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-rw-r--r--mm/slub.c184
1 files changed, 181 insertions, 3 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 4251917c5da1..a6231963cae5 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -97,9 +97,6 @@
*
* - Support PAGE_ALLOC_DEBUG. Should be easy to do.
*
- * - Support DEBUG_SLAB_LEAK. Trouble is we do not know where the full
- * slabs are in SLUB.
- *
* - SLAB_DEBUG_INITIAL is not supported but I have never seen a use of
* it.
*
@@ -2659,6 +2656,169 @@ static unsigned long validate_slab_cache(struct kmem_cache *s)
return count;
}
+/*
+ * Generate lists of locations where slabcache objects are allocated
+ * and freed.
+ */
+
+struct location {
+ unsigned long count;
+ void *addr;
+};
+
+struct loc_track {
+ unsigned long max;
+ unsigned long count;
+ struct location *loc;
+};
+
+static void free_loc_track(struct loc_track *t)
+{
+ if (t->max)
+ free_pages((unsigned long)t->loc,
+ get_order(sizeof(struct location) * t->max));
+}
+
+static int alloc_loc_track(struct loc_track *t, unsigned long max)
+{
+ struct location *l;
+ int order;
+
+ if (!max)
+ max = PAGE_SIZE / sizeof(struct location);
+
+ order = get_order(sizeof(struct location) * max);
+
+ l = (void *)__get_free_pages(GFP_KERNEL, order);
+
+ if (!l)
+ return 0;
+
+ if (t->count) {
+ memcpy(l, t->loc, sizeof(struct location) * t->count);
+ free_loc_track(t);
+ }
+ t->max = max;
+ t->loc = l;
+ return 1;
+}
+
+static int add_location(struct loc_track *t, struct kmem_cache *s,
+ void *addr)
+{
+ long start, end, pos;
+ struct location *l;
+ void *caddr;
+
+ start = -1;
+ end = t->count;
+
+ for ( ; ; ) {
+ pos = start + (end - start + 1) / 2;
+
+ /*
+ * There is nothing at "end". If we end up there
+ * we need to add something to before end.
+ */
+ if (pos == end)
+ break;
+
+ caddr = t->loc[pos].addr;
+ if (addr == caddr) {
+ t->loc[pos].count++;
+ return 1;
+ }
+
+ if (addr < caddr)
+ end = pos;
+ else
+ start = pos;
+ }
+
+ /*
+ * Not found. Insert new tracking element
+ */
+ if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max))
+ return 0;
+
+ l = t->loc + pos;
+ if (pos < t->count)
+ memmove(l + 1, l,
+ (t->count - pos) * sizeof(struct location));
+ t->count++;
+ l->count = 1;
+ l->addr = addr;
+ return 1;
+}
+
+static void process_slab(struct loc_track *t, struct kmem_cache *s,
+ struct page *page, enum track_item alloc)
+{
+ void *addr = page_address(page);
+ unsigned long map[BITS_TO_LONGS(s->objects)];
+ void *p;
+
+ bitmap_zero(map, s->objects);
+ for (p = page->freelist; p; p = get_freepointer(s, p))
+ set_bit((p - addr) / s->size, map);
+
+ for (p = addr; p < addr + s->objects * s->size; p += s->size)
+ if (!test_bit((p - addr) / s->size, map)) {
+ void *addr = get_track(s, p, alloc)->addr;
+
+ add_location(t, s, addr);
+ }
+}
+
+static int list_locations(struct kmem_cache *s, char *buf,
+ enum track_item alloc)
+{
+ int n = 0;
+ unsigned long i;
+ struct loc_track t;
+ int node;
+
+ t.count = 0;
+ t.max = 0;
+
+ /* Push back cpu slabs */
+ flush_all(s);
+
+ for_each_online_node(node) {
+ struct kmem_cache_node *n = get_node(s, node);
+ unsigned long flags;
+ struct page *page;
+
+ if (!atomic_read(&n->nr_slabs))
+ continue;
+
+ spin_lock_irqsave(&n->list_lock, flags);
+ list_for_each_entry(page, &n->partial, lru)
+ process_slab(&t, s, page, alloc);
+ list_for_each_entry(page, &n->full, lru)
+ process_slab(&t, s, page, alloc);
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ }
+
+ for (i = 0; i < t.count; i++) {
+ void *addr = t.loc[i].addr;
+
+ if (n > PAGE_SIZE - 100)
+ break;
+ n += sprintf(buf + n, "%7ld ", t.loc[i].count);
+ if (addr)
+ n += sprint_symbol(buf + n, (unsigned long)t.loc[i].addr);
+ else
+ n += sprintf(buf + n, "<not-available>");
+ n += sprintf(buf + n, "\n");
+ }
+
+ free_loc_track(&t);
+ if (!t.count)
+ n += sprintf(buf, "No data\n");
+ return n;
+}
+
static unsigned long count_partial(struct kmem_cache_node *n)
{
unsigned long flags;
@@ -3009,6 +3169,22 @@ static ssize_t validate_store(struct kmem_cache *s,
}
SLAB_ATTR(validate);
+static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
+{
+ if (!(s->flags & SLAB_STORE_USER))
+ return -ENOSYS;
+ return list_locations(s, buf, TRACK_ALLOC);
+}
+SLAB_ATTR_RO(alloc_calls);
+
+static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
+{
+ if (!(s->flags & SLAB_STORE_USER))
+ return -ENOSYS;
+ return list_locations(s, buf, TRACK_FREE);
+}
+SLAB_ATTR_RO(free_calls);
+
#ifdef CONFIG_NUMA
static ssize_t defrag_ratio_show(struct kmem_cache *s, char *buf)
{
@@ -3049,6 +3225,8 @@ static struct attribute * slab_attrs[] = {
&poison_attr.attr,
&store_user_attr.attr,
&validate_attr.attr,
+ &alloc_calls_attr.attr,
+ &free_calls_attr.attr,
#ifdef CONFIG_ZONE_DMA
&cache_dma_attr.attr,
#endif