signal.c

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	err |= __put_user(scr->pt.pr, &sc->sc_pr);			/* predicates */
	err |= __put_user(scr->pt.b0, &sc->sc_br[0]);			/* b0 (rp) */
	err |= __put_user(scr->pt.b6, &sc->sc_br[6]);			/* b6 */
	err |= __put_user(scr->pt.b7, &sc->sc_br[7]);			/* b7 */

	err |= __copy_to_user(&sc->sc_gr[1], &scr->pt.r1, 3*8);		/* r1-r3 */
	err |= __copy_to_user(&sc->sc_gr[8], &scr->pt.r8, 4*8);		/* r8-r11 */
	err |= __copy_to_user(&sc->sc_gr[12], &scr->pt.r12, 4*8);	/* r12-r15 */
	err |= __copy_to_user(&sc->sc_gr[16], &scr->pt.r16, 16*8);	/* r16-r31 */

	err |= __put_user(scr->pt.cr_iip + ia64_psr(&scr->pt)->ri, &sc->sc_ip);
	return err;
}

static long
setup_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set,
	     struct sigscratch *scr)
{
	extern char ia64_sigtramp[], __start_gate_section[];
	unsigned long tramp_addr, new_rbs = 0;
	struct sigframe *frame;
	struct siginfo si;
	long err;

	frame = (void *) scr->pt.r12;
	tramp_addr = GATE_ADDR + (ia64_sigtramp - __start_gate_section);
	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && !on_sig_stack((unsigned long) frame)) {
		new_rbs  = (current->sas_ss_sp + sizeof(long) - 1) & ~(sizeof(long) - 1);
		frame = (void *) ((current->sas_ss_sp + current->sas_ss_size)
				  & ~(STACK_ALIGN - 1));
	}
	frame = (void *) frame - ((sizeof(*frame) + STACK_ALIGN - 1) & ~(STACK_ALIGN - 1));

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		goto give_sigsegv;

	err  = copy_siginfo_to_user(&frame->info, info);

	err |= __put_user(current->sas_ss_sp, &frame->sc.sc_stack.ss_sp);
	err |= __put_user(current->sas_ss_size, &frame->sc.sc_stack.ss_size);
	err |= __put_user(sas_ss_flags(scr->pt.r12), &frame->sc.sc_stack.ss_flags);
	err |= setup_sigcontext(&frame->sc, set, scr);

	if (err)
		goto give_sigsegv;

	scr->pt.r12 = (unsigned long) frame - 16;		/* new stack pointer */
	scr->pt.r2  = sig;					/* signal number */
	scr->pt.r3  = (unsigned long) ka->sa.sa_handler;	/* addr. of handler's proc desc */
	scr->pt.r15 = new_rbs;
	scr->pt.ar_fpsr = FPSR_DEFAULT;			/* reset fpsr for signal handler */
	scr->pt.cr_iip = tramp_addr;
	ia64_psr(&scr->pt)->ri = 0;			/* start executing in first slot */

#ifdef CONFIG_IA64_NEW_UNWIND
	/*
	 * Note: this affects only the NaT bits of the scratch regs
	 * (the ones saved in pt_regs), which is exactly what we want.
	 */
	scr->scratch_unat = 0; /* ensure NaT bits of at least r2, r3, r12, and r15 are clear */
#else
	/*
	 * Note: this affects only the NaT bits of the scratch regs
	 * (the ones saved in pt_regs), which is exactly what we want.
	 * The NaT bits for the preserved regs (r4-r7) are in
	 * sw->ar_unat iff this process is being PTRACED.
	 */
	scr->sw.caller_unat = 0; /* ensure NaT bits of at least r2, r3, r12, and r15 are clear */
#endif

#if DEBUG_SIG
	printk("SIG deliver (%s:%d): sig=%d sp=%lx ip=%lx handler=%lx\n",
	       current->comm, current->pid, sig, scr->pt.r12, scr->pt.cr_iip, scr->pt.r3);
#endif
	return 1;

  give_sigsegv:
	if (sig == SIGSEGV)
		ka->sa.sa_handler = SIG_DFL;
	si.si_signo = SIGSEGV;
	si.si_errno = 0;
	si.si_code = SI_KERNEL;
	si.si_pid = current->pid;
	si.si_uid = current->uid;
	si.si_addr = frame;
	force_sig_info(SIGSEGV, &si, current);
	return 0;
}

static long
handle_signal (unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset,
	       struct sigscratch *scr)
{
#ifdef CONFIG_IA32_SUPPORT
	if (IS_IA32_PROCESS(&scr->pt)) {
		/* send signal to IA-32 process */
		if (!ia32_setup_frame1(sig, ka, info, oldset, &scr->pt))
			return 0;
	} else
#endif
	/* send signal to IA-64 process */
	if (!setup_frame(sig, ka, info, oldset, scr))
		return 0;

	if (ka->sa.sa_flags & SA_ONESHOT)
		ka->sa.sa_handler = SIG_DFL;

	if (!(ka->sa.sa_flags & SA_NODEFER)) {
		spin_lock_irq(&current->sigmask_lock);
		{
			sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
			sigaddset(&current->blocked, sig);
			recalc_sigpending(current);
		}
		spin_unlock_irq(&current->sigmask_lock);
	}
	return 1;
}

/*
 * Note that `init' is a special process: it doesn't get signals it
 * doesn't want to handle.  Thus you cannot kill init even with a
 * SIGKILL even by mistake.
 *
 * Note that we go through the signals twice: once to check the
 * signals that the kernel can handle, and then we build all the
 * user-level signal handling stack-frames in one go after that.
 */
long
ia64_do_signal (sigset_t *oldset, struct sigscratch *scr, long in_syscall)
{
	struct k_sigaction *ka;
	siginfo_t info;
	long restart = in_syscall;
	long errno = scr->pt.r8;

