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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> | |
b7454ad3 GC |
16 | #include <linux/seq_file.h> |
17 | #include <linux/proc_fs.h> | |
039363f3 CL |
18 | #include <asm/cacheflush.h> |
19 | #include <asm/tlbflush.h> | |
20 | #include <asm/page.h> | |
21 | ||
97d06609 CL |
22 | #include "slab.h" |
23 | ||
24 | enum slab_state slab_state; | |
18004c5d CL |
25 | LIST_HEAD(slab_caches); |
26 | DEFINE_MUTEX(slab_mutex); | |
9b030cb8 | 27 | struct kmem_cache *kmem_cache; |
97d06609 | 28 | |
77be4b13 SK |
29 | #ifdef CONFIG_DEBUG_VM |
30 | static int kmem_cache_sanity_check(const char *name, size_t size) | |
039363f3 CL |
31 | { |
32 | struct kmem_cache *s = NULL; | |
33 | ||
039363f3 CL |
34 | if (!name || in_interrupt() || size < sizeof(void *) || |
35 | size > KMALLOC_MAX_SIZE) { | |
77be4b13 SK |
36 | pr_err("kmem_cache_create(%s) integrity check failed\n", name); |
37 | return -EINVAL; | |
039363f3 | 38 | } |
b920536a | 39 | |
20cea968 CL |
40 | list_for_each_entry(s, &slab_caches, list) { |
41 | char tmp; | |
42 | int res; | |
43 | ||
44 | /* | |
45 | * This happens when the module gets unloaded and doesn't | |
46 | * destroy its slab cache and no-one else reuses the vmalloc | |
47 | * area of the module. Print a warning. | |
48 | */ | |
49 | res = probe_kernel_address(s->name, tmp); | |
50 | if (res) { | |
77be4b13 | 51 | pr_err("Slab cache with size %d has lost its name\n", |
20cea968 CL |
52 | s->object_size); |
53 | continue; | |
54 | } | |
55 | ||
56 | if (!strcmp(s->name, name)) { | |
77be4b13 SK |
57 | pr_err("%s (%s): Cache name already exists.\n", |
58 | __func__, name); | |
20cea968 CL |
59 | dump_stack(); |
60 | s = NULL; | |
77be4b13 | 61 | return -EINVAL; |
20cea968 CL |
62 | } |
63 | } | |
64 | ||
65 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ | |
77be4b13 SK |
66 | return 0; |
67 | } | |
68 | #else | |
69 | static inline int kmem_cache_sanity_check(const char *name, size_t size) | |
70 | { | |
71 | return 0; | |
72 | } | |
20cea968 CL |
73 | #endif |
74 | ||
77be4b13 SK |
75 | /* |
76 | * kmem_cache_create - Create a cache. | |
77 | * @name: A string which is used in /proc/slabinfo to identify this cache. | |
78 | * @size: The size of objects to be created in this cache. | |
79 | * @align: The required alignment for the objects. | |
80 | * @flags: SLAB flags | |
81 | * @ctor: A constructor for the objects. | |
82 | * | |
83 | * Returns a ptr to the cache on success, NULL on failure. | |
84 | * Cannot be called within a interrupt, but can be interrupted. | |
85 | * The @ctor is run when new pages are allocated by the cache. | |
86 | * | |
87 | * The flags are | |
88 | * | |
89 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
90 | * to catch references to uninitialised memory. | |
91 | * | |
92 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check | |
93 | * for buffer overruns. | |
94 | * | |
95 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
96 | * cacheline. This can be beneficial if you're counting cycles as closely | |
97 | * as davem. | |
98 | */ | |
99 | ||
100 | struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align, | |
101 | unsigned long flags, void (*ctor)(void *)) | |
102 | { | |
103 | struct kmem_cache *s = NULL; | |
686d550d | 104 | int err = 0; |
039363f3 | 105 | |
77be4b13 SK |
106 | get_online_cpus(); |
107 | mutex_lock(&slab_mutex); | |
686d550d CL |
108 | |
109 | if (!kmem_cache_sanity_check(name, size) == 0) | |
110 | goto out_locked; | |
111 | ||
112 | ||
cbb79694 CL |
113 | s = __kmem_cache_alias(name, size, align, flags, ctor); |
114 | if (s) | |
115 | goto out_locked; | |
116 | ||
278b1bb1 | 117 | s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); |
db265eca | 118 | if (s) { |
8a13a4cc CL |
119 | s->object_size = s->size = size; |
120 | s->align = align; | |
121 | s->ctor = ctor; | |
122 | s->name = kstrdup(name, GFP_KERNEL); | |
123 | if (!s->name) { | |
124 | kmem_cache_free(kmem_cache, s); | |
125 | err = -ENOMEM; | |
126 | goto out_locked; | |
127 | } | |
