kmemleak: Release the object lock before calling put_object()

[net-next-2.6.git] / mm / kmemleak.c

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 4ea4510e2996cb5dab18852cb1f5e285f7fbd81e..f06c0921e4721646669d1bcc5d78574949fb3bfd 100644 (file)
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -119,8 +119,8 @@
 /* scanning area inside a memory block */
 struct kmemleak_scan_area {
        struct hlist_node node;
-       unsigned long offset;
-       size_t length;
+       unsigned long start;
+       size_t size;
 };
 
 #define KMEMLEAK_GREY  0
@@ -241,8 +241,6 @@ struct early_log {
        const void *ptr;                /* allocated/freed memory block */
        size_t size;                    /* memory block size */
        int min_count;                  /* minimum reference count */
-       unsigned long offset;           /* scan area offset */
-       size_t length;                  /* scan area length */
        unsigned long trace[MAX_TRACE]; /* stack trace */
        unsigned int trace_len;         /* stack trace length */
 };
@@ -720,14 +718,13 @@ static void make_black_object(unsigned long ptr)
  * Add a scanning area to the object. If at least one such area is added,
  * kmemleak will only scan these ranges rather than the whole memory block.
  */
-static void add_scan_area(unsigned long ptr, unsigned long offset,
-                         size_t length, gfp_t gfp)
+static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp)
 {
        unsigned long flags;
        struct kmemleak_object *object;
        struct kmemleak_scan_area *area;
 
-       object = find_and_get_object(ptr, 0);
+       object = find_and_get_object(ptr, 1);
        if (!object) {
                kmemleak_warn("Adding scan area to unknown object at 0x%08lx\n",
                              ptr);
@@ -741,7 +738,7 @@ static void add_scan_area(unsigned long ptr, unsigned long offset,
        }
 
        spin_lock_irqsave(&object->lock, flags);
-       if (offset + length > object->size) {
+       if (ptr + size > object->pointer + object->size) {
                kmemleak_warn("Scan area larger than object 0x%08lx\n", ptr);
                dump_object_info(object);
                kmem_cache_free(scan_area_cache, area);
@@ -749,8 +746,8 @@ static void add_scan_area(unsigned long ptr, unsigned long offset,
        }
 
        INIT_HLIST_NODE(&area->node);
-       area->offset = offset;
-       area->length = length;
+       area->start = ptr;
+       area->size = size;
 
        hlist_add_head(&area->node, &object->area_list);
 out_unlock:
@@ -786,7 +783,7 @@ static void object_no_scan(unsigned long ptr)
  * processed later once kmemleak is fully initialized.
  */
 static void __init log_early(int op_type, const void *ptr, size_t size,
-                            int min_count, unsigned long offset, size_t length)
+                            int min_count)
 {
        unsigned long flags;
        struct early_log *log;
@@ -808,8 +805,6 @@ static void __init log_early(int op_type, const void *ptr, size_t size,
        log->ptr = ptr;
        log->size = size;
        log->min_count = min_count;
-       log->offset = offset;
-       log->length = length;
        if (op_type == KMEMLEAK_ALLOC)
                log->trace_len = __save_stack_trace(log->trace);
        crt_early_log++;
@@ -833,12 +828,15 @@ static void early_alloc(struct early_log *log)
         */
        rcu_read_lock();
        object = create_object((unsigned long)log->ptr, log->size,
-                              log->min_count, GFP_KERNEL);
+                              log->min_count, GFP_ATOMIC);
+       if (!object)
+               goto out;
        spin_lock_irqsave(&object->lock, flags);
        for (i = 0; i < log->trace_len; i++)
                object->trace[i] = log->trace[i];
        object->trace_len = log->trace_len;
        spin_unlock_irqrestore(&object->lock, flags);
+out:
        rcu_read_unlock();
 }
 
@@ -855,7 +853,7 @@ void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count,
        if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                create_object((unsigned long)ptr, size, min_count, gfp);
        else if (atomic_read(&kmemleak_early_log))
-               log_early(KMEMLEAK_ALLOC, ptr, size, min_count, 0, 0);
+               log_early(KMEMLEAK_ALLOC, ptr, size, min_count);
 }
 EXPORT_SYMBOL_GPL(kmemleak_alloc);
 
