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.
Unified · Split
| @@ -99,6 +99,8 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf, · 98 unmodified lines | |||
| 99 | ssize_t res; | 99 | ssize_t res; |
| 100 | 100 | ||
| 101 | data = filp->private_data; | 101 | data = filp->private_data; |
| 102 | if (!data->ready) | ||
| 103 | return -ENODATA; | ||
| 102 | res = snapshot_read_next(&data->handle, count); | 104 | res = snapshot_read_next(&data->handle, count); |
| 103 | if (res > 0) { | 105 | if (res > 0) { |
| 104 | if (copy_to_user(buf, data_of(data->handle), res)) | 106 | if (copy_to_user(buf, data_of(data->handle), res)) |
| @@ -245,7 +247,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, · 140 unmodified lines | |||
| 245 | break; | 247 | break; |
| 246 | 248 | ||
| 247 | case SNAPSHOT_UNFREEZE: | 249 | case SNAPSHOT_UNFREEZE: |
| 248 | if (!data->frozen) | 250 | if (!data->frozen || data->ready) |
| 249 | break; | 251 | break; |
| 250 | mutex_lock(&pm_mutex); | 252 | mutex_lock(&pm_mutex); |
| 251 | thaw_processes(); | 253 | thaw_processes(); |