[1/2] i2c-dev: don't get i2c adapter via i2c_dev

Message ID c2ac0349b818d3f3787b939d5eb83e3c80fc205d.1467772840.git.viresh.kumar@linaro.org
State Accepted
Commit 5136ed4fcb05cd4981cc6034a11e66370ed84789
Headers show

Commit Message

Viresh Kumar July 6, 2016, 2:57 a.m.
There is no code protecting i2c_dev to be freed after it is returned
from i2c_dev_get_by_minor() and using it to access the value which we
already have (minor) isn't safe really.

Avoid using it and get the adapter directly from 'minor'.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

---
 drivers/i2c/i2c-dev.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

-- 
2.7.4

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Comments

Viresh Kumar July 7, 2016, 3:35 p.m. | #1
On 07-07-16, 15:16, Jean Delvare wrote:
> Anyway, this is a good cleanup/optimization on its own, on top of

> fixing a race condition, independently of what we decide for the rest

> of the problems being discussed in this thread. So:

> 

> Reviewed-by: Jean Delvare <jdelvare@suse.de>

> Tested-by: Jean Delvare <jdelvare@suse.de>


Thanks Jean.

-- 
viresh
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Patch

diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 6ecfd76270f2..66f323fd3982 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -485,13 +485,8 @@  static int i2cdev_open(struct inode *inode, struct file *file)
 	unsigned int minor = iminor(inode);
 	struct i2c_client *client;
 	struct i2c_adapter *adap;
-	struct i2c_dev *i2c_dev;
-
-	i2c_dev = i2c_dev_get_by_minor(minor);
-	if (!i2c_dev)
-		return -ENODEV;
 
-	adap = i2c_get_adapter(i2c_dev->adap->nr);
+	adap = i2c_get_adapter(minor);
 	if (!adap)
 		return -ENODEV;