/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <fcntl.h>
#include <getopt.h>
#include <linux/oom.h>
#include <linux/vt.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/utsname.h>
#include <unistd.h>

#if HAVE_VALGRIND_VALGRIND_H
#  include <valgrind/valgrind.h>
#endif

#include "sd-bus.h"
#include "sd-daemon.h"
#include "sd-messages.h"

#include "alloc-util.h"
#include "apparmor-setup.h"
#include "architecture.h"
#include "argv-util.h"
#include "build.h"
#include "bus-error.h"
#include "capability-util.h"
#include "cgroup-setup.h"
#include "chase.h"
#include "clock-util.h"
#include "clock-warp.h"
#include "conf-parser.h"
#include "confidential-virt.h"
#include "constants.h"
#include "copy.h"
#include "coredump-util.h"
#include "cpu-set-util.h"
#include "crash-handler.h"
#include "dbus.h"
#include "dbus-manager.h"
#include "dev-setup.h"
#include "efi-random.h"
#include "emergency-action.h"
#include "env-util.h"
#include "escape.h"
#include "fd-util.h"
#include "fdset.h"
#include "fileio.h"
#include "format-util.h"
#include "getopt-defs.h"
#include "hexdecoct.h"
#include "hostname-setup.h"
#include "id128-util.h"
#include "ima-setup.h"
#include "import-creds.h"
#include "initrd-util.h"
#include "io-util.h"
#include "ipe-setup.h"
#include "killall.h"
#include "kmod-setup.h"
#include "label-util.h"
#include "libmount-util.h"
#include "limits-util.h"
#include "load-fragment.h"
#include "log.h"
#include "loopback-setup.h"
#include "machine-id-setup.h"
#include "main.h"
#include "manager.h"
#include "manager-dump.h"
#include "manager-serialize.h"
#include "mkdir-label.h"
#include "mount-setup.h"
#include "mount-util.h"
#include "os-util.h"
#include "osc-context.h"
#include "pager.h"
#include "parse-argument.h"
#include "parse-util.h"
#include "path-util.h"
#include "pretty-print.h"
#include "proc-cmdline.h"
#include "process-util.h"
#include "random-util.h"
#include "rlimit-util.h"
#include "rm-rf.h"
#include "seccomp-util.h"
#include "selinux-setup.h"
#include "selinux-util.h"
#include "serialize.h"
#include "set.h"
#include "signal-util.h"
#include "smack-setup.h"
#include "special.h"
#include "stat-util.h"
#include "stdio-util.h"
#include "strv.h"
#include "switch-root.h"
#include "sysctl-util.h"
#include "terminal-util.h"
#include "time-util.h"
#include "umask-util.h"
#include "unit-name.h"
#include "user-util.h"
#include "utf8.h"
#include "version.h"
#include "virt.h"
#include "watchdog.h"

#if HAS_FEATURE_ADDRESS_SANITIZER
#include <sanitizer/lsan_interface.h>
#endif

static enum {
        ACTION_RUN,
        ACTION_HELP,
        ACTION_VERSION,
        ACTION_TEST,
        ACTION_DUMP_CONFIGURATION_ITEMS,
        ACTION_DUMP_BUS_PROPERTIES,
        ACTION_BUS_INTROSPECT,
} arg_action = ACTION_RUN;

static const char *arg_bus_introspect = NULL;

/* Those variables are initialized to 0 automatically, so we avoid uninitialized memory access.  Real
 * defaults are assigned in reset_arguments() below. */
static char *arg_default_unit;
static RuntimeScope arg_runtime_scope;
bool arg_dump_core;
int arg_crash_chvt;
bool arg_crash_shell;
CrashAction arg_crash_action;
static char *arg_confirm_spawn;
static ShowStatus arg_show_status;
static StatusUnitFormat arg_status_unit_format;
static bool arg_switched_root;
static PagerFlags arg_pager_flags;
static bool arg_service_watchdogs;
static UnitDefaults arg_defaults;
static usec_t arg_runtime_watchdog;
static usec_t arg_reboot_watchdog;
static usec_t arg_kexec_watchdog;
static usec_t arg_pretimeout_watchdog;
static char *arg_early_core_pattern;
static char *arg_watchdog_pretimeout_governor;
static char *arg_watchdog_device;
static char **arg_default_environment;
static char **arg_manager_environment;
static uint64_t arg_capability_bounding_set;
static bool arg_no_new_privs;
static int arg_protect_system;
static nsec_t arg_timer_slack_nsec;
static Set* arg_syscall_archs;
static FILE* arg_serialization;
static sd_id128_t arg_machine_id;
static bool arg_machine_id_from_firmware = false;
static EmergencyAction arg_cad_burst_action;
static CPUSet arg_cpu_affinity;
static NUMAPolicy arg_numa_policy;
static usec_t arg_clock_usec;
static void *arg_random_seed;
static size_t arg_random_seed_size;
static usec_t arg_reload_limit_interval_sec;
static unsigned arg_reload_limit_burst;

/* A copy of the original environment block */
static char **saved_env = NULL;

static int parse_configuration(const struct rlimit *saved_rlimit_nofile,
                               const struct rlimit *saved_rlimit_memlock);

static DEFINE_CONFIG_PARSE_ENUM_WITH_DEFAULT(config_parse_crash_action, crash_action, CrashAction, CRASH_FREEZE);

static int manager_find_user_config_paths(char ***ret_files, char ***ret_dirs) {
        _cleanup_free_ char *base = NULL;
        _cleanup_strv_free_ char **files = NULL, **dirs = NULL;
        int r;

        r = xdg_user_config_dir("/systemd", &base);
        if (r < 0)
                return r;

        r = strv_extendf(&files, "%s/user.conf", base);
        if (r < 0)
                return r;

        r = strv_extend(&files, PKGSYSCONFDIR "/user.conf");
        if (r < 0)
                return r;

        r = strv_consume(&dirs, TAKE_PTR(base));
        if (r < 0)
                return r;

        r = strv_extend_strv(&dirs, CONF_PATHS_STRV("systemd"), false);
        if (r < 0)
                return r;

        *ret_files = TAKE_PTR(files);
        *ret_dirs = TAKE_PTR(dirs);
        return 0;
}

static int save_console_winsize_in_environment(int tty_fd) {
        int r;

        assert(tty_fd >= 0);

        struct winsize ws = {};
        if (ioctl(tty_fd, TIOCGWINSZ, &ws) < 0) {
                log_debug_errno(errno, "Failed to acquire console window size, ignoring.");
                goto unset;
        }

        if (ws.ws_col <= 0 && ws.ws_row <= 0) {
                log_debug("No console window size set, ignoring.");
                goto unset;
        }

        r = setenvf("COLUMNS", /* overwrite= */ true, "%u", ws.ws_col);
        if (r < 0) {
                log_debug_errno(r, "Failed to set $COLUMNS, ignoring: %m");
                goto unset;
        }

        r = setenvf("LINES", /* overwrite= */ true, "%u", ws.ws_row);
        if (r < 0) {
                log_debug_errno(r, "Failed to set $LINES, ignoring: %m");
                goto unset;
        }

        log_debug("Recorded console dimensions in environment: $COLUMNS=%u $LINES=%u.", ws.ws_col, ws.ws_row);
        return 1;

unset:
        (void) unsetenv("COLUMNS");
        (void) unsetenv("LINES");
        return 0;
}

static int console_setup(void) {

        if (getpid_cached() != 1)
                return 0;

