diff mbox

[15/46] selinux: One check and function call less in genfs_read() after error detection

Message ID dbd8e89d-45a1-5785-f2dd-673389ac01a3@users.sourceforge.net
State New, archived
Headers show

Commit Message

SF Markus Elfring Jan. 15, 2017, 3:15 p.m. UTC
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 14 Jan 2017 18:29:20 +0100

Adjust a jump target to avoid a check repetition at the end after a memory
allocation failed for the local variable "newgenfs".

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 security/selinux/ss/policydb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Casey Schaufler Jan. 17, 2017, 4:32 p.m. UTC | #1
On 1/15/2017 7:15 AM, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sat, 14 Jan 2017 18:29:20 +0100
>
> Adjust a jump target to avoid a check repetition at the end after a memory
> allocation failed for the local variable "newgenfs".
>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>  security/selinux/ss/policydb.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
> index 5dc31faa601f..e7b882251da8 100644
> --- a/security/selinux/ss/policydb.c
> +++ b/security/selinux/ss/policydb.c
> @@ -2015,7 +2015,7 @@ static int genfs_read(struct policydb *p, void *fp)
>  		newgenfs = kzalloc(sizeof(*newgenfs), GFP_KERNEL);
>  		if (!newgenfs) {
>  			rc = -ENOMEM;
> -			goto out;
> +			goto exit;
>  		}
>  
>  		rc = str_read(&newgenfs->fstype, GFP_KERNEL, fp, len);
> @@ -2101,7 +2101,7 @@ static int genfs_read(struct policydb *p, void *fp)
>  		kfree(newgenfs);
>  	}
>  	ocontext_destroy(newc, OCON_FSUSE);
> -
> +exit:
>  	return rc;

Why not replace the "goto out" with "return rc" rather
than add a target?

>  }
>  

--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
SF Markus Elfring Jan. 17, 2017, 4:37 p.m. UTC | #2
>> @@ -2015,7 +2015,7 @@ static int genfs_read(struct policydb *p, void *fp)
>>  		newgenfs = kzalloc(sizeof(*newgenfs), GFP_KERNEL);
>>  		if (!newgenfs) {
>>  			rc = -ENOMEM;
>> -			goto out;
>> +			goto exit;
>>  		}
>>  
>>  		rc = str_read(&newgenfs->fstype, GFP_KERNEL, fp, len);
>> @@ -2101,7 +2101,7 @@ static int genfs_read(struct policydb *p, void *fp)
>>  		kfree(newgenfs);
>>  	}
>>  	ocontext_destroy(newc, OCON_FSUSE);
>> -
>> +exit:
>>  	return rc;
> 
> Why not replace the "goto out" with "return rc" rather
> than add a target?

Would you accept to use the statement "return -ENOMEM;" there instead?

Regards,
Markus
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Casey Schaufler Jan. 17, 2017, 5:53 p.m. UTC | #3
On 1/17/2017 8:37 AM, SF Markus Elfring wrote:
>>> @@ -2015,7 +2015,7 @@ static int genfs_read(struct policydb *p, void *fp)
>>>  		newgenfs = kzalloc(sizeof(*newgenfs), GFP_KERNEL);
>>>  		if (!newgenfs) {
>>>  			rc = -ENOMEM;
>>> -			goto out;
>>> +			goto exit;
>>>  		}
>>>  
>>>  		rc = str_read(&newgenfs->fstype, GFP_KERNEL, fp, len);
>>> @@ -2101,7 +2101,7 @@ static int genfs_read(struct policydb *p, void *fp)
>>>  		kfree(newgenfs);
>>>  	}
>>>  	ocontext_destroy(newc, OCON_FSUSE);
>>> -
>>> +exit:
>>>  	return rc;
>> Why not replace the "goto out" with "return rc" rather
>> than add a target?
> Would you accept to use the statement "return -ENOMEM;" there instead?

That would be even better.

>
> Regards,
> Markus
>

--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Paul Moore March 23, 2017, 10:05 p.m. UTC | #4
On Tue, Jan 17, 2017 at 12:53 PM, Casey Schaufler
<casey@schaufler-ca.com> wrote:
> On 1/17/2017 8:37 AM, SF Markus Elfring wrote:
>>>> @@ -2015,7 +2015,7 @@ static int genfs_read(struct policydb *p, void *fp)
>>>>             newgenfs = kzalloc(sizeof(*newgenfs), GFP_KERNEL);
>>>>             if (!newgenfs) {
>>>>                     rc = -ENOMEM;
>>>> -                   goto out;
>>>> +                   goto exit;
>>>>             }
>>>>
>>>>             rc = str_read(&newgenfs->fstype, GFP_KERNEL, fp, len);
>>>> @@ -2101,7 +2101,7 @@ static int genfs_read(struct policydb *p, void *fp)
>>>>             kfree(newgenfs);
>>>>     }
>>>>     ocontext_destroy(newc, OCON_FSUSE);
>>>> -
>>>> +exit:
>>>>     return rc;
>>> Why not replace the "goto out" with "return rc" rather
>>> than add a target?
>> Would you accept to use the statement "return -ENOMEM;" there instead?
>
> That would be even better.

I *hate* code that does a jump to a label only to then do a
return/exit.  That said, see my earlier comments about not worrying
too much about performance of the error path and in this case I like
the "feel good" nature of the code where ever failure in the loop goes
to "out".
diff mbox

Patch

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 5dc31faa601f..e7b882251da8 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -2015,7 +2015,7 @@  static int genfs_read(struct policydb *p, void *fp)
 		newgenfs = kzalloc(sizeof(*newgenfs), GFP_KERNEL);
 		if (!newgenfs) {
 			rc = -ENOMEM;
-			goto out;
+			goto exit;
 		}
 
 		rc = str_read(&newgenfs->fstype, GFP_KERNEL, fp, len);
@@ -2101,7 +2101,7 @@  static int genfs_read(struct policydb *p, void *fp)
 		kfree(newgenfs);
 	}
 	ocontext_destroy(newc, OCON_FSUSE);
-
+exit:
 	return rc;
 }