Slab allocators: consistent ZERO_SIZE_PTR support and NULL result semantics

[linux-2.6-block.git] / mm / slob.c

diff --git a/mm/slob.c b/mm/slob.c
index 154e7bdf3544c7ad1572c20dcafa72b47c8fadb1..41d32c3c0be4d333d80c8d8afd6a4cfe658535a6 100644 (file)
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -347,7 +347,7 @@ static void slob_free(void *block, int size)
        slobidx_t units;
        unsigned long flags;
 
-       if (!block)
+       if (ZERO_OR_NULL_PTR(block))
                return;
        BUG_ON(!size);
 
@@ -424,10 +424,13 @@ out:
 
 void *__kmalloc_node(size_t size, gfp_t gfp, int node)
 {
+       unsigned int *m;
        int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
 
        if (size < PAGE_SIZE - align) {
-               unsigned int *m;
+               if (!size)
+                       return ZERO_SIZE_PTR;
+
                m = slob_alloc(size + align, gfp, align, node);
                if (m)
                        *m = size;
@@ -450,7 +453,7 @@ void kfree(const void *block)
 {
        struct slob_page *sp;
 
-       if (!block)
+       if (ZERO_OR_NULL_PTR(block))
                return;
 
        sp = (struct slob_page *)virt_to_page(block);
@@ -468,7 +471,7 @@ size_t ksize(const void *block)
 {
        struct slob_page *sp;
 
-       if (!block)
+       if (ZERO_OR_NULL_PTR(block))
                return 0;
 
        sp = (struct slob_page *)virt_to_page(block);