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 8E839C433EF for ; Fri, 1 Jul 2022 14:29:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231495AbiGAO3J (ORCPT ); Fri, 1 Jul 2022 10:29:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232594AbiGAO12 (ORCPT ); Fri, 1 Jul 2022 10:27:28 -0400 Received: from mail-ed1-x549.google.com (mail-ed1-x549.google.com [IPv6:2a00:1450:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D910F5A2EA for ; Fri, 1 Jul 2022 07:24:53 -0700 (PDT) Received: by mail-ed1-x549.google.com with SMTP id z17-20020a05640235d100b0043762b1e1e3so1878711edc.21 for ; Fri, 01 Jul 2022 07:24:53 -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=CG3pZwK286Wp+stKkliNeTwrORF17cOHhcnhVfCJeQE=; b=bYQ2u2U8tj3aHjd9MCtMixUrYfpSQwTg4WPOIoCPEeukhh64yxMHafM5vs/LGNKnzQ WbZCO/BXLkzB63X6UKAseam1QIfdrrDcHBVOGpbspRYW0ejgy0BAvw5OVpGh3iBOeZEX aaVkXTg3A0tuwa1e18PtKkEW1bZ16MVMyhI4LHrOLoqfrXkdK5JLNMCCXCzP+UqlS+7Y jMHKRvPORQSh2gGeBXFyCiEXw+TmFxCdnaNG5nGomGgf7TAWqOwR/NSipZV8JXpF91j0 T7T+oh1yqE70PVoxhXBFXshJGT1hPLtyEjj27zgL+pSYm9TNfYDnuWL3u/qLN7pkNGWn fRFw== 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=CG3pZwK286Wp+stKkliNeTwrORF17cOHhcnhVfCJeQE=; b=tRNyO+7Bm5apKT2Y80jon9cBaaVomtOxJZbE9WToBw65oEtN/BPh1JgpG69WXKBqNx t9bzkXBL7RNYS8JsBYHhiLzsbgxbM9Zeas+N4PEWv/xMy0xxd81AN3qQakR+VZJ+jPFq PMzW2fR13NvjHcrip63RnvvnnYyEcRaRlbZGtt+IOiPCmpIeE3+Kb8yUlQlqH1CEz88p dKdBYmol8VxApHdqeCeLe8QVRg8DZIuAG2lIgzwHxETln4CG6IPH2uSnGk4es1yjI7r3 iHGgktCxm75SGSiQ9FUzSlAUqvxfZ6e39MEWIadR+brAbbuZjiATF1+m2ux/gidtvpfF Em3Q== X-Gm-Message-State: AJIora+xwHcZtRF47XcWzl4u2NwZWYqNgxaKw1aVQqwhNu9crd4gfNiW uaEjQ5BOXvZYFdqMhtQv19u//h2KJtw= X-Google-Smtp-Source: AGRyM1vuhrwmXAXJ9wJid3cKYDBtVUPAQNXpJsIZnZORqGteH/3hS1Qh3dFSI+7P2W3d1z7T02mluBgbb3c= X-Received: from glider.muc.corp.google.com ([2a00:79e0:9c:201:a6f5:f713:759c:abb6]) (user=glider job=sendgmr) by 2002:a05:6402:2403:b0:439:682f:d12c with SMTP id t3-20020a056402240300b00439682fd12cmr7312146eda.301.1656685493399; Fri, 01 Jul 2022 07:24:53 -0700 (PDT) Date: Fri, 1 Jul 2022 16:23:00 +0200 In-Reply-To: <20220701142310.2188015-1-glider@google.com> Message-Id: <20220701142310.2188015-36-glider@google.com> Mime-Version: 1.0 References: <20220701142310.2188015-1-glider@google.com> X-Mailer: git-send-email 2.37.0.rc0.161.g10f37bed90-goog Subject: [PATCH v4 35/45] x86: kmsan: handle open-coded assembly in lib/iomem.c 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 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 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); -- 2.37.0.rc0.161.g10f37bed90-goog