This patch fixes a race condition between the functions disconnect and poll.
Signed-off-by: Christian Gromm <christian.gromm@xxxxxxxxxxxxx>
---
drivers/staging/most/cdev/cdev.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/most/cdev/cdev.c b/drivers/staging/most/cdev/cdev.c
index 8e76525..4569838 100644
--- a/drivers/staging/most/cdev/cdev.c
+++ b/drivers/staging/most/cdev/cdev.c
@@ -292,13 +292,15 @@ static __poll_t comp_poll(struct file *filp, poll_table *wait)
poll_wait(filp, &c->wq, wait);
+ mutex_lock(&c->io_mutex);
if (c->cfg->direction == MOST_CH_RX) {
- if (!kfifo_is_empty(&c->fifo))
+ if (!c->dev || !kfifo_is_empty(&c->fifo))
mask |= EPOLLIN | EPOLLRDNORM;
} else {
- if (!kfifo_is_empty(&c->fifo) || ch_has_mbo(c))
+ if (!c->dev || !kfifo_is_empty(&c->fifo) || ch_has_mbo(c))
mask |= EPOLLOUT | EPOLLWRNORM;
}
+ mutex_unlock(&c->io_mutex);
return mask;
}
--
2.7.4
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