1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 27402fea9b79..0289ec89300a 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -31,6 +31,19 @@
 #define SLAB_TRACE              0x00200000UL    /* Trace allocations and frees */
 
 /*
+ * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
+ *
+ * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
+ *
+ * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
+ * Both make kfree a no-op.
+ */
+#define ZERO_SIZE_PTR ((void *)16)
+
+#define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) < \
+                                (unsigned long)ZERO_SIZE_PTR)
+
+/*
  * struct kmem_cache related prototypes
  */
 void __init kmem_cache_init(void);