[RESEND PATCH v4 1/8] i2c: Add pointer dereference protection to i2c_match_id()

Kieran Bingham
2015-09-11T11:59:50Z

From: Lee Jones <lee.jones@linaro.org>

Here we're providing dereference protection for i2c_match_id(), which
saves us having to do it each time it's called. We're also stripping
out the (now) needless checks in i2c_device_match(). This patch paves
the way for other, similar code trimming.

Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Kieran Bingham <kieranbingham@gmail.com>
---
drivers/i2c/i2c-core.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index c83e4d1..30d8a77 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -450,6 +450,9 @@ static inline int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
const struct i2c_client *client)
{
+ if (!(id && client))
+ return NULL;
+
while (id->name[0]) {
if (strcmp(client->name, id->name) == 0)
return id;
@@ -463,8 +466,6 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv)
struct i2c_client *client = i2c_verify_client(dev);
struct i2c_driver *driver;

- if (!client)
- return 0;

/* Attempt an OF style match */
if (of_driver_match_device(dev, drv))
@@ -475,9 +476,10 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv)
return 1;

driver = to_i2c_driver(drv);
- /* match on an id table if there is one */
- if (driver->id_table)
- return i2c_match_id(driver->id_table, client) != NULL;
+
+ /* Finally an I2C match */
+ if (i2c_match_id(driver->id_table, client))
+ return 1;

return 0;
}
--
2.1.4