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authorChristian Gromm <christian.gromm@microchip.com>2018-05-08 11:45:10 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-08 13:41:51 +0200
commit993c1637a08f436eacc7b3f4eacbda8dac0b304b (patch)
tree51dbb92b98b9d103e4fda89c5351625dd20c8a92 /drivers/staging/most
parent021fa2dbc49b7759945735250b56eba40e5166ce (diff)
staging: most: cdev: fix race condition
This patch fixes a race condition between the functions disconnect and poll. Signed-off-by: Christian Gromm <christian.gromm@microchip.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/most')
-rw-r--r--drivers/staging/most/cdev/cdev.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/staging/most/cdev/cdev.c b/drivers/staging/most/cdev/cdev.c
index 8e7652545402..4569838f27a0 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;
}