[PATCH v2 4/8] PM / Hibernate: Disable usermode helpers right before freezing tasks

From: Rafael J. Wysocki
Date: Wed Mar 28 2012 - 17:24:34 EST


From: Rafael J. Wysocki <rjw@xxxxxxx>

There is no reason to call usermodehelper_disable() before creating
memory bitmaps in hibernate() and software_resume(), so call it right
before freeze_processes(), in accordance with the other suspend and
hibernation code. Consequently, call usermodehelper_enable() right
after the thawing of tasks rather than after freeing the memory
bitmaps.

Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/power/hibernate.c | 23 ++++++++++-------------
1 file changed, 10 insertions(+), 13 deletions(-)

Index: linux/kernel/power/hibernate.c
===================================================================
--- linux.orig/kernel/power/hibernate.c
+++ linux/kernel/power/hibernate.c
@@ -611,19 +611,19 @@ int hibernate(void)
if (error)
goto Exit;

- error = usermodehelper_disable();
- if (error)
- goto Exit;
-
/* Allocate memory management structures */
error = create_basic_memory_bitmaps();
if (error)
- goto Enable_umh;
+ goto Exit;

printk(KERN_INFO "PM: Syncing filesystems ... ");
sys_sync();
printk("done.\n");

+ error = usermodehelper_disable();
+ if (error)
+ goto Exit;
+
error = freeze_processes();
if (error)
goto Free_bitmaps;
@@ -660,9 +660,8 @@ int hibernate(void)
freezer_test_done = false;

Free_bitmaps:
- free_basic_memory_bitmaps();
- Enable_umh:
usermodehelper_enable();
+ free_basic_memory_bitmaps();
Exit:
pm_notifier_call_chain(PM_POST_HIBERNATION);
pm_restore_console();
@@ -777,15 +776,13 @@ static int software_resume(void)
if (error)
goto close_finish;

- error = usermodehelper_disable();
+ error = create_basic_memory_bitmaps();
if (error)
goto close_finish;

- error = create_basic_memory_bitmaps();
- if (error) {
- usermodehelper_enable();
+ error = usermodehelper_disable();
+ if (error)
goto close_finish;
- }

pr_debug("PM: Preparing processes for restore.\n");
error = freeze_processes();
@@ -805,8 +802,8 @@ static int software_resume(void)
swsusp_free();
thaw_processes();
Done:
- free_basic_memory_bitmaps();
usermodehelper_enable();
+ free_basic_memory_bitmaps();
Finish:
pm_notifier_call_chain(PM_POST_RESTORE);
pm_restore_console();

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