[PATCH 2/3] i2c: Add pointer dereference protection to i2c_match_id()

From: Lee Jones
Date: Mon Jun 02 2014 - 09:41:32 EST


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 check in i2c_device_match(). This patch paves
the way for other, similar code trimming.

Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
---
drivers/i2c/i2c-core.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 2e47641..d0c7180 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -83,6 +83,9 @@ void i2c_transfer_trace_unreg(void)
static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
const struct i2c_client *client)
{
+ if (!id)
+ return NULL;
+
while (id->name[0]) {
if (strcmp(client->name, id->name) == 0)
return id;
@@ -108,9 +111,10 @@ 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;
}
--
1.8.3.2

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