[PATCH 1/1] char: tpm: Deletion of unnecessary checks before the function call "tpm_dev_vendor_release"

[PATCH 1/1] char: tpm: Deletion of unnecessary checks before the function call "tpm_dev_vendor_release"

[Peter Hüwe]

Applied to my tree:
https://github.com/PeterHuewe/linux-tpmdd for-james

Will be included in the next pull-request.

Thanks,
Peter

Re: [PATCH with Coccinelle?] Deletion of unnecessary checks before specific function calls

[SF Markus Elfring]

> If you are convinced that dropping the null tests is a good idea, then you 
> can submit the patch that makes the change to the relevant maintainers and 
> mailing lists.

Hello,

A couple of functions perform input parameter validation before their
implementations will try further actions with side effects. Some calling
functions perform similar safety checks.

Functions which release a system resource are often documented in the way that
they tolerate the passing of a null pointer for example. I do not see a need
because of this fact that a function caller repeats a corresponding check.

Now I would like to propose such a change again.

1. Extension of the infrastructure for the analysis tool "coccicheck"
   Semantic patch patterns can help to identify update candidates also in the
Linux source file hierarchy.

https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/scripts/coccinelle?id=79f0345fefaafb7cde301a830471edd21a37989b

2. Clarification for some automated update suggestions
   My source code search approach found seventy functions at least which might
need another review and corresponding corrections for Linux 3.14-rc5. Further
software development will point out even more potentially open issues.

Regards,
Markus

[PATCH 1/1] char: tpm: Deletion of unnecessary checks before the function call "tpm_dev_vendor_release"

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Wed, 19 Nov 2014 14:44:15 +0100

The tpm_dev_vendor_release() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/char/tpm/tpm_i2c_atmel.c   | 3 +--
 drivers/char/tpm/tpm_i2c_nuvoton.c | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm_i2c_atmel.c b/drivers/char/tpm/tpm_i2c_atmel.c
index 7727292..19c3a7b 100644
--- a/drivers/char/tpm/tpm_i2c_atmel.c
+++ b/drivers/char/tpm/tpm_i2c_atmel.c
@@ -202,8 +202,7 @@ static int i2c_atmel_remove(struct i2c_client *client)
 	struct device *dev = &(client->dev);
 	struct tpm_chip *chip = dev_get_drvdata(dev);
 
-	if (chip)
-		tpm_dev_vendor_release(chip);
+	tpm_dev_vendor_release(chip);
 	tpm_remove_hardware(dev);
 	kfree(chip);
 	return 0;
diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
index 7b158ef..8d09628 100644
--- a/drivers/char/tpm/tpm_i2c_nuvoton.c
+++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
@@ -625,8 +625,7 @@ static int i2c_nuvoton_remove(struct i2c_client *client)
 	struct device *dev = &(client->dev);
 	struct tpm_chip *chip = dev_get_drvdata(dev);
 
-	if (chip)
-		tpm_dev_vendor_release(chip);
+	tpm_dev_vendor_release(chip);
 	tpm_remove_hardware(dev);
 	kfree(chip);
 	return 0;
-- 
2.1.3