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Commit 8cdd4936 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
Browse files

PM: disable usermode helper before hibernation and suspend 



Use a hibernation and suspend notifier to disable the user mode helper before
a hibernation/suspend and enable it after the operation.

[akpm@linux-foundation.org: build fix]
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Acked-by: default avatarNigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b10d9117

kernel/kmod.c

+30 −1
Original line number Diff line number Diff line
@@ -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);

}