diff mbox series

[v4,12/17] slab: create kmem_cache_create() compatibility layer

Message ID 20240905-work-kmem_cache_args-v4-12-ed45d5380679@kernel.org (mailing list archive)
State New
Headers show
Series slab: add struct kmem_cache_args | expand

Commit Message

Christian Brauner Sept. 5, 2024, 7:56 a.m. UTC 
Use _Generic() to create a compatibility layer that type switches on the
third argument to either call __kmem_cache_create() or
__kmem_cache_create_args(). If NULL is passed for the struct
kmem_cache_args argument use default args making porting for callers
that don't care about additional arguments easy.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 include/linux/slab.h | 29 ++++++++++++++++++++++++++---
 mm/slab_common.c     | 10 +++++-----
 2 files changed, 31 insertions(+), 8 deletions(-)

Comments

Mike Rapoport Sept. 5, 2024, 8:15 a.m. UTC | #1 
On Thu, Sep 05, 2024 at 09:56:55AM +0200, Christian Brauner wrote:
> Use _Generic() to create a compatibility layer that type switches on the
> third argument to either call __kmem_cache_create() or
> __kmem_cache_create_args(). If NULL is passed for the struct
> kmem_cache_args argument use default args making porting for callers
> that don't care about additional arguments easy.
> 
> Reviewed-by: Kees Cook <kees@kernel.org>
> Reviewed-by: Jens Axboe <axboe@kernel.dk>
> Signed-off-by: Christian Brauner <brauner@kernel.org>

Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

> ---
>  include/linux/slab.h | 29 ++++++++++++++++++++++++++---
>  mm/slab_common.c     | 10 +++++-----
>  2 files changed, 31 insertions(+), 8 deletions(-)
> 
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index cb264dded324..f74ceb788ac1 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -261,9 +261,10 @@ struct kmem_cache *__kmem_cache_create_args(const char *name,
>  					    unsigned int object_size,
>  					    struct kmem_cache_args *args,
>  					    slab_flags_t flags);
> -struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
> -			unsigned int align, slab_flags_t flags,
> -			void (*ctor)(void *));
> +
> +struct kmem_cache *__kmem_cache_create(const char *name, unsigned int size,
> +				       unsigned int align, slab_flags_t flags,
> +				       void (*ctor)(void *));
>  struct kmem_cache *kmem_cache_create_usercopy(const char *name,
>  			unsigned int size, unsigned int align,
>  			slab_flags_t flags,
> @@ -272,6 +273,28 @@ struct kmem_cache *kmem_cache_create_usercopy(const char *name,
>  struct kmem_cache *kmem_cache_create_rcu(const char *name, unsigned int size,
>  					 unsigned int freeptr_offset,
>  					 slab_flags_t flags);
> +
> +/* If NULL is passed for @args, use this variant with default arguments. */
> +static inline struct kmem_cache *
> +__kmem_cache_default_args(const char *name, unsigned int size,
> +			  struct kmem_cache_args *args,
> +			  slab_flags_t flags)
> +{
> +	struct kmem_cache_args kmem_default_args = {};
> +
> +	/* Make sure we don't get passed garbage. */
> +	if (WARN_ON_ONCE(args))
> +		return NULL;
> +
> +	return __kmem_cache_create_args(name, size, &kmem_default_args, flags);
> +}
> +
> +#define kmem_cache_create(__name, __object_size, __args, ...)           \
> +	_Generic((__args),                                              \
> +		struct kmem_cache_args *: __kmem_cache_create_args,	\
> +		void *: __kmem_cache_default_args,			\
> +		default: __kmem_cache_create)(__name, __object_size, __args, __VA_ARGS__)
> +
>  void kmem_cache_destroy(struct kmem_cache *s);
>  int kmem_cache_shrink(struct kmem_cache *s);
>  
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index 19ae3dd6e36f..418459927670 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -383,7 +383,7 @@ kmem_cache_create_usercopy(const char *name, unsigned int size,
>  EXPORT_SYMBOL(kmem_cache_create_usercopy);
>  
>  /**
> - * kmem_cache_create - Create a cache.
> + * __kmem_cache_create - Create a cache.
>   * @name: A string which is used in /proc/slabinfo to identify this cache.
>   * @size: The size of objects to be created in this cache.
>   * @align: The required alignment for the objects.
> @@ -407,9 +407,9 @@ EXPORT_SYMBOL(kmem_cache_create_usercopy);
>   *
>   * Return: a pointer to the cache on success, NULL on failure.
>   */
> -struct kmem_cache *
> -kmem_cache_create(const char *name, unsigned int size, unsigned int align,
> -		slab_flags_t flags, void (*ctor)(void *))
> +struct kmem_cache *__kmem_cache_create(const char *name, unsigned int size,
> +				       unsigned int align, slab_flags_t flags,
> +				       void (*ctor)(void *))
>  {
>  	struct kmem_cache_args kmem_args = {
>  		.align	= align,
> @@ -418,7 +418,7 @@ kmem_cache_create(const char *name, unsigned int size, unsigned int align,
>  
>  	return __kmem_cache_create_args(name, size, &kmem_args, flags);
>  }
> -EXPORT_SYMBOL(kmem_cache_create);
> +EXPORT_SYMBOL(__kmem_cache_create);
>  
>  /**
>   * kmem_cache_create_rcu - Create a SLAB_TYPESAFE_BY_RCU cache.
> 
> -- 
> 2.45.2
>
Vlastimil Babka Sept. 5, 2024, 11:54 a.m. UTC | #2 
On 9/5/24 9:56 AM, Christian Brauner wrote:
> Use _Generic() to create a compatibility layer that type switches on the
> third argument to either call __kmem_cache_create() or
> __kmem_cache_create_args(). If NULL is passed for the struct
> kmem_cache_args argument use default args making porting for callers
> that don't care about additional arguments easy.
> 
> Reviewed-by: Kees Cook <kees@kernel.org>
> Reviewed-by: Jens Axboe <axboe@kernel.dk>
> Signed-off-by: Christian Brauner <brauner@kernel.org>
> ---
>  include/linux/slab.h | 29 ++++++++++++++++++++++++++---
>  mm/slab_common.c     | 10 +++++-----
>  2 files changed, 31 insertions(+), 8 deletions(-)
> 
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index cb264dded324..f74ceb788ac1 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -261,9 +261,10 @@ struct kmem_cache *__kmem_cache_create_args(const char *name,
>  					    unsigned int object_size,
>  					    struct kmem_cache_args *args,
>  					    slab_flags_t flags);
> -struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
> -			unsigned int align, slab_flags_t flags,
> -			void (*ctor)(void *));
> +
> +struct kmem_cache *__kmem_cache_create(const char *name, unsigned int size,
> +				       unsigned int align, slab_flags_t flags,
> +				       void (*ctor)(void *));
>  struct kmem_cache *kmem_cache_create_usercopy(const char *name,
>  			unsigned int size, unsigned int align,
>  			slab_flags_t flags,
> @@ -272,6 +273,28 @@ struct kmem_cache *kmem_cache_create_usercopy(const char *name,
>  struct kmem_cache *kmem_cache_create_rcu(const char *name, unsigned int size,
>  					 unsigned int freeptr_offset,
>  					 slab_flags_t flags);
> +
> +/* If NULL is passed for @args, use this variant with default arguments. */
> +static inline struct kmem_cache *
> +__kmem_cache_default_args(const char *name, unsigned int size,
> +			  struct kmem_cache_args *args,
> +			  slab_flags_t flags)
> +{
> +	struct kmem_cache_args kmem_default_args = {};
> +
> +	/* Make sure we don't get passed garbage. */
> +	if (WARN_ON_ONCE(args))
> +		return NULL;

