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Commit f4957d5b authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by Linus Torvalds
Browse files

slab: make kmem_cache_create() work with 32-bit sizes 

struct kmem_cache::size and ::align were always 32-bit.

Out of curiosity I created 4GB kmem_cache, it oopsed with division by 0.
kmem_cache_create(1UL<<32+1) created 1-byte cache as expected.

size_t doesn't work and never did.

Link: http://lkml.kernel.org/r/20180305200730.15812-6-adobriyan@gmail.com


Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
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>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 361d575e

include/linux/slab.h

+4 −3
Original line number Diff line number Diff line
@@ -137,11 +137,12 @@ bool slab_is_available(void); 


extern bool usercopy_fallback;



struct kmem_cache *kmem_cache_create(const char *name, size_t size,

			size_t align, 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_usercopy(const char *name,

			size_t size, size_t align, slab_flags_t flags,

			unsigned int size, unsigned int align,

			slab_flags_t flags,

			size_t useroffset, size_t usersize,

			void (*ctor)(void *));

void kmem_cache_destroy(struct kmem_cache *);

mm/slab.c

+1 −1
Original line number Diff line number Diff line
@@ -1877,7 +1877,7 @@ slab_flags_t kmem_cache_flags(unsigned long object_size, 
}



struct kmem_cache *

__kmem_cache_alias(const char *name, size_t size, size_t align,

__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,

		   slab_flags_t flags, void (*ctor)(void *))

{

	struct kmem_cache *cachep;

mm/slab.h

+3 −3
Original line number Diff line number Diff line
@@ -101,11 +101,11 @@ extern void create_boot_cache(struct kmem_cache *, const char *name, 
			unsigned int useroffset, unsigned int usersize);



int slab_unmergeable(struct kmem_cache *s);

struct kmem_cache *find_mergeable(size_t size, size_t align,

struct kmem_cache *find_mergeable(unsigned size, unsigned align,

		slab_flags_t flags, const char *name, void (*ctor)(void *));

#ifndef CONFIG_SLOB

struct kmem_cache *

__kmem_cache_alias(const char *name, size_t size, size_t align,

__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,

		   slab_flags_t flags, void (*ctor)(void *));



slab_flags_t kmem_cache_flags(unsigned long object_size,
@@ -113,7 +113,7 @@ slab_flags_t kmem_cache_flags(unsigned long object_size, 
	void (*ctor)(void *));

#else

static inline struct kmem_cache *

__kmem_cache_alias(const char *name, size_t size, size_t align,

__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,

		   slab_flags_t flags, void (*ctor)(void *))

{ return NULL; }

mm/slab_common.c

+10 −9
Original line number Diff line number Diff line
@@ -82,7 +82,7 @@ unsigned int kmem_cache_size(struct kmem_cache *s) 
EXPORT_SYMBOL(kmem_cache_size);



#ifdef CONFIG_DEBUG_VM

static int kmem_cache_sanity_check(const char *name, size_t size)

static int kmem_cache_sanity_check(const char *name, unsigned int size)

{

	struct kmem_cache *s = NULL;
@@ -113,7 +113,7 @@ static int kmem_cache_sanity_check(const char *name, size_t size) 
	return 0;

}

#else

static inline int kmem_cache_sanity_check(const char *name, size_t size)

static inline int kmem_cache_sanity_check(const char *name, unsigned int size)

{

	return 0;

}
@@ -280,8 +280,8 @@ static inline void memcg_unlink_cache(struct kmem_cache *s) 
 * Figure out what the alignment of the objects will be given a set of

 * flags, a user specified alignment and the size of the objects.

 */

static unsigned long calculate_alignment(slab_flags_t flags,

		unsigned long align, unsigned long size)

static unsigned int calculate_alignment(slab_flags_t flags,

		unsigned int align, unsigned int size)

{

	/*

	 * If the user wants hardware cache aligned objects then follow that
@@ -291,7 +291,7 @@ static unsigned long calculate_alignment(slab_flags_t flags, 
	 * alignment though. If that is greater then use it.

	 */

	if (flags & SLAB_HWCACHE_ALIGN) {

		unsigned long ralign;

		unsigned int ralign;



		ralign = cache_line_size();

		while (size <= ralign / 2)
@@ -331,7 +331,7 @@ int slab_unmergeable(struct kmem_cache *s) 
	return 0;

}



struct kmem_cache *find_mergeable(size_t size, size_t align,

struct kmem_cache *find_mergeable(unsigned int size, unsigned int align,

		slab_flags_t flags, const char *name, void (*ctor)(void *))

{

	struct kmem_cache *s;
@@ -379,7 +379,7 @@ struct kmem_cache *find_mergeable(size_t size, size_t align, 
}



static struct kmem_cache *create_cache(const char *name,

		size_t object_size, size_t size, size_t align,

		unsigned int object_size, unsigned int size, unsigned int align,

		slab_flags_t flags, size_t useroffset,

		size_t usersize, void (*ctor)(void *),

		struct mem_cgroup *memcg, struct kmem_cache *root_cache)
@@ -452,7 +452,8 @@ static struct kmem_cache *create_cache(const char *name, 
 * as davem.

 */

struct kmem_cache *

kmem_cache_create_usercopy(const char *name, size_t size, size_t align,

kmem_cache_create_usercopy(const char *name,

		  unsigned int size, unsigned int align,

		  slab_flags_t flags, size_t useroffset, size_t usersize,

		  void (*ctor)(void *))

{
@@ -532,7 +533,7 @@ kmem_cache_create_usercopy(const char *name, size_t size, size_t align, 
EXPORT_SYMBOL(kmem_cache_create_usercopy);



struct kmem_cache *

kmem_cache_create(const char *name, size_t size, size_t align,

kmem_cache_create(const char *name, unsigned int size, unsigned int align,

		slab_flags_t flags, void (*ctor)(void *))

{

	return kmem_cache_create_usercopy(name, size, align, flags, 0, 0,

mm/slub.c

+1 −1
Original line number Diff line number Diff line
@@ -4242,7 +4242,7 @@ void __init kmem_cache_init_late(void) 
}



struct kmem_cache *

__kmem_cache_alias(const char *name, size_t size, size_t align,

__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,

		   slab_flags_t flags, void (*ctor)(void *))

{

	struct kmem_cache *s, *c;