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=-14.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 F14B9C433DF for ; Mon, 15 Jun 2020 04:00:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CAAF7207CD for ; Mon, 15 Jun 2020 04:00:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725941AbgFOEAj (ORCPT ); Mon, 15 Jun 2020 00:00:39 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:50400 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725294AbgFOEAj (ORCPT ); Mon, 15 Jun 2020 00:00:39 -0400 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id BDD5E5499FB0A399A876; Mon, 15 Jun 2020 12:00:36 +0800 (CST) Received: from huawei.com (10.175.127.227) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.487.0; Mon, 15 Jun 2020 12:00:28 +0800 From: Jason Yan To: , , , , CC: , Jason Yan , Kees Cook , Chao Yu Subject: [PATCH] erofs: Eliminate usage of uninitialized_var() macro Date: Mon, 15 Jun 2020 12:01:41 +0800 Message-ID: <20200615040141.3627746-1-yanaijie@huawei.com> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.127.227] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an effort to eliminate the uninitialized_var() macro[1]. The use of this macro is the wrong solution because it forces off ANY analysis by the compiler for a given variable. It even masks "unused variable" warnings. Quoted from Linus[2]: "It's a horrible thing to use, in that it adds extra cruft to the source code, and then shuts up a compiler warning (even the _reliable_ warnings from gcc)." The gcc option "-Wmaybe-uninitialized" has been disabled and this change will not produce any warnnings even with "make W=1". [1] https://github.com/KSPP/linux/issues/81 [2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Cc: Kees Cook Cc: Chao Yu Signed-off-by: Jason Yan --- fs/erofs/data.c | 4 ++-- fs/erofs/zdata.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/erofs/data.c b/fs/erofs/data.c index 64b56c7df023..d0542151e8c4 100644 --- a/fs/erofs/data.c +++ b/fs/erofs/data.c @@ -265,7 +265,7 @@ static inline struct bio *erofs_read_raw_page(struct bio *bio, */ static int erofs_raw_access_readpage(struct file *file, struct page *page) { - erofs_off_t uninitialized_var(last_block); + erofs_off_t last_block; struct bio *bio; trace_erofs_readpage(page, true); @@ -282,7 +282,7 @@ static int erofs_raw_access_readpage(struct file *file, struct page *page) static void erofs_raw_access_readahead(struct readahead_control *rac) { - erofs_off_t uninitialized_var(last_block); + erofs_off_t last_block; struct bio *bio = NULL; struct page *page; diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index be50a4d9d273..24a26aaf847f 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -1161,7 +1161,7 @@ static void z_erofs_submit_queue(struct super_block *sb, struct z_erofs_decompressqueue *q[NR_JOBQUEUES]; void *bi_private; /* since bio will be NULL, no need to initialize last_index */ - pgoff_t uninitialized_var(last_index); + pgoff_t last_index; unsigned int nr_bios = 0; struct bio *bio = NULL; -- 2.25.4