| Message ID | 1663002336-11809-2-git-send-email-quic_deesin@quicinc.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | rpmsg_char/ctrl driver fixes | expand |
The commit subject should start with "rpmsg: char:" no glink driver update... Regards, Arnaud On 9/12/22 19:05, Deepak Kumar Singh wrote: > When remote host goes down glink char device channel is freed and > associated rpdev is destroyed through rpmsg_chrdev_eptdev_destroy(), > At the same time user space apps can still try to open/poll rpmsg > char device which will result in calling rpmsg_create_ept()/rpmsg_poll(). > These functions will try to reference rpdev which has already been freed > through rpmsg_chrdev_eptdev_destroy(). > > File operation functions and device removal function must be protected > with lock. This patch adds existing ept lock in remove function as well. > > Signed-off-by: Deepak Kumar Singh <quic_deesin@quicinc.com> > --- > drivers/rpmsg/rpmsg_char.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c > index 4f21891..5500dc0 100644 > --- a/drivers/rpmsg/rpmsg_char.c > +++ b/drivers/rpmsg/rpmsg_char.c > @@ -75,6 +75,7 @@ int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data) > struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev); > > mutex_lock(&eptdev->ept_lock); > + eptdev->rpdev = NULL; > if (eptdev->ept) { > rpmsg_destroy_ept(eptdev->ept); > eptdev->ept = NULL; > @@ -126,6 +127,11 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) > return -EBUSY; > } > > + if (!eptdev->rpdev) { > + mutex_unlock(&eptdev->ept_lock); > + return -ENETRESET; > + } > + > get_device(dev); > > /* > @@ -277,7 +283,9 @@ static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait) > if (!skb_queue_empty(&eptdev->queue)) > mask |= EPOLLIN | EPOLLRDNORM; > > + mutex_lock(&eptdev->ept_lock); > mask |= rpmsg_poll(eptdev->ept, filp, wait); > + mutex_unlock(&eptdev->ept_lock); > > return mask; > }
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c index 4f21891..5500dc0 100644 --- a/drivers/rpmsg/rpmsg_char.c +++ b/drivers/rpmsg/rpmsg_char.c @@ -75,6 +75,7 @@ int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data) struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev); mutex_lock(&eptdev->ept_lock); + eptdev->rpdev = NULL; if (eptdev->ept) { rpmsg_destroy_ept(eptdev->ept); eptdev->ept = NULL; @@ -126,6 +127,11 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) return -EBUSY; } + if (!eptdev->rpdev) { + mutex_unlock(&eptdev->ept_lock); + return -ENETRESET; + } + get_device(dev); /* @@ -277,7 +283,9 @@ static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait) if (!skb_queue_empty(&eptdev->queue)) mask |= EPOLLIN | EPOLLRDNORM; + mutex_lock(&eptdev->ept_lock); mask |= rpmsg_poll(eptdev->ept, filp, wait); + mutex_unlock(&eptdev->ept_lock); return mask; }
When remote host goes down glink char device channel is freed and associated rpdev is destroyed through rpmsg_chrdev_eptdev_destroy(), At the same time user space apps can still try to open/poll rpmsg char device which will result in calling rpmsg_create_ept()/rpmsg_poll(). These functions will try to reference rpdev which has already been freed through rpmsg_chrdev_eptdev_destroy(). File operation functions and device removal function must be protected with lock. This patch adds existing ept lock in remove function as well. Signed-off-by: Deepak Kumar Singh <quic_deesin@quicinc.com> --- drivers/rpmsg/rpmsg_char.c | 8 ++++++++ 1 file changed, 8 insertions(+)