diff mbox series

LoongArch: Delete debugfs checking

Message ID 7627f2b9-2287-46d2-b461-d33aa69931a8@moroto.mountain
State New
Headers
Series LoongArch: Delete debugfs checking |

Commit Message

Dan Carpenter June 20, 2023, 8:06 a.m. UTC 
  Debugfs functions are not supposed to be checked for errors.  This
is sort of unusual but it is described in the comments for the
debugfs_create_dir() function.  Also debugfs_create_dir() can never
return NULL.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
I spotted this code because I was looking at patches which were sent
to stable but without a Fixes tag.  The correct way of checking for
error pointers is not IS_ERR_OR_NULL(), it's IS_ERR().  When a function
returns both error pointers and NULL, the NULL should be treated as a
special kind of success.  Please see my blog for more details.

https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/

I have not included a Fixes tag here, because it's not really a bug fix,
it's just a clean up.

 arch/loongarch/kernel/unaligned.c | 2 --
 1 file changed, 2 deletions(-)

Comments

WANG Xuerui June 28, 2023, 2:22 p.m. UTC | #1 
Hi,

On 2023/6/20 16:06, Dan Carpenter wrote:
> Debugfs functions are not supposed to be checked for errors.  This
> is sort of unusual but it is described in the comments for the
> debugfs_create_dir() function.  Also debugfs_create_dir() can never
> return NULL.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
> I spotted this code because I was looking at patches which were sent
> to stable but without a Fixes tag.  The correct way of checking for
> error pointers is not IS_ERR_OR_NULL(), it's IS_ERR().  When a function
> returns both error pointers and NULL, the NULL should be treated as a
> special kind of success.  Please see my blog for more details.
> 
> https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
> 
> I have not included a Fixes tag here, because it's not really a bug fix,
> it's just a clean up.

Thanks for the patch and sorry for the late review. I didn't notice this 
back then (just recovering from covid around that time) but since 
loongarch-next isn't tagged yet I think the patch could make it this 
cycle. (Somehow Huacai didn't see the mail either, weird...)

> 
>   arch/loongarch/kernel/unaligned.c | 2 --
>   1 file changed, 2 deletions(-)
> 
> diff --git a/arch/loongarch/kernel/unaligned.c b/arch/loongarch/kernel/unaligned.c
> index 85fae3d2d71a..3abf163dda05 100644
> --- a/arch/loongarch/kernel/unaligned.c
> +++ b/arch/loongarch/kernel/unaligned.c
> @@ -485,8 +485,6 @@ static int __init debugfs_unaligned(void)
>   	struct dentry *d;
>   
>   	d = debugfs_create_dir("loongarch", NULL);
> -	if (IS_ERR_OR_NULL(d))
> -		return -ENOMEM;
>   
>   	debugfs_create_u32("unaligned_instructions_user",
>   				S_IRUGO, d, &unaligned_instructions_user);

Trivial enough, thanks!

Reviewed-by: WANG Xuerui <git@xen0n.name>
Huacai Chen June 28, 2023, 3:37 p.m. UTC | #2 
Queued for loongarch-next, thanks.


Huacai

On Wed, Jun 28, 2023 at 10:22 PM WANG Xuerui <kernel@xen0n.name> wrote:
>
> Hi,
>
> On 2023/6/20 16:06, Dan Carpenter wrote:
> > Debugfs functions are not supposed to be checked for errors.  This
> > is sort of unusual but it is described in the comments for the
> > debugfs_create_dir() function.  Also debugfs_create_dir() can never
> > return NULL.
> >
> > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> > ---
> > I spotted this code because I was looking at patches which were sent
> > to stable but without a Fixes tag.  The correct way of checking for
> > error pointers is not IS_ERR_OR_NULL(), it's IS_ERR().  When a function
> > returns both error pointers and NULL, the NULL should be treated as a
> > special kind of success.  Please see my blog for more details.
> >
> > https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
> >
> > I have not included a Fixes tag here, because it's not really a bug fix,
> > it's just a clean up.
>
> Thanks for the patch and sorry for the late review. I didn't notice this
> back then (just recovering from covid around that time) but since
> loongarch-next isn't tagged yet I think the patch could make it this
> cycle. (Somehow Huacai didn't see the mail either, weird...)
>
> >
> >   arch/loongarch/kernel/unaligned.c | 2 --
> >   1 file changed, 2 deletions(-)
> >
> > diff --git a/arch/loongarch/kernel/unaligned.c b/arch/loongarch/kernel/unaligned.c
> > index 85fae3d2d71a..3abf163dda05 100644
> > --- a/arch/loongarch/kernel/unaligned.c
> > +++ b/arch/loongarch/kernel/unaligned.c
> > @@ -485,8 +485,6 @@ static int __init debugfs_unaligned(void)
> >       struct dentry *d;
> >
> >       d = debugfs_create_dir("loongarch", NULL);
> > -     if (IS_ERR_OR_NULL(d))
> > -             return -ENOMEM;
> >
> >       debugfs_create_u32("unaligned_instructions_user",
> >                               S_IRUGO, d, &unaligned_instructions_user);
>
> Trivial enough, thanks!
>
> Reviewed-by: WANG Xuerui <git@xen0n.name>
>
> --
> WANG "xen0n" Xuerui
>
> Linux/LoongArch mailing list: https://lore.kernel.org/loongarch/
>
>
diff mbox series

Patch

diff --git a/arch/loongarch/kernel/unaligned.c b/arch/loongarch/kernel/unaligned.c
index 85fae3d2d71a..3abf163dda05 100644
--- a/arch/loongarch/kernel/unaligned.c
+++ b/arch/loongarch/kernel/unaligned.c
@@ -485,8 +485,6 @@  static int __init debugfs_unaligned(void)
 	struct dentry *d;
 
 	d = debugfs_create_dir("loongarch", NULL);
-	if (IS_ERR_OR_NULL(d))
-		return -ENOMEM;
 
 	debugfs_create_u32("unaligned_instructions_user",
 				S_IRUGO, d, &unaligned_instructions_user);