2023-05-23 01:44:54

by Gustavo A. R. Silva

Subject: [PATCH 1/2][next] vfio/ccw: Replace one-element array with flexible-array member

One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element array with flexible-array
member in struct vfio_ccw_parent and refactor the the rest of the code
accordingly.

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/297
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/s390/cio/vfio_ccw_drv.c | 3 ++-
drivers/s390/cio/vfio_ccw_private.h | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index ff538a086fc7..57906a9c6324 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -171,7 +171,8 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
return -ENODEV;
}

- parent = kzalloc(sizeof(*parent), GFP_KERNEL);
+ parent = kzalloc(sizeof(*parent) + sizeof(struct mdev_type *),
+ GFP_KERNEL);
if (!parent)
return -ENOMEM;

diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index b441ae6700fd..b62bbc5c6376 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -79,7 +79,7 @@ struct vfio_ccw_parent {

struct mdev_parent parent;
struct mdev_type mdev_type;
- struct mdev_type *mdev_types[1];
+ struct mdev_type *mdev_types[];
};

/**
--
2.34.1

2023-05-23 16:50:48

by Eric Farman

Subject: Re: [PATCH 1/2][next] vfio/ccw: Replace one-element array with flexible-array member

On Mon, 2023-05-22 at 19:35 -0600, Gustavo A. R. Silva wrote:
> One-element arrays are deprecated, and we are replacing them with
> flexible
> array members instead. So, replace one-element array with flexible-
> array
> member in struct vfio_ccw_parent and refactor the the rest of the

s/the the/the/

> code
> accordingly.
>
> Link: https://github.com/KSPP/linux/issues/79
> Link: https://github.com/KSPP/linux/issues/297
> Signed-off-by: Gustavo A. R. Silva <[email protected]>

Reviewed-by: Eric Farman <[email protected]>

> ---
>  drivers/s390/cio/vfio_ccw_drv.c     | 3 ++-
>  drivers/s390/cio/vfio_ccw_private.h | 2 +-
>  2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/s390/cio/vfio_ccw_drv.c
> b/drivers/s390/cio/vfio_ccw_drv.c
> index ff538a086fc7..57906a9c6324 100644
> --- a/drivers/s390/cio/vfio_ccw_drv.c
> +++ b/drivers/s390/cio/vfio_ccw_drv.c
> @@ -171,7 +171,8 @@ static int vfio_ccw_sch_probe(struct subchannel
> *sch)
>                 return -ENODEV;
>         }
>  
> -       parent = kzalloc(sizeof(*parent), GFP_KERNEL);
> +       parent = kzalloc(sizeof(*parent) + sizeof(struct mdev_type
> *),
> +                        GFP_KERNEL);
>         if (!parent)
>                 return -ENOMEM;
>  
> diff --git a/drivers/s390/cio/vfio_ccw_private.h
> b/drivers/s390/cio/vfio_ccw_private.h
> index b441ae6700fd..b62bbc5c6376 100644
> --- a/drivers/s390/cio/vfio_ccw_private.h
> +++ b/drivers/s390/cio/vfio_ccw_private.h
> @@ -79,7 +79,7 @@ struct vfio_ccw_parent {
>  
>         struct mdev_parent      parent;
>         struct mdev_type        mdev_type;
> -       struct mdev_type        *mdev_types[1];
> +       struct mdev_type        *mdev_types[];
>  };
>  
>  /**

2023-05-23 17:40:40

by Kees Cook

Subject: Re: [PATCH 1/2][next] vfio/ccw: Replace one-element array with flexible-array member

On Mon, May 22, 2023 at 07:35:12PM -0600, Gustavo A. R. Silva wrote:
> One-element arrays are deprecated, and we are replacing them with flexible
> array members instead. So, replace one-element array with flexible-array
> member in struct vfio_ccw_parent and refactor the the rest of the code
> accordingly.
>
> Link: https://github.com/KSPP/linux/issues/79
> Link: https://github.com/KSPP/linux/issues/297
> Signed-off-by: Gustavo A. R. Silva <[email protected]>

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook

2023-05-23 17:53:19

by Christophe JAILLET

Subject: Re: [PATCH 1/2][next] vfio/ccw: Replace one-element array with flexible-array member

