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 B1EBDC43219 for ; Tue, 29 Mar 2022 12:48:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234229AbiC2Mt7 (ORCPT ); Tue, 29 Mar 2022 08:49:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236831AbiC2MsH (ORCPT ); Tue, 29 Mar 2022 08:48:07 -0400 Received: from mail-ej1-x649.google.com (mail-ej1-x649.google.com [IPv6:2a00:1450:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 758BF224749 for ; Tue, 29 Mar 2022 05:42:22 -0700 (PDT) Received: by mail-ej1-x649.google.com with SMTP id gv17-20020a1709072bd100b006dfcc7f7962so8127026ejc.5 for ; Tue, 29 Mar 2022 05:42:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=6EKMd0bjP1WkGhZZPkjCgU25E3DWfYJCasURW7mFnYs=; b=P1k71GssRqu7HsErV73nnblS85PhkUFheLyBFZgmPWLpl7OKiy1Bqi/JlOtZzfJVPy VAc7cvO8fwjHIxHwD4P9pVu2rdNH8e0p6iE439JugyKP3tEZpAogt6YoEY/b5rvhs6YN OlYMWP+8vwtXjv8eNiLfoejuKaPkdCuMEozoeNlW8PpIb+edtD9db/0+pmWKLdNhwURR 5E3Lth/p8S4d05TzSLze03fVsfkwrT++EyTKtUjOhLVyC4kbo3lKGGRltm0PtD2GB/IH Q3WE4SbVcH6AFhiknkVN5O3R1HMm1J+ZfOcalpdSexIx4dKDpVcT7q34bBD07dT9kvEi C7Fw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=6EKMd0bjP1WkGhZZPkjCgU25E3DWfYJCasURW7mFnYs=; b=rPJuR5MEzyzLKzKLm81Sz3UQ4ii9YtT0rVjc7jime4/vS1Lc6FS7XfhYjvdMyHp7tG 8TCrefZGujaFe/KvRe3mpezAoR6uryr6KnnSqR39RujTzZuY1MpDcvxZzxye2PNmZ9JY iuMAl24Uay7SlUb4HVLni4aRpltGx+XCCkbnpaA/3EeMpky3gX0OA9t6gghNcdvLrjiL pAKSsNZs5e0LoHDoXF9K/HzxB+xGmhSIRTdr3xx+ZswM2Ef5OPXF82KcPSN1J3rVVQR5 GxMNwm6C0Mbka5uIAxGfeZNA11wFb88LA5oMJXMD13WnQNN508K8dTEXxLhNCyQ1lrsc V48g== X-Gm-Message-State: AOAM531a6mAMO552v74Dz5dQ7/9kSOIQEZ+u0GdiMEGzKeDvfmFjng5p nXXgJ4Fh75eV0XTknYf0Qnu1f4XX+GA= X-Google-Smtp-Source: ABdhPJyN/u61iYoRLkPCDJv7Xs3UegKZjTjkx8b5A87Fx1oaelxWk3uqKnX5mytmcMKvTp7b3Wewv/gEEvA= X-Received: from glider.muc.corp.google.com ([2a00:79e0:15:13:36eb:759:798f:98c3]) (user=glider job=sendgmr) by 2002:a17:906:3042:b0:6cd:20ed:7c5c with SMTP id d2-20020a170906304200b006cd20ed7c5cmr33818169ejd.241.1648557740796; Tue, 29 Mar 2022 05:42:20 -0700 (PDT) Date: Tue, 29 Mar 2022 14:40:11 +0200 In-Reply-To: <20220329124017.737571-1-glider@google.com> Message-Id: <20220329124017.737571-43-glider@google.com> Mime-Version: 1.0 References: <20220329124017.737571-1-glider@google.com> X-Mailer: git-send-email 2.35.1.1021.g381101b075-goog Subject: [PATCH v2 42/48] x86: kmsan: handle open-coded assembly in lib/iomem.c From: Alexander Potapenko To: glider@google.com Cc: Alexander Viro , 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 , linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org KMSAN cannot intercept memory accesses within asm() statements. That's why we add kmsan_unpoison_memory() and kmsan_check_memory() to hint it how to handle memory copied from/to I/O memory. Signed-off-by: Alexander Potapenko --- Link: https://linux-review.googlesource.com/id/Icb16bf17269087e475debf07a7fe7d4bebc3df23 --- arch/x86/lib/iomem.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/lib/iomem.c b/arch/x86/lib/iomem.c index df50451d94ef7..2307770f3f4c8 100644 --- a/arch/x86/lib/iomem.c +++ b/arch/x86/lib/iomem.c @@ -1,6 +1,7 @@ #include #include #include +#include #define movs(type,to,from) \ asm volatile("movs" type:"=&D" (to), "=&S" (from):"0" (to), "1" (from):"memory") @@ -37,6 +38,8 @@ void memcpy_fromio(void *to, const volatile void __iomem *from, size_t n) n-=2; } rep_movs(to, (const void *)from, n); + /* KMSAN must treat values read from devices as initialized. */ + kmsan_unpoison_memory(to, n); } EXPORT_SYMBOL(memcpy_fromio); @@ -45,6 +48,8 @@ void memcpy_toio(volatile void __iomem *to, const void *from, size_t n) if (unlikely(!n)) return; + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(from, n); /* Align any unaligned destination IO */ if (unlikely(1 & (unsigned long)to)) { movs("b", to, from); -- 2.35.1.1021.g381101b075-goog