In some error handling cases the lock is not unlocked.
A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@r exists@
expression E1;
identifier f;
@@
f (...) { <+...
* spin_lock_irqsave (E1,...);
... when != E1
* return ...;
...+> }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
while ((in_8(&adb->ctrl.r) & ADB_RST) != 0) {
if (--timeout == 0) {
out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) & ~ADB_RST);
+ spin_unlock_irqrestore(&macio_lock, flags);
return -1;
}
}
return -EOVERFLOW;
spin_lock_irqsave(&pp->lock, flags);
if (pp->cmd.status == 1) {
- if (file->f_flags & O_NONBLOCK)
+ if (file->f_flags & O_NONBLOCK) {
+ spin_unlock_irqrestore(&pp->lock, flags);
return -EAGAIN;
+ }
add_wait_queue(&pp->wait, &wait);
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);