Re: [PATCH RFC v2] slab: introduce kmalloc_array

[Jesper Juhl]

On Thu, 9 Feb 2012, Xi Wang wrote:

> This patch introduces a kmalloc_array() wrapper that performs integer
> overflow checking without zeroing the memory.
> 
> Suggested-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Suggested-by: Jens Axboe <axboe@xxxxxxxxx>
> Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
> ---
> Let's take "kxnalloc" off for now and keep the patch simple.
> ---
>  include/linux/slab.h |   17 ++++++++++++++---
>  1 files changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index 573c809..a595dce 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -190,7 +190,7 @@ size_t ksize(const void *);
>  #endif
>  
>  /**
> - * kcalloc - allocate memory for an array. The memory is set to zero.
> + * kmalloc_array - allocate memory for an array.
>   * @n: number of elements.
>   * @size: element size.
>   * @flags: the type of memory to allocate.
> @@ -240,11 +240,22 @@ size_t ksize(const void *);
>   * for general use, and so are not documented here. For a full list of
>   * potential flags, always refer to linux/gfp.h.
>   */
> -static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
> +static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
>  {
>  	if (size != 0 && n > ULONG_MAX / size)
>  		return NULL;
> -	return __kmalloc(n * size, flags | __GFP_ZERO);
> +	return __kmalloc(n * size, flags);
> +}
> +
> +/**
> + * kcalloc - allocate memory for an array. The memory is set to zero.
> + * @n: number of elements.
> + * @size: element size.
> + * @flags: the type of memory to allocate (see kmalloc).
> + */
> +static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
> +{
> +	return kmalloc_array(n, size, flags | __GFP_ZERO);
>  }
>  
>  #if !defined(CONFIG_NUMA) && !defined(CONFIG_SLOB)
> 

Does this want adding to Documentation/CodingStyle "Chapter 14: Allocating 
memory" ?

-- 
Jesper Juhl <jj@xxxxxxxxxxxxx>       http://www.chaosbits.net/
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