On Tue, Nov 01, 2022 at 03:33:09PM -0700, Kees Cook wrote:
> As already done for kmalloc_node(), clean up the #ifdef usage in the
> definition of kmalloc() so that the SLOB-only version is an entirely
> separate and much more readable function.
>
> Cc: Vlastimil Babka <vbabka@xxxxxxx>
> Cc: Christoph Lameter <cl@xxxxxxxxx>
> Cc: Pekka Enberg <penberg@xxxxxxxxxx>
> Cc: David Rientjes <rientjes@xxxxxxxxxx>
> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
> Cc: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
> Cc: linux-mm@xxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> ---
> include/linux/slab.h | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index 90877fcde70b..e08fe7978b5c 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -559,15 +559,15 @@ void *kmalloc_large_node(size_t size, gfp_t flags, int node) __assume_page_align
> * Try really hard to succeed the allocation but fail
> * eventually.
> */
> +#ifndef CONFIG_SLOB
> static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags)
> {
> if (__builtin_constant_p(size)) {
> -#ifndef CONFIG_SLOB
> unsigned int index;
> -#endif
> +
> if (size > KMALLOC_MAX_CACHE_SIZE)
> return kmalloc_large(size, flags);
> -#ifndef CONFIG_SLOB
> +
> index = kmalloc_index(size);
>
> if (!index)
> @@ -576,10 +576,18 @@ static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags)
> return kmalloc_trace(
> kmalloc_caches[kmalloc_type(flags)][index],
> flags, size);
> -#endif
> }
> return __kmalloc(size, flags);
> }
> +#else
> +static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags)
> +{
> + if (__builtin_constant_p(size) && size > KMALLOC_MAX_CACHE_SIZE)
> + return kmalloc_large(size, flags);
> +
> + return __kmalloc(size, flags);
> +}
> +#endif
>
> #ifndef CONFIG_SLOB
> static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t flags, int node)
> --
> 2.34.1
Looks good to me.
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
--
Thanks,
Hyeonggon
