diff options
| -rw-r--r-- | mm/kmemleak.c | 43 |
1 files changed, 40 insertions, 3 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 7cfb7d014a2..466d3900726 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -106,6 +106,7 @@ #define MSECS_MIN_AGE 5000 /* minimum object age for reporting */ #define SECS_FIRST_SCAN 60 /* delay before the first scan */ #define SECS_SCAN_WAIT 600 /* subsequent auto scanning delay */ +#define GRAY_LIST_PASSES 25 /* maximum number of gray list scans */ #define BYTES_PER_POINTER sizeof(void *) @@ -157,6 +158,8 @@ struct kmemleak_object { #define OBJECT_REPORTED (1 << 1) /* flag set to not scan the object */ #define OBJECT_NO_SCAN (1 << 2) +/* flag set on newly allocated objects */ +#define OBJECT_NEW (1 << 3) /* the list of all allocated objects */ static LIST_HEAD(object_list); @@ -270,6 +273,11 @@ static int color_gray(const struct kmemleak_object *object) return object->min_count != -1 && object->count >= object->min_count; } +static int color_black(const struct kmemleak_object *object) +{ + return object->min_count == -1; +} + /* * Objects are considered unreferenced only if their color is white, they have * not be deleted and have a minimum age to avoid false positives caused by @@ -447,7 +455,7 @@ static void create_object(unsigned long ptr, size_t size, int min_count, INIT_HLIST_HEAD(&object->area_list); spin_lock_init(&object->lock); atomic_set(&object->use_count, 1); - object->flags = OBJECT_ALLOCATED; + object->flags = OBJECT_ALLOCATED | OBJECT_NEW; object->pointer = ptr; object->size = size; object->min_count = min_count; @@ -901,6 +909,7 @@ static void kmemleak_scan(void) struct task_struct *task; int i; int new_leaks = 0; + int gray_list_pass = 0; jiffies_last_scan = jiffies; @@ -921,6 +930,7 @@ static void kmemleak_scan(void) #endif /* reset the reference count (whiten the object) */ object->count = 0; + object->flags &= ~OBJECT_NEW; if (color_gray(object) && get_object(object)) list_add_tail(&object->gray_list, &gray_list); @@ -983,6 +993,7 @@ static void kmemleak_scan(void) * kmemleak objects cannot be freed from outside the loop because their * use_count was increased. */ +repeat: object = list_entry(gray_list.next, typeof(*object), gray_list); while (&object->gray_list != &gray_list) { cond_resched(); @@ -1000,12 +1011,38 @@ static void kmemleak_scan(void) object = tmp; } + + if (scan_should_stop() || ++gray_list_pass >= GRAY_LIST_PASSES) + goto scan_end; + + /* + * Check for new objects allocated during this scanning and add them + * to the gray list. + */ + rcu_read_lock(); + list_for_each_entry_rcu(object, &object_list, object_list) { + spin_lock_irqsave(&object->lock, flags); + if ((object->flags & OBJECT_NEW) && !color_black(object) && + get_object(object)) { + object->flags &= ~OBJECT_NEW; + list_add_tail(&object->gray_list, &gray_list); + } + spin_unlock_irqrestore(&object->lock, flags); + } + rcu_read_unlock(); + + if (!list_empty(&gray_list)) + goto repeat; + +scan_end: WARN_ON(!list_empty(&gray_list)); /* - * If scanning was stopped do not report any new unreferenced objects. + * If scanning was stopped or new objects were being allocated at a + * higher rate than gray list scanning, do not report any new + * unreferenced objects. */ - if (scan_should_stop()) + if (scan_should_stop() || gray_list_pass >= GRAY_LIST_PASSES) return; /* |