[PATCH 3.11 019/121] pinctrl: protect pinctrl_list add

[Luis Henriques]

3.11.10.5 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stanislaw Gruszka <sgruszka at redhat.com>

commit 7b320cb1ed2dbd2c5f2a778197baf76fd6bf545a upstream.

We have few fedora bug reports about list corruption on pinctrl,
for example:
https://bugzilla.redhat.com/show_bug.cgi?id=1051918

Most likely corruption happen due lack of protection of pinctrl_list
when adding new nodes to it. Patch corrects that.

Fixes: 42fed7ba44e ("pinctrl: move subsystem mutex to pinctrl_dev struct")
Signed-off-by: Stanislaw Gruszka <sgruszka at redhat.com>
Acked-by: Stephen Warren <swarren at nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/pinctrl/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 2a00239..dbcf284 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -827,7 +827,9 @@ static struct pinctrl *create_pinctrl(struct device *dev)
 	kref_init(&p->users);
 
 	/* Add the pinctrl handle to the global list */
+	mutex_lock(&pinctrl_list_mutex);
 	list_add_tail(&p->node, &pinctrl_list);
+	mutex_unlock(&pinctrl_list_mutex);
 
 	return p;
 }
-- 
1.9.0