I'm changing to return ERR_PTR(-EINVAL); locally
although it's not too important

> +
> +	return __kmem_cache_create_args(name, size, &kmem_default_args, flags);
> +}
> +
> +#define kmem_cache_create(__name, __object_size, __args, ...)           \
> +	_Generic((__args),                                              \
> +		struct kmem_cache_args *: __kmem_cache_create_args,	\
> +		void *: __kmem_cache_default_args,			\
> +		default: __kmem_cache_create)(__name, __object_size, __args, __VA_ARGS__)
> +
>  void kmem_cache_destroy(struct kmem_cache *s);
>  int kmem_cache_shrink(struct kmem_cache *s);
>  
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index 19ae3dd6e36f..418459927670 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -383,7 +383,7 @@ kmem_cache_create_usercopy(const char *name, unsigned int size,
>  EXPORT_SYMBOL(kmem_cache_create_usercopy);
>  
>  /**
> - * kmem_cache_create - Create a cache.
> + * __kmem_cache_create - Create a cache.
>   * @name: A string which is used in /proc/slabinfo to identify this cache.
>   * @size: The size of objects to be created in this cache.
>   * @align: The required alignment for the objects.
> @@ -407,9 +407,9 @@ EXPORT_SYMBOL(kmem_cache_create_usercopy);
>   *
>   * Return: a pointer to the cache on success, NULL on failure.
>   */
> -struct kmem_cache *
> -kmem_cache_create(const char *name, unsigned int size, unsigned int align,
> -		slab_flags_t flags, void (*ctor)(void *))
> +struct kmem_cache *__kmem_cache_create(const char *name, unsigned int size,
> +				       unsigned int align, slab_flags_t flags,
> +				       void (*ctor)(void *))
>  {
>  	struct kmem_cache_args kmem_args = {
>  		.align	= align,
> @@ -418,7 +418,7 @@ kmem_cache_create(const char *name, unsigned int size, unsigned int align,
>  
>  	return __kmem_cache_create_args(name, size, &kmem_args, flags);
>  }
> -EXPORT_SYMBOL(kmem_cache_create);
> +EXPORT_SYMBOL(__kmem_cache_create);
>  
>  /**
>   * kmem_cache_create_rcu - Create a SLAB_TYPESAFE_BY_RCU cache.
>
Roman Gushchin Sept. 6, 2024, 1:05 a.m. UTC | #3 
On Thu, Sep 05, 2024 at 09:56:55AM +0200, Christian Brauner wrote:
> Use _Generic() to create a compatibility layer that type switches on the
> third argument to either call __kmem_cache_create() or
> __kmem_cache_create_args(). If NULL is passed for the struct
> kmem_cache_args argument use default args making porting for callers
> that don't care about additional arguments easy.
> 
> Reviewed-by: Kees Cook <kees@kernel.org>
> Reviewed-by: Jens Axboe <axboe@kernel.dk>
> Signed-off-by: Christian Brauner <brauner@kernel.org>

Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
diff mbox series

Patch

diff --git a/include/linux/slab.h b/include/linux/slab.h
index cb264dded324..f74ceb788ac1 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -261,9 +261,10 @@  struct kmem_cache *__kmem_cache_create_args(const char *name,
 					    unsigned int object_size,
 					    struct kmem_cache_args *args,
 					    slab_flags_t flags);
-struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
-			unsigned int align, slab_flags_t flags,
-			void (*ctor)(void *));
+
+struct kmem_cache *__kmem_cache_create(const char *name, unsigned int size,
+				       unsigned int align, slab_flags_t flags,
+				       void (*ctor)(void *));
 struct kmem_cache *kmem_cache_create_usercopy(const char *name,
 			unsigned int size, unsigned int align,
 			slab_flags_t flags,
@@ -272,6 +273,28 @@  struct kmem_cache *kmem_cache_create_usercopy(const char *name,
 struct kmem_cache *kmem_cache_create_rcu(const char *name, unsigned int size,
 					 unsigned int freeptr_offset,
 					 slab_flags_t flags);
+
+/* If NULL is passed for @args, use this variant with default arguments. */
+static inline struct kmem_cache *
+__kmem_cache_default_args(const char *name, unsigned int size,
+			  struct kmem_cache_args *args,
+			  slab_flags_t flags)
+{
+	struct kmem_cache_args kmem_default_args = {};
+
+	/* Make sure we don't get passed garbage. */
+	if (WARN_ON_ONCE(args))
+		return NULL;
+
+	return __kmem_cache_create_args(name, size, &kmem_default_args, flags);
+}
+
+#define kmem_cache_create(__name, __object_size, __args, ...)           \
+	_Generic((__args),                                              \
+		struct kmem_cache_args *: __kmem_cache_create_args,	\
+		void *: __kmem_cache_default_args,			\
+		default: __kmem_cache_create)(__name, __object_size, __args, __VA_ARGS__)
+
 void kmem_cache_destroy(struct kmem_cache *s);
 int kmem_cache_shrink(struct kmem_cache *s);
 
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 19ae3dd6e36f..418459927670 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -383,7 +383,7 @@  kmem_cache_create_usercopy(const char *name, unsigned int size,
 EXPORT_SYMBOL(kmem_cache_create_usercopy);
 
 /**
- * kmem_cache_create - Create a cache.
+ * __kmem_cache_create - Create a cache.
  * @name: A string which is used in /proc/slabinfo to identify this cache.
  * @size: The size of objects to be created in this cache.
  * @align: The required alignment for the objects.
@@ -407,9 +407,9 @@  EXPORT_SYMBOL(kmem_cache_create_usercopy);
  *
  * Return: a pointer to the cache on success, NULL on failure.
  */
-struct kmem_cache *
-kmem_cache_create(const char *name, unsigned int size, unsigned int align,
-		slab_flags_t flags, void (*ctor)(void *))
+struct kmem_cache *__kmem_cache_create(const char *name, unsigned int size,
+				       unsigned int align, slab_flags_t flags,
+				       void (*ctor)(void *))
 {
 	struct kmem_cache_args kmem_args = {
 		.align	= align,
@@ -418,7 +418,7 @@  kmem_cache_create(const char *name, unsigned int size, unsigned int align,
 
 	return __kmem_cache_create_args(name, size, &kmem_args, flags);
 }
-EXPORT_SYMBOL(kmem_cache_create);
+EXPORT_SYMBOL(__kmem_cache_create);
 
 /**
  * kmem_cache_create_rcu - Create a SLAB_TYPESAFE_BY_RCU cache.