[PATCH] leak tracking for kmalloc_node

We have variants of kmalloc and kmem_cache_alloc that leave leak tracking to
the caller.  This is used for subsystem-specific allocators like skb_alloc.

To make skb_alloc node-aware we need similar routines for the node-aware slab
allocator, which this patch adds.

Note that the code is rather ugly, but it mirrors the non-node-aware code 1:1:

[akpm@osdl.org: add module export]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 65 insertions, 13 deletions

diff --git a/include/linux/slab.h b/include/linux/slab.h
index c4947b8a2c03..66c4640d3656 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -236,7 +236,25 @@ found:
         }
         return __kmalloc_node(size, flags, node);
 }
+
+/*
+ * kmalloc_node_track_caller is a special version of kmalloc_node that
+ * records the calling function of the routine calling it for slab leak
+ * tracking instead of just the calling function (confusing, eh?).
+ * It's useful when the call to kmalloc_node comes from a widely-used
+ * standard allocator where we care about the real place the memory
+ * allocation request comes from.
+ */
+#ifndef CONFIG_DEBUG_SLAB
+#define kmalloc_node_track_caller(size, flags, node) \
+        __kmalloc_node(size, flags, node)
 #else
+extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *);
+#define kmalloc_node_track_caller(size, flags, node) \
+        __kmalloc_node_track_caller(size, flags, node, \
+                        __builtin_return_address(0))
+#endif
+#else /* CONFIG_NUMA */
 static inline void *kmem_cache_alloc_node(kmem_cache_t *cachep, gfp_t flags, int node)
 {
         return kmem_cache_alloc(cachep, flags);
@@ -245,6 +263,9 @@ static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 {
         return kmalloc(size, flags);
 }
+
+#define kmalloc_node_track_caller(size, flags, node) \
+        kmalloc_track_caller(size, flags)
 #endif
 
 extern int FASTCALL(kmem_cache_reap(int));
@@ -283,6 +304,8 @@ static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
 #define kzalloc(s, f) __kzalloc(s, f)
 #define kmalloc_track_caller kmalloc
 
+#define kmalloc_node_track_caller kmalloc_node
+
 #endif /* CONFIG_SLOB */
 
 /* System wide caches */
diff --git a/mm/slab.c b/mm/slab.c
index bfd654c0ef41..8f3f61cacb5c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1015,7 +1015,7 @@ static inline void *alternate_node_alloc(struct kmem_cache *cachep,
         return NULL;
 }
 
-static inline void *__cache_alloc_node(struct kmem_cache *cachep,
+static inline void *____cache_alloc_node(struct kmem_cache *cachep,
                  gfp_t flags, int nodeid)
 {
         return NULL;
@@ -1023,7 +1023,7 @@ static inline void *__cache_alloc_node(struct kmem_cache *cachep,
 
 #else   /* CONFIG_NUMA */
 
-static void *__cache_alloc_node(struct kmem_cache *, gfp_t, int);
+static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
 static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
 
 static struct array_cache **alloc_alien_cache(int node, int limit)
@@ -3130,10 +3130,10 @@ static __always_inline void *__cache_alloc(struct kmem_cache *cachep,
                 objp = ____cache_alloc(cachep, flags);
         /*
          * We may just have run out of memory on the local node.
-         * __cache_alloc_node() knows how to locate memory on other nodes
+         * ____cache_alloc_node() knows how to locate memory on other nodes
          */
         if (NUMA_BUILD && !objp)
-                objp = __cache_alloc_node(cachep, flags, numa_node_id());
+                objp = ____cache_alloc_node(cachep, flags, numa_node_id());
         local_irq_restore(save_flags);
         objp = cache_alloc_debugcheck_after(cachep, flags, objp,
                                             caller);
@@ -3160,7 +3160,7 @@ static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
         else if (current->mempolicy)
                 nid_alloc = slab_node(current->mempolicy);
         if (nid_alloc != nid_here)
-                return __cache_alloc_node(cachep, flags, nid_alloc);
+                return ____cache_alloc_node(cachep, flags, nid_alloc);
         return NULL;
 }
 
@@ -3183,7 +3183,7 @@ void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
                 if (zone_idx(*z) <= ZONE_NORMAL &&
                                 cpuset_zone_allowed(*z, flags) &&
                                 cache->nodelists[nid])
-                        obj = __cache_alloc_node(cache,
+                        obj = ____cache_alloc_node(cache,
                                         flags | __GFP_THISNODE, nid);
         }
         return obj;
@@ -3192,7 +3192,7 @@ void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
 /*
  * A interface to enable slab creation on nodeid
  */
-static void *__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
+static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
                                 int nodeid)
 {
         struct list_head *entry;
@@ -3465,7 +3465,9 @@ out:
  * New and improved: it will now make sure that the object gets
  * put on the correct node list so that there is no false sharing.
  */
-void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
+static __always_inline void *
+__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
+                int nodeid, void *caller)
 {
         unsigned long save_flags;
         void *ptr;
@@ -3477,17 +3479,23 @@ void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
                         !cachep->nodelists[nodeid])
                 ptr = ____cache_alloc(cachep, flags);
         else
-                ptr = __cache_alloc_node(cachep, flags, nodeid);
+                ptr = ____cache_alloc_node(cachep, flags, nodeid);
         local_irq_restore(save_flags);
 
-        ptr = cache_alloc_debugcheck_after(cachep, flags, ptr,
-                                           __builtin_return_address(0));
+        ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
 
         return ptr;
 }
+
+void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
+{
+        return __cache_alloc_node(cachep, flags, nodeid,
+                        __builtin_return_address(0));
+}
 EXPORT_SYMBOL(kmem_cache_alloc_node);
 
-void *__kmalloc_node(size_t size, gfp_t flags, int node)
+static __always_inline void *
+__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
 {
         struct kmem_cache *cachep;
 
@@ -3496,8 +3504,29 @@ void *__kmalloc_node(size_t size, gfp_t flags, int node)
                 return NULL;
         return kmem_cache_alloc_node(cachep, flags, node);
 }
+
+#ifdef CONFIG_DEBUG_SLAB
+void *__kmalloc_node(size_t size, gfp_t flags, int node)
+{
+        return __do_kmalloc_node(size, flags, node,
+                        __builtin_return_address(0));
+}
 EXPORT_SYMBOL(__kmalloc_node);
-#endif
+
+void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
+                int node, void *caller)
+{
+        return __do_kmalloc_node(size, flags, node, caller);
+}
+EXPORT_SYMBOL(__kmalloc_node_track_caller);
+#else
+void *__kmalloc_node(size_t size, gfp_t flags, int node)
+{
+        return __do_kmalloc_node(size, flags, node, NULL);
+}
+EXPORT_SYMBOL(__kmalloc_node);
+#endif /* CONFIG_DEBUG_SLAB */
+#endif /* CONFIG_NUMA */
 
 /**
  * __do_kmalloc - allocate memory