From patchwork Tue Apr 7 03:09:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11477373 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 F391B92A for ; Tue, 7 Apr 2020 03:09:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C151B2082D for ; Tue, 7 Apr 2020 03:09:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="IiFATpwz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C151B2082D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 34E9A8E006C; Mon, 6 Apr 2020 23:09:29 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 326748E0062; Mon, 6 Apr 2020 23:09:29 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2152E8E006C; Mon, 6 Apr 2020 23:09:29 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0095.hostedemail.com [216.40.44.95]) by kanga.kvack.org (Postfix) with ESMTP id 058C18E0062 for ; Mon, 6 Apr 2020 23:09:29 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id CDD862DFC for ; Tue, 7 Apr 2020 03:09:28 +0000 (UTC) X-FDA: 76679578416.16.print93_8cf293eba6d24 X-Spam-Summary: 2,0,0,e7707b5be17c9655,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1263:1345:1359:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:1801:2393:2525:2559:2564:2682:2685:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3352:3865:3866:3867:3868:3870:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:4605:5007:6119:6261:6653:7514:7576:8599:8957:9025:9149:9545:10004:10913:11026:11658:11914:12043:12048:12294:12297:12438:12517:12519:12555:12679:12783:12986:13069:13161:13229:13311:13357:13846:14181:14384:14721:14849:21080:21451:21611:21627:21939:30054:30070,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-62.2.0.100 64.100.201.201,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:2,LUA_SUMMARY:none X-HE-Tag: print93_8cf293eba6d24 X-Filterd-Recvd-Size: 3037 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Apr 2020 03:09:28 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8E1BF20716; Tue, 7 Apr 2020 03:09:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586228967; bh=8DJic0aysvqWpd3Q3caPeCm2w0YS5mH1qIXHfl05I7E=; h=Date:From:To:Subject:In-Reply-To:From; b=IiFATpwzZCG2QHPP8bjPybf0Drv02mVBf5g3QaRhc/7QDEcLIpdWnIEEzQnHg6Wnc XUJWSOQj5CYDdUwft8dfopL0sYupxUTQAR1sURxrLTEg/NtGDypCn50193DIDG65dm vmeZNC5xqD/+0y7Sih7gkmZUA0UmkYnLOGdEjjZs= Date: Mon, 06 Apr 2020 20:09:27 -0700 From: Andrew Morton To: akpm@linux-foundation.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, natechancellor@gmail.com, ndesaulniers@google.com, torvalds@linux-foundation.org Subject: [patch 102/166] kernel/extable.c: use address-of operator on section symbols Message-ID: <20200407030927.cWCFKGYsv%akpm@linux-foundation.org> In-Reply-To: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Nathan Chancellor Subject: kernel/extable.c: use address-of operator on section symbols Clang warns: ../kernel/extable.c:37:52: warning: array comparison always evaluates to a constant [-Wtautological-compare] if (main_extable_sort_needed && __stop___ex_table > __start___ex_table) { ^ 1 warning generated. These are not true arrays, they are linker defined symbols, which are just addresses. Using the address of operator silences the warning and does not change the resulting assembly with either clang/ld.lld or gcc/ld (tested with diff + objdump -Dr). Link: https://github.com/ClangBuiltLinux/linux/issues/892 Link: http://lkml.kernel.org/r/20200219202036.45702-1-natechancellor@gmail.com Signed-off-by: Nathan Chancellor Suggested-by: Nick Desaulniers Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton --- kernel/extable.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/kernel/extable.c~kernel-extable-use-address-of-operator-on-section-symbols +++ a/kernel/extable.c @@ -34,7 +34,8 @@ u32 __initdata __visible main_extable_so /* Sort the kernel's built-in exception table */ void __init sort_main_extable(void) { - if (main_extable_sort_needed && __stop___ex_table > __start___ex_table) { + if (main_extable_sort_needed && + &__stop___ex_table > &__start___ex_table) { pr_notice("Sorting __ex_table...\n"); sort_extable(__start___ex_table, __stop___ex_table); }