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>

diff --git a/mm/slub.c b/mm/slub.c
index 6641025c597f30c2a01286918b01a038e192869d..67f7d60689342f5f604d9e02d8357f1ded7dfc26 100644 (file)
--- 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));
 }