends on KASAN_GENERIC || KASAN_SW_TAGS help The LLVM stack address sanitizer has a know problem that causes excessive stack usage in a lot of functions, see -- 2.29.2.222.g5d2a92d10f8-goog