linux-stable/include/linux/slab_def.h
Feng Tang bbc61844b4 mm/kasan: simplify and refine kasan_cache code
struct 'kasan_cache' has a member 'is_kmalloc' indicating whether its host
kmem_cache is a kmalloc cache.  With newly introduced is_kmalloc_cache()
helper, 'is_kmalloc' and its related function can be replaced and removed.

Also 'kasan_cache' is only needed by KASAN generic mode, and not by SW/HW
tag modes, so refine its protection macro accordingly, suggested by Andrey
Konoval.

Link: https://lkml.kernel.org/r/20230104060605.930910-2-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:55 -08:00

124 lines
3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_SLAB_DEF_H
#define _LINUX_SLAB_DEF_H
#include <linux/kfence.h>
#include <linux/reciprocal_div.h>
/*
* Definitions unique to the original Linux SLAB allocator.
*/
struct kmem_cache {
struct array_cache __percpu *cpu_cache;
/* 1) Cache tunables. Protected by slab_mutex */
unsigned int batchcount;
unsigned int limit;
unsigned int shared;
unsigned int size;
struct reciprocal_value reciprocal_buffer_size;
/* 2) touched by every alloc & free from the backend */
slab_flags_t flags; /* constant flags */
unsigned int num; /* # of objs per slab */
/* 3) cache_grow/shrink */
/* order of pgs per slab (2^n) */
unsigned int gfporder;
/* force GFP flags, e.g. GFP_DMA */
gfp_t allocflags;
size_t colour; /* cache colouring range */
unsigned int colour_off; /* colour offset */
unsigned int freelist_size;
/* constructor func */
void (*ctor)(void *obj);
/* 4) cache creation/removal */
const char *name;
struct list_head list;
int refcount;
int object_size;
int align;
/* 5) statistics */
#ifdef CONFIG_DEBUG_SLAB
unsigned long num_active;
unsigned long num_allocations;
unsigned long high_mark;
unsigned long grown;
unsigned long reaped;
unsigned long errors;
unsigned long max_freeable;
unsigned long node_allocs;
unsigned long node_frees;
unsigned long node_overflow;
atomic_t allochit;
atomic_t allocmiss;
atomic_t freehit;
atomic_t freemiss;
/*
* If debugging is enabled, then the allocator can add additional
* fields and/or padding to every object. 'size' contains the total
* object size including these internal fields, while 'obj_offset'
* and 'object_size' contain the offset to the user object and its
* size.
*/
int obj_offset;
#endif /* CONFIG_DEBUG_SLAB */
#ifdef CONFIG_KASAN_GENERIC
struct kasan_cache kasan_info;
#endif
#ifdef CONFIG_SLAB_FREELIST_RANDOM
unsigned int *random_seq;
#endif
#ifdef CONFIG_HARDENED_USERCOPY
unsigned int useroffset; /* Usercopy region offset */
unsigned int usersize; /* Usercopy region size */
#endif
struct kmem_cache_node *node[MAX_NUMNODES];
};
static inline void *nearest_obj(struct kmem_cache *cache, const struct slab *slab,
void *x)
{
void *object = x - (x - slab->s_mem) % cache->size;
void *last_object = slab->s_mem + (cache->num - 1) * cache->size;
if (unlikely(object > last_object))
return last_object;
else
return object;
}
/*
* We want to avoid an expensive divide : (offset / cache->size)
* Using the fact that size is a constant for a particular cache,
* we can replace (offset / cache->size) by
* reciprocal_divide(offset, cache->reciprocal_buffer_size)
*/
static inline unsigned int obj_to_index(const struct kmem_cache *cache,
const struct slab *slab, void *obj)
{
u32 offset = (obj - slab->s_mem);
return reciprocal_divide(offset, cache->reciprocal_buffer_size);
}
static inline int objs_per_slab(const struct kmem_cache *cache,
const struct slab *slab)
{
if (is_kfence_address(slab_address(slab)))
return 1;
return cache->num;
}
#endif /* _LINUX_SLAB_DEF_H */