2015-06-24 20:48:41

by SF Markus Elfring

Subject: [PATCH] s390/process: Delete an unnecessary check before the function call "kfree"

From: Markus Elfring <[email protected]>
Date: Wed, 24 Jun 2015 22:40:30 +0200

The kfree() 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 <[email protected]>
---
arch/s390/kernel/process.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index dc5edc2..22e6448 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -81,8 +81,7 @@ void release_thread(struct task_struct *dead_task)

void arch_release_task_struct(struct task_struct *tsk)
{
- if (tsk->thread.vxrs)
- kfree(tsk->thread.vxrs);
+ kfree(tsk->thread.vxrs);
}

int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
--
2.4.4

2015-06-25 10:02:50

by walter harms

Subject: Re: [PATCH] s390/process: Delete an unnecessary check before the function call "kfree"

Am 24.06.2015 22:48, schrieb SF Markus Elfring:
> From: Markus Elfring <[email protected]>
> Date: Wed, 24 Jun 2015 22:40:30 +0200
>
> The kfree() 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 <[email protected]>
> ---
> arch/s390/kernel/process.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
> index dc5edc2..22e6448 100644
> --- a/arch/s390/kernel/process.c
> +++ b/arch/s390/kernel/process.c
> @@ -81,8 +81,7 @@ void release_thread(struct task_struct *dead_task)
>
> void arch_release_task_struct(struct task_struct *tsk)
> {
> - if (tsk->thread.vxrs)
> - kfree(tsk->thread.vxrs);
> + kfree(tsk->thread.vxrs);
> }
>
> int copy_thread(unsigned long clone_flags, unsigned long new_stackp,

maybe the intention was to check tsk != NULL ?

re,
wh

2015-06-25 11:37:26

by Heiko Carstens

Subject: Re: [PATCH] s390/process: Delete an unnecessary check before the function call "kfree"

On Thu, Jun 25, 2015 at 12:02:28PM +0200, walter harms wrote:
>
> Am 24.06.2015 22:48, schrieb SF Markus Elfring:
> > From: Markus Elfring <[email protected]>
> > Date: Wed, 24 Jun 2015 22:40:30 +0200
> >
> > The kfree() 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 <[email protected]>
> > ---
> > arch/s390/kernel/process.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
> > index dc5edc2..22e6448 100644
> > --- a/arch/s390/kernel/process.c
> > +++ b/arch/s390/kernel/process.c
> > @@ -81,8 +81,7 @@ void release_thread(struct task_struct *dead_task)
> >
> > void arch_release_task_struct(struct task_struct *tsk)
> > {
> > - if (tsk->thread.vxrs)
> > - kfree(tsk->thread.vxrs);
> > + kfree(tsk->thread.vxrs);
> > }

This code will be changed soon anyway. So it would be rather pointless
to apply your patch now. Thanks anyway!

> > int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
> maybe the intention was to check tsk != NULL ?

No.