@@ -870,7 +868,7 @@ void __ref kmemleak_free(const void *ptr)
        if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                delete_object_full((unsigned long)ptr);
        else if (atomic_read(&kmemleak_early_log))
-               log_early(KMEMLEAK_FREE, ptr, 0, 0, 0, 0);
+               log_early(KMEMLEAK_FREE, ptr, 0, 0);
 }
 EXPORT_SYMBOL_GPL(kmemleak_free);
 
@@ -885,7 +883,7 @@ void __ref kmemleak_free_part(const void *ptr, size_t size)
        if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                delete_object_part((unsigned long)ptr, size);
        else if (atomic_read(&kmemleak_early_log))
-               log_early(KMEMLEAK_FREE_PART, ptr, size, 0, 0, 0);
+               log_early(KMEMLEAK_FREE_PART, ptr, size, 0);
 }
 EXPORT_SYMBOL_GPL(kmemleak_free_part);
 
@@ -900,7 +898,7 @@ void __ref kmemleak_not_leak(const void *ptr)
        if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                make_gray_object((unsigned long)ptr);
        else if (atomic_read(&kmemleak_early_log))
-               log_early(KMEMLEAK_NOT_LEAK, ptr, 0, 0, 0, 0);
+               log_early(KMEMLEAK_NOT_LEAK, ptr, 0, 0);
 }
 EXPORT_SYMBOL(kmemleak_not_leak);
 
@@ -916,22 +914,21 @@ void __ref kmemleak_ignore(const void *ptr)
        if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                make_black_object((unsigned long)ptr);
        else if (atomic_read(&kmemleak_early_log))
-               log_early(KMEMLEAK_IGNORE, ptr, 0, 0, 0, 0);
+               log_early(KMEMLEAK_IGNORE, ptr, 0, 0);
 }
 EXPORT_SYMBOL(kmemleak_ignore);
 
 /*
  * Limit the range to be scanned in an allocated memory block.
  */
-void __ref kmemleak_scan_area(const void *ptr, unsigned long offset,
-                             size_t length, gfp_t gfp)
+void __ref kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp)
 {
        pr_debug("%s(0x%p)\n", __func__, ptr);
 
        if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
-               add_scan_area((unsigned long)ptr, offset, length, gfp);
+               add_scan_area((unsigned long)ptr, size, gfp);
        else if (atomic_read(&kmemleak_early_log))
-               log_early(KMEMLEAK_SCAN_AREA, ptr, 0, 0, offset, length);
+               log_early(KMEMLEAK_SCAN_AREA, ptr, size, 0);
 }
 EXPORT_SYMBOL(kmemleak_scan_area);
 
@@ -945,7 +942,7 @@ void __ref kmemleak_no_scan(const void *ptr)
        if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                object_no_scan((unsigned long)ptr);
        else if (atomic_read(&kmemleak_early_log))
-               log_early(KMEMLEAK_NO_SCAN, ptr, 0, 0, 0, 0);
+               log_early(KMEMLEAK_NO_SCAN, ptr, 0, 0);
 }
 EXPORT_SYMBOL(kmemleak_no_scan);
 
@@ -1028,11 +1025,14 @@ static void scan_block(void *_start, void *_end,
                 * added to the gray_list.
                 */
                object->count++;
-               if (color_gray(object))
+               if (color_gray(object)) {
                        list_add_tail(&object->gray_list, &gray_list);
-               else
-                       put_object(object);
+                       spin_unlock_irqrestore(&object->lock, flags);
+                       continue;
+               }
+
                spin_unlock_irqrestore(&object->lock, flags);
+               put_object(object);
        }
 }
 
@@ -1072,9 +1072,9 @@ static void scan_object(struct kmemleak_object *object)
                }
        } else
                hlist_for_each_entry(area, elem, &object->area_list, node)
-                       scan_block((void *)(object->pointer + area->offset),
-                                  (void *)(object->pointer + area->offset
-                                           + area->length), object, 0);
+                       scan_block((void *)area->start,
+                                  (void *)(area->start + area->size),
+                                  object, 0);
 out:
        spin_unlock_irqrestore(&object->lock, flags);
 }
@@ -1639,8 +1639,7 @@ void __init kmemleak_init(void)
                        kmemleak_ignore(log->ptr);
                        break;
                case KMEMLEAK_SCAN_AREA:
-                       kmemleak_scan_area(log->ptr, log->offset, log->length,
-                                          GFP_KERNEL);
+                       kmemleak_scan_area(log->ptr, log->size, GFP_KERNEL);
                        break;
                case KMEMLEAK_NO_SCAN:
                        kmemleak_no_scan(log->ptr);