From patchwork Fri Aug 26 15:07:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Potapenko X-Patchwork-Id: 12956180 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF0F4ECAAD4 for ; Fri, 26 Aug 2022 15:08:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7E96A94000E; Fri, 26 Aug 2022 11:08:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 776FA940007; Fri, 26 Aug 2022 11:08:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5752094000E; Fri, 26 Aug 2022 11:08:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 45C26940007 for ; Fri, 26 Aug 2022 11:08:34 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 22C74A0FAD for ; Fri, 26 Aug 2022 15:08:34 +0000 (UTC) X-FDA: 79842075348.13.C6368AF Received: from mail-ed1-f74.google.com (mail-ed1-f74.google.com [209.85.208.74]) by imf24.hostedemail.com (Postfix) with ESMTP id D420D18001B for ; Fri, 26 Aug 2022 15:08:33 +0000 (UTC) Received: by mail-ed1-f74.google.com with SMTP id z6-20020a05640240c600b0043e1d52fd98so1240249edb.22 for ; Fri, 26 Aug 2022 08:08:33 -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=c5NepUxkZ67sJe7jHUeDkh2lejA2rZ0n/lgzGJfAW+w=; b=c+6A8OMgE+PXXvaKjkvUnzf0Zny9FaGQw3ITZ0eOqhvk/xJ6RvxfKh+stOxXyatXl4 YGr0F0FGxuPcv8CUWTObk59qFjdxmNbRa0oHquDksvKKfT8Zu2vHF6G0vca6kOpAbhNI OVOEZTiTMx/xUIeNXpsat3eCswFWmSuMpYNt42aS00HKw95twaAXWDw2g1FqoKpczn16 IuVC8oufvBy3n96QICaiFTQbEIjqBDPQxH/4XN690eGkbiZ3y/ft7KJ0uT7Yb+5MevGJ DRahR3sL+vhkXEP7eUoI9WqyhhSukcLsMWy7BqvewYy5XGfr72OPIP7WRVR5q3FgsYZn IVMA== 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=c5NepUxkZ67sJe7jHUeDkh2lejA2rZ0n/lgzGJfAW+w=; b=4BTywblyexXLpQv9eKNfrZV2STZ0no0ur++z3jNnhJurfLqres+0vdSwvrmk/oA5VA xxVcZ7/BBpf4ovswIUn0878ZP/PApXk0LQDPVm84YaN8T2z7GUkG/P40GB2WHU3OUTih WAhyPYho4IHM9aDHxDGL6SAQF+evCIBXJN2IVd4uU/WSpqKKsTQc2/qSd40TCOkfcyew Ig+/ev+dzgaicJToTstA05MNTF6zBdpZsB9ZX89kxoc8QN2ha8Xrwih5a5H+fBTNg54J HBWWGoToQjKCGtNkjGNrQuQ86iJeWnwPYBX/mIcSnqgxbNq1dAD0GZFl6WFuVRt8FNN4 OZvA== X-Gm-Message-State: ACgBeo0Cv1OKz7KhCXh3NjzmjCdlAsuXfIYxkCqxTddms3taJePtXSRt FX3g1nzgDhoyGaWXwvTyoGrDK42RvsQ= X-Google-Smtp-Source: AA6agR5ehbhUugsFXAPBIbmUJl2ccI1z6E6toZVNB9pK3XsABZI5EGu5QKmG8MsBqiQScrt+e+ok3n5vJiE= X-Received: from glider.muc.corp.google.com ([2a00:79e0:9c:201:5207:ac36:fdd3:502d]) (user=glider job=sendgmr) by 2002:a05:6402:515:b0:447:780c:39d6 with SMTP id m21-20020a056402051500b00447780c39d6mr7244136edv.265.1661526512626; Fri, 26 Aug 2022 08:08:32 -0700 (PDT) Date: Fri, 26 Aug 2022 17:07:30 +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: <20220826150807.723137-8-glider@google.com> Subject: [PATCH v5 07/44] kmsan: introduce __no_sanitize_memory and __no_kmsan_checks 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 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661526513; a=rsa-sha256; cv=none; b=FO2FXl/JP7je49MshLexPUE/ADN+c0+PgjflwtswQXY5J2baOUmV1AqtnO1aQHN7sQyi7M n4ojMezUb5tkCJqAu05c8N4RZXY55XT9R0/78sPZKm20UHioUnrjUPZFpyzL8L3vMVio9C 7Ge/jW4rSxM4ppNUBBvHZyG1NY/glwM= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=c+6A8OMg; spf=pass (imf24.hostedemail.com: domain of 38OEIYwYKCPUdifabodlldib.Zljifkru-jjhsXZh.lod@flex--glider.bounces.google.com designates 209.85.208.74 as permitted sender) smtp.mailfrom=38OEIYwYKCPUdifabodlldib.Zljifkru-jjhsXZh.lod@flex--glider.