From patchwork Fri May 13 14:23:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 572522 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 1F950C433F5 for ; Fri, 13 May 2022 14:28:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380729AbiEMO17 (ORCPT ); Fri, 13 May 2022 10:27:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1380739AbiEMO1H (ORCPT ); Fri, 13 May 2022 10:27:07 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 248D4DFB7; Fri, 13 May 2022 07:26:59 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E01586216C; Fri, 13 May 2022 14:26:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E19A0C36AE2; Fri, 13 May 2022 14:26:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652452018; bh=8nYjadxN9N1RTFRbp0seHgxawJmSGG0+3SicY1sPKHM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CTtJ6nZUyUWDNx+Qf3rl9LI2Ur0Qi/F1JbzIHdMkr4URhc1UfsqjUGmwDPyUNW87Y cX55ODQIUzSJPtnix4K80unqQw8P6LbKlM5W4aXjCxmLYVDAQiep52f6Wr3culwBhi n+iGzSKScZ/4DPtPpDufGmHEZKfMTmrweo3VYpC8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?utf-8?q?Michel_D=C3=A4nzer?= , Jani Nikula , Nathan Chancellor Subject: [PATCH 5.4 04/18] drm/i915: Cast remain to unsigned long in eb_relocate_vma Date: Fri, 13 May 2022 16:23:30 +0200 Message-Id: <20220513142229.281127401@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220513142229.153291230@linuxfoundation.org> References: <20220513142229.153291230@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nathan Chancellor commit 7bf03e7504e433da274963c447648876902b86df upstream. 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. Closes: https://github.com/ClangBuiltLinux/linux/issues/778 Suggested-by: Michel Dänzer Reviewed-by: Jani Nikula Signed-off-by: Nathan Chancellor Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20200214054706.33870-1-natechancellor@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -1452,7 +1452,7 @@ static int eb_relocate_vma(struct i915_e 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; /*