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=-8.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 5088FC2BA1A for ; Tue, 7 Apr 2020 03:10:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 14DC420716 for ; Tue, 7 Apr 2020 03:10:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="x+BJUNZH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 14DC420716 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 BB2F08E0077; Mon, 6 Apr 2020 23:10:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B3D028E0062; Mon, 6 Apr 2020 23:10:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A2B888E0077; Mon, 6 Apr 2020 23:10:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0166.hostedemail.com [216.40.44.166]) by kanga.kvack.org (Postfix) with ESMTP id 862698E0062 for ; Mon, 6 Apr 2020 23:10:05 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 5538C801B427 for ; Tue, 7 Apr 2020 03:10:05 +0000 (UTC) X-FDA: 76679579970.16.jewel67_b93cf0a805f X-HE-Tag: jewel67_b93cf0a805f X-Filterd-Recvd-Size: 2835 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf01.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Apr 2020 03:10:04 +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 E7173206B8; Tue, 7 Apr 2020 03:10:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586229004; bh=PHEwBNXmiA5cKHM2OtJT2n6pmV3rMlv2BORY5vDP3+0=; h=Date:From:To:Subject:In-Reply-To:From; b=x+BJUNZHZKOhbCxHUJJO4jBpDo6vmFfIHiwo5TrPKdR4FxkoRLbtxjjd3klC06ijB u0+OsfwXKO0dHcZiCNrD3zgu7V1QZHPo7uLsa40r2ddjrmSOessZzs/faMZiyQiIVo SmjNBzL1z/plUsRXGI7nSTmaHQh5Yq3/wf80NlzQ= Date: Mon, 06 Apr 2020 20:10:03 -0700 From: Andrew Morton To: akpm@linux-foundation.org, gustavo@embeddedor.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 113/166] lib/ts_fsm.c: replace zero-length array with flexible-array member Message-ID: <20200407031003.wPPp7AGjP%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: "Gustavo A. R. Silva" Subject: lib/ts_fsm.c: replace zero-length array with flexible-array member The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Link: http://lkml.kernel.org/r/20200211205813.GA25602@embeddedor Signed-off-by: Gustavo A. R. Silva Signed-off-by: Andrew Morton --- lib/ts_fsm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/ts_fsm.c~lib-ts_fsm-replace-zero-length-array-with-flexible-array-member +++ a/lib/ts_fsm.c @@ -32,7 +32,7 @@ struct ts_fsm { unsigned int ntokens; - struct ts_fsm_token tokens[0]; + struct ts_fsm_token tokens[]; }; /* other values derived from ctype.h */ _