Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933245Ab3CHGQF (ORCPT ); Fri, 8 Mar 2013 01:16:05 -0500 Received: from mail-gh0-f180.google.com ([209.85.160.180]:46796 "EHLO mail-gh0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752984Ab3CHGQB (ORCPT ); Fri, 8 Mar 2013 01:16:01 -0500 From: Lucas De Marchi To: lucas.de.marchi@gmail.com Cc: David Howells , James Morris , Andrew Morton , Oleg Nesterov , Lucas De Marchi , linux-kernel@vger.kernel.org Subject: [PATCH v2 2/7] usermodehelper: Export _exec() and _setup() functions Date: Fri, 8 Mar 2013 03:15:08 -0300 Message-Id: <1362723313-839-3-git-send-email-lucas.demarchi@profusion.mobi> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1362723313-839-1-git-send-email-lucas.demarchi@profusion.mobi> References: <1362723313-839-1-git-send-email-lucas.demarchi@profusion.mobi> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5493 Lines: 149 call_usermodehelper_setup() + call_usermodehelper_exec() need to be called instead of call_usermodehelper_fns() when the cleanup function needs to be called even when an ENOMEM error occurs. In this case using call_usermodehelper_fns() the user can't distinguish if the cleanup function was called or not. Signed-off-by: Lucas De Marchi --- include/linux/kmod.h | 8 ++++++++ kernel/kmod.c | 56 +++++++++++++++++++++------------------------------- 2 files changed, 31 insertions(+), 33 deletions(-) diff --git a/include/linux/kmod.h b/include/linux/kmod.h index 5398d58..7eebcf5 100644 --- a/include/linux/kmod.h +++ b/include/linux/kmod.h @@ -71,6 +71,14 @@ call_usermodehelper_fns(char *path, char **argv, char **envp, int wait, int (*init)(struct subprocess_info *info, struct cred *new), void (*cleanup)(struct subprocess_info *), void *data); +extern struct subprocess_info * +call_usermodehelper_setup(char *path, char **argv, char **envp, gfp_t gfp_mask, + int (*init)(struct subprocess_info *info, struct cred *new), + void (*cleanup)(struct subprocess_info *), void *data); + +extern int +call_usermodehelper_exec(struct subprocess_info *info, int wait); + static inline int call_usermodehelper(char *path, char **argv, char **envp, int wait) { diff --git a/kernel/kmod.c b/kernel/kmod.c index 56dd349..b39f240 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -502,14 +502,28 @@ static void helper_unlock(void) * @argv: arg vector for process * @envp: environment for process * @gfp_mask: gfp mask for memory allocation + * @cleanup: a cleanup function + * @init: an init function + * @data: arbitrary context sensitive data * * 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. + * + * The init function is used to customize the helper process prior to + * exec. A non-zero return code causes the process to error out, exit, + * and return the failure to the calling process + * + * The cleanup function is just before ethe subprocess_info is about to + * be freed. This can be used for freeing the argv and envp. The + * Function must be runnable in either a process context or the + * context in which call_usermodehelper_exec is called. */ -static struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, - char **envp, gfp_t gfp_mask) + char **envp, gfp_t gfp_mask, + int (*init)(struct subprocess_info *info, struct cred *new), + void (*cleanup)(struct subprocess_info *info), + void *data) { struct subprocess_info *sub_info; sub_info = kzalloc(sizeof(struct subprocess_info), gfp_mask); @@ -520,38 +534,15 @@ struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, sub_info->path = path; sub_info->argv = argv; sub_info->envp = envp; + + sub_info->cleanup = cleanup; + sub_info->init = init; + sub_info->data = data; out: return sub_info; } /** - * call_usermodehelper_setfns - set a cleanup/init function - * @info: a subprocess_info returned by call_usermodehelper_setup - * @cleanup: a cleanup function - * @init: an init function - * @data: arbitrary context sensitive data - * - * The init function is used to customize the helper process prior to - * exec. A non-zero return code causes the process to error out, exit, - * and return the failure to the calling process - * - * The cleanup function is just before ethe subprocess_info is about to - * be freed. This can be used for freeing the argv and envp. The - * Function must be runnable in either a process context or the - * context in which call_usermodehelper_exec is called. - */ -static -void call_usermodehelper_setfns(struct subprocess_info *info, - int (*init)(struct subprocess_info *info, struct cred *new), - void (*cleanup)(struct subprocess_info *info), - void *data) -{ - info->cleanup = cleanup; - info->init = init; - info->data = data; -} - -/** * call_usermodehelper_exec - start a usermode application * @sub_info: information about the subprocessa * @wait: wait for the application to finish and return status. @@ -563,7 +554,6 @@ void call_usermodehelper_setfns(struct subprocess_info *info, * asynchronously if wait is not set, and runs as a child of keventd. * (ie. it runs with full root capabilities). */ -static int call_usermodehelper_exec(struct subprocess_info *sub_info, int wait) { DECLARE_COMPLETION_ONSTACK(done); @@ -615,6 +605,7 @@ unlock: helper_unlock(); return retval; } +EXPORT_SYMBOL(call_usermodehelper_exec); /* * call_usermodehelper_fns() will not run the caller-provided cleanup function @@ -630,13 +621,12 @@ int call_usermodehelper_fns( struct subprocess_info *info; gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL; - info = call_usermodehelper_setup(path, argv, envp, gfp_mask); + info = call_usermodehelper_setup(path, argv, envp, gfp_mask, + init, cleanup, data); if (info == NULL) return -ENOMEM; - call_usermodehelper_setfns(info, init, cleanup, data); - return call_usermodehelper_exec(info, wait); } EXPORT_SYMBOL(call_usermodehelper_fns); -- 1.8.1.5 -- 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/