void kprobe_ftrace_handler()

in kernel/ftrace.c [201:243]

• 35 lines of code
• 8 McCabe index (conditional complexity)

void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
			   struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
	struct kprobe_ctlblk *kcb;
	struct pt_regs *regs;
	struct kprobe *p;
	int bit;

	bit = ftrace_test_recursion_trylock(ip, parent_ip);
	if (bit < 0)
		return;

	regs = ftrace_get_regs(fregs);
	p = get_kprobe((kprobe_opcode_t *)ip);
	if (unlikely(!p) || kprobe_disabled(p))
		goto out;

	if (kprobe_running()) {
		kprobes_inc_nmissed_count(p);
		goto out;
	}

	__this_cpu_write(current_kprobe, p);

	kcb = get_kprobe_ctlblk();
	kcb->kprobe_status = KPROBE_HIT_ACTIVE;

	regs->iaoq[0] = ip;
	regs->iaoq[1] = ip + 4;

	if (!p->pre_handler || !p->pre_handler(p, regs)) {
		regs->iaoq[0] = ip + 4;
		regs->iaoq[1] = ip + 8;

		if (unlikely(p->post_handler)) {
			kcb->kprobe_status = KPROBE_HIT_SSDONE;
			p->post_handler(p, regs, 0);
		}
	}
	__this_cpu_write(current_kprobe, NULL);
out:
	ftrace_test_recursion_unlock(bit);
}