示例#1
0
/*
 * 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.
 */
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;
#	define ERR_CODE(c)	(IS_IA32_PROCESS(&scr->pt) ? -(c) : (c))

	/*
	 * 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;

	if (IS_IA32_PROCESS(&scr->pt)) {
		if (in_syscall) {
			if (errno >= 0)
				restart = 0;
			else
				errno = -errno;
		}
	} else 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 can clear the "restart" flag here.
		 */
		restart = 0;

	while (1) {
		int signr = get_signal_to_deliver(&info, &scr->pt);

		if (signr <= 0)
			break;

		ka = &current->sighand->action[signr - 1];

		if (restart) {
			switch (errno) {
			      case ERESTARTNOHAND:
				scr->pt.r8 = ERR_CODE(EINTR);
				/* note: scr->pt.r10 is already -1 */
				break;

			      case ERESTARTSYS:
				if ((ka->sa.sa_flags & SA_RESTART) == 0) {
					scr->pt.r8 = ERR_CODE(EINTR);
					/* note: scr->pt.r10 is already -1 */
					break;
				}
			      case ERESTARTNOINTR:
				if (IS_IA32_PROCESS(&scr->pt)) {
					scr->pt.r8 = scr->pt.r1;
					scr->pt.cr_iip -= 2;
				} else
					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)
		{
			if (IS_IA32_PROCESS(&scr->pt)) {
				scr->pt.r8 = scr->pt.r1;
				scr->pt.cr_iip -= 2;
			} else {
				/*
				 * 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;
}
示例#2
0
/*
 * 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.
 */
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;
#	define ERR_CODE(c)	(IS_IA32_PROCESS(&scr->pt) ? -(c) : (c))

	/*
	 * 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;

	/*
	 * This only loops in the rare cases of handle_signal() failing, in which case we
	 * need to push through a forced SIGSEGV.
	 */
	while (1) {
		int signr = get_signal_to_deliver(&info, &ka, &scr->pt, NULL);

		/*
		 * get_signal_to_deliver() may have run a debugger (via notify_parent())
		 * and the debugger may have modified the state (e.g., to arrange for an
		 * inferior call), thus it's important to check for restarting _after_
		 * get_signal_to_deliver().
		 */
		if (IS_IA32_PROCESS(&scr->pt)) {
			if (in_syscall) {
				if (errno >= 0)
					restart = 0;
				else
					errno = -errno;
			}
		} else if ((long) 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 can clear the "restart" flag here.
			 */
			restart = 0;

		if (signr <= 0)
			break;

		if (unlikely(restart)) {
			switch (errno) {
			      case ERESTART_RESTARTBLOCK:
			      case ERESTARTNOHAND:
				scr->pt.r8 = ERR_CODE(EINTR);
				/* note: scr->pt.r10 is already -1 */
				break;

			      case ERESTARTSYS:
				if ((ka.sa.sa_flags & SA_RESTART) == 0) {
					scr->pt.r8 = ERR_CODE(EINTR);
					/* note: scr->pt.r10 is already -1 */
					break;
				}
			      case ERESTARTNOINTR:
				if (IS_IA32_PROCESS(&scr->pt)) {
					scr->pt.r8 = scr->pt.r1;
					scr->pt.cr_iip -= 2;
				} else
					ia64_decrement_ip(&scr->pt);
				restart = 0; /* don't restart twice if handle_signal() fails... */
			}
		}

		/*
		 * 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
		    || errno == ERESTART_RESTARTBLOCK)
		{
			if (IS_IA32_PROCESS(&scr->pt)) {
				scr->pt.r8 = scr->pt.r1;
				scr->pt.cr_iip -= 2;
				if (errno == ERESTART_RESTARTBLOCK)
					scr->pt.r8 = 0;	/* x86 version of __NR_restart_syscall */
			} else {
				/*
				 * 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);
				if (errno == ERESTART_RESTARTBLOCK)
					scr->pt.r15 = __NR_restart_syscall;
			}
		}
	}
	return 0;
}