Allow map and unmap of the client dma buffer only when the client is not
connected. The functions return -EPROTO if the client is already connected.
This is to fix the race when traffic may start or stop when buffer
is not available.
Cc: <[email protected]> #v5.11+
Signed-off-by: Tomas Winkler <[email protected]>
---
drivers/misc/mei/client.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 4378a9b25848..2cc370adb238 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -2286,8 +2286,8 @@ int mei_cl_dma_alloc_and_map(struct mei_cl *cl, const struct file *fp,
if (buffer_id == 0)
return -EINVAL;
- if (!mei_cl_is_connected(cl))
- return -ENODEV;
+ if (mei_cl_is_connected(cl))
+ return -EPROTO;
if (cl->dma_mapped)
return -EPROTO;
@@ -2327,9 +2327,7 @@ int mei_cl_dma_alloc_and_map(struct mei_cl *cl, const struct file *fp,
mutex_unlock(&dev->device_lock);
wait_event_timeout(cl->wait,
- cl->dma_mapped ||
- cl->status ||
- !mei_cl_is_connected(cl),
+ cl->dma_mapped || cl->status,
mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
mutex_lock(&dev->device_lock);
@@ -2376,8 +2374,9 @@ int mei_cl_dma_unmap(struct mei_cl *cl, const struct file *fp)
return -EOPNOTSUPP;
}
- if (!mei_cl_is_connected(cl))
- return -ENODEV;
+ /* do not allow unmap for connected client */
+ if (mei_cl_is_connected(cl))
+ return -EPROTO;
if (!cl->dma_mapped)
return -EPROTO;
@@ -2405,9 +2404,7 @@ int mei_cl_dma_unmap(struct mei_cl *cl, const struct file *fp)
mutex_unlock(&dev->device_lock);
wait_event_timeout(cl->wait,
- !cl->dma_mapped ||
- cl->status ||
- !mei_cl_is_connected(cl),
+ !cl->dma_mapped || cl->status,
mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
mutex_lock(&dev->device_lock);
--
2.26.3