Exemplo n.º 1
0
SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
	struct sigaction __user *, oact)
{
	struct k_sigaction new_ka, old_ka;
	int ret;
	int err = 0;

	if (act) {
		old_sigset_t mask;

		if (!access_ok(VERIFY_READ, act, sizeof(*act)))
			return -EFAULT;
		err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
		err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
		err |= __get_user(mask, &act->sa_mask.sig[0]);
		if (err)
			return -EFAULT;

		siginitset(&new_ka.sa.sa_mask, mask);
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
			return -EFAULT;
		err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
		err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
		err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
		err |= __put_user(0, &oact->sa_mask.sig[1]);
		err |= __put_user(0, &oact->sa_mask.sig[2]);
		err |= __put_user(0, &oact->sa_mask.sig[3]);
		if (err)
			return -EFAULT;
	}

	return ret;
}
Exemplo n.º 2
0
asmlinkage long compat_sys_sigaction(int sig, struct old_sigaction32 __user *act,
				     struct old_sigaction32 __user *oact)
{
        struct k_sigaction new_ka, old_ka;
        int ret;

	if (sig < 0) {
		set_thread_flag(TIF_NEWSIGNALS);
		sig = -sig;
	}

        if (act) {
		compat_old_sigset_t mask;
		u32 u_handler, u_restorer;
		
		ret = get_user(u_handler, &act->sa_handler);
		new_ka.sa.sa_handler =  compat_ptr(u_handler);
		ret |= __get_user(u_restorer, &act->sa_restorer);
		new_ka.sa.sa_restorer = compat_ptr(u_restorer);
		ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
		ret |= __get_user(mask, &act->sa_mask);
		if (ret)
			return ret;
		new_ka.ka_restorer = NULL;
		siginitset(&new_ka.sa.sa_mask, mask);
        }

        ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		ret = put_user(ptr_to_compat(old_ka.sa.sa_handler), &oact->sa_handler);
		ret |= __put_user(ptr_to_compat(old_ka.sa.sa_restorer), &oact->sa_restorer);
		ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
		ret |= __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
        }

	return ret;
}
asmlinkage long
sys32_rt_sigaction(int sig, const struct sigaction32 __user *act,
	   struct sigaction32 __user *oact,  size_t sigsetsize)
{
	struct k_sigaction new_ka, old_ka;
	unsigned long sa_handler;
	int ret;
	compat_sigset_t set32;

	/* XXX: Don't preclude handling different sized sigset_t's.  */
	if (sigsetsize != sizeof(compat_sigset_t))
		return -EINVAL;

	if (act) {
		ret = get_user(sa_handler, &act->sa_handler);
		ret |= __copy_from_user(&set32, &act->sa_mask,
					sizeof(compat_sigset_t));
		new_ka.sa.sa_mask.sig[0] =
			set32.sig[0] | (((long)set32.sig[1]) << 32);
		ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);

		if (ret)
			return -EFAULT;
		new_ka.sa.sa_handler = (__sighandler_t) sa_handler;
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		set32.sig[1] = (old_ka.sa.sa_mask.sig[0] >> 32);
		set32.sig[0] = old_ka.sa.sa_mask.sig[0];
		ret = put_user((unsigned long)old_ka.sa.sa_handler, &oact->sa_handler);
		ret |= __copy_to_user(&oact->sa_mask, &set32,
				      sizeof(compat_sigset_t));
		ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
	}
asmlinkage long
sys32_sigaction(int sig, const struct old_sigaction32 __user *act,
		 struct old_sigaction32 __user *oact)
{
        struct k_sigaction new_ka, old_ka;
	unsigned long sa_handler, sa_restorer;
        int ret;

        if (act) {
		compat_old_sigset_t mask;
		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
		    __get_user(sa_handler, &act->sa_handler) ||
		    __get_user(sa_restorer, &act->sa_restorer) ||
		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
		    __get_user(mask, &act->sa_mask))
			return -EFAULT;
		new_ka.sa.sa_handler = (__sighandler_t) sa_handler;
		new_ka.sa.sa_restorer = (void (*)(void)) sa_restorer;
		siginitset(&new_ka.sa.sa_mask, mask);
        }

        ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		sa_handler = (unsigned long) old_ka.sa.sa_handler;
		sa_restorer = (unsigned long) old_ka.sa.sa_restorer;
		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
		    __put_user(sa_handler, &oact->sa_handler) ||
		    __put_user(sa_restorer, &oact->sa_restorer) ||
		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
			return -EFAULT;
        }

	return ret;
}
Exemplo n.º 5
0
asmlinkage int
sparc_sigaction (int sig, const struct old_sigaction __user *act,
		 struct old_sigaction __user *oact)
{
	struct k_sigaction new_ka, old_ka;
	int ret;

	WARN_ON_ONCE(sig >= 0);
	sig = -sig;

	if (act) {
		unsigned long mask;

