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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 F164FC47247 for ; Thu, 30 Apr 2020 21:33:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C41E72071C for ; Thu, 30 Apr 2020 21:33:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728034AbgD3Vdh (ORCPT ); Thu, 30 Apr 2020 17:33:37 -0400 Received: from mout.kundenserver.de ([212.227.126.133]:43175 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726909AbgD3Vdf (ORCPT ); Thu, 30 Apr 2020 17:33:35 -0400 Received: from threadripper.lan ([149.172.19.189]) by mrelayeu.kundenserver.de (mreue010 [212.227.15.129]) with ESMTPA (Nemesis) id 1MpUEO-1iplaj2mCa-00pvQZ; Thu, 30 Apr 2020 23:33:09 +0200 From: Arnd Bergmann To: linux-kernel@vger.kernel.org, Bob Copeland , Andrew Morton Cc: Arnd Bergmann , Alexios Zavras , John Hubbard , "Matthew Wilcox (Oracle)" , linux-karma-devel@lists.sourceforge.net Subject: [PATCH 11/15] omfs: avoid gcc-10 stringop-overflow warning Date: Thu, 30 Apr 2020 23:30:53 +0200 Message-Id: <20200430213101.135134-12-arnd@arndb.de> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200430213101.135134-1-arnd@arndb.de> References: <20200430213101.135134-1-arnd@arndb.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Provags-ID: V03:K1:+XaRPp7CfnZLZHQoG9KIZwKOhoXML5HT3OMDT+We9eFTOHl/MTa IQ1PuZBMq2cX47pExs/skvs5u6D2ZyNzv8l4dWO+94IWDT5VoeuzE+AzFnRtjtJynitNvsp AP+Ws1jGG7IWExBBTTSklFLhUYqW+J8UbX+Bk+zztYSY5iFcP7pwuW8M4A32XFbGKiqbvx0 vPhzUS91KVLo3cnojKbTw== X-UI-Out-Filterresults: notjunk:1;V03:K0:63DZ90Mcukc=:NhBphJT0hHhxTJWL41gHwf dY7o0UaxL66NyWsLABtXl/iMz51Df9L3LwCB1O/ZuzHh7Gawk1Nqi/P6StwNMJh4nVRk6Z7aX xjf0/AAD1Bf+FBt5NkDgBpobKwkfWSzKzBmLIJrASVK/rE8bQplnoUbcRnT6Bl++FJEv9TB4V 2ahN1zcsNWeUhUHwqea0GNichUMsxdBqx1GjWddfQ1qdUpmryUwqpGMYjmadRXpPBMluQZZaT QikAobFixmsiCiqrfXlVk32X3tg7jrCgNrF9CKOHpVYwawItj340hUwrvGMjcJzvr3y8tS/WT mrzOLh/DMVvktcyn/2XTkGzjsV+u9rGPqlgZSgZTEnW6oph5ZCUN1ykuTDcq8uvl19qY1PAQw Spi6dg+nDDTPmkvOkC78mquAaqmmaDqwAIT7CifiswPyiHrBWkVySVQNOUAJHz5+gBJy4RMd6 Rf0ehNtYUwrP/RvimsG6wEBMi4ini6bzNPXy3rXIHdRJ3/KJI9GBa+dMvjdUUPu3y17BGDoC9 sdMrV+YKB3HVT2kJppRfDYkveC0VdX6AcLTL+Iehh4OJDitadlcMnlNj55vI3wdK/z2fxr+DG a3oB0nUtw0UsTP6nya76PgOKKU4RbxnvZe3wrEv54mOn0PQdD9JtVIO1ASGPHnDitTZZNu8/p KxjHOTajkj1TpZhY0A0F2rzMftN/v4SKZGvp85G83d2FBJK4hteZ8mJ9FdGzWqxMOZhhvxCFK 1VmiXcwu5xRe4fpcgh6ZT76Y22NflToqhSiSEma6B+65SVpMmXpLyOtEAqMhdruHY84NS29Fv u/ao5xy5Q2KXHT1FaW47fTpLXLjJ4nUiqmXlTAYwAuWIyXVQgU= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org gcc-10 correctly points out a memcpy beyond the end of the structure it gets copied into: fs/omfs/file.c: In function 'omfs_grow_extent': cc1: warning: writing 16 bytes into a region of size 0 [-Wstringop-overflow=] In file included from fs/omfs/omfs.h:8, from fs/omfs/file.c:11: fs/omfs/omfs_fs.h:80:27: note: at offset 0 to object 