        _cleanup_close_ int tty_fd = -EBADF;

        tty_fd = open_terminal("/dev/console", O_RDWR|O_NOCTTY|O_CLOEXEC);
        if (tty_fd < 0)
                return log_error_errno(tty_fd, "Failed to open %s: %m", "/dev/console");

        /* We don't want to force text mode. Plymouth may be showing pictures already from initrd. */
        reset_dev_console_fd(tty_fd, /* switch_to_text= */ false);

        save_console_winsize_in_environment(tty_fd);

        return 0;
}

static int parse_timeout(const char *value, usec_t *ret) {
        int r = 0;

        assert(value);
        assert(ret);

        if (streq(value, "default"))
                *ret = USEC_INFINITY;
        else if (streq(value, "off"))
                *ret = 0;
        else
                r = parse_sec(value, ret);

        return r;
}

static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
        int r;

        assert(key);

        if (STR_IN_SET(key, "systemd.unit", "rd.systemd.unit")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                if (!unit_name_is_valid(value, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE))
                        log_warning("Unit name specified on %s= is not valid, ignoring: %s", key, value);
                else if (in_initrd() == !!startswith(key, "rd."))
                        return free_and_strdup_warn(&arg_default_unit, value);

        } else if (proc_cmdline_key_streq(key, "systemd.dump_core")) {

                r = value ? parse_boolean(value) : true;
                if (r < 0)
                        log_warning_errno(r, "Failed to parse dump core switch %s, ignoring: %m", value);
                else
                        arg_dump_core = r;

        } else if (proc_cmdline_key_streq(key, "systemd.early_core_pattern")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                if (path_is_absolute(value))
                        (void) parse_path_argument(value, false, &arg_early_core_pattern);
                else
                        log_warning("Specified core pattern '%s' is not an absolute path, ignoring.", value);

        } else if (proc_cmdline_key_streq(key, "systemd.crash_chvt")) {

                if (!value)
                        arg_crash_chvt = 0; /* turn on */
                else {
                        r = parse_crash_chvt(value, &arg_crash_chvt);
                        if (r < 0)
                                log_warning_errno(r, "Failed to parse crash chvt switch %s, ignoring: %m", value);
                }

        } else if (proc_cmdline_key_streq(key, "systemd.crash_shell")) {

                r = value ? parse_boolean(value) : true;
                if (r < 0)
                        log_warning_errno(r, "Failed to parse crash shell switch %s, ignoring: %m", value);
                else
                        arg_crash_shell = r;

        } else if (proc_cmdline_key_streq(key, "systemd.crash_reboot")) {

                r = value ? parse_boolean(value) : true;
                if (r < 0)
                        log_warning_errno(r, "Failed to parse crash reboot switch %s, ignoring: %m", value);
                else
                        arg_crash_action = r ? CRASH_REBOOT : CRASH_FREEZE;

        } else if (proc_cmdline_key_streq(key, "systemd.crash_action")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = crash_action_from_string(value);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse crash action switch %s, ignoring: %m", value);
                else
                        arg_crash_action = r;

        } else if (proc_cmdline_key_streq(key, "systemd.confirm_spawn")) {
                char *s;

                r = parse_confirm_spawn(value, &s);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse confirm_spawn switch %s, ignoring: %m", value);
                else
                        free_and_replace(arg_confirm_spawn, s);

        } else if (proc_cmdline_key_streq(key, "systemd.service_watchdogs")) {

                r = value ? parse_boolean(value) : true;
                if (r < 0)
                        log_warning_errno(r, "Failed to parse service watchdog switch %s, ignoring: %m", value);
                else
                        arg_service_watchdogs = r;

        } else if (proc_cmdline_key_streq(key, "systemd.show_status")) {

                if (value) {
                        r = parse_show_status(value, &arg_show_status);
                        if (r < 0)
                                log_warning_errno(r, "Failed to parse show status switch %s, ignoring: %m", value);
                } else
                        arg_show_status = SHOW_STATUS_YES;

        } else if (proc_cmdline_key_streq(key, "systemd.status_unit_format")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = status_unit_format_from_string(value);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse %s=%s, ignoring: %m", key, value);
                else
                        arg_status_unit_format = r;

        } else if (proc_cmdline_key_streq(key, "systemd.default_standard_output")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = exec_output_from_string(value);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse default standard output switch %s, ignoring: %m", value);
                else
                        arg_defaults.std_output = r;

        } else if (proc_cmdline_key_streq(key, "systemd.default_standard_error")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = exec_output_from_string(value);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse default standard error switch %s, ignoring: %m", value);
                else
                        arg_defaults.std_error = r;

        } else if (streq(key, "systemd.setenv")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                if (!env_assignment_is_valid(value))
                        log_warning("Environment variable assignment '%s' is not valid. Ignoring.", value);
                else {
                        r = strv_env_replace_strdup(&arg_default_environment, value);
                        if (r < 0)
                                return log_oom();
                }

        } else if (proc_cmdline_key_streq(key, "systemd.machine_id")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                if (streq(value, "firmware"))
                        arg_machine_id_from_firmware = true;
                else {
                        r = id128_from_string_nonzero(value, &arg_machine_id);
                        if (r < 0)
                                log_warning_errno(r, "MachineID '%s' is not valid, ignoring: %m", value);
                        else
                                arg_machine_id_from_firmware = false;
                }
        } else if (proc_cmdline_key_streq(key, "systemd.default_timeout_start_sec")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = parse_sec(value, &arg_defaults.timeout_start_usec);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse default start timeout '%s', ignoring: %m", value);

                if (arg_defaults.timeout_start_usec <= 0)
                        arg_defaults.timeout_start_usec = USEC_INFINITY;

        } else if (proc_cmdline_key_streq(key, "systemd.default_device_timeout_sec")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = parse_sec(value, &arg_defaults.device_timeout_usec);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse default device timeout '%s', ignoring: %m", value);

                if (arg_defaults.device_timeout_usec <= 0)
                        arg_defaults.device_timeout_usec = USEC_INFINITY;

        } else if (proc_cmdline_key_streq(key, "systemd.cpu_affinity")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = parse_cpu_set(value, &arg_cpu_affinity);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse CPU affinity mask '%s', ignoring: %m", value);

        } else if (proc_cmdline_key_streq(key, "systemd.watchdog_device")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                (void) parse_path_argument(value, false, &arg_watchdog_device);

        } else if (proc_cmdline_key_streq(key, "systemd.watchdog_sec")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = parse_timeout(value, &arg_runtime_watchdog);
                if (r < 0) {
                        log_warning_errno(r, "Failed to parse systemd.watchdog_sec= argument '%s', ignoring: %m", value);
                        return 0;
                }

                arg_kexec_watchdog = arg_reboot_watchdog = arg_runtime_watchdog;

        } else if (proc_cmdline_key_streq(key, "systemd.watchdog_pre_sec")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = parse_timeout(value, &arg_pretimeout_watchdog);
                if (r < 0) {
                        log_warning_errno(r, "Failed to parse systemd.watchdog_pre_sec= argument '%s', ignoring: %m", value);
                        return 0;
                }

        } else if (proc_cmdline_key_streq(key, "systemd.watchdog_pretimeout_governor")) {

                if (proc_cmdline_value_missing(key, value) || isempty(value)) {
                        arg_watchdog_pretimeout_governor = mfree(arg_watchdog_pretimeout_governor);
                        return 0;
                }

                if (!string_is_safe(value)) {
                        log_warning("Watchdog pretimeout governor '%s' is not valid, ignoring.", value);
                        return 0;
                }

                return free_and_strdup_warn(&arg_watchdog_pretimeout_governor, value);