		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
		    __get_user(mask, &act->sa_mask))
			return -EFAULT;
		siginitset(&new_ka.sa.sa_mask, mask);
		new_ka.ka_restorer = NULL;
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
			return -EFAULT;
	}

	return ret;
}
Exemplo n.º 6
0
int ckpt_restore_signals(ckpt_desc_t desc)
{
    int i;
    int ret;
    stack_t sigstack;
    sigset_t sigblocked;

    log_restore_signals("restoring sigstack ...");
    if (ckpt_read(desc, &sigstack, sizeof(stack_t)) != sizeof(stack_t)) {
        log_err("failed to get sigstack");
        return -EIO;
    }

    ret = compat_sigaltstack(current, &sigstack, NULL, 0);
    if (ret) {
        log_err("failed to restore sigstack (ret=%d)", ret);
        return ret;
    }

    log_restore_signals("restoring sigblocked ...");
    if (ckpt_read(desc, &sigblocked, sizeof(sigset_t)) != sizeof(sigset_t)) {
        log_err("failed to restore sigstack");
        return -EIO;
    }

    sigdelsetmask(&sigblocked, sigmask(SIGKILL) | sigmask(SIGSTOP));
    spin_lock_irq(&current->sighand->siglock);
    current->blocked = sigblocked;
    recalc_sigpending();
    spin_unlock_irq(&current->sighand->siglock);

    log_restore_signals("restoring pending ...");
    ret = ckpt_restore_sigpending(&current->pending, 0, desc);
    if (ret) {
        log_err("failed to restore pending");
        return ret;
    }

    ret = ckpt_restore_sigpending(&current->signal->shared_pending, 1, desc);
    if (ret) {
        log_err("failed to restore shared_pending");
        return ret;
    }

    log_restore_signals("restoring sigaction ...");
    for (i = 0; i < _NSIG; i++) {
        struct k_sigaction sigaction;

        if (ckpt_read(desc, &sigaction, sizeof(struct k_sigaction)) != sizeof(struct k_sigaction)) {
            log_err("failed to get sigaction");
            return -EIO;
        }

        if ((i != SIGKILL - 1) && (i != SIGSTOP - 1)) {
            ret = do_sigaction(i + 1, &sigaction, 0);
            if (ret) {
                log_err("failed to restore sigaction (ret=%d)", ret);
                return ret;
            }
        }
    }
    log_restore_pos(desc);
    return 0;
}
Exemplo n.º 7
0
static uint32_t
sys_linux_sigaction(uint32_t arg[]) {
	return do_sigaction((int)arg[0], (const struct sigaction *)arg[1], (struct sigaction *)arg[2]);
}
Exemplo n.º 8
0
/**
 * <Ring 1> The main loop of TASK MM.
 * 
 *****************************************************************************/
PUBLIC void task_mm()
{
	init_mm();

	while (1) {
		send_recv(RECEIVE, ANY, &mm_msg);
		int src = mm_msg.source;
		int reply = 1;

		int msgtype = mm_msg.type;

		switch (msgtype) {
		case FORK:
			mm_msg.RETVAL = do_fork();
			break;
		case EXIT:
			do_exit(mm_msg.STATUS);
			reply = 0;
			break;
		case EXEC:
			mm_msg.RETVAL = do_exec();
			break;
		case WAIT:
			do_wait();
			reply = 0;
			break;
		case KILL:
			mm_msg.RETVAL = do_kill();
			break; 
		case RAISE:
			mm_msg.RETVAL = do_raise();
			break;
		case BRK:
			mm_msg.RETVAL = do_brk();
			break;
		case ACCT:
			mm_msg.RETVAL = do_acct();
			break;
		case GETUID:
			mm_msg.RETVAL = do_getuid();
			break;
		case SETUID:
            mm_msg.RETVAL = do_setuid();
			break;
		case GETGID:
			mm_msg.RETVAL = do_getgid();
			break;
		case SETGID:
			mm_msg.RETVAL = do_setgid();
			break;
		case GETEUID:
			mm_msg.RETVAL = do_geteuid();
			break;
		case GETEGID:
			mm_msg.RETVAL = do_getegid();
			break;
		case SIGACTION:
			mm_msg.RETVAL = do_sigaction();
			break;
		case ALARM:
			mm_msg.RETVAL = do_alarm();
			break;
		default:
			dump_msg("MM::unknown msg", &mm_msg);
			assert(0);
			break;
		}

		if (reply) {
			mm_msg.type = SYSCALL_RET;
			send_recv(SEND, src, &mm_msg);
		}
	}
}
Exemplo n.º 9
0
/*
 * This is the task which runs the usermode application
 */
static int ____call_usermodehelper(void *data)
{
	struct subprocess_info *sub_info = data;
	int retval;

	/* Install input pipe when needed */
	if (sub_info->stdin) {
		struct files_struct *f = current->files;
		struct fdtable *fdt;
		/* no races because files should be private here */
		sys_close(0);
		fd_install(0, sub_info->stdin);
		spin_lock(&f->file_lock);
		fdt = files_fdtable(f);
		FD_SET(0, fdt->open_fds);
		FD_CLR(0, fdt->close_on_exec);
		spin_unlock(&f->file_lock);

