swsusp: Fix userland interface

2f41dddb · Rafael J. Wysocki <[email protected]> · 2007-06-16 10:16:03 -07:00

Fix oops caused by 'cat /dev/snapshot', reported by Arkadiusz Miskiewicz,
and make it impossible to thaw tasks with the help of the swsusp userland
interface while there is a snapshot image ready to save.

Signed-off-by: Rafael J. Wysocki <[email protected]>
Acked-by: Pavel Machek <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: 2f41dddbbd7193fb5cdae0a24db4d378d56885fd
Parents: b1d93de3

Changes

1 files changed · +3 −1

File	Status	Add	Del	Content
kernel/power/user.c	modified	+3	−1	View file

kernel/power/user.c

View file

diff --git a/kernel/power/user.c b/kernel/power/user.c
index 24d7d78..d65305b 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -99,6 +99,8 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf,
 	ssize_t res;
 
 	data = filp->private_data;
+	if (!data->ready)
+		return -ENODATA;
 	res = snapshot_read_next(&data->handle, count);
 	if (res > 0) {
 		if (copy_to_user(buf, data_of(data->handle), res))
@@ -245,7 +247,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
 		break;
 
 	case SNAPSHOT_UNFREEZE:
-		if (!data->frozen)
+		if (!data->frozen || data->ready)
 			break;
 		mutex_lock(&pm_mutex);
 		thaw_processes();