        } else if (proc_cmdline_key_streq(key, "systemd.clock_usec")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = safe_atou64(value, &arg_clock_usec);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse systemd.clock_usec= argument, ignoring: %s", value);

        } else if (proc_cmdline_key_streq(key, "systemd.random_seed")) {
                void *p;
                size_t sz;

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = unbase64mem(value, &p, &sz);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse systemd.random_seed= argument, ignoring: %s", value);

                free(arg_random_seed);
                arg_random_seed = sz > 0 ? p : mfree(p);
                arg_random_seed_size = sz;

        } else if (proc_cmdline_key_streq(key, "systemd.reload_limit_interval_sec")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = parse_sec(value, &arg_reload_limit_interval_sec);
                if (r < 0) {
                        log_warning_errno(r, "Failed to parse systemd.reload_limit_interval_sec= argument '%s', ignoring: %m", value);
                        return 0;
                }

        } else if (proc_cmdline_key_streq(key, "systemd.reload_limit_burst")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                r = safe_atou(value, &arg_reload_limit_burst);
                if (r < 0) {
                        log_warning_errno(r, "Failed to parse systemd.reload_limit_burst= argument '%s', ignoring: %m", value);
                        return 0;
                }

        } else if (streq(key, "quiet") && !value) {

                if (arg_show_status == _SHOW_STATUS_INVALID)
                        arg_show_status = SHOW_STATUS_ERROR;

        } else if (streq(key, "debug") && !value) {

                /* Note that log_parse_environment() handles 'debug'
                 * too, and sets the log level to LOG_DEBUG. */

                if (detect_container() > 0)
                        log_set_target(LOG_TARGET_CONSOLE);

        } else if (!value) {
                const char *target;

                /* Compatible with SysV, but supported independently even if SysV compatibility is disabled. */
                target = runlevel_to_target(key);
                if (target)
                        return free_and_strdup_warn(&arg_default_unit, target);
        }

        return 0;
}

#define DEFINE_SETTER(name, func, descr)                              \
        static int name(const char *unit,                             \
                        const char *filename,                         \
                        unsigned line,                                \
                        const char *section,                          \
                        unsigned section_line,                        \
                        const char *lvalue,                           \
                        int ltype,                                    \
                        const char *rvalue,                           \
                        void *data,                                   \
                        void *userdata) {                             \
                                                                      \
                int r;                                                \
                                                                      \
                assert(filename);                                     \
                assert(lvalue);                                       \
                assert(rvalue);                                       \
                                                                      \
                r = func(rvalue);                                     \
                if (r < 0)                                            \
                        log_syntax(unit, LOG_ERR, filename, line, r,  \
                                   "Invalid " descr "'%s': %m",       \
                                   rvalue);                           \
                                                                      \
                return 0;                                             \
        }

DEFINE_SETTER(config_parse_level2, log_set_max_level_from_string, "log level");
DEFINE_SETTER(config_parse_target, log_set_target_from_string, "target");
DEFINE_SETTER(config_parse_color, log_show_color_from_string, "color");
DEFINE_SETTER(config_parse_location, log_show_location_from_string, "location");
DEFINE_SETTER(config_parse_time, log_show_time_from_string, "time");

static int config_parse_default_timeout_abort(
                const char *unit,
                const char *filename,
                unsigned line,
                const char *section,
                unsigned section_line,
                const char *lvalue,
                int ltype,
                const char *rvalue,
                void *data,
                void *userdata) {
        int r;

        r = config_parse_timeout_abort(
                        unit,
                        filename,
                        line,
                        section,
                        section_line,
                        lvalue,
                        ltype,
                        rvalue,
                        &arg_defaults.timeout_abort_usec,
                        userdata);
        if (r >= 0)
                arg_defaults.timeout_abort_set = r;
        return 0;
}

static int config_parse_oom_score_adjust(
                const char *unit,
                const char *filename,
                unsigned line,
                const char *section,
                unsigned section_line,
                const char *lvalue,
                int ltype,
                const char *rvalue,
                void *data,
                void *userdata) {

        int oa, r;

        if (isempty(rvalue)) {
                arg_defaults.oom_score_adjust_set = false;
                return 0;
        }

        r = parse_oom_score_adjust(rvalue, &oa);
        if (r < 0)
                return log_syntax_parse_error(unit, filename, line, r, lvalue, rvalue);

        arg_defaults.oom_score_adjust = oa;
        arg_defaults.oom_score_adjust_set = true;

        return 0;
}

static int config_parse_protect_system_pid1(
                const char *unit,
                const char *filename,
                unsigned line,
                const char *section,
                unsigned section_line,
                const char *lvalue,
                int ltype,
                const char *rvalue,
                void *data,
                void *userdata) {

        int *v = ASSERT_PTR(data), r;

        /* This is modelled after the per-service ProtectSystem= setting, but a bit more restricted on one
         * hand, and more automatic in another. i.e. we currently only support yes/no (not "strict" or
         * "full"). And we will enable this automatically for the initrd unless configured otherwise.
         *
         * We might extend this later to match more closely what the per-service ProtectSystem= can do, but
         * this is not trivial, due to ordering constraints: besides /usr/ we don't really have much mounted
         * at the moment we enable this logic. */

        if (isempty(rvalue) || streq(rvalue, "auto")) {
                *v = -1;
                return 0;
        }

        r = parse_boolean(rvalue);
        if (r < 0)
                return log_syntax_parse_error(unit, filename, line, r, lvalue, rvalue);

        *v = r;
        return 0;
}

static int config_parse_crash_reboot(
                const char *unit,
                const char *filename,
                unsigned line,
                const char *section,
                unsigned section_line,
                const char *lvalue,
                int ltype,
                const char *rvalue,
                void *data,
                void *userdata) {

        CrashAction *v = ASSERT_PTR(data);
        int r;

        if (isempty(rvalue)) {
                *v = CRASH_REBOOT;
                return 0;
        }

        r = parse_boolean(rvalue);
        if (r < 0)
                return log_syntax_parse_error(unit, filename, line, r, lvalue, rvalue);

