unsigned long __get_wchan()

in kernel/process.c [236:257]

• 20 lines of code
• 5 McCabe index (conditional complexity)

unsigned long __get_wchan(struct task_struct *p)
{
	unsigned long fp, lr;
	unsigned long stack_start, stack_end;
	int count = 0;

	if (IS_ENABLED(CONFIG_FRAME_POINTER)) {
		stack_start = (unsigned long)end_of_stack(p);
		stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;

		fp = thread_saved_fp(p);
		do {
			if (fp < stack_start || fp > stack_end)
				return 0;
			lr = ((unsigned long *)fp)[0];
			if (!in_sched_functions(lr))
				return lr;
			fp = *(unsigned long *)(fp + 4);
		} while (count++ < 16);
	}
	return 0;
}