From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933913Ab0BEWCP (ORCPT ); Fri, 5 Feb 2010 17:02:15 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:55142 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933863Ab0BEWCO (ORCPT ); Fri, 5 Feb 2010 17:02:14 -0500 Date: Fri, 5 Feb 2010 14:01:50 -0800 From: Andrew Morton To: Amerigo Wang Cc: linux-kernel@vger.kernel.org, Alexander Viro , Arnd Bergmann Subject: Re: [Patch] compat ioctl: fix some build warnings Message-Id: <20100205140150.7f5df97b.akpm@linux-foundation.org> In-Reply-To: <20100205070921.4179.39579.sendpatchset@localhost.localdomain> References: <20100205070921.4179.39579.sendpatchset@localhost.localdomain> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.9; 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 On Fri, 5 Feb 2010 02:05:56 -0500 Amerigo Wang wrote: > I got these warnings: > > fs/compat_ioctl.c: In function ___compat_sys_ioctl': > fs/compat_ioctl.c:534: warning: ___karg' may be used uninitialized in this function > fs/compat_ioctl.c:533: warning: ___kcmd' may be used uninitialized in this function > fs/compat_ioctl.c:656: warning: ___ret' may be used uninitialized in this function > > These warnings are harmless, so just shut gcc up. > > Signed-off-by: WANG Cong > Cc: Alexander Viro > Cc: Arnd Bergmann > > --- > diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c > index c5c45de..2468f80 100644 > --- a/fs/compat_ioctl.c > +++ b/fs/compat_ioctl.c > @@ -543,6 +543,8 @@ static int mt_ioctl_trans(unsigned int fd, unsigned int cmd, void __user *argp) > kcmd = MTIOCGET; > karg = &get; > break; > + default: > + return -EINVAL; > } > set_fs (KERNEL_DS); > err = sys_ioctl (fd, kcmd, (unsigned long)karg); > @@ -653,7 +655,7 @@ static int set_raw32_request(struct raw_config_request *req, struct raw32_config > static int raw_ioctl(unsigned fd, unsigned cmd, > struct raw32_config_request __user *user_req) > { > - int ret; > + int ret = -EINVAL; > > switch (cmd) { > case RAW_SETBIND: Unfortunately that adds more code for something which cannot happen at runtime. I guess we could do this trick: --- a/fs/compat_ioctl.c~a +++ a/fs/compat_ioctl.c @@ -539,7 +539,7 @@ static int mt_ioctl_trans(unsigned int f kcmd = MTIOCPOS; karg = &pos; break; - case MTIOCGET32: + default: /* MTIOCGET32 */ kcmd = MTIOCGET; karg = &get; break; @@ -657,7 +657,7 @@ static int raw_ioctl(unsigned fd, unsign switch (cmd) { case RAW_SETBIND: - case RAW_GETBIND: { + default: { /* RAW_GETBIND */ struct raw_config_request req; mm_segment_t oldfs = get_fs(); _ Which actually reduces code: akpm:/usr/src/25> size fs/compat_ioctl.o text data bss dec hex filename 9012 2232 2864 14108 371c fs/compat_ioctl.o 8968 2232 2848 14048 36e0 fs/compat_ioctl.o