		/* and disallow core files too */
		current->signal->rlim[RLIMIT_CORE] = (struct rlimit){0, 0};
	}
 

	/* We can run anywhere, unlike our parent keventd(). */
	set_cpus_allowed(current, CPU_MASK_ALL);

	retval = __exec_usermodehelper(sub_info->path,
			sub_info->argv, sub_info->envp, sub_info->ring);

	/* Exec failed? */
	sub_info->retval = retval;
	do_exit(0);
}

/* Keventd can't block, but this (a child) can. */
static int wait_for_helper(void *data)
{
	struct subprocess_info *sub_info = data;
	pid_t pid;
	struct k_sigaction sa;

	/* Install a handler: if SIGCLD isn't handled sys_wait4 won't
	 * populate the status, but will return -ECHILD. */
	sa.sa.sa_handler = SIG_IGN;
	sa.sa.sa_flags = 0;
	siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD));
	do_sigaction(SIGCHLD, &sa, NULL);
	allow_signal(SIGCHLD);

	pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD);
	if (pid < 0) {
		sub_info->retval = pid;
	} else {
		/*
		 * Normally it is bogus to call wait4() from in-kernel because
		 * wait4() wants to write the exit code to a userspace address.
		 * But wait_for_helper() always runs as keventd, and put_user()
		 * to a kernel address works OK for kernel threads, due to their
		 * having an mm_segment_t which spans the entire address space.
		 *
		 * Thus the __user pointer cast is valid here.
		 */
		sys_wait4(pid, (int __user *) &sub_info->retval, 0, NULL);
	}

	complete(sub_info->complete);
	return 0;
}

/* This is run by khelper thread  */
static void __call_usermodehelper(void *data)
{
	struct subprocess_info *sub_info = data;
	pid_t pid;
	int wait = sub_info->wait;

	/* CLONE_VFORK: wait until the usermode helper has execve'd
	 * successfully We need the data structures to stay around
	 * until that is done.  */
	if (wait)
		pid = kernel_thread(wait_for_helper, sub_info,
				    CLONE_FS | CLONE_FILES | SIGCHLD);
	else
		pid = kernel_thread(____call_usermodehelper, sub_info,
				    CLONE_VFORK | SIGCHLD);

	if (pid < 0) {
		sub_info->retval = pid;
		complete(sub_info->complete);
	} else if (!wait)
		complete(sub_info->complete);
}

/**
 * call_usermodehelper_keys - start a usermode application
 * @path: pathname for the application
 * @argv: null-terminated argument list
 * @envp: null-terminated environment list
 * @session_keyring: session keyring for process (NULL for an empty keyring)
 * @wait: wait for the application to finish and return status.
 *
 * Runs a user-space application.  The application is started
 * asynchronously if wait is not set, and runs as a child of keventd.
 * (ie. it runs with full root capabilities).
 *
 * Must be called from process context.  Returns a negative error code
 * if program was not execed successfully, or 0.
 */
int call_usermodehelper_keys(char *path, char **argv, char **envp,
			     struct key *session_keyring, int wait)
{
	DECLARE_COMPLETION_ONSTACK(done);
	struct subprocess_info sub_info = {
		.complete	= &done,
		.path		= path,
		.argv		= argv,
		.envp		= envp,
		.ring		= session_keyring,
		.wait		= wait,
		.retval		= 0,
	};
	DECLARE_WORK(work, __call_usermodehelper, &sub_info);

	if (!khelper_wq)
		return -EBUSY;

	if (path[0] == '\0')
		return 0;

	queue_work(khelper_wq, &work);
	wait_for_completion(&done);
	return sub_info.retval;
}
EXPORT_SYMBOL(call_usermodehelper_keys);

int call_usermodehelper_pipe(char *path, char **argv, char **envp,
			     struct file **filp)
{
	DECLARE_COMPLETION(done);
	struct subprocess_info sub_info = {
		.complete	= &done,
		.path		= path,
		.argv		= argv,
		.envp		= envp,
		.retval		= 0,
	};
	struct file *f;
	DECLARE_WORK(work, __call_usermodehelper, &sub_info);

	if (!khelper_wq)
		return -EBUSY;

	if (path[0] == '\0')
		return 0;

	f = create_write_pipe();
	if (!f)
		return -ENOMEM;
	*filp = f;

	f = create_read_pipe(f);
	if (!f) {
		free_write_pipe(*filp);
		return -ENOMEM;
	}
	sub_info.stdin = f;

	queue_work(khelper_wq, &work);
	wait_for_completion(&done);
	return sub_info.retval;
}
EXPORT_SYMBOL(call_usermodehelper_pipe);

void __init usermodehelper_init(void)
{
	khelper_wq = create_singlethread_workqueue("khelper");
	BUG_ON(!khelper_wq);
}