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-rw-r--r--drivers/rpmsg/virtio_rpmsg_bus.c25
-rw-r--r--include/linux/rpmsg.h3
2 files changed, 22 insertions, 6 deletions
diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
index 9623327ba50..39d3aa41add 100644
--- a/drivers/rpmsg/virtio_rpmsg_bus.c
+++ b/drivers/rpmsg/virtio_rpmsg_bus.c
@@ -227,6 +227,7 @@ static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp,
}
kref_init(&ept->refcount);
+ mutex_init(&ept->cb_lock);
ept->rpdev = rpdev;
ept->cb = cb;
@@ -324,10 +325,16 @@ EXPORT_SYMBOL(rpmsg_create_ept);
static void
__rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept)
{
+ /* make sure new inbound messages can't find this ept anymore */
mutex_lock(&vrp->endpoints_lock);
idr_remove(&vrp->endpoints, ept->addr);
mutex_unlock(&vrp->endpoints_lock);
+ /* make sure in-flight inbound messages won't invoke cb anymore */
+ mutex_lock(&ept->cb_lock);
+ ept->cb = NULL;
+ mutex_unlock(&ept->cb_lock);
+
kref_put(&ept->refcount, __ept_release);
}
@@ -821,14 +828,20 @@ static void rpmsg_recv_done(struct virtqueue *rvq)
mutex_unlock(&vrp->endpoints_lock);
- if (ept && ept->cb)
- ept->cb(ept->rpdev, msg->data, msg->len, ept->priv, msg->src);
- else
- dev_warn(dev, "msg received with no recepient\n");
+ if (ept) {
+ /* make sure ept->cb doesn't go away while we use it */
+ mutex_lock(&ept->cb_lock);
- /* farewell, ept, we don't need you anymore */
- if (ept)
+ if (ept->cb)
+ ept->cb(ept->rpdev, msg->data, msg->len, ept->priv,
+ msg->src);
+
+ mutex_unlock(&ept->cb_lock);
+
+ /* farewell, ept, we don't need you anymore */
kref_put(&ept->refcount, __ept_release);
+ } else
+ dev_warn(dev, "msg received with no recepient\n");
/* publish the real size of the buffer */
sg_init_one(&sg, msg, RPMSG_BUF_SIZE);
diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
index 195f373590b..82a673905ed 100644
--- a/include/linux/rpmsg.h
+++ b/include/linux/rpmsg.h
@@ -39,6 +39,7 @@
#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <linux/kref.h>
+#include <linux/mutex.h>
/* The feature bitmap for virtio rpmsg */
#define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */
@@ -123,6 +124,7 @@ typedef void (*rpmsg_rx_cb_t)(struct rpmsg_channel *, void *, int, void *, u32);
* @rpdev: rpmsg channel device
* @refcount: when this drops to zero, the ept is deallocated
* @cb: rx callback handler
+ * @cb_lock: must be taken before accessing/changing @cb
* @addr: local rpmsg address
* @priv: private data for the driver's use
*
@@ -144,6 +146,7 @@ struct rpmsg_endpoint {
struct rpmsg_channel *rpdev;
struct kref refcount;
rpmsg_rx_cb_t cb;
+ struct mutex cb_lock;
u32 addr;
void *priv;
};