Le 23/05/2023 à 03:35, Gustavo A. R. Silva a écrit :
> One-element arrays are deprecated, and we are replacing them with flexible
> array members instead. So, replace one-element array with flexible-array
> member in struct vfio_ccw_parent and refactor the the rest of the code
> accordingly.
>
> Link: https://github.com/KSPP/linux/issues/79
> Link: https://github.com/KSPP/linux/issues/297
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> drivers/s390/cio/vfio_ccw_drv.c | 3 ++-
> drivers/s390/cio/vfio_ccw_private.h | 2 +-
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
> index ff538a086fc7..57906a9c6324 100644
> --- a/drivers/s390/cio/vfio_ccw_drv.c
> +++ b/drivers/s390/cio/vfio_ccw_drv.c
> @@ -171,7 +171,8 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
> return -ENODEV;
> }
>
> - parent = kzalloc(sizeof(*parent), GFP_KERNEL);
> + parent = kzalloc(sizeof(*parent) + sizeof(struct mdev_type *),

Hi, wouldn't:

parent = kzalloc(struct_size(parent, mdev_types, 1)),

be more informative and in the spirit of flexible array use?

Just my 2c,

CJ

> + GFP_KERNEL);
> if (!parent)
> return -ENOMEM;
>
> diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
> index b441ae6700fd..b62bbc5c6376 100644
> --- a/drivers/s390/cio/vfio_ccw_private.h
> +++ b/drivers/s390/cio/vfio_ccw_private.h
> @@ -79,7 +79,7 @@ struct vfio_ccw_parent {
>
> struct mdev_parent parent;
> struct mdev_type mdev_type;
> - struct mdev_type *mdev_types[1];
> + struct mdev_type *mdev_types[];
> };
>
> /**

2023-05-23 18:21:09

by Christophe JAILLET

Subject: Re: [PATCH 1/2][next] vfio/ccw: Replace one-element array with flexible-array member

Le 23/05/2023 à 19:45, Christophe JAILLET a écrit :
> Le 23/05/2023 à 03:35, Gustavo A. R. Silva a écrit :
>> One-element arrays are deprecated, and we are replacing them with
>> flexible
>> array members instead. So, replace one-element array with flexible-array
>> member in struct vfio_ccw_parent and refactor the the rest of the code
>> accordingly.
>>
>> Link: https://github.com/KSPP/linux/issues/79
>> Link: https://github.com/KSPP/linux/issues/297
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>> ---
>>   drivers/s390/cio/vfio_ccw_drv.c     | 3 ++-
>>   drivers/s390/cio/vfio_ccw_private.h | 2 +-
>>   2 files changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/s390/cio/vfio_ccw_drv.c
>> b/drivers/s390/cio/vfio_ccw_drv.c
>> index ff538a086fc7..57906a9c6324 100644
>> --- a/drivers/s390/cio/vfio_ccw_drv.c
>> +++ b/drivers/s390/cio/vfio_ccw_drv.c
>> @@ -171,7 +171,8 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
>>           return -ENODEV;
>>       }
>> -    parent = kzalloc(sizeof(*parent), GFP_KERNEL);
>> +    parent = kzalloc(sizeof(*parent) + sizeof(struct mdev_type *),
>
> Hi, wouldn't:
>
>    parent = kzalloc(struct_size(parent, mdev_types, 1)),
>
> be more informative and in the spirit of flexible array use?

Ok, patch 2/2.

Sorry for the noise.

CJ

>
> Just my 2c,
>
> CJ
>
>> +             GFP_KERNEL);
>>       if (!parent)
>>           return -ENOMEM;
>> diff --git a/drivers/s390/cio/vfio_ccw_private.h
>> b/drivers/s390/cio/vfio_ccw_private.h
>> index b441ae6700fd..b62bbc5c6376 100644
>> --- a/drivers/s390/cio/vfio_ccw_private.h
>> +++ b/drivers/s390/cio/vfio_ccw_private.h
>> @@ -79,7 +79,7 @@ struct vfio_ccw_parent {
>>       struct mdev_parent    parent;
>>       struct mdev_type    mdev_type;
>> -    struct mdev_type    *mdev_types[1];
>> +    struct mdev_type    *mdev_types[];
>>   };
>>   /**
>
>