Patch "remoteproc: Fix potential race condition in rproc_add" has been added to the 4.7-stable tree

Patch "remoteproc: Fix potential race condition in rproc_add" has been added to the 4.7-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    remoteproc: Fix potential race condition in rproc_add

to the 4.7-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     remoteproc-fix-potential-race-condition-in-rproc_add.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From d2e12e66a939c54ed84e5f1b6947f0c45f6c56eb Mon Sep 17 00:00:00 2001
From: Dave Gerlach <d-gerlach@ti.com>
Date: Wed, 25 May 2016 15:41:28 -0500
Subject: remoteproc: Fix potential race condition in rproc_add

From: Dave Gerlach <d-gerlach@ti.com>

commit d2e12e66a939c54ed84e5f1b6947f0c45f6c56eb upstream.

rproc_add adds the newly created remoteproc to a list for use by
rproc_get_by_phandle and then does some additional processing to finish
adding the remoteproc. This leaves a small window of time in which the
rproc is available in the list but not yet fully initialized, so if
another driver comes along and gets a handle to the rproc, it will be
invalid. Rearrange the code in rproc_add to make sure the rproc is added
to the list only after it has been successfuly initialized.

Fixes: fec47d863587 ("remoteproc: introduce rproc_get_by_phandle API")
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/remoteproc/remoteproc_core.c |   15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1264,11 +1264,6 @@ int rproc_add(struct rproc *rproc)
 	if (ret < 0)
 		return ret;
 
-	/* expose to rproc_get_by_phandle users */
-	mutex_lock(&rproc_list_mutex);
-	list_add(&rproc->node, &rproc_list);
-	mutex_unlock(&rproc_list_mutex);
-
 	dev_info(dev, "%s is available\n", rproc->name);
 
 	dev_info(dev, "Note: remoteproc is still under development and considered experimental.\n");
@@ -1276,8 +1271,16 @@ int rproc_add(struct rproc *rproc)
 
 	/* create debugfs entries */
 	rproc_create_debug_dir(rproc);
+	ret = rproc_add_virtio_devices(rproc);
+	if (ret < 0)
+		return ret;
+
+	/* expose to rproc_get_by_phandle users */
+	mutex_lock(&rproc_list_mutex);
+	list_add(&rproc->node, &rproc_list);
+	mutex_unlock(&rproc_list_mutex);
 
-	return rproc_add_virtio_devices(rproc);
+	return 0;
 }
 EXPORT_SYMBOL(rproc_add);
 


Patches currently in stable-queue which might be from d-gerlach@ti.com are

queue-4.7/remoteproc-fix-potential-race-condition-in-rproc_add.patch