diff --git a/lib/flua/libjail/lua_jail.c b/lib/flua/libjail/lua_jail.c
index 9981fd5421c6..b66c60b43bc8 100644
--- a/lib/flua/libjail/lua_jail.c
+++ b/lib/flua/libjail/lua_jail.c
@@ -1,391 +1,389 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2020, Ryan Moeller <freqlabs@FreeBSD.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  * $FreeBSD$
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/jail.h>
 #include <errno.h>
 #include <jail.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <lua.h>
 #include <lauxlib.h>
 #include <lualib.h>
 
 int luaopen_jail(lua_State *);
 
 static int
 l_getid(lua_State *L)
 {
 	const char *name;
 	int jid;
 
 	name = luaL_checkstring(L, 1);
 	jid = jail_getid(name);
 	if (jid == -1) {
 		lua_pushnil(L);
 		lua_pushstring(L, jail_errmsg);
 		return (2);
 	}
 	lua_pushinteger(L, jid);
 	return (1);
 }
 
 static int
 l_getname(lua_State *L)
 {
 	char *name;
 	int jid;
 
 	jid = luaL_checkinteger(L, 1);
 	name = jail_getname(jid);
 	if (name == NULL) {
 		lua_pushnil(L);
 		lua_pushstring(L, jail_errmsg);
 		return (2);
 	}
 	lua_pushstring(L, name);
 	free(name);
 	return (1);
 }
 
 static int
 l_allparams(lua_State *L)
 {
 	struct jailparam *params;
 	int params_count;
 
 	params_count = jailparam_all(&params);
 	if (params_count == -1) {
 		lua_pushnil(L);
 		lua_pushstring(L, jail_errmsg);
 		return (2);
 	}
 	lua_newtable(L);
 	for (int i = 0; i < params_count; ++i) {
 		lua_pushstring(L, params[i].jp_name);
 		lua_rawseti(L, -2, i + 1);
 	}
 	jailparam_free(params, params_count);
 	free(params);
 	return (1);
 }
 
 static int
 l_getparams(lua_State *L)
 {
 	const char *name;
 	struct jailparam *params;
 	size_t params_count, skipped;
 	int flags, jid, type;
 
 	type = lua_type(L, 1);
 	luaL_argcheck(L, type == LUA_TSTRING || type == LUA_TNUMBER, 1,
 	    "expected a jail name (string) or id (integer)");
 	luaL_checktype(L, 2, LUA_TTABLE);
 	params_count = 1 + lua_rawlen(L, 2);
-	luaL_argcheck(L, params_count > 1, 2, "expected #params > 0");
 	flags = luaL_optinteger(L, 3, 0);
 
 	params = malloc(params_count * sizeof(struct jailparam));
 	if (params == NULL)
 		return (luaL_error(L, "malloc: %s", strerror(errno)));
 
 	/*
 	 * Set the jail name or id param as determined by the first arg.
 	 */
 
 	if (type == LUA_TSTRING) {
 		if (jailparam_init(&params[0], "name") == -1) {
 			free(params);
 			return (luaL_error(L, "jailparam_init: %s",
 			    jail_errmsg));
 		}
 		name = lua_tostring(L, 1);
 		if (jailparam_import(&params[0], name) == -1) {
 			jailparam_free(params, 1);
 			free(params);
 			return (luaL_error(L, "jailparam_import: %s",
 			    jail_errmsg));
 		}
 	} else /* type == LUA_TNUMBER */ {
 		if (jailparam_init(&params[0], "jid") == -1) {
 			free(params);
 			return (luaL_error(L, "jailparam_init: %s",
 			    jail_errmsg));
 		}
 		jid = lua_tointeger(L, 1);
 		if (jailparam_import_raw(&params[0], &jid, sizeof(jid)) == -1) {
 			jailparam_free(params, 1);
 			free(params);
 			return (luaL_error(L, "jailparam_import_raw: %s",
 			    jail_errmsg));
 		}
 	}
 
 	/*
 	 * Set the remaining param names being requested.
 	 */
 
 	skipped = 0;
 	for (size_t i = 1; i < params_count; ++i) {
 		const char *param_name;
 
 		lua_rawgeti(L, -1, i);
 		param_name = lua_tostring(L, -1);
 		if (param_name == NULL) {
 			jailparam_free(params, i - skipped);
 			free(params);
 			return (luaL_argerror(L, 2,
 			    "param names must be strings"));
 		}
 		lua_pop(L, 1);
 		/* Skip name or jid, whichever was given. */
 		if (type == LUA_TSTRING) {
 			if (strcmp(param_name, "name") == 0) {
 				++skipped;
 				continue;
 			}
 		} else /* type == LUA_TNUMBER */ {
 			if (strcmp(param_name, "jid") == 0) {
 				++skipped;
 				continue;
 			}
 		}
 		if (jailparam_init(&params[i - skipped], param_name) == -1) {
 			jailparam_free(params, i - skipped);
 			free(params);
 			return (luaL_error(L, "jailparam_init: %s",
 			    jail_errmsg));
 		}
 	}
 	params_count -= skipped;
 
