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authorRafael J. Wysocki <rjw@sisk.pl>2012-03-28 23:30:21 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2012-03-28 23:30:21 +0200
commit1e73203cd1157a03facc41ffb54050f5b28e55bd (patch)
tree12781ea69aa706291949bb1a10141a8a043e09d9
parent7b5179ac14dbad945647ac9e76bbbf14ed9e0dbe (diff)
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
-rw-r--r--kernel/power/hibernate.c11
-rw-r--r--kernel/power/process.c7
-rw-r--r--kernel/power/suspend.c7
-rw-r--r--kernel/power/user.c10
4 files changed, 8 insertions, 27 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 639ff6e4ae9e..e09dfbfeecee 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -16,7 +16,6 @@
#include <linux/string.h>
#include <linux/device.h>
#include <linux/async.h>
-#include <linux/kmod.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/mount.h>
@@ -620,10 +619,6 @@ int hibernate(void)
sys_sync();
printk("done.\n");
- error = usermodehelper_disable();
- if (error)
- goto Exit;
-
error = freeze_processes();
if (error)
goto Free_bitmaps;
@@ -660,7 +655,6 @@ int hibernate(void)
freezer_test_done = false;
Free_bitmaps:
- usermodehelper_enable();
free_basic_memory_bitmaps();
Exit:
pm_notifier_call_chain(PM_POST_HIBERNATION);
@@ -780,10 +774,6 @@ static int software_resume(void)
if (error)
goto close_finish;
- error = usermodehelper_disable();
- if (error)
- goto close_finish;
-
pr_debug("PM: Preparing processes for restore.\n");
error = freeze_processes();
if (error) {
@@ -802,7 +792,6 @@ static int software_resume(void)
swsusp_free();
thaw_processes();
Done:
- usermodehelper_enable();
free_basic_memory_bitmaps();
Finish:
pm_notifier_call_chain(PM_POST_RESTORE);
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 0d2aeb226108..56eaac7e88ab 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -16,6 +16,7 @@
#include <linux/freezer.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
+#include <linux/kmod.h>
/*
* Timeout for stopping processes
@@ -122,6 +123,10 @@ int freeze_processes(void)
{
int error;
+ error = usermodehelper_disable();
+ if (error)
+ return error;
+
if (!pm_freezing)
atomic_inc(&system_freezing_cnt);
@@ -187,6 +192,8 @@ void thaw_processes(void)
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
+ usermodehelper_enable();
+
schedule();
printk("done.\n");
}
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 88e5c967370d..396d262b8fd0 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -12,7 +12,6 @@
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
-#include <linux/kmod.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/syscalls.h>
@@ -102,17 +101,12 @@ static int suspend_prepare(void)
if (error)
goto Finish;
- error = usermodehelper_disable();
- if (error)
- goto Finish;
-
error = suspend_freeze_processes();
if (!error)
return 0;
suspend_stats.failed_freeze++;
dpm_save_failed_step(SUSPEND_FREEZE);
- usermodehelper_enable();
Finish:
pm_notifier_call_chain(PM_POST_SUSPEND);
pm_restore_console();
@@ -259,7 +253,6 @@ int suspend_devices_and_enter(suspend_state_t state)
static void suspend_finish(void)
{
suspend_thaw_processes();
- usermodehelper_enable();
pm_notifier_call_chain(PM_POST_SUSPEND);
pm_restore_console();
}
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;