static void do_signal()

in kernel/signal.c [433:505]

• 52 lines of code
• 16 McCabe index (conditional complexity)

static void do_signal(struct pt_regs *regs)
{
	struct ksignal ksig;

	task_pt_regs(current)->icountlevel = 0;

	if (get_signal(&ksig)) {
		int ret;

		/* Are we from a system call? */

		if (regs->syscall != NO_SYSCALL) {

			/* If so, check system call restarting.. */

			switch (regs->areg[2]) {
				case -ERESTARTNOHAND:
				case -ERESTART_RESTARTBLOCK:
					regs->areg[2] = -EINTR;
					break;

				case -ERESTARTSYS:
					if (!(ksig.ka.sa.sa_flags & SA_RESTART)) {
						regs->areg[2] = -EINTR;
						break;
					}
					fallthrough;
				case -ERESTARTNOINTR:
					regs->areg[2] = regs->syscall;
					regs->pc -= 3;
					break;

				default:
					/* nothing to do */
					if (regs->areg[2] != 0)
					break;
			}
		}

		/* Whee!  Actually deliver the signal.  */
		/* Set up the stack frame */
		ret = setup_frame(&ksig, sigmask_to_save(), regs);
		signal_setup_done(ret, &ksig, 0);
		if (current->ptrace & PT_SINGLESTEP)
			task_pt_regs(current)->icountlevel = 1;

		return;
	}

	/* Did we come from a system call? */
	if (regs->syscall != NO_SYSCALL) {
		/* Restart the system call - no handlers present */
		switch (regs->areg[2]) {
		case -ERESTARTNOHAND:
		case -ERESTARTSYS:
		case -ERESTARTNOINTR:
			regs->areg[2] = regs->syscall;
			regs->pc -= 3;
			break;
		case -ERESTART_RESTARTBLOCK:
			regs->areg[2] = __NR_restart_syscall;
			regs->pc -= 3;
			break;
		}
	}

	/* If there's no signal to deliver, we just restore the saved mask.  */
	restore_saved_sigmask();

	if (current->ptrace & PT_SINGLESTEP)
		task_pt_regs(current)->icountlevel = 1;
	return;
}