Commit | Line | Data |
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039363f3 CL |
1 | /* |
2 | * Slab allocator functions that are independent of the allocator strategy | |
3 | * | |
4 | * (C) 2012 Christoph Lameter <cl@linux.com> | |
5 | */ | |
6 | #include <linux/slab.h> | |
7 | ||
8 | #include <linux/mm.h> | |
9 | #include <linux/poison.h> | |
10 | #include <linux/interrupt.h> | |
11 | #include <linux/memory.h> | |
12 | #include <linux/compiler.h> | |
13 | #include <linux/module.h> | |
20cea968 CL |
14 | #include <linux/cpu.h> |
15 | #include <linux/uaccess.h> | |
039363f3 CL |
16 | #include <asm/cacheflush.h> |
17 | #include <asm/tlbflush.h> | |
18 | #include <asm/page.h> | |
19 | ||
97d06609 CL |
20 | #include "slab.h" |
21 | ||
22 | enum slab_state slab_state; | |
18004c5d CL |
23 | LIST_HEAD(slab_caches); |
24 | DEFINE_MUTEX(slab_mutex); | |
9b030cb8 | 25 | struct kmem_cache *kmem_cache; |
97d06609 | 26 | |
77be4b13 SK |
27 | #ifdef CONFIG_DEBUG_VM |
28 | static int kmem_cache_sanity_check(const char *name, size_t size) | |
039363f3 CL |
29 | { |
30 | struct kmem_cache *s = NULL; | |
31 | ||
039363f3 CL |
32 | if (!name || in_interrupt() || size < sizeof(void *) || |
33 | size > KMALLOC_MAX_SIZE) { | |
77be4b13 SK |
34 | pr_err("kmem_cache_create(%s) integrity check failed\n", name); |
35 | return -EINVAL; | |
039363f3 | 36 | } |
b920536a | 37 | |
20cea968 CL |
38 | list_for_each_entry(s, &slab_caches, list) { |
39 | char tmp; | |
40 | int res; | |
41 | ||
42 | /* | |
43 | * This happens when the module gets unloaded and doesn't | |
44 | * destroy its slab cache and no-one else reuses the vmalloc | |
45 | * area of the module. Print a warning. | |
46 | */ | |
47 | res = probe_kernel_address(s->name, tmp); | |
48 | if (res) { | |
77be4b13 | 49 | pr_err("Slab cache with size %d has lost its name\n", |
20cea968 CL |
50 | s->object_size); |
51 | continue; | |
52 | } | |
53 | ||
54 | if (!strcmp(s->name, name)) { | |
77be4b13 SK |
55 | pr_err("%s (%s): Cache name already exists.\n", |
56 | __func__, name); | |
20cea968 CL |
57 | dump_stack(); |
58 | s = NULL; | |
77be4b13 | 59 | return -EINVAL; |
20cea968 CL |
60 | } |
61 | } | |
62 | ||
63 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ | |
77be4b13 SK |
64 | return 0; |
65 | } | |
66 | #else | |
67 | static inline int kmem_cache_sanity_check(const char *name, size_t size) | |
68 | { | |
69 | return 0; | |
70 | } | |
20cea968 CL |
71 | #endif |
72 | ||
77be4b13 SK |
73 | /* |
74 | * kmem_cache_create - Create a cache. | |
75 | * @name: A string which is used in /proc/slabinfo to identify this cache. | |
76 | * @size: The size of objects to be created in this cache. | |
77 | * @align: The required alignment for the objects. | |
78 | * @flags: SLAB flags | |
79 | * @ctor: A constructor for the objects. | |
80 | * | |
81 | * Returns a ptr to the cache on success, NULL on failure. | |
82 | * Cannot be called within a interrupt, but can be interrupted. | |
83 | * The @ctor is run when new pages are allocated by the cache. | |
84 | * | |
85 | * The flags are | |
86 | * | |
87 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
88 | * to catch references to uninitialised memory. | |
89 | * | |
90 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check | |
