mm/sl[aou]b: Use "kmem_cache" name for slab cache with kmem_cache struct

[firefly-linux-kernel-4.4.55.git] / mm / slab_common.c

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 50e1ff10bff9d0f89b0a7b71e52ac413a3856f64..5374150f54866c5ae33e75354d9fc7a2d7c47e67 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>
@@ -21,6 +22,53 @@
 enum slab_state slab_state;
 LIST_HEAD(slab_caches);
 DEFINE_MUTEX(slab_mutex);
+struct kmem_cache *kmem_cache;
+
+#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.
@@ -51,28 +99,73 @@ 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;
+       int err = 0;
+
+       get_online_cpus();
+       mutex_lock(&slab_mutex);
+
+       if (!kmem_cache_sanity_check(name, size) == 0)
+               goto out_locked;
 
-#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
 
        s = __kmem_cache_create(name, size, align, flags, ctor);
+       if (!s)
+               err = -ENOSYS; /* Until __kmem_cache_create returns code */
 
-#ifdef CONFIG_DEBUG_VM
-out:
-#endif
-       if (!s && (flags & SLAB_PANIC))
-               panic("kmem_cache_create: Failed to create slab '%s'\n", name);
+       /*
+        * Check if the slab has actually been created and if it was a
+        * real instatiation. Aliases do not belong on the list
+        */
+       if (s && s->refcount == 1)
+               list_add(&s->list, &slab_caches);
+
+out_locked:
+       mutex_unlock(&slab_mutex);
+       put_online_cpus();
+
+       if (err) {
+
+               if (flags & SLAB_PANIC)
+                       panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
+                               name, err);
+               else {
+                       printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
+                               name, err);
+                       dump_stack();
+               }
+
+               return NULL;
+       }
 
        return s;
 }
 EXPORT_SYMBOL(kmem_cache_create);
 
+void kmem_cache_destroy(struct kmem_cache *s)
+{
+       get_online_cpus();
+       mutex_lock(&slab_mutex);
+       s->refcount--;
+       if (!s->refcount) {
+               list_del(&s->list);
+
+               if (!__kmem_cache_shutdown(s)) {
+                       if (s->flags & SLAB_DESTROY_BY_RCU)
+                               rcu_barrier();
+
+                       __kmem_cache_destroy(s);
+               } else {
+                       list_add(&s->list, &slab_caches);
+                       printk(KERN_ERR "kmem_cache_destroy %s: Slab cache still has objects\n",
+                               s->name);
+                       dump_stack();
+               }
+       }
+       mutex_unlock(&slab_mutex);
+       put_online_cpus();
+}
+EXPORT_SYMBOL(kmem_cache_destroy);
+
 int slab_is_available(void)
 {
        return slab_state >= UP;