swsusp: Fix userland interface

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 <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Rafael J. Wysocki 2007-06-16 10:16:03 -07:00 committed by Linus Torvalds
parent b1d93de3e4
commit 2f41dddbbd
1 changed files with 3 additions and 1 deletions

View File

@ -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();