Re: [PATCH v2 1/4] device: provide devm_krealloc_array()

[Jonathan Cameron]

On Mon,  2 Nov 2020 15:22:25 +0100
Bartosz Golaszewski <brgl@xxxxxxxx> wrote:

> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> 
> When allocating an array of elements, users should check for
> multiplication overflow or preferably use one of the provided helpers
> like: devm_kmalloc_array().
> 
> This provides devm_krealloc_array() for users who want to reallocate
> managed arrays.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>

+CC Greg KH. 

As this is going into a very generic place I'd like a relevant ack.
That file is a bit of a wild west for acks, but Greg seems most
appropriate person.

So Greg, any comments on this one?

Thanks,

Jonathan

> ---
>  include/linux/device.h | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 5ed101be7b2e..e77203faea55 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -226,6 +226,17 @@ static inline void *devm_kmalloc_array(struct device *dev,
>  
>  	return devm_kmalloc(dev, bytes, flags);
>  }
> +static inline void *
> +devm_krealloc_array(struct device *dev, void *ptr, size_t new_n,
> +		    size_t new_size, gfp_t gfp)
> +{
> +	size_t bytes;
> +
> +	if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))
> +		return NULL;
> +
> +	return devm_krealloc(dev, ptr, bytes, gfp);
> +}
>  static inline void *devm_kcalloc(struct device *dev,
>  				 size_t n, size_t size, gfp_t flags)
>  {