PM / Sleep: Move disabling of usermode helpers to the freezer

The core suspend/hibernation code calls usermodehelper_disable() to
avoid race conditions between the freezer and the starting of
usermode helpers and each code path has to do that on its own.
However, it is always called right before freeze_processes()
and usermodehelper_enable() is always called right after
thaw_processes().  For this reason, to avoid code duplication and
to make the connection between usermodehelper_disable() and the
freezer more visible, make freeze_processes() call it and remove the
direct usermodehelper_disable() and usermodehelper_enable() calls
from all suspend/hibernation code paths.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org

1 files changed, 1 insertions, 9 deletions

diff --git a/kernel/power/user.c b/kernel/power/user.c
index 33c4329205af..91b0fd021a95 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -12,7 +12,6 @@
 #include <linux/suspend.h>
 #include <linux/syscalls.h>
 #include <linux/reboot.h>
-#include <linux/kmod.h>
 #include <linux/string.h>
 #include <linux/device.h>
 #include <linux/miscdevice.h>
@@ -222,14 +221,8 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
                 sys_sync();
                 printk("done.\n");
 
-                error = usermodehelper_disable();
-                if (error)
-                        break;
-
                 error = freeze_processes();
-                if (error)
-                        usermodehelper_enable();
-                else
+                if (!error)
                         data->frozen = 1;
                 break;
 
@@ -238,7 +231,6 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
                         break;
                 pm_restore_gfp_mask();
                 thaw_processes();
-                usermodehelper_enable();
                 data->frozen = 0;
                 break;