91 | * for buffer overruns. | |
92 | * | |
93 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
94 | * cacheline. This can be beneficial if you're counting cycles as closely | |
95 | * as davem. | |
96 | */ | |
97 | ||
98 | struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align, | |
99 | unsigned long flags, void (*ctor)(void *)) | |
100 | { | |
101 | struct kmem_cache *s = NULL; | |
686d550d | 102 | int err = 0; |
039363f3 | 103 | |
77be4b13 SK |
104 | get_online_cpus(); |
105 | mutex_lock(&slab_mutex); | |
686d550d CL |
106 | |
107 | if (!kmem_cache_sanity_check(name, size) == 0) | |
108 | goto out_locked; | |
109 | ||
110 | ||
cbb79694 CL |
111 | s = __kmem_cache_alias(name, size, align, flags, ctor); |
112 | if (s) | |
113 | goto out_locked; | |
114 | ||
278b1bb1 | 115 | s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); |
db265eca | 116 | if (s) { |
8a13a4cc CL |
117 | s->object_size = s->size = size; |
118 | s->align = align; | |
119 | s->ctor = ctor; | |
120 | s->name = kstrdup(name, GFP_KERNEL); | |
121 | if (!s->name) { | |
122 | kmem_cache_free(kmem_cache, s); | |
123 | err = -ENOMEM; | |
124 | goto out_locked; | |
125 | } | |
126 | ||
127 | err = __kmem_cache_create(s, flags); | |
cce89f4f | 128 | if (!err) { |
278b1bb1 | 129 | |
cce89f4f | 130 | s->refcount = 1; |
db265eca | 131 | list_add(&s->list, &slab_caches); |
686d550d | 132 | |
cce89f4f | 133 | } else { |
8a13a4cc | 134 | kfree(s->name); |
278b1bb1 CL |
135 | kmem_cache_free(kmem_cache, s); |
136 | } | |
8a13a4cc | 137 | } else |
278b1bb1 | 138 | err = -ENOMEM; |
7c9adf5a | 139 | |
686d550d | 140 | out_locked: |
20cea968 CL |
141 | mutex_unlock(&slab_mutex); |
142 | put_online_cpus(); | |
143 | ||
686d550d CL |
144 | if (err) { |
145 | ||
146 | if (flags & SLAB_PANIC) | |
147 | panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n", | |
148 | name, err); | |
149 | else { | |
150 | printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d", | |
151 | name, err); | |
152 | dump_stack(); | |
153 | } | |
154 | ||
155 | return NULL; | |
156 | } | |
039363f3 CL |
157 | |
158 | return s; | |
159 | } | |
160 | EXPORT_SYMBOL(kmem_cache_create); | |
97d06609 | 161 | |
945cf2b6 CL |
162 | void kmem_cache_destroy(struct kmem_cache *s) |
163 | { | |
164 | get_online_cpus(); | |
165 | mutex_lock(&slab_mutex); | |
166 | s->refcount--; | |
167 | if (!s->refcount) { | |
168 | list_del(&s->list); | |
169 | ||
170 | if (!__kmem_cache_shutdown(s)) { | |
210ed9de | 171 | mutex_unlock(&slab_mutex); |
945cf2b6 CL |
172 | if (s->flags & SLAB_DESTROY_BY_RCU) |
173 | rcu_barrier(); | |
174 | ||
db265eca | 175 | kfree(s->name); |
8f4c765c | 176 | kmem_cache_free(kmem_cache, s); |
945cf2b6 CL |
177 | } else { |
178 | list_add(&s->list, &slab_caches); | |
210ed9de | 179 | mutex_unlock(&slab_mutex); |
945cf2b6 CL |
180 | printk(KERN_ERR "kmem_cache_destroy %s: Slab cache still has objects\n", |
181 | s->name); | |
182 | dump_stack(); | |
183 | } | |
210ed9de JK |
184 | } else { |
185 | mutex_unlock(&slab_mutex); | |
945cf2b6 | 186 | } |
945cf2b6 CL |
187 | put_online_cpus(); |
188 | } | |
189 | EXPORT_SYMBOL(kmem_cache_destroy); | |
190 | ||
97d06609 CL |
191 | int slab_is_available(void) |
192 | { | |
193 | return slab_state >= UP; | |
194 | } |