Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756294Ab1DKXSz (ORCPT ); Mon, 11 Apr 2011 19:18:55 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:53319 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755944Ab1DKXSy (ORCPT ); Mon, 11 Apr 2011 19:18:54 -0400 Date: Mon, 11 Apr 2011 16:18:38 -0700 From: Andrew Morton To: Harry Wei Cc: petr@vandrovec.name, viro@zeniv.linux.org.uk, arnd@arndb.de, npiggin@kernel.dk, jens.axboe@oracle.com, greg@kroah.com, joe@perches.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH]initialize the array of fs/ncpfs/inode.c Message-Id: <20110411161838.dabbc3f3.akpm@linux-foundation.org> In-Reply-To: <20110410100816.GB4953@gmail.com> References: <20110410100816.GB4953@gmail.com> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2964 Lines: 87 On Sun, 10 Apr 2011 18:08:18 +0800 Harry Wei wrote: > Hi us, > When i compile the linux-2.6.38.2, some warnings happened > to me. One of them is like following. > > fs/ncpfs/inode.c: In function 'ncp_fill_super': > fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[1u]' may be used > uninitialized in this function > ... > See details by the URL: > http://s1202.photobucket.com/albums/bb364/harrywei/Kernel/?action=view¤t=patched.png Yup. The compiler is "wrong" because it doesn't know that the uninitialised bytes will never be read, because they fall after the '\0' in a null-terminated string. > @@ -461,6 +462,7 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent) > #endif > struct ncp_entry_info finfo; > > + data.mounted_vol[NCP_VOLNAME_LEN + 1] = {0}; > data.wdog_pid = NULL; > server = kzalloc(sizeof(struct ncp_server), GFP_KERNEL); > if (!server) hm. I'm not sure that this fixed data.mounted_vol[2u], data.mounted_vol[3u], etc. How about we use the big hammer? From: Andrew Morton fs/ncpfs/inode.c: In function 'ncp_fill_super': fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[1u]' may be used uninitialized in this function fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[2u]' may be used uninitialized in this function fs/ncpfs/inode.c:451: warning: 'data.mounted_vol[3u]' may be used uninitialized in this function ... It's notabug, but we can easily fix it with a memset(). Reported-by: Harry Wei Cc: Petr Vandrovec Signed-off-by: Andrew Morton --- fs/ncpfs/inode.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff -puN fs/ncpfs/inode.c~fs-ncpfs-inodec-suppress-used-uninitialised-warning fs/ncpfs/inode.c --- a/fs/ncpfs/inode.c~fs-ncpfs-inodec-suppress-used-uninitialised-warning +++ a/fs/ncpfs/inode.c @@ -461,7 +461,7 @@ static int ncp_fill_super(struct super_b #endif struct ncp_entry_info finfo; - data.wdog_pid = NULL; + memset(data, 0, sizeof(data)); server = kzalloc(sizeof(struct ncp_server), GFP_KERNEL); if (!server) return -ENOMEM; @@ -496,7 +496,6 @@ static int ncp_fill_super(struct super_b struct ncp_mount_data_v4* md = (struct ncp_mount_data_v4*)raw_data; data.flags = md->flags; - data.int_flags = 0; data.mounted_uid = md->mounted_uid; data.wdog_pid = find_get_pid(md->wdog_pid); data.ncp_fd = md->ncp_fd; @@ -507,7 +506,6 @@ static int ncp_fill_super(struct super_b data.file_mode = md->file_mode; data.dir_mode = md->dir_mode; data.info_fd = -1; - data.mounted_vol[0] = 0; } break; default: _ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/