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 A9C8EC433EF for ; Tue, 26 Apr 2022 16:48:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353356AbiDZQvb (ORCPT ); Tue, 26 Apr 2022 12:51:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353309AbiDZQvA (ORCPT ); Tue, 26 Apr 2022 12:51:00 -0400 Received: from mail-ed1-x54a.google.com (mail-ed1-x54a.google.com [IPv6:2a00:1450:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E87ED28E11 for ; Tue, 26 Apr 2022 09:46:05 -0700 (PDT) Received: by mail-ed1-x54a.google.com with SMTP id n4-20020a5099c4000000b00418ed58d92fso10619216edb.0 for ; Tue, 26 Apr 2022 09:46:05 -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=xs3mnLw1SF/DZ/Tq7NTZzrdEtEEoGjj1tkhOxGSNVPQ=; b=Dp8fDgewCtm7EfJ+NxSWPaqf4fjHXCb5jsKUHsqjOQlRwQkgkKZ/UWCSiVVrRs/uZW OQRNetbiqEwnG85Z0p1Sf25DydKgfbA8aQ0Bsb8u1giNx3oJsml+h06KXd12ZFl+7zlh 88EaOBCQpujgyWZhEQULbY92x5FazQAo2pGdWFAwltYHX4X7vprtu3R+YlyuxLW4bV7A kz4jOXTPx7d0TC785iMRbaV+fkvSej+QsvFkw8jbYuayp+vHkk5UYhSq7fmBnGbZjeRh ej2EyGUQvI2W9wRBjeiQzBogyryUJQVM1Tt85ycKl00a26JFtroHDFnq/8e7RZbUcfE0 4QnQ== 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=xs3mnLw1SF/DZ/Tq7NTZzrdEtEEoGjj1tkhOxGSNVPQ=; b=GJ1eJg3QexzKOcjJTvmbP1nSFbXJjATXmiX5B7TEwSIHl9+wtFUUqSgPqi0PZj8+mQ 07pt71tMwaPAs2n4ttrl/XN4UTmwkwuX/dI+2EDD5bqFhB5wKVyjfJITGPeJKW5L4Dso fuuBwBgLMi5MGzH5DzrAcSbOhu4+uuPVNSjzo4m3GpPr1UbbmWhGm//oyLDMi0apP2+e s5ULebh0crs/axCEwsSFDTwN8a8RyUwmdzRqtdj0dok1aNDkX8vW2ZZUL/nAag+QC4NJ q327zY9o/I72w/47OnpJ+8oJOOWNtVAteeg/OYMT4lFNco7uWVC8VUtOvAtBQGU68c/G UWYA== X-Gm-Message-State: AOAM533uXB4XfU9czhq7GPhqjAd/cuJproklqbnp1VTCr2fnWH1DfIwp 54O/YV9Vu5+HW2EJJHNDrOA52gqbzMk= X-Google-Smtp-Source: ABdhPJyVycewaYAOLWq91OXZaqwuaaJYgCPy/6P6fQ6DCJX8eHTBHY2JtlW8ZAI35LArwnFF6hd2OCloeNo= X-Received: from glider.muc.corp.google.com ([2a00:79e0:15:13:d580:abeb:bf6d:5726]) (user=glider job=sendgmr) by 2002:aa7:c70f:0:b0:425:f70d:b34 with SMTP id i15-20020aa7c70f000000b00425f70d0b34mr7131646edq.306.1650991564200; Tue, 26 Apr 2022 09:46:04 -0700 (PDT) Date: Tue, 26 Apr 2022 18:43:09 +0200 In-Reply-To: <20220426164315.625149-1-glider@google.com> Message-Id: <20220426164315.625149-41-glider@google.com> Mime-Version: 1.0 References: <20220426164315.625149-1-glider@google.com> X-Mailer: git-send-email 2.36.0.rc2.479.g8af0fa9b8e-goog Subject: [PATCH v3 40/46] 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 , kasan-dev@googlegroups.com, 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-arch@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 3e2f33fc33de2..e0411a3774d49 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 @@ static void string_memcpy_fromio(void *to, const volatile void __iomem *from, si n-=2; } rep_movs(to, (const void *)from, n); + /* KMSAN must treat values read from devices as initialized. */ + kmsan_unpoison_memory(to, n); } static void string_memcpy_toio(volatile void __iomem *to, const void *from, size_t n) @@ -44,6 +47,8 @@ static void string_memcpy_toio(volatile void __iomem *to, const void *from, size 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); -- 2.36.0.rc2.479.g8af0fa9b8e-goog