        *v = r > 0 ? CRASH_REBOOT : CRASH_FREEZE;
        return 0;
}

static int parse_config_file(void) {
        const ConfigTableItem items[] = {
                { "Manager", "LogLevel",                     config_parse_level2,                0,                        NULL                              },
                { "Manager", "LogTarget",                    config_parse_target,                0,                        NULL                              },
                { "Manager", "LogColor",                     config_parse_color,                 0,                        NULL                              },
                { "Manager", "LogLocation",                  config_parse_location,              0,                        NULL                              },
                { "Manager", "LogTime",                      config_parse_time,                  0,                        NULL                              },
                { "Manager", "DumpCore",                     config_parse_bool,                  0,                        &arg_dump_core                    },
                { "Manager", "CrashChVT", /* legacy */       config_parse_crash_chvt,            0,                        &arg_crash_chvt                   },
                { "Manager", "CrashChangeVT",                config_parse_crash_chvt,            0,                        &arg_crash_chvt                   },
                { "Manager", "CrashShell",                   config_parse_bool,                  0,                        &arg_crash_shell                  },
                { "Manager", "CrashReboot",                  config_parse_crash_reboot,          0,                        &arg_crash_action                 },
                { "Manager", "CrashAction",                  config_parse_crash_action,          0,                        &arg_crash_action                 },
                { "Manager", "ShowStatus",                   config_parse_show_status,           0,                        &arg_show_status                  },
                { "Manager", "StatusUnitFormat",             config_parse_status_unit_format,    0,                        &arg_status_unit_format           },
                { "Manager", "CPUAffinity",                  config_parse_cpu_set,               0,                        &arg_cpu_affinity                 },
                { "Manager", "NUMAPolicy",                   config_parse_numa_policy,           0,                        &arg_numa_policy.type             },
                { "Manager", "NUMAMask",                     config_parse_numa_mask,             0,                        &arg_numa_policy.nodes            },
                { "Manager", "JoinControllers",              config_parse_warn_compat,           DISABLED_LEGACY,          NULL                              },
                { "Manager", "RuntimeWatchdogSec",           config_parse_watchdog_sec,          0,                        &arg_runtime_watchdog             },
                { "Manager", "RuntimeWatchdogPreSec",        config_parse_watchdog_sec,          0,                        &arg_pretimeout_watchdog          },
                { "Manager", "RebootWatchdogSec",            config_parse_watchdog_sec,          0,                        &arg_reboot_watchdog              },
                { "Manager", "ShutdownWatchdogSec",          config_parse_watchdog_sec,          0,                        &arg_reboot_watchdog              }, /* obsolete alias */
                { "Manager", "KExecWatchdogSec",             config_parse_watchdog_sec,          0,                        &arg_kexec_watchdog               },
                { "Manager", "WatchdogDevice",               config_parse_path,                  0,                        &arg_watchdog_device              },
                { "Manager", "RuntimeWatchdogPreGovernor",   config_parse_string,                CONFIG_PARSE_STRING_SAFE, &arg_watchdog_pretimeout_governor },
                { "Manager", "CapabilityBoundingSet",        config_parse_capability_set,        0,                        &arg_capability_bounding_set      },
                { "Manager", "NoNewPrivileges",              config_parse_bool,                  0,                        &arg_no_new_privs                 },
                { "Manager", "ProtectSystem",                config_parse_protect_system_pid1,   0,                        &arg_protect_system               },
#if HAVE_SECCOMP
                { "Manager", "SystemCallArchitectures",      config_parse_syscall_archs,         0,                        &arg_syscall_archs                },
#else
                { "Manager", "SystemCallArchitectures",      config_parse_warn_compat,           DISABLED_CONFIGURATION,   NULL                              },

#endif
                { "Manager", "TimerSlackNSec",               config_parse_nsec,                  0,                        &arg_timer_slack_nsec             },
                { "Manager", "DefaultTimerAccuracySec",      config_parse_sec,                   0,                        &arg_defaults.timer_accuracy_usec },
                { "Manager", "DefaultStandardOutput",        config_parse_output_restricted,     0,                        &arg_defaults.std_output          },
                { "Manager", "DefaultStandardError",         config_parse_output_restricted,     0,                        &arg_defaults.std_error           },
                { "Manager", "DefaultTimeoutStartSec",       config_parse_sec,                   0,                        &arg_defaults.timeout_start_usec  },
                { "Manager", "DefaultTimeoutStopSec",        config_parse_sec,                   0,                        &arg_defaults.timeout_stop_usec   },
                { "Manager", "DefaultTimeoutAbortSec",       config_parse_default_timeout_abort, 0,                        NULL                              },
                { "Manager", "DefaultDeviceTimeoutSec",      config_parse_sec,                   0,                        &arg_defaults.device_timeout_usec },
                { "Manager", "DefaultRestartSec",            config_parse_sec,                   0,                        &arg_defaults.restart_usec        },
                { "Manager", "DefaultStartLimitInterval",    config_parse_sec,                   0,                        &arg_defaults.start_limit.interval}, /* obsolete alias */
                { "Manager", "DefaultStartLimitIntervalSec", config_parse_sec,                   0,                        &arg_defaults.start_limit.interval},
                { "Manager", "DefaultStartLimitBurst",       config_parse_unsigned,              0,                        &arg_defaults.start_limit.burst   },
                { "Manager", "DefaultRestrictSUIDSGID",      config_parse_bool,                  0,                        &arg_defaults.restrict_suid_sgid  },
                { "Manager", "DefaultEnvironment",           config_parse_environ,               arg_runtime_scope,        &arg_default_environment          },
                { "Manager", "ManagerEnvironment",           config_parse_environ,               arg_runtime_scope,        &arg_manager_environment          },
                { "Manager", "DefaultLimitCPU",              config_parse_rlimit,                RLIMIT_CPU,               arg_defaults.rlimit               },
                { "Manager", "DefaultLimitFSIZE",            config_parse_rlimit,                RLIMIT_FSIZE,             arg_defaults.rlimit               },
                { "Manager", "DefaultLimitDATA",             config_parse_rlimit,                RLIMIT_DATA,              arg_defaults.rlimit               },
                { "Manager", "DefaultLimitSTACK",            config_parse_rlimit,                RLIMIT_STACK,             arg_defaults.rlimit               },
                { "Manager", "DefaultLimitCORE",             config_parse_rlimit,                RLIMIT_CORE,              arg_defaults.rlimit               },
                { "Manager", "DefaultLimitRSS",              config_parse_rlimit,                RLIMIT_RSS,               arg_defaults.rlimit               },
                { "Manager", "DefaultLimitNOFILE",           config_parse_rlimit,                RLIMIT_NOFILE,            arg_defaults.rlimit               },
                { "Manager", "DefaultLimitAS",               config_parse_rlimit,                RLIMIT_AS,                arg_defaults.rlimit               },
                { "Manager", "DefaultLimitNPROC",            config_parse_rlimit,                RLIMIT_NPROC,             arg_defaults.rlimit               },
                { "Manager", "DefaultLimitMEMLOCK",          config_parse_rlimit,                RLIMIT_MEMLOCK,           arg_defaults.rlimit               },
                { "Manager", "DefaultLimitLOCKS",            config_parse_rlimit,                RLIMIT_LOCKS,             arg_defaults.rlimit               },
                { "Manager", "DefaultLimitSIGPENDING",       config_parse_rlimit,                RLIMIT_SIGPENDING,        arg_defaults.rlimit               },
                { "Manager", "DefaultLimitMSGQUEUE",         config_parse_rlimit,                RLIMIT_MSGQUEUE,          arg_defaults.rlimit               },
                { "Manager", "DefaultLimitNICE",             config_parse_rlimit,                RLIMIT_NICE,              arg_defaults.rlimit               },
                { "Manager", "DefaultLimitRTPRIO",           config_parse_rlimit,                RLIMIT_RTPRIO,            arg_defaults.rlimit               },
                { "Manager", "DefaultLimitRTTIME",           config_parse_rlimit,                RLIMIT_RTTIME,            arg_defaults.rlimit               },
                { "Manager", "DefaultCPUAccounting",         config_parse_warn_compat,           DISABLED_LEGACY,          NULL                              },
                { "Manager", "DefaultIOAccounting",          config_parse_bool,                  0,                        &arg_defaults.io_accounting       },
                { "Manager", "DefaultIPAccounting",          config_parse_bool,                  0,                        &arg_defaults.ip_accounting       },
                { "Manager", "DefaultBlockIOAccounting",     config_parse_warn_compat,           DISABLED_LEGACY,          NULL                              },
                { "Manager", "DefaultMemoryAccounting",      config_parse_bool,                  0,                        &arg_defaults.memory_accounting   },
                { "Manager", "DefaultTasksAccounting",       config_parse_bool,                  0,                        &arg_defaults.tasks_accounting    },
                { "Manager", "DefaultTasksMax",              config_parse_tasks_max,             0,                        &arg_defaults.tasks_max           },
                { "Manager", "DefaultMemoryPressureThresholdSec", config_parse_sec,              0,                        &arg_defaults.memory_pressure_threshold_usec },
                { "Manager", "DefaultMemoryPressureWatch",   config_parse_memory_pressure_watch, 0,                        &arg_defaults.memory_pressure_watch },
                { "Manager", "CtrlAltDelBurstAction",        config_parse_emergency_action,      arg_runtime_scope,        &arg_cad_burst_action             },
                { "Manager", "DefaultOOMPolicy",             config_parse_oom_policy,            0,                        &arg_defaults.oom_policy          },
                { "Manager", "DefaultOOMScoreAdjust",        config_parse_oom_score_adjust,      0,                        NULL                              },
                { "Manager", "ReloadLimitIntervalSec",       config_parse_sec,                   0,                        &arg_reload_limit_interval_sec    },
                { "Manager", "ReloadLimitBurst",             config_parse_unsigned,              0,                        &arg_reload_limit_burst           },
#if ENABLE_SMACK
                { "Manager", "DefaultSmackProcessLabel",     config_parse_string,                0,                        &arg_defaults.smack_process_label },
#else
                { "Manager", "DefaultSmackProcessLabel",     config_parse_warn_compat,           DISABLED_CONFIGURATION,   NULL                              },
#endif
                {}
        };

