@@ -615,13 +615,13 @@ static void linereq_put_event(struct linereq *lr,
{
bool overflow = false;
- spin_lock(&lr->wait.lock);
+ spin_lock_bh(&lr->wait.lock);
if (kfifo_is_full(&lr->events)) {
overflow = true;
kfifo_skip(&lr->events);
}
kfifo_in(&lr->events, le, 1);
- spin_unlock(&lr->wait.lock);
+ spin_unlock_bh(&lr->wait.lock);
if (!overflow)
wake_up_poll(&lr->wait, EPOLLIN);
else
@@ -1514,28 +1514,28 @@ static ssize_t linereq_read_unlocked(struct file *file, char __user *buf,
return -EINVAL;
do {
- spin_lock(&lr->wait.lock);
+ spin_lock_irq(&lr->wait.lock);
if (kfifo_is_empty(&lr->events)) {
if (bytes_read) {
- spin_unlock(&lr->wait.lock);
+ spin_unlock_irq(&lr->wait.lock);
return bytes_read;
}
if (file->f_flags & O_NONBLOCK) {
- spin_unlock(&lr->wait.lock);
+ spin_unlock_irq(&lr->wait.lock);
return -EAGAIN;
}
- ret = wait_event_interruptible_locked(lr->wait,
+ ret = wait_event_interruptible_locked_irq(lr->wait,
!kfifo_is_empty(&lr->events));
if (ret) {
- spin_unlock(&lr->wait.lock);
+ spin_unlock_irq(&lr->wait.lock);
return ret;
}
}
ret = kfifo_out(&lr->events, &le, 1);
- spin_unlock(&lr->wait.lock);
+ spin_unlock_irq(&lr->wait.lock);
if (ret != 1) {
/*
* This should never happen - we were holding the
linereq_put_event is called from both interrupt context (e.g., edge_irq_thread) and process context (process_hw_ts_thread). Therefore, interrupt should be disabled before acquiring lock &lr->wait.lock inside linereq_put_event to avoid deadlock when the lock is held in process context and edge_irq_thread comes. Similarly, linereq_read_unlocked running in process context also acquies the same lock. It also need to disable interrupt otherwise deadlock could happen if the irq edge_irq_thread comes to execution while the lock is held. Fix the two potential deadlock issues by spin_lock_bh() and spin_lock_irq() separately. Fixes: 73e0341992b6 ("gpiolib: cdev: support edge detection for uAPI v2") Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk> --- drivers/gpio/gpiolib-cdev.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)