static int setup_rt_frame()

in kernel/signal_32.c [320:415]

• 78 lines of code
• 11 McCabe index (conditional complexity)

static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs,
			  sigset_t *oldset)
{
	struct rt_signal_frame __user *sf;
	int sigframe_size, wsaved;
	void __user *tail;
	unsigned int psr;
	int err;

	synchronize_user_stack();
	wsaved = current_thread_info()->w_saved;
	sigframe_size = sizeof(*sf);
	if (used_math())
		sigframe_size += sizeof(__siginfo_fpu_t);
	if (wsaved)
		sigframe_size += sizeof(__siginfo_rwin_t);
	sf = (struct rt_signal_frame __user *)
		get_sigframe(ksig, regs, sigframe_size);
	if (invalid_frame_pointer(sf, sigframe_size)) {
		force_exit_sig(SIGILL);
		return -EINVAL;
	}

	tail = sf + 1;
	err  = __put_user(regs->pc, &sf->regs.pc);
	err |= __put_user(regs->npc, &sf->regs.npc);
	err |= __put_user(regs->y, &sf->regs.y);
	psr = regs->psr;
	if (used_math())
		psr |= PSR_EF;
	err |= __put_user(psr, &sf->regs.psr);
	err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
	err |= __put_user(0, &sf->extra_size);

	if (psr & PSR_EF) {
		__siginfo_fpu_t __user *fp = tail;
		tail += sizeof(*fp);
		err |= save_fpu_state(regs, fp);
		err |= __put_user(fp, &sf->fpu_save);
	} else {
		err |= __put_user(0, &sf->fpu_save);
	}
	if (wsaved) {
		__siginfo_rwin_t __user *rwp = tail;
		tail += sizeof(*rwp);
		err |= save_rwin_state(wsaved, rwp);
		err |= __put_user(rwp, &sf->rwin_save);
	} else {
		err |= __put_user(0, &sf->rwin_save);
	}
	err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
	
	/* Setup sigaltstack */
	err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
	
	if (!wsaved) {
		err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
				      sizeof(struct reg_window32));
	} else {
		struct reg_window32 *rp;

		rp = &current_thread_info()->reg_window[wsaved - 1];
		err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	}

	err |= copy_siginfo_to_user(&sf->info, &ksig->info);

	if (err)
		return err;

	regs->u_regs[UREG_FP] = (unsigned long) sf;
	regs->u_regs[UREG_I0] = ksig->sig;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;

	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
	regs->npc = (regs->pc + 4);

	if (ksig->ka.ka_restorer)
		regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
	else {
		regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

		/* mov __NR_rt_sigreturn, %g1 */
		err |= __put_user(0x82102065, &sf->insns[0]);

		/* t 0x10 */
		err |= __put_user(0x91d02010, &sf->insns[1]);
		if (err)
			return err;

		/* Flush instruction space. */
		flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	}
	return 0;
}