diff mbox series

[1/6] slab: Clean up SLOB vs kmalloc() definition

Message ID 20221101223321.1326815-1-keescook@chromium.org
State New
Headers
Series slab: Provide full coverage for __alloc_size attribute |

Commit Message

Kees Cook Nov. 1, 2022, 10:33 p.m. UTC 
  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@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: linux-mm@kvack.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/slab.h | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

Comments

Hyeonggon Yoo Nov. 3, 2022, 1:32 p.m. UTC | #1 
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@suse.cz>
> Cc: Christoph Lameter <cl@linux.com>
> Cc: Pekka Enberg <penberg@kernel.org>
> Cc: David Rientjes <rientjes@google.com>
> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Roman Gushchin <roman.gushchin@linux.dev>
> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
> Cc: linux-mm@kvack.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  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@gmail.com>
diff mbox series

Patch

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)