Re: [PATCH] tools/virtio: Use the __GFP_ZERO flag of kmalloc to complete the memory initialization.

[Jason Wang]

On Wed, Jun 5, 2024 at 9:56 PM cuitao <cuitao@xxxxxxxxxx> wrote:
>
> Use the __GFP_ZERO flag of kmalloc to initialize memory while allocating it,
> without the need for an additional memset call.
>
> Signed-off-by: cuitao <cuitao@xxxxxxxxxx>
> ---
>  tools/virtio/linux/kernel.h | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/tools/virtio/linux/kernel.h b/tools/virtio/linux/kernel.h
> index 6702008f7f5c..9e401fb7c215 100644
> --- a/tools/virtio/linux/kernel.h
> +++ b/tools/virtio/linux/kernel.h
> @@ -66,10 +66,7 @@ static inline void *kmalloc_array(unsigned n, size_t s, gfp_t gfp)
>
>  static inline void *kzalloc(size_t s, gfp_t gfp)
>  {
> -       void *p = kmalloc(s, gfp);
> -
> -       memset(p, 0, s);
> -       return p;
> +       return kmalloc(s, gfp | __GFP_ZERO);
>  }
>
>  static inline void *alloc_pages_exact(size_t s, gfp_t gfp)
> --
> 2.25.1
>

Does this really work?

extern void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end;
static inline void *kmalloc(size_t s, gfp_t gfp)
{
  if (__kmalloc_fake)
                return __kmalloc_fake;
        return malloc(s);
}

Thanks