C++ (Cpp) handle_syscall_restart Examples

Example #1

File: signal_64.c Project: markosilla/linux-raspberry

/*
 * 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.
 */
static void do_signal(struct pt_regs *regs)
{
    siginfo_t info;
    int signr;
    struct k_sigaction ka;

    /*
     * 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(regs))
        return;

    signr = get_signal_to_deliver(&info, &ka, regs, 0);
    if (signr > 0) {
        handle_syscall_restart(regs, &ka.sa);

        /* Whee!  Actually deliver the signal.  */
        handle_signal(signr, &info, &ka, regs);
        return;
    }

    /* Did we come from a system call? */
    if (regs->syscall_nr >= 0) {
        /* Restart the system call - no handlers present */
        switch (regs->regs[REG_RET]) {
        case -ERESTARTNOHAND:
        case -ERESTARTSYS:
        case -ERESTARTNOINTR:
            /* Decode Syscall # */
            regs->regs[REG_RET] = regs->syscall_nr;
            regs->pc -= 4;
            break;

        case -ERESTART_RESTARTBLOCK:
            regs->regs[REG_RET] = __NR_restart_syscall;
            regs->pc -= 4;
            break;
        }
    }

    /* No signal to deliver -- put the saved sigmask back */
    restore_saved_sigmask();
}

Example #2

File: signal_32.c Project: 1ee7/linux_l4t_tx1

/*
 * 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.
 */
static void do_signal(struct pt_regs *regs, unsigned int save_r0)
{
	siginfo_t info;
	int signr;
	struct k_sigaction ka;

	/*
	 * 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(regs))
		return;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		handle_syscall_restart(save_r0, regs, &ka.sa);

		/* Whee!  Actually deliver the signal.  */
		handle_signal(signr, &ka, &info, regs, save_r0);
		return;
	}

	/* Did we come from a system call? */
	if (regs->tra >= 0) {
		/* Restart the system call - no handlers present */
		if (regs->regs[0] == -ERESTARTNOHAND ||
		    regs->regs[0] == -ERESTARTSYS ||
		    regs->regs[0] == -ERESTARTNOINTR) {
			regs->regs[0] = save_r0;
			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
		} else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
			regs->regs[3] = __NR_restart_syscall;
		}
	}

	/*
	 * If there's no signal to deliver, we just put the saved sigmask
	 * back.
	 */
	restore_saved_sigmask();
}

Example #3

File: signal_32.c Project: moddingg33k/deprecated_android_kernel_synopsis

/*
 * 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.
 */
static void do_signal(struct pt_regs *regs, unsigned int save_r0)
{
	siginfo_t info;
	int signr;
	struct k_sigaction ka;
	sigset_t *oldset;

	/*
	 * 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(regs))
		return;

	if (current_thread_info()->status & TS_RESTORE_SIGMASK)
		oldset = &current->saved_sigmask;
	else
		oldset = &current->blocked;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		handle_syscall_restart(save_r0, regs, &ka.sa);

		/* Whee!  Actually deliver the signal.  */
		if (handle_signal(signr, &ka, &info, oldset,
				  regs, save_r0) == 0) {
			/*
			 * A signal was successfully delivered; the saved
			 * sigmask will have been stored in the signal frame,
			 * and will be restored by sigreturn, so we can simply
			 * clear the TS_RESTORE_SIGMASK flag
			 */
			current_thread_info()->status &= ~TS_RESTORE_SIGMASK;

			tracehook_signal_handler(signr, &info, &ka, regs,
					test_thread_flag(TIF_SINGLESTEP));
		}

		return;
	}

	/* Did we come from a system call? */
	if (regs->tra >= 0) {
		/* Restart the system call - no handlers present */
		if (regs->regs[0] == -ERESTARTNOHAND ||
		    regs->regs[0] == -ERESTARTSYS ||
		    regs->regs[0] == -ERESTARTNOINTR) {
			regs->regs[0] = save_r0;
			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
		} else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
			regs->regs[3] = __NR_restart_syscall;
		}
	}

	/*
	 * If there's no signal to deliver, we just put the saved sigmask
	 * back.
	 */
	if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
		current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	}
}

Example #4

File: signal_64.c Project: 458941968/mini2440-kernel-2.6.29

/*
 * 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.
 */
static int do_signal(struct pt_regs *regs, sigset_t *oldset)
{
	siginfo_t info;
	int signr;
	struct k_sigaction ka;

	/*
	 * 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(regs))
		return 1;

	if (try_to_freeze())
		goto no_signal;

	if (test_thread_flag(TIF_RESTORE_SIGMASK))
		oldset = &current->saved_sigmask;
	else if (!oldset)
		oldset = &current->blocked;

	signr = get_signal_to_deliver(&info, &ka, regs, 0);
	if (signr > 0) {
		handle_syscall_restart(regs, &ka.sa);

		/* Whee!  Actually deliver the signal.  */
		if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
			/*
			 * If a signal was successfully delivered, the
			 * saved sigmask is in its frame, and we can
			 * clear the TIF_RESTORE_SIGMASK flag.
			 */
			if (test_thread_flag(TIF_RESTORE_SIGMASK))
				clear_thread_flag(TIF_RESTORE_SIGMASK);

			tracehook_signal_handler(signr, &info, &ka, regs, 0);
			return 1;
		}
	}

no_signal:
	/* Did we come from a system call? */
	if (regs->syscall_nr >= 0) {
		/* Restart the system call - no handlers present */
		switch (regs->regs[REG_RET]) {
		case -ERESTARTNOHAND:
		case -ERESTARTSYS:
		case -ERESTARTNOINTR:
			/* Decode Syscall # */
			regs->regs[REG_RET] = regs->syscall_nr;
			regs->pc -= 4;
			break;

		case -ERESTART_RESTARTBLOCK:
			regs->regs[REG_RET] = __NR_restart_syscall;
			regs->pc -= 4;
			break;
		}
	}

	/* No signal to deliver -- put the saved sigmask back */
	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
		clear_thread_flag(TIF_RESTORE_SIGMASK);
		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	}

	return 0;
}