slub: for_each_object must be passed the number of objects in a slab

Pass the number of objects to the for_each_object macro. Most of these are
debug related.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

1 files changed, 18 insertions, 6 deletions

diff --git a/mm/slub.c b/mm/slub.c
index 6641025c597f..67f7d6068934 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -327,8 +327,8 @@ static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
 }
 
 /* Loop over all objects in a slab */
-#define for_each_object(__p, __s, __addr) \
-        for (__p = (__addr); __p < (__addr) + (__s)->objects * (__s)->size;\
+#define for_each_object(__p, __s, __addr, __objects) \
+        for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
                         __p += (__s)->size)
 
 /* Scan freelist */
@@ -774,6 +774,7 @@ static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
         int nr = 0;
         void *fp = page->freelist;
         void *object = NULL;
+        unsigned long max_objects;
 
         while (fp && nr <= page->objects) {
                 if (fp == search)
@@ -798,6 +799,16 @@ static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
                 nr++;
         }
 
+        max_objects = (PAGE_SIZE << compound_order(page)) / s->size;
+        if (max_objects > 65535)
+                max_objects = 65535;
+
+        if (page->objects != max_objects) {
+                slab_err(s, page, "Wrong number of objects. Found %d but "
+                        "should be %d", page->objects, max_objects);
+                page->objects = max_objects;
+                slab_fix(s, "Number of objects adjusted.");
+        }
         if (page->inuse != page->objects - nr) {
                 slab_err(s, page, "Wrong object count. Counter is %d but "
                         "counted were %d", page->inuse, page->objects - nr);
@@ -1135,7 +1146,7 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
                 memset(start, POISON_INUSE, PAGE_SIZE << s->order);
 
         last = start;
-        for_each_object(p, s, start) {
+        for_each_object(p, s, start, page->objects) {
                 setup_object(s, page, last);
                 set_freepointer(s, last, p);
                 last = p;
@@ -1157,7 +1168,8 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
                 void *p;
 
                 slab_pad_check(s, page);
-                for_each_object(p, s, page_address(page))
+                for_each_object(p, s, page_address(page),
+                                                page->objects)
                         check_object(s, page, p, 0);
                 ClearSlabDebug(page);
         }
@@ -3273,7 +3285,7 @@ static int validate_slab(struct kmem_cache *s, struct page *page,
                         return 0;
         }
 
-        for_each_object(p, s, addr)
+        for_each_object(p, s, addr, page->objects)
                 if (!test_bit(slab_index(p, s, addr), map))
                         if (!check_object(s, page, p, 1))
                                 return 0;
@@ -3549,7 +3561,7 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s,
         for_each_free_object(p, s, page->freelist)
                 set_bit(slab_index(p, s, addr), map);
 
-        for_each_object(p, s, addr)
+        for_each_object(p, s, addr, page->objects)
                 if (!test_bit(slab_index(p, s, addr), map))
                         add_location(t, s, get_track(s, p, alloc));
 }