77be4b1366
kmem_cache_create() does cache integrity checks when CONFIG_DEBUG_VM is defined. These checks interspersed with the regular code path has lead to compile time warnings when compiled without CONFIG_DEBUG_VM defined. Restructuring the code to move the integrity checks in to a new function would eliminate the current compile warning problem and also will allow for future changes to the debug only code to evolve without introducing new warnings in the regular path. This restructuring work is based on the discussion in the following thread: https://lkml.org/lkml/2012/7/13/424 [akpm@linux-foundation.org: fix build, cleanup] Signed-off-by: Shuah Khan <shuah.khan@hp.com> Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@kernel.org>
120 lines
3 KiB
C
120 lines
3 KiB
C
/*
|
|
* 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);
|
|
|
|
#ifdef CONFIG_DEBUG_VM
|
|
static int kmem_cache_sanity_check(const char *name, size_t size)
|
|
{
|
|
struct kmem_cache *s = NULL;
|
|
|
|
if (!name || in_interrupt() || size < sizeof(void *) ||
|
|
size > KMALLOC_MAX_SIZE) {
|
|
pr_err("kmem_cache_create(%s) integrity check failed\n", name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
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) {
|
|
pr_err("Slab cache with size %d has lost its name\n",
|
|
s->object_size);
|
|
continue;
|
|
}
|
|
|
|
if (!strcmp(s->name, name)) {
|
|
pr_err("%s (%s): Cache name already exists.\n",
|
|
__func__, name);
|
|
dump_stack();
|
|
s = NULL;
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
WARN_ON(strchr(name, ' ')); /* It confuses parsers */
|
|
return 0;
|
|
}
|
|
#else
|
|
static inline int kmem_cache_sanity_check(const char *name, size_t size)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 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;
|
|
|
|
get_online_cpus();
|
|
mutex_lock(&slab_mutex);
|
|
if (kmem_cache_sanity_check(name, size) == 0)
|
|
s = __kmem_cache_create(name, size, align, flags, ctor);
|
|
mutex_unlock(&slab_mutex);
|
|
put_online_cpus();
|
|
|
|
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;
|
|
}
|