pinctrl: add checks for empty function names

This is needed as otherwise we can get the following when
dealing with buggy data in a pinmux driver for
pinmux_search_function:

Unable to handle kernel NULL pointer dereference at virtual
address 00000000
...
PC is at strcmp+0xc/0x34
LR is at pinmux_get+0x350/0x8f4
...

As we need pctldev initialized to call ops->list_functions,
let's initialize it before check_ops calls and pass the
pctldev to the check_ops functions. Do this for both pinmux
and pinconf check_ops functions.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/pinctrl/pinconf.h b/drivers/pinctrl/pinconf.h
index e7dc6165032a..006b77fa737e 100644
--- a/drivers/pinctrl/pinconf.h
+++ b/drivers/pinctrl/pinconf.h
@@ -13,7 +13,7 @@
 
 #ifdef CONFIG_PINCONF
 
-int pinconf_check_ops(const struct pinconf_ops *ops);
+int pinconf_check_ops(struct pinctrl_dev *pctldev);
 void pinconf_init_device_debugfs(struct dentry *devroot,
                                  struct pinctrl_dev *pctldev);
 int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
@@ -23,7 +23,7 @@ int pin_config_set_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
 
 #else
 
-static inline int pinconf_check_ops(const struct pinconf_ops *ops)
+static inline int pinconf_check_ops(struct pinctrl_dev *pctldev)
 {
         return 0;
 }