[PATCH] SELinux: Do not assign the same value twice to the same variable

[PATCH] SELinux: Do not assign the same value twice to the same variable

[Jesper Juhl]

Hi,

It makes little sense to assign the same value to the same variable twice 
when there is no code inbetween which could have changed the value of that 
variable.


Signed-off-by: Jesper Juhl <jj@chaosbits.net>
---
Untested patch below.

 policydb.c |    1 -
 1 file changed, 1 deletion(-)

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 94f630d..e5a30ff 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -1866,7 +1866,6 @@ static int genfs_read(struct policydb *p, void *fp)
 			if (!newc)
 				goto out;
 
-			rc = -ENOMEM;
 			newc->u.name = kmalloc(len + 1, GFP_KERNEL);
 			if (!newc->u.name)
 				goto out;


-- 
Jesper Juhl <jj@chaosbits.net>             http://www.chaosbits.net/
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Re: [PATCH] SELinux: Do not assign the same value twice to the same variable

[Eric Paris]

On Sat, 2010-10-30 at 23:10 +0200, Jesper Juhl wrote:
> Hi,
> 
> It makes little sense to assign the same value to the same variable twice 
> when there is no code inbetween which could have changed the value of that 
> variable.

I don't like the patch.  The compiler will optimize it away (actually it
will optimize both of them away) and it make it clear that if a new
block is added in the middle that error codes can't be wrong....

It's just a personal preference I guess, but I like always setting the
error code before goto outs.  Is there a reason doing this is a problem?

-Eric
> 
> 
> Signed-off-by: Jesper Juhl <jj@chaosbits.net>
> ---
> Untested patch below.
> 
>  policydb.c |    1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
> index 94f630d..e5a30ff 100644
> --- a/security/selinux/ss/policydb.c
> +++ b/security/selinux/ss/policydb.c
> @@ -1866,7 +1866,6 @@ static int genfs_read(struct policydb *p, void *fp)
>  			if (!newc)
>  				goto out;
>  
> -			rc = -ENOMEM;
>  			newc->u.name = kmalloc(len + 1, GFP_KERNEL);
>  			if (!newc->u.name)
>  				goto out;
> 
> 

Re: [PATCH] SELinux: Do not assign the same value twice to the same variable

[Jesper Juhl]

On Sat, 30 Oct 2010, Eric Paris wrote:

> On Sat, 2010-10-30 at 23:10 +0200, Jesper Juhl wrote:
> > Hi,
> > 
> > It makes little sense to assign the same value to the same variable twice 
> > when there is no code inbetween which could have changed the value of that 
> > variable.
> 
> I don't like the patch.  The compiler will optimize it away (actually it
> will optimize both of them away) and it make it clear that if a new
> block is added in the middle that error codes can't be wrong....
> 
> It's just a personal preference I guess, but I like always setting the
> error code before goto outs.  Is there a reason doing this is a problem?
> 
It's not a problem as such, it just seemed a silly thing to do when I came 
across it. But, I can see your point in leaving it, so just forget about 
the patch.

-- 
Jesper Juhl <jj@chaosbits.net>             http://www.chaosbits.net/
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