mm/slab_common.c: cleanup

[deliverable/linux.git] / mm / slab_common.c

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 50e1ff10bff9d0f89b0a7b71e52ac413a3856f64..281600b30100bf21d6a43d813f5d53995a27019d 100644 (file)
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -11,7 +11,8 @@
 #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>
@@ -52,20 +53,55 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align
 {
        struct kmem_cache *s = NULL;
 
+       get_online_cpus();
+       mutex_lock(&slab_mutex);
+
 #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;
+                               " failed\n", name);
+               goto oops;
+       }
+
+       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
-out:
+oops:
 #endif
+       mutex_unlock(&slab_mutex);
+       put_online_cpus();
+
        if (!s && (flags & SLAB_PANIC))
                panic("kmem_cache_create: Failed to create slab '%s'\n", name);