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 X-Spam-Level: X-Spam-Status: No, score=-14.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 577F9C46470 for ; Thu, 2 May 2019 16:31:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D78920675 for ; Thu, 2 May 2019 16:31:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qw6j5mpw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726608AbfEBQbm (ORCPT ); Thu, 2 May 2019 12:31:42 -0400 Received: from mail-ed1-f65.google.com ([209.85.208.65]:39919 "EHLO mail-ed1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726303AbfEBQbl (ORCPT ); Thu, 2 May 2019 12:31:41 -0400 Received: by mail-ed1-f65.google.com with SMTP id e24so2671944edq.6 for ; Thu, 02 May 2019 09:31:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=7Oy1RG3BUKEsx4VUlFgLOKgTT7HGDm6BmTdCPYEVHzI=; b=qw6j5mpwSwKYxN/oL4IAsK/zH1v/EkIn+dDLKuZam7yyhsQTM8KB9cL677/5Oz7MVy IexCjBqxB23TohGwbBNWIteLggib7PQ3HCSGF844ugqO8ODk5dxWwnXEZg9sKL1DIzyR J/+ASLTaOgJswbMKQq8KaHH3d5PttebWx1MBEpVqQ93t2Os4ETMG7fcecg0n18fINZuk fWyvoeQsc12VsByCTBs3lt6WG9FvJ9kaNvf+e8CIKjw4G35upmxBIcv//uweMZ6jFNL8 D79gY0owa3HXwk0qwp26NVPUdg9mRp/hYXIhEdDJ1ZNlad7IQv9ewy6AszUJc2gWsEip EYWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=7Oy1RG3BUKEsx4VUlFgLOKgTT7HGDm6BmTdCPYEVHzI=; b=MmKlwzpW32bSSfIKQn8e07ShcxKgCk1Twbw/gIK6FCaFSQNQwtSF3sp3DAFHIs3IfK OBk7zFRcdyVRM/7sV2tU7oJcbPSRxABG59QRRzr2SMo/uKRpdnMApgAnrxFBsj9hIpqC 30cAREs5HB8tGTQoUfTb4XiQmqoRjEwP8knZbgD8NtTyyV0J/POCpJH/oj+YlTCNJR5c XCmURCye6LIFioZ8MILwnNlYdZ6/QQ3vmB18Fj4lf1o8jRYh281BuODoLFjP96RmyJoL AMAa7Wintw11fx2h4tPp3hUK8vOos8Q/d6ekD0m2NLjRiwrwUQgcSsD0b49IBdJjkvfO AxGQ== X-Gm-Message-State: APjAAAUbGtWcLeyJPWh9SWloDtKO7JkxJmDlkutUesd6B8RIhUnpac3E z8L2zkyGnprgQwETugytzOQ= X-Google-Smtp-Source: APXvYqz4jS4aZzqlMk96rIVkIK1ahQvD2cBXh7geHSHkh6Ve3klRmskSiNbCIGL6V2kmJmVabxVeIg== X-Received: by 2002:a17:906:5fd7:: with SMTP id k23mr2318906ejv.201.1556814699691; Thu, 02 May 2019 09:31:39 -0700 (PDT) Received: from localhost.localdomain ([2a01:4f9:2b:2b84::2]) by smtp.gmail.com with ESMTPSA id oq25sm7460093ejb.46.2019.05.02.09.31.38 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 02 May 2019 09:31:38 -0700 (PDT) From: Nathan Chancellor To: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov Cc: kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Nick Desaulniers , clang-built-linux@googlegroups.com, Nathan Chancellor Subject: [PATCH v2] kasan: Initialize tag to 0xff in __kasan_kmalloc Date: Thu, 2 May 2019 09:30:58 -0700 Message-Id: <20190502163057.6603-1-natechancellor@gmail.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190502153538.2326-1-natechancellor@gmail.com> References: <20190502153538.2326-1-natechancellor@gmail.com> MIME-Version: 1.0 X-Patchwork-Bot: notify Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When building with -Wuninitialized and CONFIG_KASAN_SW_TAGS unset, Clang warns: mm/kasan/common.c:484:40: warning: variable 'tag' is uninitialized when used here [-Wuninitialized] kasan_unpoison_shadow(set_tag(object, tag), size); ^~~ set_tag ignores tag in this configuration but clang doesn't realize it at this point in its pipeline, as it points to arch_kasan_set_tag as being the point where it is used, which will later be expanded to (void *)(object) without a use of tag. Initialize tag to 0xff, as it removes this warning and doesn't change the meaning of the code. Link: https://github.com/ClangBuiltLinux/linux/issues/465 Signed-off-by: Nathan Chancellor --- v1 -> v2: * Initialize tag to 0xff at Andrey's request mm/kasan/common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 36afcf64e016..242fdc01aaa9 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -464,7 +464,7 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, { unsigned long redzone_start; unsigned long redzone_end; - u8 tag; + u8 tag = 0xff; if (gfpflags_allow_blocking(flags)) quarantine_reduce(); -- 2.21.0