diff options
| -rw-r--r-- | kernel/kmod.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/kernel/kmod.c b/kernel/kmod.c index 78d365c524e..928f3678142 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -33,12 +33,22 @@ #include <linux/kernel.h> #include <linux/init.h> #include <linux/resource.h> +#include <linux/notifier.h> +#include <linux/suspend.h> #include <asm/uaccess.h> extern int max_threads; static struct workqueue_struct *khelper_wq; +/* + * If set, both call_usermodehelper_keys() and call_usermodehelper_pipe() exit + * immediately returning -EBUSY. Used for preventing user land processes from + * being created after the user land has been frozen during a system-wide + * hibernation or suspend operation. + */ +static int usermodehelper_disabled; + #ifdef CONFIG_KMOD /* @@ -265,6 +275,24 @@ static void __call_usermodehelper(struct work_struct *work) } } +static int usermodehelper_pm_callback(struct notifier_block *nfb, + unsigned long action, + void *ignored) +{ + switch (action) { + case PM_HIBERNATION_PREPARE: + case PM_SUSPEND_PREPARE: + usermodehelper_disabled = 1; + return NOTIFY_OK; + case PM_POST_HIBERNATION: + case PM_POST_SUSPEND: + usermodehelper_disabled = 0; + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + /** * call_usermodehelper_setup - prepare to call a usermode helper * @path - path to usermode executable @@ -374,7 +402,7 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info, goto out; } - if (!khelper_wq) { + if (!khelper_wq || usermodehelper_disabled) { retval = -EBUSY; goto out; } @@ -431,4 +459,5 @@ void __init usermodehelper_init(void) { khelper_wq = create_singlethread_workqueue("khelper"); BUG_ON(!khelper_wq); + pm_notifier(usermodehelper_pm_callback, 0); } |