        if (arg_runtime_scope == RUNTIME_SCOPE_SYSTEM)
                (void) config_parse_standard_file_with_dropins(
                                "systemd/system.conf",
                                "Manager\0",
                                config_item_table_lookup, items,
                                CONFIG_PARSE_WARN,
                                /* userdata= */ NULL);
        else {
                _cleanup_strv_free_ char **files = NULL, **dirs = NULL;
                int r;

                assert(arg_runtime_scope == RUNTIME_SCOPE_USER);

                r = manager_find_user_config_paths(&files, &dirs);
                if (r < 0)
                        return log_error_errno(r, "Failed to determine config file paths: %m");

                (void) config_parse_many(
                                (const char* const*) files,
                                (const char* const*) dirs,
                                "user.conf.d",
                                "Manager\0",
                                config_item_table_lookup, items,
                                CONFIG_PARSE_WARN,
                                /* userdata= */ NULL);
        }

        /* Traditionally "0" was used to turn off the default unit timeouts. Fix this up so that we use
         * USEC_INFINITY like everywhere else. */
        if (arg_defaults.timeout_start_usec <= 0)
                arg_defaults.timeout_start_usec = USEC_INFINITY;
        if (arg_defaults.timeout_stop_usec <= 0)
                arg_defaults.timeout_stop_usec = USEC_INFINITY;

        return 0;
}

static void set_manager_defaults(Manager *m) {
        int r;

        assert(m);

        /* Propagates the various default unit property settings into the manager object, i.e. properties
         * that do not affect the manager itself, but are just what newly allocated units will have set if
         * they haven't set anything else. (Also see set_manager_settings() for the settings that affect the
         * manager's own behaviour) */

        r = manager_set_unit_defaults(m, &arg_defaults);
        if (r < 0)
                log_warning_errno(r, "Failed to set manager defaults, ignoring: %m");

        r = manager_default_environment(m);
        if (r < 0)
                log_warning_errno(r, "Failed to set manager default environment, ignoring: %m");

        r = manager_transient_environment_add(m, arg_default_environment);
        if (r < 0)
                log_warning_errno(r, "Failed to add to transient environment, ignoring: %m");
}

static void set_manager_settings(Manager *m) {
        int r;

        assert(m);

        /* Propagates the various manager settings into the manager object, i.e. properties that
         * affect the manager itself (as opposed to just being inherited into newly allocated
         * units, see set_manager_defaults() above). */

        m->confirm_spawn = arg_confirm_spawn;
        m->service_watchdogs = arg_service_watchdogs;
        m->cad_burst_action = arg_cad_burst_action;
        /* Note that we don't do structured initialization here, otherwise it will reset the rate limit
         * counter on every daemon-reload. */
        m->reload_reexec_ratelimit.interval = arg_reload_limit_interval_sec;
        m->reload_reexec_ratelimit.burst = arg_reload_limit_burst;

        manager_set_watchdog(m, WATCHDOG_RUNTIME, arg_runtime_watchdog);
        manager_set_watchdog(m, WATCHDOG_REBOOT, arg_reboot_watchdog);
        manager_set_watchdog(m, WATCHDOG_KEXEC, arg_kexec_watchdog);
        manager_set_watchdog(m, WATCHDOG_PRETIMEOUT, arg_pretimeout_watchdog);
        r = manager_set_watchdog_pretimeout_governor(m, arg_watchdog_pretimeout_governor);
        if (r < 0)
                log_warning_errno(r, "Failed to set watchdog pretimeout governor to '%s', ignoring: %m", arg_watchdog_pretimeout_governor);

        manager_set_show_status(m, arg_show_status, "command line");
        m->status_unit_format = arg_status_unit_format;
}

static int parse_argv(int argc, char *argv[]) {
        enum {
                COMMON_GETOPT_ARGS,
                SYSTEMD_GETOPT_ARGS,
        };

        static const struct option options[] = {
                COMMON_GETOPT_OPTIONS,
                SYSTEMD_GETOPT_OPTIONS,
                {}
        };

        int c, r;
        bool user_arg_seen = false;

        assert(argc >= 1);
        assert(argv);

        if (getpid_cached() == 1)
                opterr = 0;

        while ((c = getopt_long(argc, argv, SYSTEMD_GETOPT_SHORT_OPTIONS, options, NULL)) >= 0)

                switch (c) {

                case ARG_LOG_LEVEL:
                        r = log_set_max_level_from_string(optarg);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse log level \"%s\": %m", optarg);

                        break;

                case ARG_LOG_TARGET:
                        r = log_set_target_from_string(optarg);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse log target \"%s\": %m", optarg);

                        break;

                case ARG_LOG_COLOR:

                        if (optarg) {
                                r = log_show_color_from_string(optarg);
                                if (r < 0)
                                        return log_error_errno(r, "Failed to parse log color setting \"%s\": %m",
                                                               optarg);
                        } else
                                log_show_color(true);

                        break;

                case ARG_LOG_LOCATION:
                        if (optarg) {
                                r = log_show_location_from_string(optarg);
                                if (r < 0)
                                        return log_error_errno(r, "Failed to parse log location setting \"%s\": %m",
                                                               optarg);
                        } else
                                log_show_location(true);

                        break;

                case ARG_LOG_TIME:

                        if (optarg) {
                                r = log_show_time_from_string(optarg);
                                if (r < 0)
                                        return log_error_errno(r, "Failed to parse log time setting \"%s\": %m",
                                                               optarg);
                        } else
                                log_show_time(true);

                        break;

                case ARG_DEFAULT_STD_OUTPUT:
                        r = exec_output_from_string(optarg);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse default standard output setting \"%s\": %m",
                                                       optarg);
                        arg_defaults.std_output = r;
                        break;

                case ARG_DEFAULT_STD_ERROR:
                        r = exec_output_from_string(optarg);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse default standard error output setting \"%s\": %m",
                                                       optarg);
                        arg_defaults.std_error = r;
                        break;

                case ARG_UNIT:
                        r = free_and_strdup(&arg_default_unit, optarg);
                        if (r < 0)
                                return log_error_errno(r, "Failed to set default unit \"%s\": %m", optarg);

                        break;

                case ARG_SYSTEM:
                        arg_runtime_scope = RUNTIME_SCOPE_SYSTEM;
                        break;

                case ARG_USER:
                        arg_runtime_scope = RUNTIME_SCOPE_USER;
                        user_arg_seen = true;
                        break;

                case ARG_TEST:
                        arg_action = ACTION_TEST;
                        break;

                case ARG_NO_PAGER:
                        arg_pager_flags |= PAGER_DISABLE;
                        break;

                case ARG_VERSION:
                        arg_action = ACTION_VERSION;
                        break;

                case ARG_DUMP_CONFIGURATION_ITEMS:
                        arg_action = ACTION_DUMP_CONFIGURATION_ITEMS;
                        break;

                case ARG_DUMP_BUS_PROPERTIES:
                        arg_action = ACTION_DUMP_BUS_PROPERTIES;
                        break;

                case ARG_BUS_INTROSPECT:
                        arg_bus_introspect = optarg;
                        arg_action = ACTION_BUS_INTROSPECT;
                        break;

                case ARG_DUMP_CORE:
                        r = parse_boolean_argument("--dump-core", optarg, &arg_dump_core);
                        if (r < 0)
                                return r;
                        break;

                case ARG_CRASH_CHVT:
                        r = parse_crash_chvt(optarg, &arg_crash_chvt);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse crash virtual terminal index: \"%s\": %m",
                                                       optarg);
                        break;

                case ARG_CRASH_SHELL:
                        r = parse_boolean_argument("--crash-shell", optarg, &arg_crash_shell);
                        if (r < 0)
                                return r;
                        break;

                case ARG_CRASH_REBOOT:
                        r = parse_boolean_argument("--crash-reboot", optarg, NULL);
                        if (r < 0)
                                return r;
                        arg_crash_action = r > 0 ? CRASH_REBOOT : CRASH_FREEZE;
                        break;

                case ARG_CRASH_ACTION:
                        r = crash_action_from_string(optarg);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse crash action \"%s\": %m", optarg);
                        arg_crash_action = r;
                        break;

                case ARG_CONFIRM_SPAWN:
                        arg_confirm_spawn = mfree(arg_confirm_spawn);

                        r = parse_confirm_spawn(optarg, &arg_confirm_spawn);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse confirm spawn option: \"%s\": %m",
                                                       optarg);
                        break;

                case ARG_SERVICE_WATCHDOGS:
                        r = parse_boolean_argument("--service-watchdogs=", optarg, &arg_service_watchdogs);
                        if (r < 0)
                                return r;
                        break;

                case ARG_SHOW_STATUS:
                        if (optarg) {
                                r = parse_show_status(optarg, &arg_show_status);
                                if (r < 0)
                                        return log_error_errno(r, "Failed to parse show status boolean: \"%s\": %m",
                                                               optarg);
                        } else
                                arg_show_status = SHOW_STATUS_YES;
                        break;

                case ARG_DESERIALIZE: {
                        int fd;
                        FILE *f;

                        fd = parse_fd(optarg);
                        if (fd < 0)
                                return log_error_errno(fd, "Failed to parse serialization fd \"%s\": %m", optarg);

                        (void) fd_cloexec(fd, true);

                        f = fdopen(fd, "r");
                        if (!f)
                                return log_error_errno(errno, "Failed to open serialization fd %d: %m", fd);

                        safe_fclose(arg_serialization);
                        arg_serialization = f;

                        break;
                }

                case ARG_SWITCHED_ROOT:
                        arg_switched_root = true;
                        break;

                case ARG_MACHINE_ID:
                        r = id128_from_string_nonzero(optarg, &arg_machine_id);
                        if (r < 0)
                                return log_error_errno(r, "MachineID '%s' is not valid: %m", optarg);
                        break;

                case 'h':
                        arg_action = ACTION_HELP;
                        break;

                case 'D':
                        log_set_max_level(LOG_DEBUG);
                        break;

                case 'b':
                case 's':
                case 'z':
                        /* Just to eat away the sysvinit kernel cmdline args that we'll parse in
                         * parse_proc_cmdline_item() or ignore, without any getopt() error messages.
                         */
                case '?':
                        if (getpid_cached() != 1)
                                return -EINVAL;
                        else
                                return 0;

                default:
                        assert_not_reached();
                }

        if (optind < argc && getpid_cached() != 1)
                /* Hmm, when we aren't run as init system let's complain about excess arguments */
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Excess arguments.");

        if (arg_action == ACTION_RUN && arg_runtime_scope == RUNTIME_SCOPE_USER && !user_arg_seen)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Explicit --user argument required to run as user manager.");

        return 0;
}

static int help(void) {
        _cleanup_free_ char *link = NULL;
        int r;

        r = terminal_urlify_man("systemd", "1", &link);
        if (r < 0)
                return log_oom();

        printf("%s [OPTIONS...]\n\n"
               "%sStarts and monitors system and user services.%s\n\n"
               "This program takes no positional arguments.\n\n"
               "%sOptions%s:\n"
               "  -h --help                      Show this help\n"
               "     --version                   Show version\n"
               "     --test                      Determine initial transaction, dump it and exit\n"
               "     --system                    Combined with --test: operate in system mode\n"
               "     --user                      Combined with --test: operate in user mode\n"
               "     --dump-configuration-items  Dump understood unit configuration items\n"
               "     --dump-bus-properties       Dump exposed bus properties\n"
               "     --bus-introspect=PATH       Write XML introspection data\n"
               "     --unit=UNIT                 Set default unit\n"
               "     --dump-core[=BOOL]          Dump core on crash\n"
               "     --crash-vt=NR               Change to specified VT on crash\n"
               "     --crash-action=ACTION       Specify what to do on crash\n"
               "     --crash-shell[=BOOL]        Run shell on crash\n"
               "     --confirm-spawn[=BOOL]      Ask for confirmation when spawning processes\n"
               "     --show-status[=BOOL]        Show status updates on the console during boot\n"
               "     --log-target=TARGET         Set log target (console, journal, kmsg,\n"
               "                                                 journal-or-kmsg, null)\n"
               "     --log-level=LEVEL           Set log level (debug, info, notice, warning,\n"
               "                                                err, crit, alert, emerg)\n"
               "     --log-color[=BOOL]          Highlight important log messages\n"
               "     --log-location[=BOOL]       Include code location in log messages\n"
               "     --log-time[=BOOL]           Prefix log messages with current time\n"
               "     --default-standard-output=  Set default standard output for services\n"
               "     --default-standard-error=   Set default standard error output for services\n"
               "     --no-pager                  Do not pipe output into a pager\n"
               "\nSee the %s for details.\n",
               program_invocation_short_name,
               ansi_highlight(),
               ansi_normal(),
               ansi_underline(),
               ansi_normal(),
               link);

        return 0;
}

static int prepare_reexecute(
                Manager *m,
                FILE **ret_f,
                FDSet **ret_fds,
                bool switching_root) {

        _cleanup_fdset_free_ FDSet *fds = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        int r;

        assert(m);
        assert(ret_f);
        assert(ret_fds);

        /* Make sure nothing is really destructed when we shut down */
        m->n_reloading++;
        bus_manager_send_reloading(m, true);

        r = manager_open_serialization(m, &f);
        if (r < 0)
                return log_error_errno(r, "Failed to create serialization file: %m");

        fds = fdset_new();
        if (!fds)
                return log_oom();

        r = manager_serialize(m, f, fds, switching_root);
        if (r < 0)
                return r;

        r = finish_serialization_file(f);
        if (r < 0)
                return log_error_errno(r, "Failed to finish serialization file: %m");

        r = fd_cloexec(fileno(f), false);
        if (r < 0)
                return log_error_errno(r, "Failed to disable O_CLOEXEC for serialization: %m");

        r = fdset_cloexec(fds, false);
        if (r < 0)
                return log_error_errno(r, "Failed to disable O_CLOEXEC for serialization fds: %m");

        *ret_f = TAKE_PTR(f);
        *ret_fds = TAKE_PTR(fds);

        return 0;
}

static void bump_file_max_and_nr_open(void) {

        /* Let's bump fs.file-max and fs.nr_open to their respective maximums. On current kernels large
         * numbers of file descriptors are no longer a performance problem and their memory is properly
         * tracked by memcg, thus counting them and limiting them in another two layers of limits is
         * unnecessary and just complicates things. This function hence turns off 2 of the 4 levels of limits
         * on file descriptors, and makes RLIMIT_NOLIMIT (soft + hard) the only ones that really matter. */

#if BUMP_PROC_SYS_FS_FILE_MAX || BUMP_PROC_SYS_FS_NR_OPEN
        int r;
#endif

#if BUMP_PROC_SYS_FS_FILE_MAX
        /* The maximum the kernel allows for this since 5.2 is LONG_MAX, use that. (Previously things were
         * different, but the operation would fail silently.) */
        r = sysctl_write("fs/file-max", LONG_MAX_STR);
        if (r < 0)
                log_full_errno(ERRNO_IS_NEG_FS_WRITE_REFUSED(r) ? LOG_DEBUG : LOG_WARNING, r,
                               "Failed to bump fs.file-max, ignoring: %m");
#endif

#if BUMP_PROC_SYS_FS_NR_OPEN
        /* The kernel enforces maximum and minimum values on the fs.nr_open, but they are not directly
         * exposed, but hardcoded in fs/file.c. Hopefully, these values will not be changed, but not sure.
         * Let's first try the hardcoded maximum value, and if it does not work, try the half of it. */

        for (unsigned v = NR_OPEN_MAXIMUM; v >= NR_OPEN_MINIMUM; v /= 2) {
                unsigned k = read_nr_open();
                if (k >= v) { /* Already larger */
                        log_debug("Skipping bump, value is already larger.");
                        break;
                }

                r = sysctl_writef("fs/nr_open", "%u", v);
                if (r == -EINVAL) {
                        log_debug("Couldn't write fs.nr_open as %u, halving it.", v);
                        continue;
                }
                if (r < 0) {
                        log_full_errno(ERRNO_IS_NEG_FS_WRITE_REFUSED(r) ? LOG_DEBUG : LOG_WARNING, r,
                                       "Failed to bump fs.nr_open, ignoring: %m");
                        break;
                }

                log_debug("Successfully bumped fs.nr_open to %u", v);
                break;
        }
#endif
}

static int bump_rlimit_nofile(const struct rlimit *saved_rlimit) {
        struct rlimit new_rlimit;
        int r;

        /* Get the underlying absolute limit the kernel enforces */
        unsigned nr = read_nr_open();

        /* Calculate the new limits to use for us. Never lower from what we inherited. */
        new_rlimit = (struct rlimit) {
                .rlim_cur = MAX((rlim_t) nr, saved_rlimit->rlim_cur),
                .rlim_max = MAX((rlim_t) nr, saved_rlimit->rlim_max),
        };

        /* Shortcut if nothing changes. */
        if (saved_rlimit->rlim_max >= new_rlimit.rlim_max &&
            saved_rlimit->rlim_cur >= new_rlimit.rlim_cur) {
                log_debug("RLIMIT_NOFILE is already as high or higher than we need it, not bumping.");
                return 0;
        }

        /* Bump up the resource limit for ourselves substantially, all the way to the maximum the kernel allows, for
         * both hard and soft. */
        r = setrlimit_closest(RLIMIT_NOFILE, &new_rlimit);
        if (r < 0)
                return log_warning_errno(r, "Setting RLIMIT_NOFILE failed, ignoring: %m");

        return 0;
}

static int bump_rlimit_memlock(const struct rlimit *saved_rlimit) {
        struct rlimit new_rlimit;
        uint64_t mm;
        int r;

        /* BPF_MAP_TYPE_LPM_TRIE bpf maps are charged against RLIMIT_MEMLOCK, even if we have CAP_IPC_LOCK
         * which should normally disable such checks. We need them to implement IPAddressAllow= and
         * IPAddressDeny=, hence let's bump the value high enough for our user. */

        /* Using MAX() on resource limits only is safe if RLIM_INFINITY is > 0. POSIX declares that rlim_t
         * must be unsigned, hence this is a given, but let's make this clear here. */
        assert_cc(RLIM_INFINITY > 0);

        mm = physical_memory_scale(1, 8); /* Let's scale how much we allow to be locked by the amount of
                                           * physical RAM. We allow an eighth to be locked by us, just to
                                           * pick a value. */

        new_rlimit = (struct rlimit) {
                .rlim_cur = MAX3(HIGH_RLIMIT_MEMLOCK, saved_rlimit->rlim_cur, mm),
                .rlim_max = MAX3(HIGH_RLIMIT_MEMLOCK, saved_rlimit->rlim_max, mm),
        };

        if (saved_rlimit->rlim_max >= new_rlimit.rlim_cur &&
            saved_rlimit->rlim_cur >= new_rlimit.rlim_max) {
                log_debug("RLIMIT_MEMLOCK is already as high or higher than we need it, not bumping.");
                return 0;
        }

        r = setrlimit_closest(RLIMIT_MEMLOCK, &new_rlimit);
        if (r < 0)
                return log_warning_errno(r, "Setting RLIMIT_MEMLOCK failed, ignoring: %m");

        return 0;
}

static int enforce_syscall_archs(Set *archs) {
#if HAVE_SECCOMP
        int r;

        if (!is_seccomp_available())
                return 0;

        r = seccomp_restrict_archs(arg_syscall_archs);
        if (r < 0)
                return log_error_errno(r, "Failed to enforce system call architecture restriction: %m");
#endif
        return 0;
}

static int os_release_status(void) {
        _cleanup_free_ char *pretty_name = NULL, *fancy_name = NULL,
                *name = NULL, *version = NULL, *ansi_color = NULL, *support_end = NULL, *codename = NULL;
        int r;

        r = parse_os_release(NULL,
                             "PRETTY_NAME",      &pretty_name,
                             "FANCY_NAME",       &fancy_name,
                             "NAME",             &name,
                             "VERSION",          &version,
                             "VERSION_CODENAME", &codename,
                             "ANSI_COLOR",       &ansi_color,
                             "SUPPORT_END",      &support_end);
        if (r < 0)
                return log_full_errno(r == -ENOENT ? LOG_DEBUG : LOG_WARNING, r,
                                      "Failed to read os-release file, ignoring: %m");

        const char *label = os_release_pretty_name(pretty_name, name);

        if (show_status_on(arg_show_status)) {
                const char *color = empty_to_null(ansi_color) ?: "1";