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661526513; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=c5NepUxkZ67sJe7jHUeDkh2lejA2rZ0n/lgzGJfAW+w=; b=IQxzafEdDZgMAAgn207KGSzWvUvrlq8I4pqt4Oe/RYOq78esALZY0Vttbnr0OT8bW5s1WX k7//PmKHh5Yk3Oe9o2+vSKC+t3vrJDqJAGUReb6jAeAdEUS4koQ7Nq9tQax6OAfTYDhlR8 ZN/JImum16Buo7RIi9qFBhIY1XrcUT8= X-Rspam-User: Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=c+6A8OMg; spf=pass (imf24.hostedemail.com: domain of 38OEIYwYKCPUdifabodlldib.Zljifkru-jjhsXZh.lod@flex--glider.bounces.google.com designates 209.85.208.74 as permitted sender) smtp.mailfrom=38OEIYwYKCPUdifabodlldib.Zljifkru-jjhsXZh.lod@flex--glider.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam08 X-Stat-Signature: eairi6rioxn5t4tpe66mfto3m4ggik9r X-Rspamd-Queue-Id: D420D18001B X-HE-Tag: 1661526513-456240 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: __no_sanitize_memory is a function attribute that instructs KMSAN to skip a function during instrumentation. This is needed to e.g. implement the noinstr functions. __no_kmsan_checks is a function attribute that makes KMSAN ignore the uninitialized values coming from the function's inputs, and initialize the function's outputs. Functions marked with this attribute can't be inlined into functions not marked with it, and vice versa. This behavior is overridden by __always_inline. __SANITIZE_MEMORY__ is a macro that's defined iff the file is instrumented with KMSAN. This is not the same as CONFIG_KMSAN, which is defined for every file. Signed-off-by: Alexander Potapenko Reviewed-by: Marco Elver --- Link: https://linux-review.googlesource.com/id/I004ff0360c918d3cd8b18767ddd1381c6d3281be --- include/linux/compiler-clang.h | 23 +++++++++++++++++++++++ include/linux/compiler-gcc.h | 6 ++++++ 2 files changed, 29 insertions(+) diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index c84fec767445d..4fa0cc4cbd2c8 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -51,6 +51,29 @@ #define __no_sanitize_undefined #endif +#if __has_feature(memory_sanitizer) +#define __SANITIZE_MEMORY__ +/* + * Unlike other sanitizers, KMSAN still inserts code into functions marked with + * no_sanitize("kernel-memory"). Using disable_sanitizer_instrumentation + * provides the behavior consistent with other __no_sanitize_ attributes, + * guaranteeing that __no_sanitize_memory functions remain uninstrumented. + */ +#define __no_sanitize_memory __disable_sanitizer_instrumentation + +/* + * The __no_kmsan_checks attribute ensures that a function does not produce + * false positive reports by: + * - initializing all local variables and memory stores in this function; + * - skipping all shadow checks; + * - passing initialized arguments to this function's callees. + */ +#define __no_kmsan_checks __attribute__((no_sanitize("kernel-memory"))) +#else +#define __no_sanitize_memory +#define __no_kmsan_checks +#endif + /* * Support for __has_feature(coverage_sanitizer) was added in Clang 13 together * with no_sanitize("coverage"). Prior versions of Clang support coverage diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index 9b157b71036f1..f55a37efdb974 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -114,6 +114,12 @@ #define __SANITIZE_ADDRESS__ #endif +/* + * GCC does not support KMSAN. + */ +#define __no_sanitize_memory +#define __no_kmsan_checks + /* * Turn individual warnings and errors on and off locally, depending * on version.