diff options
| -rw-r--r-- | mm/kmemleak.c | 64 |
1 files changed, 52 insertions, 12 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 576c0a4cec52..8172154502a6 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -229,6 +229,8 @@ struct early_log { 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 */ }; /* early logging buffer and current position */ @@ -437,21 +439,36 @@ static struct kmemleak_object *find_and_get_object(unsigned long ptr, int alias) } /* + * Save stack trace to the given array of MAX_TRACE size. + */ +static int __save_stack_trace(unsigned long *trace) +{ + struct stack_trace stack_trace; + + stack_trace.max_entries = MAX_TRACE; + stack_trace.nr_entries = 0; + stack_trace.entries = trace; + stack_trace.skip = 2; + save_stack_trace(&stack_trace); + + return stack_trace.nr_entries; +} + +/* * Create the metadata (struct kmemleak_object) corresponding to an allocated * memory block and add it to the object_list and object_tree_root. */ -static void create_object(unsigned long ptr, size_t size, int min_count, - gfp_t gfp) +static struct kmemleak_object *create_object(unsigned long ptr, size_t size, + int min_count, gfp_t gfp) { unsigned long flags; struct kmemleak_object *object; struct prio_tree_node *node; - struct stack_trace trace; object = kmem_cache_alloc(object_cache, gfp & GFP_KMEMLEAK_MASK); if (!object) { kmemleak_stop("Cannot allocate a kmemleak_object structure\n"); - return; + return NULL; } INIT_LIST_HEAD(&object->object_list); @@ -485,12 +502,7 @@ static void create_object(unsigned long ptr, size_t size, int min_count, } /* kernel backtrace */ - trace.max_entries = MAX_TRACE; - trace.nr_entries = 0; - trace.entries = object->trace; - trace.skip = 1; - save_stack_trace(&trace); - object->trace_len = trace.nr_entries; + object->trace_len = __save_stack_trace(object->trace); INIT_PRIO_TREE_NODE(&object->tree_node); object->tree_node.start = ptr; @@ -521,6 +533,7 @@ static void create_object(unsigned long ptr, size_t size, int min_count, list_add_tail_rcu(&object->object_list, &object_list); out: write_unlock_irqrestore(&kmemleak_lock, flags); + return object; } /* @@ -743,11 +756,39 @@ static void __init log_early(int op_type, const void *ptr, size_t 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++; local_irq_restore(flags); } /* + * Log an early allocated block and populate the stack trace. + */ +static void early_alloc(struct early_log *log) +{ + struct kmemleak_object *object; + unsigned long flags; + int i; + + if (!atomic_read(&kmemleak_enabled) || !log->ptr || IS_ERR(log->ptr)) + return; + + /* + * RCU locking needed to ensure object is not freed via put_object(). + */ + rcu_read_lock(); + object = create_object((unsigned long)log->ptr, log->size, + log->min_count, GFP_KERNEL); + 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); + rcu_read_unlock(); +} + +/* * Memory allocation function callback. This function is called from the * kernel allocators when a new block is allocated (kmem_cache_alloc, kmalloc, * vmalloc etc.). @@ -1509,8 +1550,7 @@ void __init kmemleak_init(void) switch (log->op_type) { case KMEMLEAK_ALLOC: - kmemleak_alloc(log->ptr, log->size, log->min_count, - GFP_KERNEL); + early_alloc(log); break; case KMEMLEAK_FREE: kmemleak_free(log->ptr); |