1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef IOU_ALLOC_CACHE_H
3 #define IOU_ALLOC_CACHE_H
4
5 #include <linux/io_uring_types.h>
6 #include <linux/kasan.h>
7
8 /*
9 * Don't allow the cache to grow beyond this size.
10 */
11 #define IO_ALLOC_CACHE_MAX 128
12
13 void io_alloc_cache_free(struct io_alloc_cache *cache,
14 void (*free)(const void *));
15 bool io_alloc_cache_init(struct io_alloc_cache *cache,
16 unsigned max_nr, unsigned int size,
17 unsigned int init_bytes);
18
19 void *io_cache_alloc_new(struct io_alloc_cache *cache, gfp_t gfp);
20
io_alloc_cache_put(struct io_alloc_cache * cache,void * entry)21 static inline bool io_alloc_cache_put(struct io_alloc_cache *cache,
22 void *entry)
23 {
24 if (cache->nr_cached < cache->max_cached) {
25 if (!kasan_mempool_poison_object(entry))
26 return false;
27 cache->entries[cache->nr_cached++] = entry;
28 return true;
29 }
30 return false;
31 }
32
io_alloc_cache_get(struct io_alloc_cache * cache)33 static inline void *io_alloc_cache_get(struct io_alloc_cache *cache)
34 {
35 if (cache->nr_cached) {
36 void *entry = cache->entries[--cache->nr_cached];
37
38 /*
39 * If KASAN is enabled, always clear the initial bytes that
40 * must be zeroed post alloc, in case any of them overlap
41 * with KASAN storage.
42 */
43 #if defined(CONFIG_KASAN)
44 kasan_mempool_unpoison_object(entry, cache->elem_size);
45 if (cache->init_clear)
46 memset(entry, 0, cache->init_clear);
47 #endif
48 return entry;
49 }
50
51 return NULL;
52 }
53
io_cache_alloc(struct io_alloc_cache * cache,gfp_t gfp)54 static inline void *io_cache_alloc(struct io_alloc_cache *cache, gfp_t gfp)
55 {
56 void *obj;
57
58 obj = io_alloc_cache_get(cache);
59 if (obj)
60 return obj;
61 return io_cache_alloc_new(cache, gfp);
62 }
63
io_cache_free(struct io_alloc_cache * cache,void * obj)64 static inline void io_cache_free(struct io_alloc_cache *cache, void *obj)
65 {
66 if (!io_alloc_cache_put(cache, obj))
67 kfree(obj);
68 }
69
70 #endif
71