2022-06-14 09:25:39

by Dongliang Mu

Subject: [PATCH] x86: kvm: remove NULL check before kfree

From: mudongliang <[email protected]>

kfree can handle NULL pointer as its argument.
According to coccinelle isnullfree check, remove NULL check
before kfree operation.

Signed-off-by: mudongliang <[email protected]>
---
arch/x86/kernel/kvm.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 1a3658f7e6d9..d4e48b4a438b 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -236,8 +236,7 @@ void kvm_async_pf_task_wake(u32 token)
raw_spin_unlock(&b->lock);

/* A dummy token might be allocated and ultimately not used. */
- if (dummy)
- kfree(dummy);
+ kfree(dummy);
}
EXPORT_SYMBOL_GPL(kvm_async_pf_task_wake);

--
2.35.1

2022-06-14 12:11:08

by Vitaly Kuznetsov

Subject: Re: [PATCH] x86: kvm: remove NULL check before kfree

Dongliang Mu <[email protected]> writes:

> From: mudongliang <[email protected]>
>
> kfree can handle NULL pointer as its argument.
> According to coccinelle isnullfree check, remove NULL check
> before kfree operation.
>
> Signed-off-by: mudongliang <[email protected]>
> ---
> arch/x86/kernel/kvm.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
> index 1a3658f7e6d9..d4e48b4a438b 100644
> --- a/arch/x86/kernel/kvm.c
> +++ b/arch/x86/kernel/kvm.c
> @@ -236,8 +236,7 @@ void kvm_async_pf_task_wake(u32 token)
> raw_spin_unlock(&b->lock);
>
> /* A dummy token might be allocated and ultimately not used. */
> - if (dummy)
> - kfree(dummy);
> + kfree(dummy);
> }
> EXPORT_SYMBOL_GPL(kvm_async_pf_task_wake);

Reviewed-by: Vitaly Kuznetsov <[email protected]>

--
Vitaly

2022-06-14 14:09:36

by Dongliang Mu

Subject: Re: [PATCH] x86: kvm: remove NULL check before kfree

On Tue, Jun 14, 2022 at 8:01 PM Vitaly Kuznetsov <[email protected]> wrote:
>
> Dongliang Mu <[email protected]> writes:
>
> > From: mudongliang <[email protected]>
> >
> > kfree can handle NULL pointer as its argument.
> > According to coccinelle isnullfree check, remove NULL check
> > before kfree operation.
> >
> > Signed-off-by: mudongliang <[email protected]>
> > ---
> > arch/x86/kernel/kvm.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
> > index 1a3658f7e6d9..d4e48b4a438b 100644
> > --- a/arch/x86/kernel/kvm.c
> > +++ b/arch/x86/kernel/kvm.c
> > @@ -236,8 +236,7 @@ void kvm_async_pf_task_wake(u32 token)
> > raw_spin_unlock(&b->lock);
> >
> > /* A dummy token might be allocated and ultimately not used. */
> > - if (dummy)
> > - kfree(dummy);
> > + kfree(dummy);
> > }
> > EXPORT_SYMBOL_GPL(kvm_async_pf_task_wake);
>
> Reviewed-by: Vitaly Kuznetsov <[email protected]>

Thanks for your review. My signature seems with an incorrect format,
so I send a v2 patch.


>
> --
> Vitaly
>