commit 7fd6b1413082c303613fc137aca9a004740cacf0
author Pekka Enberg <penberg@cs.helsinki.fi> Wed Feb 01 03:05:52 2006 -0800
committer Linus Torvalds <torvalds@g5.osdl.org> Wed Feb 01 08:53:18 2006 -0800
tree 3186f4fdecbda4f16558c393a05408f7d3799ad4
parent b958f7d9f35bfb61625f201cd92a3fc39504af7a

[PATCH] slab: fix kzalloc and kstrdup caller report for CONFIG_DEBUG_SLAB

Fix kzalloc() and kstrdup() caller report for CONFIG_DEBUG_SLAB.  We must
pass the caller to __cache_alloc() instead of directly doing
__builtin_return_address(0) there; otherwise kzalloc() and kstrdup() are
reported as the allocation site instead of the real one.

Thanks to Valdis Kletnieks for reporting the problem and Steven Rostedt for
the original idea.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

mm/slab.c

diff --git a/mm/slab.c b/mm/slab.c
index 6fbd6a1..6752726 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2687,7 +2687,8 @@
 	return objp;
 }
 
-static inline void *__cache_alloc(struct kmem_cache *cachep, gfp_t flags)
+static __always_inline void *
+__cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
 {
 	unsigned long save_flags;
 	void *objp;
@@ -2698,7 +2699,7 @@
 	objp = ____cache_alloc(cachep, flags);
 	local_irq_restore(save_flags);
 	objp = cache_alloc_debugcheck_after(cachep, flags, objp,
-					    __builtin_return_address(0));
+					    caller);
 	prefetchw(objp);
 	return objp;
 }
@@ -2927,7 +2928,7 @@
  */
 void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
 {
-	return __cache_alloc(cachep, flags);
+	return __cache_alloc(cachep, flags, __builtin_return_address(0));
 }
 EXPORT_SYMBOL(kmem_cache_alloc);
 
@@ -3041,7 +3042,8 @@
  * platforms.  For example, on i386, it means that the memory must come
  * from the first 16MB.
  */
-void *__kmalloc(size_t size, gfp_t flags)
+static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
+					  void *caller)
 {
 	struct kmem_cache *cachep;
 
@@ -3053,10 +3055,27 @@
 	cachep = __find_general_cachep(size, flags);
 	if (unlikely(cachep == NULL))
 		return NULL;
-	return __cache_alloc(cachep, flags);
+	return __cache_alloc(cachep, flags, caller);
+}
+
+#ifndef CONFIG_DEBUG_SLAB
+
+void *__kmalloc(size_t size, gfp_t flags)
+{
+	return __do_kmalloc(size, flags, NULL);
 }
 EXPORT_SYMBOL(__kmalloc);
 
+#else
+
+void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
+{
+	return __do_kmalloc(size, flags, caller);
+}
+EXPORT_SYMBOL(__kmalloc_track_caller);
+
+#endif
+
 #ifdef CONFIG_SMP
 /**
  * __alloc_percpu - allocate one copy of the object for every present