PM / Hibernate: Thaw processes in SNAPSHOT_CREATE_IMAGE ioctl test path

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() 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 in case hibernation_snapshot() returned due to a successful
freezer test. Fix this issue. But note 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@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

3 files changed, 11 insertions, 4 deletions

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 1fcf9de4506d..c10cb0f916e2 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 23a2db1ec442..0c4defe6d3b8 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 6d8f535c2b88..e2aff0fc2697 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -283,10 +283,15 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
                 }
                 pm_restore_gfp_mask();
                 error = hibernation_snapshot(data->platform_support);
-                if (!error)
+                if (!error) {
                         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: