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=-14.6 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_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 8EC55C35242 for ; Fri, 14 Feb 2020 05:47:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5FCD4217F4 for ; Fri, 14 Feb 2020 05:47:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="el9uNpAF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728650AbgBNFrO (ORCPT ); Fri, 14 Feb 2020 00:47:14 -0500 Received: from mail-ot1-f67.google.com ([209.85.210.67]:45034 "EHLO mail-ot1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725818AbgBNFrO (ORCPT ); Fri, 14 Feb 2020 00:47:14 -0500 Received: by mail-ot1-f67.google.com with SMTP id h9so8034991otj.11 for ; Thu, 13 Feb 2020 21:47:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Z2iYSLYDGYaGS4KoVmwUDz00gZO0krvmf/FASHSxL8U=; b=el9uNpAFUFfHliLH4Z4jbnVRGLrbY4XJCMgjQAInLFb1g6MHwSnoL4lr/XCT/aBRxs jLIQlIY+LYx+G42rSeanORto31kVNlfg/uPUpsgxttGWd6iYOeSkO5tBAwlvITAVKoXJ pRN7k3xbLOqI59sPcsS9sdYl3ayzl3Oi6DqQp2UHlBNfh2NLjRGuREQABww6ycZbvhik 6vbFLztDxrrUUH+YLqGOdm6B8i8KKZeXtpov7S686swqmBqCR3Lsa89cNJGJtcoy3z69 mdMThjyAHWlFfHjibcRWFgNaObxbgOjEBTpJGv+IwxgYaKuW/Sef/LqhoPdnXTVnjVkS jf6g== 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:mime-version :content-transfer-encoding; bh=Z2iYSLYDGYaGS4KoVmwUDz00gZO0krvmf/FASHSxL8U=; b=e3SWF82R6LQdXFbWpucooc22FiiZf02ZJr1/E8EAII5ttvMkWqBvpcLsLEFAIBg1yA BikSud3YN06rG8CixRWU7ZII1OxazlWeLWrbqCqtIGqX2fdm6u4jEjp6nKsxt1qP3sMl BOaqF6q5nFoNvmWzV6iIq+ghc2DhBL966XD5ufwSB9ohjlUGqD5ZwykE4jSvkN3+trWi vWGdpG5Ve4C6iPPGwEZ1VzrBX44VLavI79u6BEqPURupgGVZg3M2M1l/UyW2NBYwLx0o cQ2yoznnwdg1jgxkCmaiDmop3aWzl6aFlso2EH4ScRLgG4gs6mjllPAu89gq9J9o/KRb wOKg== X-Gm-Message-State: APjAAAUyWBNz2h/z/odQXZOkDEkUJRXDUilMTKNL0YaK8s0wlhmHluXt GIP+TQz7lYFoSoOXgoCtsHU= X-Google-Smtp-Source: APXvYqxP9k20s4Fu210nTsiauDqN0WjeicH2Gh47BzP033Qga6MrRzcCeBD+F7pQTE7qnBVo46LUqA== X-Received: by 2002:a9d:7342:: with SMTP id l2mr974746otk.98.1581659233352; Thu, 13 Feb 2020 21:47:13 -0800 (PST) Received: from localhost.localdomain ([2604:1380:4111:8b00::1]) by smtp.gmail.com with ESMTPSA id j5sm1631830otl.71.2020.02.13.21.47.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Feb 2020 21:47:12 -0800 (PST) From: Nathan Chancellor To: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Nathan Chancellor , =?UTF-8?q?Michel=20D=C3=A4nzer?= Subject: [PATCH] drm/i915: Cast remain to unsigned long in eb_relocate_vma Date: Thu, 13 Feb 2020 22:47:07 -0700 Message-Id: <20200214054706.33870-1-natechancellor@gmail.com> X-Mailer: git-send-email 2.25.0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 A recent commit in clang added -Wtautological-compare to -Wall, which is enabled for i915 after -Wtautological-compare is disabled for the rest of the kernel so we see the following warning on x86_64: ../drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:1433:22: warning: result of comparison of constant 576460752303423487 with expression of type 'unsigned int' is always false [-Wtautological-constant-out-of-range-compare] if (unlikely(remain > N_RELOC(ULONG_MAX))) ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~ ../include/linux/compiler.h:78:42: note: expanded from macro 'unlikely' # define unlikely(x) __builtin_expect(!!(x), 0) ^ 1 warning generated. It is not wrong in the case where ULONG_MAX > UINT_MAX but it does not account for the case where this file is built for 32-bit x86, where ULONG_MAX == UINT_MAX and this check is still relevant. Cast remain to unsigned long, which keeps the generated code the same (verified with clang-11 on x86_64 and GCC 9.2.0 on x86 and x86_64) and the warning is silenced so we can catch more potential issues in the future. Link: https://github.com/ClangBuiltLinux/linux/issues/778 Suggested-by: Michel Dänzer Signed-off-by: Nathan Chancellor --- Round 3 :) Previous threads/patches: https://lore.kernel.org/lkml/20191123195321.41305-1-natechancellor@gmail.com/ https://lore.kernel.org/lkml/20200211050808.29463-1-natechancellor@gmail.com/ drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c index 60c984e10c4a..47f4d8ab281e 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -1430,7 +1430,7 @@ static int eb_relocate_vma(struct i915_execbuffer *eb, struct i915_vma *vma) urelocs = u64_to_user_ptr(entry->relocs_ptr); remain = entry->relocation_count; - if (unlikely(remain > N_RELOC(ULONG_MAX))) + if (unlikely((unsigned long)remain > N_RELOC(ULONG_MAX))) return -EINVAL; /* -- 2.25.0