[PATCH] PM / Hibernate: Thaw processes in SNAPSHOT_CREATE_IMAGE ioctlerror/test paths

From: Srivatsa S. Bhat
Date: Thu Dec 01 2011 - 08:15:49 EST


Commit 2aede851ddf08666f68ffc17be446420e9d2a056 (PM / Hibernate: Freeze
kernel threads after preallocating memory) moved the freezing of kernel
threads to hibernation_snapshot() function.

So now, if the call to hibernation_snapshot() fails or returns early due
to a successful hibernation test, the caller has to thaw processes to
ensure that the system gets back to its original state.

But in SNAPSHOT_CREATE_IMAGE hibernation ioctl, the caller does not thaw
processes. Fix this issue. But note that if hibernation_snapshot() returned
due to a successful freezer test, we still send the value of 'in_suspend'
(which is now 0) to userspace, because we are not in an error path per-se,
and moreover, the value of in_suspend correctly depicts the situation here.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
---

kernel/power/hibernate.c | 2 +-
kernel/power/power.h | 2 ++
kernel/power/user.c | 13 ++++++++++---
3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index a6b0503..624538a 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -55,7 +55,7 @@ enum {

static int hibernation_mode = HIBERNATION_SHUTDOWN;

-static bool freezer_test_done;
+bool freezer_test_done;

static const struct platform_hibernation_ops *hibernation_ops;

diff --git a/kernel/power/power.h b/kernel/power/power.h
index 23a2db1..0c4defe 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -50,6 +50,8 @@ static inline char *check_image_kernel(struct swsusp_info *info)
#define SPARE_PAGES ((1024 * 1024) >> PAGE_SHIFT)

/* kernel/power/hibernate.c */
+extern bool freezer_test_done;
+
extern int hibernation_snapshot(int platform_mode);
extern int hibernation_restore(int platform_mode);
extern int hibernation_platform_enter(void);
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 6d8f535..b98b7e1 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -283,10 +283,17 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
}
pm_restore_gfp_mask();
error = hibernation_snapshot(data->platform_support);
- if (!error)
+ if (error) {
+ thaw_processes();
+ } else {
error = put_user(in_suspend, (int __user *)arg);
- if (!error)
- data->ready = 1;
+ if (!error && !freezer_test_done)
+ data->ready = 1;
+ if (freezer_test_done) {
+ freezer_test_done = false;
+ thaw_processes();
+ }
+ }
break;

case SNAPSHOT_ATOMIC_RESTORE:

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