From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757323AbYE0MbK (ORCPT ); Tue, 27 May 2008 08:31:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756627AbYE0Ma6 (ORCPT ); Tue, 27 May 2008 08:30:58 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:37067 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755983AbYE0Ma5 (ORCPT ); Tue, 27 May 2008 08:30:57 -0400 Date: Tue, 27 May 2008 21:30:34 +0900 From: KOSAKI Motohiro To: "Paul Menage" , Li Zefan , Jeremy Fitzhardinge , Rusty Russell , Andi Kleen , LKML , Andrew Morton Subject: [PATCH] call_usermodehelper() increase reliability Cc: kosaki.motohiro@jp.fujitsu.com Message-Id: <20080527212423.9CAD.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.42 [ja] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now, call_usermodehelper_setup() uses GFP_ATOMIC. but it can return NULL _very_ easily. GFP_ATOMIC is needed only when we can't sleep. and, GFP_KERNEL is robust and better. thus, I add gfp_mask argument to call_usermodehelper_setup(). So, its caller pass below, call_usermodehelper() and call_usermodehelper_keys(): depend on 'wait' argument. call_usermodehelper_pipe(): always GFP_KERNEL because always run under process context. orderly_poweroff(): pass to GFP_ATOMIC because may run under interrupt context. Signed-off-by: KOSAKI Motohiro CC: "Paul Menage" CC: Li Zefan CC: Jeremy Fitzhardinge CC: Rusty Russell CC: Andi Kleen --- include/linux/kmod.h | 11 +++++++---- kernel/kmod.c | 9 +++++---- kernel/sys.c | 2 +- 3 files changed, 13 insertions(+), 9 deletions(-) Index: b/kernel/kmod.c =================================================================== --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -352,16 +352,17 @@ static inline void register_pm_notifier_ * @path: path to usermode executable * @argv: arg vector for process * @envp: environment for process + * @gfp_mask: gfp mask for memory allocation * * Returns either %NULL on allocation failure, or a subprocess_info * structure. This should be passed to call_usermodehelper_exec to * exec the process and free the structure. */ -struct subprocess_info *call_usermodehelper_setup(char *path, - char **argv, char **envp) +struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, + char **envp, gfp_t gfp_mask) { struct subprocess_info *sub_info; - sub_info = kzalloc(sizeof(struct subprocess_info), GFP_ATOMIC); + sub_info = kzalloc(sizeof(struct subprocess_info), gfp_mask); if (!sub_info) goto out; @@ -494,7 +495,7 @@ int call_usermodehelper_pipe(char *path, struct subprocess_info *sub_info; int ret; - sub_info = call_usermodehelper_setup(path, argv, envp); + sub_info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL); if (sub_info == NULL) return -ENOMEM; Index: b/include/linux/kmod.h =================================================================== --- a/include/linux/kmod.h +++ b/include/linux/kmod.h @@ -19,6 +19,7 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ +#include #include #include #include @@ -40,8 +41,8 @@ struct file; struct subprocess_info; /* Allocate a subprocess_info structure */ -struct subprocess_info *call_usermodehelper_setup(char *path, - char **argv, char **envp); +struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, + char **envp, gfp_t gfp_mask); /* Set various pieces of state into the subprocess_info structure */ void call_usermodehelper_setkeys(struct subprocess_info *info, @@ -68,8 +69,9 @@ static inline int call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait) { struct subprocess_info *info; + gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL; - info = call_usermodehelper_setup(path, argv, envp); + info = call_usermodehelper_setup(path, argv, envp, gfp_mask); if (info == NULL) return -ENOMEM; return call_usermodehelper_exec(info, wait); @@ -80,8 +82,9 @@ call_usermodehelper_keys(char *path, cha struct key *session_keyring, enum umh_wait wait) { struct subprocess_info *info; + gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL; - info = call_usermodehelper_setup(path, argv, envp); + info = call_usermodehelper_setup(path, argv, envp, gfp_mask); if (info == NULL) return -ENOMEM; Index: b/kernel/sys.c =================================================================== --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1795,7 +1795,7 @@ int orderly_poweroff(bool force) goto out; } - info = call_usermodehelper_setup(argv[0], argv, envp); + info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC); if (info == NULL) { argv_free(argv); goto out;