From patchwork Fri Feb 14 05:47:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 11381859 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1A52B13A4 for ; Fri, 14 Feb 2020 08:08:29 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ECF06217F4 for ; Fri, 14 Feb 2020 08:08:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="el9uNpAF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECF06217F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 81C106EB4B; Fri, 14 Feb 2020 08:08:12 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-ot1-x343.google.com (mail-ot1-x343.google.com [IPv6:2607:f8b0:4864:20::343]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3C8206E438; Fri, 14 Feb 2020 05:47:14 +0000 (UTC) Received: by mail-ot1-x343.google.com with SMTP id p8so8026689oth.10; Thu, 13 Feb 2020 21:47:14 -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=HVrQEAbxaFqBSkyR+qEaZyr6nHTtTG67+BBH2fcA2hCop3fEIZk8B0XyDrxBAZzqvl idthdsiIqg+lSff4fVGGnTwcyqHYG51oFmEnYzgT2gAiH+bBKdWuvm8DbaRevyof9yMd 1meqxrr1F9coyqlixD2ELqg8vlo1PhYhAEMuAK/qXpxgdTz74T3/zWOJ3tOX2b89urdx te6aM4rXvBTloZ08IYFHMRzo1LcN9wEB5QnssBsj5Hv3RuLf5LNcMyqHhIWv4vXw9gRF 7CPZfDT36VE4PfLgFqRkaIsGcrYSuKxZD2jHmo0tsBm8OC/tEHdPaNusk63BwYJKQbnV ciuQ== X-Gm-Message-State: APjAAAUJXJMAmP5VR1ql/bt6J8GLGgSzWEdfiXMciWB6K837DmxrHjyX As+GytU9glL2LS+go/taMj8= 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 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 X-Patchwork-Bot: notify X-Mailman-Approved-At: Fri, 14 Feb 2020 08:07:58 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, clang-built-linux@googlegroups.com, Nathan Chancellor , =?utf-8?q?Michel_D=C3=A4nzer?= Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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; /*