kmemtrace: SLUB hooks for caller-tracking functions.

This patch adds kmemtrace hooks for __kmalloc_track_caller() and
__kmalloc_node_track_caller(). Currently, they set the call site pointer
to the value recieved as a parameter. (This could change if we implement
stack trace exporting in kmemtrace.)
Signed-off-by: NEduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

mm/slub.c

@@ -3256,6 +3256,7 @@ static struct notifier_block __cpuinitdata slab_notifier = {
 void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
 {
 	struct kmem_cache *s;
+	void *ret;
 
 	if (unlikely(size > PAGE_SIZE))
 		return kmalloc_large(size, gfpflags);
@@ -3265,13 +3266,20 @@ void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
 	if (unlikely(ZERO_OR_NULL_PTR(s)))
 		return s;
 
-	return slab_alloc(s, gfpflags, -1, caller);
+	ret = slab_alloc(s, gfpflags, -1, caller);
+
+	/* Honor the call site pointer we recieved. */
+	kmemtrace_mark_alloc(KMEMTRACE_TYPE_KMALLOC, (unsigned long) caller,
+			     ret, size, s->size, gfpflags);
+
+	return ret;
 }
 
 void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
 					int node, unsigned long caller)
 {
 	struct kmem_cache *s;
+	void *ret;
 
 	if (unlikely(size > PAGE_SIZE))
 		return kmalloc_large_node(size, gfpflags, node);
@@ -3281,7 +3289,14 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
 	if (unlikely(ZERO_OR_NULL_PTR(s)))
 		return s;
 
-	return slab_alloc(s, gfpflags, node, caller);
+	ret = slab_alloc(s, gfpflags, node, caller);
+
+	/* Honor the call site pointer we recieved. */
+	kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC,
+				  (unsigned long) caller, ret,
+				  size, s->size, gfpflags, node);
+
+	return ret;
 }
 
 #ifdef CONFIG_SLUB_DEBUG