if (s)
return slab_alloc(s, flags, -1, __builtin_return_address(0));
- return NULL;
+ return ZERO_SIZE_PTR;
}
EXPORT_SYMBOL(__kmalloc);
if (s)
return slab_alloc(s, flags, node, __builtin_return_address(0));
- return NULL;
+ return ZERO_SIZE_PTR;
}
EXPORT_SYMBOL(__kmalloc_node);
#endif
size_t ksize(const void *object)
{
- struct page *page = get_object_page(object);
+ struct page *page;
struct kmem_cache *s;
+ if (object == ZERO_SIZE_PTR)
+ return 0;
+
+ page = get_object_page(object);
BUG_ON(!page);
s = page->slab;
BUG_ON(!s);
struct kmem_cache *s;
struct page *page;
- if (!x)
+ /*
+ * This has to be an unsigned comparison. According to Linus
+ * some gcc version treat a pointer as a signed entity. Then
+ * this comparison would be true for all "negative" pointers
+ * (which would cover the whole upper half of the address space).
+ */
+ if ((unsigned long)x <= (unsigned long)ZERO_SIZE_PTR)
return;
page = virt_to_head_page(x);
void *ret;
size_t ks;
- if (unlikely(!p))
+ if (unlikely(!p || p == ZERO_SIZE_PTR))
return kmalloc(new_size, flags);
if (unlikely(!new_size)) {
kfree(p);
- return NULL;
+ return ZERO_SIZE_PTR;
}
ks = ksize(p);
*/
create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node",
sizeof(struct kmem_cache_node), GFP_KERNEL);
+ kmalloc_caches[0].refcount = -1;
#endif
/* Able to allocate the per node structures */
if (s->ctor)
return 1;
+ /*
+ * We may have set a slab to be unmergeable during bootstrap.
+ */
+ if (s->refcount < 0)
+ return 1;
+
return 0;
}
up_read(&slub_lock);
}
+/*
+ * Version of __flush_cpu_slab for the case that interrupts
+ * are enabled.
+ */
+static void cpu_slab_flush(struct kmem_cache *s, int cpu)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __flush_cpu_slab(s, cpu);
+ local_irq_restore(flags);
+}
+
/*
* Use the cpu notifier to insure that the cpu slabs are flushed when
* necessary.
case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
case CPU_DEAD_FROZEN:
- for_all_slabs(__flush_cpu_slab, cpu);
+ for_all_slabs(cpu_slab_flush, cpu);
break;
default:
break;
struct kmem_cache *s = get_slab(size, gfpflags);
if (!s)
- return NULL;
+ return ZERO_SIZE_PTR;
return slab_alloc(s, gfpflags, -1, caller);
}
struct kmem_cache *s = get_slab(size, gfpflags);
if (!s)
- return NULL;
+ return ZERO_SIZE_PTR;
return slab_alloc(s, gfpflags, node, caller);
}