	/*
	 * In the ia64_leave_kernel code path, we want the common case
	 * to go fast, which is why we may in certain cases get here
	 * from kernel mode. Just return without doing anything if so.
	 */
	if (!user_mode(&scr->pt))
		return 0;

	if (!oldset)
		oldset = &current->blocked;

#ifdef CONFIG_IA32_SUPPORT
	if (IS_IA32_PROCESS(&scr->pt)) {
		if (in_syscall) {
			if (errno >= 0)
				restart = 0;
			else
				errno = -errno;
		}
	} else
#endif
	if (scr->pt.r10 != -1) {
		/*
		 * A system calls has to be restarted only if one of
		 * the error codes ERESTARTNOHAND, ERESTARTSYS, or
		 * ERESTARTNOINTR is returned.  If r10 isn't -1 then
		 * r8 doesn't hold an error code and we don't need to
		 * restart the syscall, so we set in_syscall to zero.
		 */
		restart = 0;
	}

	for (;;) {
		unsigned long signr;

		spin_lock_irq(&current->sigmask_lock);
		signr = dequeue_signal(&current->blocked, &info);
		spin_unlock_irq(&current->sigmask_lock);

		if (!signr)
			break;

		if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {
			/* Let the debugger run.  */
			current->exit_code = signr;
			current->thread.siginfo = &info;
			current->state = TASK_STOPPED;
			notify_parent(current, SIGCHLD);
			schedule();

			signr = current->exit_code;
			current->thread.siginfo = 0;

			/* We're back.  Did the debugger cancel the sig?  */
			if (!signr)
				continue;
			current->exit_code = 0;

			/* The debugger continued.  Ignore SIGSTOP.  */
			if (signr == SIGSTOP)
				continue;

			/* Update the siginfo structure.  Is this good?  */
			if (signr != info.si_signo) {
				info.si_signo = signr;
				info.si_errno = 0;
				info.si_code = SI_USER;
				info.si_pid = current->p_pptr->pid;
				info.si_uid = current->p_pptr->uid;
			}

			/* If the (new) signal is now blocked, requeue it.  */
			if (sigismember(&current->blocked, signr)) {
				send_sig_info(signr, &info, current);
				continue;
			}
		}

		ka = &current->sig->action[signr - 1];
		if (ka->sa.sa_handler == SIG_IGN) {
			if (signr != SIGCHLD)
				continue;
			/* Check for SIGCHLD: it's special.  */
			while (sys_wait4(-1, NULL, WNOHANG, NULL) > 0)
				/* nothing */;
			continue;
		}

		if (ka->sa.sa_handler == SIG_DFL) {
			int exit_code = signr;

			/* Init gets no signals it doesn't want.  */
			if (current->pid == 1)
				continue;

			switch (signr) {
			      case SIGCONT: case SIGCHLD: case SIGWINCH:
				continue;

			      case SIGTSTP: case SIGTTIN: case SIGTTOU:
				if (is_orphaned_pgrp(current->pgrp))
					continue;
				/* FALLTHRU */

			      case SIGSTOP:
				current->state = TASK_STOPPED;
				current->exit_code = signr;
				if (!(current->p_pptr->sig->action[SIGCHLD-1].sa.sa_flags
				      & SA_NOCLDSTOP))
					notify_parent(current, SIGCHLD);
				schedule();
				continue;

			      case SIGQUIT: case SIGILL: case SIGTRAP:
			      case SIGABRT: case SIGFPE: case SIGSEGV:
			      case SIGBUS: case SIGSYS: case SIGXCPU: case SIGXFSZ:
				if (do_coredump(signr, &scr->pt))
					exit_code |= 0x80;
				/* FALLTHRU */

			      default:
				sigaddset(&current->pending.signal, signr);
				recalc_sigpending(current);
				current->flags |= PF_SIGNALED;
				do_exit(exit_code);
				/* NOTREACHED */
			}
		}

		if (restart) {
			switch (errno) {
			      case ERESTARTSYS:
				if ((ka->sa.sa_flags & SA_RESTART) == 0) {
			      case ERESTARTNOHAND:
#ifdef CONFIG_IA32_SUPPORT
					if (IS_IA32_PROCESS(&scr->pt))
						scr->pt.r8 = -EINTR;
					else
#endif
					scr->pt.r8 = EINTR;
					/* note: scr->pt.r10 is already -1 */
					break;
				}
			      case ERESTARTNOINTR:
#ifdef CONFIG_IA32_SUPPORT
				if (IS_IA32_PROCESS(&scr->pt)) {
					scr->pt.r8 = scr->pt.r1;
					scr->pt.cr_iip -= 2;
				} else
#endif
				ia64_decrement_ip(&scr->pt);
			}
		}

		/* Whee!  Actually deliver the signal.  If the
		   delivery failed, we need to continue to iterate in
		   this loop so we can deliver the SIGSEGV... */
		if (handle_signal(signr, ka, &info, oldset, scr))
			return 1;
	}

	/* Did we come from a system call? */
	if (restart) {
		/* Restart the system call - no handlers present */
		if (errno == ERESTARTNOHAND || errno == ERESTARTSYS || errno == ERESTARTNOINTR) {
#ifdef CONFIG_IA32_SUPPORT
			if (IS_IA32_PROCESS(&scr->pt)) {
				scr->pt.r8 = scr->pt.r1;
				scr->pt.cr_iip -= 2;
			} else
#endif
			/*
			 * Note: the syscall number is in r15 which is
			 * saved in pt_regs so all we need to do here
			 * is adjust ip so that the "break"
			 * instruction gets re-executed.
			 */
			ia64_decrement_ip(&scr->pt);
		}
	}
	return 0;
}