From a144c6a6c924aa1da04dd77fb84b89927354fdff Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 6 May 2011 20:09:42 +0200 Subject: PM: Print a warning if firmware is requested when tasks are frozen Some drivers erroneously use request_firmware() from their ->resume() (or ->thaw(), or ->restore()) callbacks, which is not going to work unless the firmware has been built in. This causes system resume to stall until the firmware-loading timeout expires, which makes users think that the resume has failed and reboot their machines unnecessarily. For this reason, make _request_firmware() print a warning and return immediately with error code if it has been called when tasks are frozen and it's impossible to start any new usermode helpers. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Reviewed-by: Valdis Kletnieks --- kernel/kmod.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'kernel/kmod.c') diff --git a/kernel/kmod.c b/kernel/kmod.c index 9cd0591c96a2..9ab513bd0c3c 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -301,6 +301,15 @@ void usermodehelper_enable(void) usermodehelper_disabled = 0; } +/** + * usermodehelper_is_disabled - check if new helpers are allowed to be started + */ +bool usermodehelper_is_disabled(void) +{ + return usermodehelper_disabled; +} +EXPORT_SYMBOL_GPL(usermodehelper_is_disabled); + static void helper_lock(void) { atomic_inc(&running_helpers); -- cgit v1.2.3 From 13d53f8775c6a00b070a3eef6833795412eb7fcd Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Tue, 10 May 2011 21:27:34 +0200 Subject: kmod: always provide usermodehelper_disable() We need to prevent kernel-forked processes during system poweroff. Such processes try to access the filesystem whose disks we are trying to shutdown at the same time. This causes delays and exceptions in the storage drivers. A follow-up patch will add these calls and need usermodehelper_disable() also on systems without suspend support. Signed-off-by: Kay Sievers Signed-off-by: Rafael J. Wysocki --- include/linux/kmod.h | 4 ---- kernel/kmod.c | 7 ------- 2 files changed, 11 deletions(-) (limited to 'kernel/kmod.c') diff --git a/include/linux/kmod.h b/include/linux/kmod.h index 7f3dbcb78116..310231823852 100644 --- a/include/linux/kmod.h +++ b/include/linux/kmod.h @@ -111,12 +111,8 @@ call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait) extern void usermodehelper_init(void); -#ifdef CONFIG_PM_SLEEP extern int usermodehelper_disable(void); extern void usermodehelper_enable(void); extern bool usermodehelper_is_disabled(void); -#else -static inline bool usermodehelper_is_disabled(void) { return false; } -#endif #endif /* __LINUX_KMOD_H__ */ diff --git a/kernel/kmod.c b/kernel/kmod.c index 9ab513bd0c3c..5ae0ff38425f 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -245,7 +245,6 @@ static void __call_usermodehelper(struct work_struct *work) } } -#ifdef CONFIG_PM_SLEEP /* * If set, call_usermodehelper_exec() will exit immediately returning -EBUSY * (used for preventing user land processes from being created after the user @@ -321,12 +320,6 @@ static void helper_unlock(void) if (atomic_dec_and_test(&running_helpers)) wake_up(&running_helpers_waitq); } -#else /* CONFIG_PM_SLEEP */ -#define usermodehelper_disabled 0 - -static inline void helper_lock(void) {} -static inline void helper_unlock(void) {} -#endif /* CONFIG_PM_SLEEP */ /** * call_usermodehelper_setup - prepare to call a usermode helper -- cgit v1.2.3