kmemleak: Simplify the reports logged by the scanning thread (bab4a34a) · Commits · 戴 / test

Documentation/kmemleak.txt

+3 −3

Original line number	Diff line number	Diff line
		@@ -16,9 +16,9 @@ Usage
		-----

		CONFIG_DEBUG_KMEMLEAK in "Kernel hacking" has to be enabled. A kernel
		thread scans the memory every 10 minutes (by default) and prints any new
		unreferenced objects found. To trigger an intermediate scan and display
		all the possible memory leaks:
		thread scans the memory every 10 minutes (by default) and prints the
		number of new unreferenced objects found. To trigger an intermediate
		scan and display the details of all the possible memory leaks:

		# mount -t debugfs nodev /sys/kernel/debug/
		# cat /sys/kernel/debug/kmemleak

mm/kmemleak.c

+16 −45

Original line number	Diff line number	Diff line
		@@ -278,15 +278,6 @@ static int color_gray(const struct kmemleak_object *object)
		return object->min_count != -1 && object->count >= object->min_count;
		}

		/*
		* Objects are considered referenced if their color is gray and they have not
		* been deleted.
		*/
		static int referenced_object(struct kmemleak_object *object)
		{
		return (object->flags & OBJECT_ALLOCATED) && color_gray(object);
		}

		/*
		* 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
		@@ -299,38 +290,23 @@ static int unreferenced_object(struct kmemleak_object *object)
		}

		/*
		* Printing of the (un)referenced objects information, either to the seq file
		* or to the kernel log. The print_referenced/print_unreferenced functions
		* must be called with the object->lock held.
		* Printing of the unreferenced objects information to the seq file. The
		* print_unreferenced function must be called with the object->lock held.
		*/
		#define print_helper(seq, x...) do { \
		struct seq_file *s = (seq); \
		if (s) \
		seq_printf(s, x); \
		else \
		pr_info(x); \
		} while (0)

		static void print_referenced(struct kmemleak_object *object)
		{
		pr_info("referenced object 0x%08lx (size %zu)\n",
		object->pointer, object->size);
		}

		static void print_unreferenced(struct seq_file *seq,
		struct kmemleak_object *object)
		{
		int i;

		print_helper(seq, "unreferenced object 0x%08lx (size %zu):\n",
		seq_printf(seq, "unreferenced object 0x%08lx (size %zu):\n",
		object->pointer, object->size);
		print_helper(seq, " comm \"%s\", pid %d, jiffies %lu\n",
		seq_printf(seq, " comm \"%s\", pid %d, jiffies %lu\n",
		object->comm, object->pid, object->jiffies);
		print_helper(seq, " backtrace:\n");
		seq_printf(seq, " backtrace:\n");

		for (i = 0; i < object->trace_len; i++) {
		void ptr = (void )object->trace[i];
		print_helper(seq, " [<%p>] %pS\n", ptr, ptr);
		seq_printf(seq, " [<%p>] %pS\n", ptr, ptr);
		}
		}

		@@ -571,8 +547,6 @@ static void delete_object(unsigned long ptr)
		* cannot be freed when it is being scanned.
		*/
		spin_lock_irqsave(&object->lock, flags);
		if (object->flags & OBJECT_REPORTED)
		print_referenced(object);
		object->flags &= ~OBJECT_ALLOCATED;
		spin_unlock_irqrestore(&object->lock, flags);
		put_object(object);
		@@ -1073,33 +1047,30 @@ static int kmemleak_scan_thread(void *arg)
		while (!kthread_should_stop()) {
		struct kmemleak_object *object;
		signed long timeout = jiffies_scan_wait;
		int new_leaks = 0;

		mutex_lock(&scan_mutex);

		kmemleak_scan();
		reported_leaks = 0;

		rcu_read_lock();
		list_for_each_entry_rcu(object, &object_list, object_list) {
		unsigned long flags;

		if (reported_leaks >= REPORTS_NR)
		break;
		spin_lock_irqsave(&object->lock, flags);
		if (!(object->flags & OBJECT_REPORTED) &&
		unreferenced_object(object)) {
		print_unreferenced(NULL, object);
		if (unreferenced_object(object) &&
		!(object->flags & OBJECT_REPORTED)) {
		object->flags \|= OBJECT_REPORTED;
		reported_leaks++;
		} else if ((object->flags & OBJECT_REPORTED) &&
		referenced_object(object)) {
		print_referenced(object);
		object->flags &= ~OBJECT_REPORTED;
		new_leaks++;
		}
		spin_unlock_irqrestore(&object->lock, flags);
		}
		rcu_read_unlock();

		if (new_leaks)
		pr_info("%d new suspected memory leaks (see "
		"/sys/kernel/debug/kmemleak)\n", new_leaks);

		mutex_unlock(&scan_mutex);
		/* wait before the next scan */
		while (timeout && !kthread_should_stop())

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