 	/*
 	 * Get the values and convert to a table.
 	 */
 
 	jid = jailparam_get(params, params_count, flags);
 	if (jid == -1) {
 		jailparam_free(params, params_count);
 		free(params);
 		lua_pushnil(L);
 		lua_pushstring(L, jail_errmsg);
 		return (2);
 	}
 	lua_pushinteger(L, jid);
 
 	lua_newtable(L);
 	for (size_t i = 0; i < params_count; ++i) {
 		char *value;
 
 		value = jailparam_export(&params[i]);
 		lua_pushstring(L, value);
 		free(value);
 		lua_setfield(L, -2, params[i].jp_name);
 	}
 
 	jailparam_free(params, params_count);
 	free(params);
 
 	return (2);
 }
 
 static int
 l_setparams(lua_State *L)
 {
 	const char *name;
 	struct jailparam *params;
 	size_t params_count;
 	int flags, jid, type;
 
 	type = lua_type(L, 1);
 	luaL_argcheck(L, type == LUA_TSTRING || type == LUA_TNUMBER, 1,
 	    "expected a jail name (string) or id (integer)");
 	luaL_checktype(L, 2, LUA_TTABLE);
 
 	lua_pushnil(L);
 	for (params_count = 1; lua_next(L, 2) != 0; ++params_count)
 		lua_pop(L, 1);
-	luaL_argcheck(L, params_count > 1, 2, "expected #params > 0");
 
 	flags = luaL_optinteger(L, 3, 0);
 
 	params = malloc(params_count * sizeof(struct jailparam));
 	if (params == NULL)
 		return (luaL_error(L, "malloc: %s", strerror(errno)));
 
 	/*
 	 * Set the jail name or id param as determined by the first arg.
 	 */
 
 	if (type == LUA_TSTRING) {
 		if (jailparam_init(&params[0], "name") == -1) {
 			free(params);
 			return (luaL_error(L, "jailparam_init: %s",
 			    jail_errmsg));
 		}
 		name = lua_tostring(L, 1);
 		if (jailparam_import(&params[0], name) == -1) {
 			jailparam_free(params, 1);
 			free(params);
 			return (luaL_error(L, "jailparam_import: %s",
 			    jail_errmsg));
 		}
 	} else /* type == LUA_TNUMBER */ {
 		if (jailparam_init(&params[0], "jid") == -1) {
 			free(params);
 			return (luaL_error(L, "jailparam_init: %s",
 			    jail_errmsg));
 		}
 		jid = lua_tointeger(L, 1);
 		if (jailparam_import_raw(&params[0], &jid, sizeof(jid)) == -1) {
 			jailparam_free(params, 1);
 			free(params);
 			return (luaL_error(L, "jailparam_import_raw: %s",
 			    jail_errmsg));
 		}
 	}
 
 	/*
 	 * Set the rest of the provided params.
 	 */
 
 	lua_pushnil(L);
 	for (size_t i = 1; i < params_count && lua_next(L, 2) != 0; ++i) {
 		const char *value;
 
 		name = lua_tostring(L, -2);
 		if (name == NULL) {
 			jailparam_free(params, i);
 			free(params);
 			return (luaL_argerror(L, 2,
 			    "param names must be strings"));
 		}
 		if (jailparam_init(&params[i], name) == -1) {
 			jailparam_free(params, i);
 			free(params);
 			return (luaL_error(L, "jailparam_init: %s",
 			    jail_errmsg));
 		}
 
 		value = lua_tostring(L, -1);
 		if (value == NULL) {
 			jailparam_free(params, i + 1);
 			free(params);
 			return (luaL_argerror(L, 2,
 			    "param values must be strings"));
 		}
 		if (jailparam_import(&params[i], value) == -1) {
 			jailparam_free(params, i + 1);
 			free(params);
 			return (luaL_error(L, "jailparam_import: %s",
 			    jail_errmsg));
 		}
 
 		lua_pop(L, 1);
 	}
 
 	/*
 	 * Attempt to set the params.
 	 */
 
 	jid = jailparam_set(params, params_count, flags);
 	if (jid == -1) {
 		jailparam_free(params, params_count);
 		free(params);
 		lua_pushnil(L);
 		lua_pushstring(L, jail_errmsg);
 		return (2);
 	}
 	lua_pushinteger(L, jid);
 
 	jailparam_free(params, params_count);
 	free(params);
 	return (1);
 }
 
 static const struct luaL_Reg l_jail[] = {
 	/** Get id of a jail by name.
 	 * @param name	jail name (string)
 	 * @return	jail id (integer)
 	 *		or nil, error (string) on error
 	 */
 	{"getid", l_getid},
 	/** Get name of a jail by id.
 	 * @param jid	jail id (integer)
 	 * @return	jail name (string)
 	 *		or nil, error (string) on error
 	 */
 	{"getname", l_getname},
 	/** Get a list of all known jail parameters.
 	 * @return	list of jail parameter names (table of strings)
 	 *		or nil, error (string) on error
 	 */
 	{"allparams", l_allparams},
 	/** Get the listed params for a given jail.
 	 * @param jail	jail name (string) or id (integer)
 	 * @param params	list of parameter names (table of strings)
 	 * @param flags	optional flags (integer)
 	 * @return	jid (integer), params (table of [string] = string)
 	 *		or nil, error (string) on error
 	 */
 	{"getparams", l_getparams},
 	/** Set params for a given jail.
 	 * @param jail	jail name (string) or id (integer)
 	 * @param params	params and values (table of [string] = string)
 	 * @param flags	optional flags (integer)
 	 * @return	jid (integer)
 	 *		or nil, error (string) on error
 	 */
 	{"setparams", l_setparams},
 	{NULL, NULL}
 };
 
 int
 luaopen_jail(lua_State *L)
 {
 	lua_newtable(L);
 
 	luaL_setfuncs(L, l_jail, 0);
 
 	lua_pushinteger(L, JAIL_CREATE);
 	lua_setfield(L, -2, "CREATE");
 	lua_pushinteger(L, JAIL_UPDATE);
 	lua_setfield(L, -2, "UPDATE");
 	lua_pushinteger(L, JAIL_ATTACH);
 	lua_setfield(L, -2, "ATTACH");
 	lua_pushinteger(L, JAIL_DYING);
 	lua_setfield(L, -2, "DYING");
 
 	return (1);
 }