From nobody Tue Apr 7 16:31:00 2026 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 7C69CECAAD4 for ; Fri, 26 Aug 2022 15:16:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344471AbiHZPQ4 (ORCPT ); Fri, 26 Aug 2022 11:16:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344576AbiHZPPp (ORCPT ); Fri, 26 Aug 2022 11:15:45 -0400 Received: from mail-lj1-x24a.google.com (mail-lj1-x24a.google.com [IPv6:2a00:1450:4864:20::24a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 98E48DD4D6 for ; Fri, 26 Aug 2022 08:10:20 -0700 (PDT) Received: by mail-lj1-x24a.google.com with SMTP id be32-20020a05651c172000b00261b5eae43eso661184ljb.10 for ; Fri, 26 Aug 2022 08:10:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc; bh=fxlXGK8qL+YVfFcW6ClvjL4YS8Ri9qaHIYNR2qoUuzA=; b=Q8VLjQ5xsWoRQwcBX26q4ZfJywgvwwYMqm7WRIZT/igOO0C+hQHvWJdj6bKE/htghx DrY+lrNXNEbosReTbTCbvhlRqJK2QXAnzf9wyBVGEBrx0xxr82tqOecv4nBtt+ZxQ/yz olXwbcf4S8A0zqAksvcEzulatqIcfYttRp+CQJcmIHJmyH6BPQSBoduAFmbbmZi1yVjp Tg6Bb8K5bppJxRqKIw0j6if6T//cGZVzeA7QuH2nxxvPggC9uSXoPvQi5rO7W7h+JR7N w+bOFVhYur+hDrR+w9sC1KCjIT/m0VnGKDSplsMs4+EUNYFwUHkEBbvxDpMspo6USKZQ VmLw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc; bh=fxlXGK8qL+YVfFcW6ClvjL4YS8Ri9qaHIYNR2qoUuzA=; b=cFAokgwv1VbL0leQ4+pI7tjryyWal5Ozbl2uXlh9nbVUqlZzXr5Ik3WaoQnhdbSqgc 4j5B6P/H5nD/9QmchQQEnFrjF198IBuq1SWTjbWA1ln+VojPvJY0H+gpkGxJbA/dvABc XsRpblUG5H7klaB4hJgZuJ5iJA1H2nd5/DJ3jrCgZaDZvC5sQ/4uVVXcgTF3L+NyKyW9 uGADMF/XUWUmWiSMXWrgt4Q9lgvudlk4M77/ZyvpLiqFsGWoE4a/L1zhb+DITo1HJyTH Lh3KIgkx5fihDGTU51Tbb1rX0saSF9ecYUOSx2nHpFPPwRrtpOjohEcEclEGws5FhOld goYA== X-Gm-Message-State: ACgBeo2FSzN4TkXRUHPuWbKL6ivGbqtgDAuclzL4Zu95wZJW8jcHLxex +ofCOGFvEJht+RVcmrB9cXm9L+sZG8I= X-Google-Smtp-Source: AA6agR4ts2QVsl2UWCVwazOIhjWaaZlRudAXUf4/lJNteJtVBKT5mB6+2t9fiOdhKBlLEptewn0gZtbEsjs= X-Received: from glider.muc.corp.google.com ([2a00:79e0:9c:201:5207:ac36:fdd3:502d]) (user=glider job=sendgmr) by 2002:a19:e012:0:b0:492:bec1:7f9d with SMTP id x18-20020a19e012000000b00492bec17f9dmr2498937lfg.585.1661526615782; Fri, 26 Aug 2022 08:10:15 -0700 (PDT) Date: Fri, 26 Aug 2022 17:08:07 +0200 In-Reply-To: <20220826150807.723137-1-glider@google.com> Mime-Version: 1.0 References: <20220826150807.723137-1-glider@google.com> X-Mailer: git-send-email 2.37.2.672.g94769d06f0-goog Message-ID: <20220826150807.723137-45-glider@google.com> Subject: [PATCH v5 44/44] x86: kmsan: enable KMSAN builds for x86 From: Alexander Potapenko To: glider@google.com Cc: Alexander Viro , Alexei Starovoitov , Andrew Morton , Andrey Konovalov , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Christoph Hellwig , Christoph Lameter , David Rientjes , Dmitry Vyukov , Eric Dumazet , Greg Kroah-Hartman , Herbert Xu , Ilya Leoshkevich , Ingo Molnar , Jens Axboe , Joonsoo Kim , Kees Cook , Marco Elver , Mark Rutland , Matthew Wilcox , "Michael S. Tsirkin" , Pekka Enberg , Peter Zijlstra , Petr Mladek , Steven Rostedt , Thomas Gleixner , Vasily Gorbik , Vegard Nossum , Vlastimil Babka , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Make KMSAN usable by adding the necessary Kconfig bits. Also declare x86-specific functions checking address validity in arch/x86/include/asm/kmsan.h. Signed-off-by: Alexander Potapenko --- v4: -- per Marco Elver's request, create arch/x86/include/asm/kmsan.h and move arch-specific inline functions there. Link: https://linux-review.googlesource.com/id/I1d295ce8159ce15faa496d20089= d953a919c125e --- arch/x86/Kconfig | 1 + arch/x86/include/asm/kmsan.h | 55 ++++++++++++++++++++++++++++++++++++ 2 files changed, 56 insertions(+) create mode 100644 arch/x86/include/asm/kmsan.h diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 697da8dae1418..bd9436cd0f29b 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -168,6 +168,7 @@ config X86 select HAVE_ARCH_KASAN if X86_64 select HAVE_ARCH_KASAN_VMALLOC if X86_64 select HAVE_ARCH_KFENCE + select HAVE_ARCH_KMSAN if X86_64 select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT diff --git a/arch/x86/include/asm/kmsan.h b/arch/x86/include/asm/kmsan.h new file mode 100644 index 0000000000000..a790b865d0a68 --- /dev/null +++ b/arch/x86/include/asm/kmsan.h @@ -0,0 +1,55 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * x86 KMSAN support. + * + * Copyright (C) 2022, Google LLC + * Author: Alexander Potapenko + */ + +#ifndef _ASM_X86_KMSAN_H +#define _ASM_X86_KMSAN_H + +#ifndef MODULE + +#include +#include + +/* + * Taken from arch/x86/mm/physaddr.h to avoid using an instrumented versio= n. + */ +static inline bool kmsan_phys_addr_valid(unsigned long addr) +{ + if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT)) + return !(addr >> boot_cpu_data.x86_phys_bits); + else + return true; +} + +/* + * Taken from arch/x86/mm/physaddr.c to avoid using an instrumented versio= n. + */ +static inline bool kmsan_virt_addr_valid(void *addr) +{ + unsigned long x =3D (unsigned long)addr; + unsigned long y =3D x - __START_KERNEL_map; + + /* use the carry flag to determine if x was < __START_KERNEL_map */ + if (unlikely(x > y)) { + x =3D y + phys_base; + + if (y >=3D KERNEL_IMAGE_SIZE) + return false; + } else { + x =3D y + (__START_KERNEL_map - PAGE_OFFSET); + + /* carry flag will be set if starting x was >=3D PAGE_OFFSET */ + if ((x > y) || !kmsan_phys_addr_valid(x)) + return false; + } + + return pfn_valid(x >> PAGE_SHIFT); +} + +#endif /* !MODULE */ + +#endif /* _ASM_X86_KMSAN_H */ --=20 2.37.2.672.g94769d06f0-goog