128 | ||
129 | err = __kmem_cache_create(s, flags); | |
cce89f4f | 130 | if (!err) { |
278b1bb1 | 131 | |
cce89f4f | 132 | s->refcount = 1; |
db265eca | 133 | list_add(&s->list, &slab_caches); |
686d550d | 134 | |
cce89f4f | 135 | } else { |
8a13a4cc | 136 | kfree(s->name); |
278b1bb1 CL |
137 | kmem_cache_free(kmem_cache, s); |
138 | } | |
8a13a4cc | 139 | } else |
278b1bb1 | 140 | err = -ENOMEM; |
7c9adf5a | 141 | |
686d550d | 142 | out_locked: |
20cea968 CL |
143 | mutex_unlock(&slab_mutex); |
144 | put_online_cpus(); | |
145 | ||
686d550d CL |
146 | if (err) { |
147 | ||
148 | if (flags & SLAB_PANIC) | |
149 | panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n", | |
150 | name, err); | |
151 | else { | |
152 | printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d", | |
153 | name, err); | |
154 | dump_stack(); | |
155 | } | |
156 | ||
157 | return NULL; | |
158 | } | |
039363f3 CL |
159 | |
160 | return s; | |
161 | } | |
162 | EXPORT_SYMBOL(kmem_cache_create); | |
97d06609 | 163 | |
945cf2b6 CL |
164 | void kmem_cache_destroy(struct kmem_cache *s) |
165 | { | |
166 | get_online_cpus(); | |
167 | mutex_lock(&slab_mutex); | |
168 | s->refcount--; | |
169 | if (!s->refcount) { | |
170 | list_del(&s->list); | |
171 | ||
172 | if (!__kmem_cache_shutdown(s)) { | |
210ed9de | 173 | mutex_unlock(&slab_mutex); |
945cf2b6 CL |
174 | if (s->flags & SLAB_DESTROY_BY_RCU) |
175 | rcu_barrier(); | |
176 | ||
db265eca | 177 | kfree(s->name); |
8f4c765c | 178 | kmem_cache_free(kmem_cache, s); |
945cf2b6 CL |
179 | } else { |
180 | list_add(&s->list, &slab_caches); | |
210ed9de | 181 | mutex_unlock(&slab_mutex); |
945cf2b6 CL |
182 | printk(KERN_ERR "kmem_cache_destroy %s: Slab cache still has objects\n", |
183 | s->name); | |
184 | dump_stack(); | |
185 | } | |
210ed9de JK |
186 | } else { |
187 | mutex_unlock(&slab_mutex); | |
945cf2b6 | 188 | } |
945cf2b6 CL |
189 | put_online_cpus(); |
190 | } | |
191 | EXPORT_SYMBOL(kmem_cache_destroy); | |
192 | ||
97d06609 CL |
193 | int slab_is_available(void) |
194 | { | |
195 | return slab_state >= UP; | |
196 | } | |
b7454ad3 GC |
197 | |
198 | #ifdef CONFIG_SLABINFO | |
199 | static void *s_start(struct seq_file *m, loff_t *pos) | |
200 | { | |
201 | loff_t n = *pos; | |
202 | ||
203 | mutex_lock(&slab_mutex); | |
204 | if (!n) | |
205 | print_slabinfo_header(m); | |
206 | ||
207 | return seq_list_start(&slab_caches, *pos); | |
208 | } | |
209 | ||
210 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) | |
211 | { | |
212 | return seq_list_next(p, &slab_caches, pos); | |
213 | } | |
214 | ||
215 | static void s_stop(struct seq_file *m, void *p) | |
216 | { | |
217 | mutex_unlock(&slab_mutex); | |
218 | } | |
219 | ||
220 | static int s_show(struct seq_file *m, void *p) | |
221 | { | |
222 | return slabinfo_show(m, p); | |
223 | } | |
224 | ||
225 | /* | |
226 | * slabinfo_op - iterator that generates /proc/slabinfo | |
227 | * | |
228 | * Output layout: | |
229 | * cache-name | |
230 | * num-active-objs | |
231 | * total-objs | |
232 | * object size | |
233 | * num-active-slabs | |
234 | * total-slabs | |
235 | * num-pages-per-slab | |
236 | * + further values on SMP and with statistics enabled | |
237 | */ | |
238 | static const struct seq_operations slabinfo_op = { | |
239 | .start = s_start, | |
240 | .next = s_next, | |
241 | .stop = s_stop, | |
242 | .show = s_show, | |
243 | }; | |
244 | ||
245 | static int slabinfo_open(struct inode *inode, struct file *file) | |
246 | { | |
247 | return seq_open(file, &slabinfo_op); | |
248 | } | |
249 | ||
250 | static const struct file_operations proc_slabinfo_operations = { | |
251 | .open = slabinfo_open, | |
252 | .read = seq_read, | |
253 | .write = slabinfo_write, | |
254 | .llseek = seq_lseek, | |
255 | .release = seq_release, | |
256 | }; | |
257 | ||
258 | static int __init slab_proc_init(void) | |
259 | { | |
260 | proc_create("slabinfo", S_IRUSR, NULL, &proc_slabinfo_operations); | |
261 | return 0; | |
262 | } | |
263 | module_init(slab_proc_init); | |
264 | #endif /* CONFIG_SLABINFO */ |