Re: [RFC PATCH] type safe allocator

[Satyam Sharma <satyam@infradead.org>]

Hi Miklos,


On Wed, 1 Aug 2007, Miklos Szeredi wrote:

> I wonder why we don't have type safe object allocators a-la new() in
> C++ or g_new() in glib?
> 
>   fooptr = k_new(struct foo, GFP_KERNEL);
> 
> is nicer and more descriptive than
> 
>   fooptr = kmalloc(sizeof(*fooptr), GFP_KERNEL);
> 
> and more safe than
> 
>   fooptr = kmalloc(sizeof(struct foo), GFP_KERNEL);
> 
> And we have zillions of both variants.
> 
> Note, I'm not advocating mass replacement, but using this in new code,
> and gradually converting old ones whenever they need touching anyway.
> [...]
>  
> +/**
> + * k_new - allocate given type object
> + * @type: the type of the object to allocate
> + * @flags: the type of memory to allocate.
> + */
> +#define k_new(type, flags) ((type *) kmalloc(sizeof(type), flags))

What others already said, plus:

kmalloc()'ing sizeof(struct foo) is not always what we want in C either.

Several kernel structs have zero-length / variable-length array members
and space must be allocated for them only at alloc() time ... would be
impossible to make them work with this scheme.


Satyam