From: Tomas Winkler <tomas.winkler@intel.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Usyskin <alexander.usyskin@intel.com>,
linux-kernel@vger.kernel.org,
Tomas Winkler <tomas.winkler@intel.com>,
stable@vger.kernel.org
Subject: [char-misc-next] mei: allow map and unmap of client dma buffer only for disconnected client
Date: Thu, 18 Mar 2021 07:59:59 +0200 [thread overview]
Message-ID: <20210318055959.305627-1-tomas.winkler@intel.com> (raw)
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: <stable@vger.kernel.org> #v5.11+
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
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
reply other threads:[~2021-03-18 6:01 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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