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/*
* Slab allocator functions that are independent of the allocator strategy
*
* (C) 2012 Christoph Lameter <cl@linux.com>
*/
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/poison.h>
#include <linux/interrupt.h>
#include <linux/memory.h>
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/cpu.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/page.h>
#include "slab.h"
enum slab_state slab_state;
LIST_HEAD(slab_caches);
DEFINE_MUTEX(slab_mutex);
/*
* kmem_cache_create - Create a cache.
* @name: A string which is used in /proc/slabinfo to identify this cache.
* @size: The size of objects to be created in this cache.
* @align: The required alignment for the objects.
* @flags: SLAB flags
* @ctor: A constructor for the objects.
*
* Returns a ptr to the cache on success, NULL on failure.
* Cannot be called within a interrupt, but can be interrupted.
* The @ctor is run when new pages are allocated by the cache.
*
* The flags are
*
* %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
* to catch references to uninitialised memory.
*
* %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
* for buffer overruns.
*
* %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
* cacheline. This can be beneficial if you're counting cycles as closely
* as davem.
*/
struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align,
unsigned long flags, void (*ctor)(void *))
{
struct kmem_cache *s = NULL;
#ifdef CONFIG_DEBUG_VM
if (!name || in_interrupt() || size < sizeof(void *) ||
size > KMALLOC_MAX_SIZE) {
printk(KERN_ERR "kmem_cache_create(%s) integrity check"
" failed\n", name);
goto out;
}
#endif
get_online_cpus();
mutex_lock(&slab_mutex);
#ifdef CONFIG_DEBUG_VM
list_for_each_entry(s, &slab_caches, list) {
char tmp;
int res;
/*
* This happens when the module gets unloaded and doesn't
* destroy its slab cache and no-one else reuses the vmalloc
* area of the module. Print a warning.
*/
res = probe_kernel_address(s->name, tmp);
if (res) {
printk(KERN_ERR
"Slab cache with size %d has lost its name\n",
s->object_size);
continue;
}
if (!strcmp(s->name, name)) {
printk(KERN_ERR "kmem_cache_create(%s): Cache name"
" already exists.\n",
name);
dump_stack();
s = NULL;
goto oops;
}
}
WARN_ON(strchr(name, ' ')); /* It confuses parsers */
#endif
s = __kmem_cache_create(name, size, align, flags, ctor);
#ifdef CONFIG_DEBUG_VM
oops:
#endif
mutex_unlock(&slab_mutex);
put_online_cpus();
#ifdef CONFIG_DEBUG_VM
out:
#endif
if (!s && (flags & SLAB_PANIC))
panic("kmem_cache_create: Failed to create slab '%s'\n", name);
return s;
}
EXPORT_SYMBOL(kmem_cache_create);
int slab_is_available(void)
{
return slab_state >= UP;
}
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