'e_entry' with size 16 declared here 80 | struct omfs_extent_entry e_entry; /* start of extent entries */ | ^~~~~~~ This is not a bug however, as the file system layout contains an array of extent entries instead of just a single one that was part of the structure definition. Changing the definition to use a c99 flexible array member makes makes the code match the actual layout, which avoids the warning and an odd '+1' in the calculation of the number of extent entries. Fixes: 8f09e98768c1 ("omfs: add file routines") Signed-off-by: Arnd Bergmann --- fs/omfs/file.c | 12 ++++++------ fs/omfs/omfs_fs.h | 2 +- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/fs/omfs/file.c b/fs/omfs/file.c index d7b5f09d298c..94344386c6ff 100644 --- a/fs/omfs/file.c +++ b/fs/omfs/file.c @@ -14,7 +14,7 @@ static u32 omfs_max_extents(struct omfs_sb_info *sbi, int offset) { return (sbi->s_sys_blocksize - offset - sizeof(struct omfs_extent)) / - sizeof(struct omfs_extent_entry) + 1; + sizeof(struct omfs_extent_entry); } void omfs_make_empty_table(struct buffer_head *bh, int offset) @@ -24,8 +24,8 @@ void omfs_make_empty_table(struct buffer_head *bh, int offset) oe->e_next = ~cpu_to_be64(0ULL); oe->e_extent_count = cpu_to_be32(1), oe->e_fill = cpu_to_be32(0x22), - oe->e_entry.e_cluster = ~cpu_to_be64(0ULL); - oe->e_entry.e_blocks = ~cpu_to_be64(0ULL); + oe->e_entry[0].e_cluster = ~cpu_to_be64(0ULL); + oe->e_entry[0].e_blocks = ~cpu_to_be64(0ULL); } int omfs_shrink_inode(struct inode *inode) @@ -68,7 +68,7 @@ int omfs_shrink_inode(struct inode *inode) last = next; next = be64_to_cpu(oe->e_next); - entry = &oe->e_entry; + entry = oe->e_entry; /* ignore last entry as it is the terminator */ for (; extent_count > 1; extent_count--) { @@ -117,7 +117,7 @@ static int omfs_grow_extent(struct inode *inode, struct omfs_extent *oe, u64 *ret_block) { struct omfs_extent_entry *terminator; - struct omfs_extent_entry *entry = &oe->e_entry; + struct omfs_extent_entry *entry = oe->e_entry; struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb); u32 extent_count = be32_to_cpu(oe->e_extent_count); u64 new_block = 0; @@ -245,7 +245,7 @@ static int omfs_get_block(struct inode *inode, sector_t block, extent_count = be32_to_cpu(oe->e_extent_count); next = be64_to_cpu(oe->e_next); - entry = &oe->e_entry; + entry = oe->e_entry; if (extent_count > max_extents) goto out_brelse; diff --git a/fs/omfs/omfs_fs.h b/fs/omfs/omfs_fs.h index caecb3d5a344..1ff6b9e41297 100644 --- a/fs/omfs/omfs_fs.h +++ b/fs/omfs/omfs_fs.h @@ -77,7 +77,7 @@ struct omfs_extent { __be64 e_next; /* next extent table location */ __be32 e_extent_count; /* total # extents in this table */ __be32 e_fill; - struct omfs_extent_entry e_entry; /* start of extent entries */ + struct omfs_extent_entry e_entry[]; /* start of extent entries */ }; #endif -- 2.26.0