kmemleak: Save the stack trace for early allocations (fd678967) · Commits · 戴 / test

mm/kmemleak.c

+52 −12

Original line number	Diff line number	Diff line
		@@ -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 */
		@@ -436,22 +438,37 @@ static struct kmemleak_object *find_and_get_object(unsigned long ptr, int alias)
		return object;
		}

		/*
		* 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;
		}

		/*
		@@ -743,10 +756,38 @@ 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,
		@@ -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);

Admin message