2 * Slab allocator functions that are independent of the allocator strategy
4 * (C) 2012 Christoph Lameter <cl@linux.com>
6 #include <linux/slab.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>
14 #include <linux/cpu.h>
15 #include <linux/uaccess.h>
16 #include <asm/cacheflush.h>
17 #include <asm/tlbflush.h>
22 enum slab_state slab_state;
23 LIST_HEAD(slab_caches);
24 DEFINE_MUTEX(slab_mutex);
26 #ifdef CONFIG_DEBUG_VM
27 static int kmem_cache_sanity_check(const char *name, size_t size)
29 struct kmem_cache *s = NULL;
31 if (!name || in_interrupt() || size < sizeof(void *) ||
32 size > KMALLOC_MAX_SIZE) {
33 pr_err("kmem_cache_create(%s) integrity check failed\n", name);
37 list_for_each_entry(s, &slab_caches, list) {
42 * This happens when the module gets unloaded and doesn't
43 * destroy its slab cache and no-one else reuses the vmalloc
44 * area of the module. Print a warning.
46 res = probe_kernel_address(s->name, tmp);
48 pr_err("Slab cache with size %d has lost its name\n",
53 if (!strcmp(s->name, name)) {
54 pr_err("%s (%s): Cache name already exists.\n",
62 WARN_ON(strchr(name, ' ')); /* It confuses parsers */
66 static inline int kmem_cache_sanity_check(const char *name, size_t size)
73 * kmem_cache_create - Create a cache.
74 * @name: A string which is used in /proc/slabinfo to identify this cache.
75 * @size: The size of objects to be created in this cache.
76 * @align: The required alignment for the objects.
78 * @ctor: A constructor for the objects.
80 * Returns a ptr to the cache on success, NULL on failure.
81 * Cannot be called within a interrupt, but can be interrupted.
82 * The @ctor is run when new pages are allocated by the cache.
86 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
87 * to catch references to uninitialised memory.
89 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
90 * for buffer overruns.
92 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
93 * cacheline. This can be beneficial if you're counting cycles as closely
97 struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align,
98 unsigned long flags, void (*ctor)(void *))
100 struct kmem_cache *s = NULL;
104 mutex_lock(&slab_mutex);
106 if (!kmem_cache_sanity_check(name, size) == 0)
110 s = __kmem_cache_create(name, size, align, flags, ctor);
112 err = -ENOSYS; /* Until __kmem_cache_create returns code */
115 mutex_unlock(&slab_mutex);
120 if (flags & SLAB_PANIC)
121 panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
124 printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
134 EXPORT_SYMBOL(kmem_cache_create);
136 int slab_is_available(void)
138 return slab_state >= UP;