                /* The fancy name may contain emoji characters and ANSI sequences. Don't use it if our locale
                 * doesn't allow that, or ANSI sequences are off, or if it is empty. */

                if (!isempty(fancy_name)) {
                        _cleanup_free_ char *unescaped = NULL;

                        /* Undo one level of C-style unescaping for this one */
                        ssize_t l = cunescape(fancy_name, /* flags= */ 0, &unescaped);
                        if (l < 0) {
                                log_debug_errno(l, "Failed to unescape FANCY_NAME=, ignoring: %m");
                                fancy_name = mfree(fancy_name);
                        } else if (!utf8_is_valid(fancy_name)) {
                                log_debug("Unescaped FANCY_NAME= contains invalid UTF-8, ignoring.");
                                fancy_name = mfree(fancy_name);
                        } else {
                                free_and_replace(fancy_name, unescaped);

                                /* FANCY_NAME= does not contain version/codename info (unlike PRETTY_NAME=),
                                 * but in this context it makes sense to show them if defined, hence append
                                 * them here. */
                                if (version && !strextend(&fancy_name, " ", version))
                                        return log_oom();

                                if (codename && !strextend(&fancy_name, " (", codename, ")"))
                                        return log_oom();
                        }
                }

                if (isempty(fancy_name) ||
                    (!emoji_enabled() && !ascii_is_valid(fancy_name)) ||
                    !log_get_show_color())
                        fancy_name = mfree(fancy_name);

                if (!fancy_name && log_get_show_color()) {
                        fancy_name = strjoin("\x1B[", color, "m", label);
                        if (!fancy_name)
                                return log_oom();
                }

                if (in_initrd()) {
                        if (log_get_show_color())
                                status_printf(NULL, 0,
                                              ANSI_HIGHLIGHT "Booting initrd of " ANSI_NORMAL "%s" ANSI_NORMAL ANSI_HIGHLIGHT "." ANSI_NORMAL,
                                              fancy_name);
                        else
                                status_printf(NULL, 0,
                                              "Booting initrd of %s...", label);
                } else {
                        if (log_get_show_color())
                                status_printf(NULL, 0,
                                              "\n" ANSI_HIGHLIGHT "Welcome to " ANSI_NORMAL "%s" ANSI_NORMAL ANSI_HIGHLIGHT "!" ANSI_NORMAL "\n",
                                              fancy_name);
                        else
                                status_printf(NULL, 0,
                                              "\nWelcome to %s!\n",
                                              label);
                }
        }

        if (support_end && os_release_support_ended(support_end, /* quiet= */ false, /* ret_eol= */ NULL) > 0)
                /* pretty_name may include the version already, so we'll print the version only if we
                 * have it and we're not using pretty_name. */
                status_printf(ANSI_HIGHLIGHT_RED "  !!  " ANSI_NORMAL, 0,
                              "This OS version (%s%s%s) is past its end-of-support date (%s)",
                              label,
                              (pretty_name || !version) ? "" : " version ",
                              (pretty_name || !version) ? "" : version,
                              support_end);

        return 0;
}

static int setup_os_release(RuntimeScope scope) {
        char os_release_dst[STRLEN("/run/user//systemd/propagate/.os-release-stage/os-release") + DECIMAL_STR_MAX(uid_t)] =
                "/run/systemd/propagate/.os-release-stage/os-release";
        const char *os_release_src = "/etc/os-release";
        int r;

        assert(IN_SET(scope, RUNTIME_SCOPE_SYSTEM, RUNTIME_SCOPE_USER));

        if (access("/etc/os-release", F_OK) < 0) {
                if (errno != ENOENT)
                        log_debug_errno(errno, "Failed to check if /etc/os-release exists, ignoring: %m");

                os_release_src = "/usr/lib/os-release";
        }

        if (scope == RUNTIME_SCOPE_USER)
                xsprintf(os_release_dst, "/run/user/" UID_FMT "/systemd/propagate/.os-release-stage/os-release", geteuid());

        r = mkdir_parents_label(os_release_dst, 0755);
        if (r < 0)
                return log_debug_errno(r, "Failed to create parent directory of '%s', ignoring: %m", os_release_dst);

        r = copy_file_atomic(os_release_src, os_release_dst, 0644, COPY_MAC_CREATE|COPY_REPLACE);
        if (r < 0)
                return log_debug_errno(r, "Failed to copy '%s' to '%s', ignoring: %m",
                                       os_release_src, os_release_dst);

        return 0;
}

static int write_container_id(void) {
        const char *c;
        int r = 0;  /* avoid false maybe-uninitialized warning */

        c = getenv("container");
        if (isempty(c))
                return 0;

        WITH_UMASK(0022)
                r = write_string_file("/run/systemd/container", c, WRITE_STRING_FILE_CREATE);
        if (r < 0)
                return log_warning_errno(r, "Failed to write /run/systemd/container, ignoring: %m");

        return 1;
}

static int write_boot_or_shutdown_osc(const char *type) {
        int r;

        assert(STRPTR_IN_SET(type, "boot", "shutdown"));

        if (getenv_terminal_is_dumb())
                return 0;

        _cleanup_close_ int fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
        if (fd < 0)
                return log_debug_errno(fd, "Failed to open /dev/console to print %s OSC, ignoring: %m", type);

        _cleanup_free_ char *seq = NULL;
        if (streq(type, "boot"))
                r = osc_context_open_boot(&seq);
        else
                r = osc_context_close(SD_ID128_ALLF, &seq);
        if (r < 0)
                return log_debug_errno(r, "Failed to acquire %s OSC sequence, ignoring: %m", type);

        r = loop_write(fd, seq, SIZE_MAX);
        if (r < 0)
                return log_debug_errno(r, "Failed to write %s OSC sequence, ignoring: %m", type);

        if (DEBUG_LOGGING) {
                _cleanup_free_ char *h = cescape(seq);
                log_debug("OSC sequence for %s successfully written: %s", type, strna(h));
        }

        return 0;
}

static int bump_unix_max_dgram_qlen(void) {
        _cleanup_free_ char *qlen = NULL;
        unsigned long v;
        int r;

        /* Let's bump the net.unix.max_dgram_qlen sysctl. The kernel default of 16 is simply too low. We set
         * the value really really early during boot, so that it is actually applied to all our sockets,
         * including the $NOTIFY_SOCKET one. */

        r = read_one_line_file("/proc/sys/net/unix/max_dgram_qlen", &qlen);
        if (r < 0)
                return log_full_errno(r == -ENOENT ? LOG_DEBUG : LOG_WARNING, r,
                                      "Failed to read AF_UNIX datagram queue length, ignoring: %m");

        r = safe_atolu(qlen, &v);
        if (r < 0)
                return log_warning_errno(r, "Failed to parse AF_UNIX datagram queue length '%s', ignoring: %m", qlen);

        if (v >= DEFAULT_UNIX_MAX_DGRAM_QLEN)
                return 0;

        r = sysctl_write("net/unix/max_dgram_qlen", STRINGIFY(DEFAULT_UNIX_MAX_DGRAM_QLEN));
        if (r < 0)
                return log_full_errno(ERRNO_IS_NEG_FS_WRITE_REFUSED(r) ? LOG_DEBUG : LOG_WARNING, r,
                                      "Failed to bump AF_UNIX datagram queue length, ignoring: %m");

        return 1;
}

static int fixup_environment(void) {
        int r;

        /* Only fix up the environment when we are started as PID 1 */
        if (getpid_cached() != 1)
                return 0;

        /* We expect the environment to be set correctly if run inside a container. */
        if (detect_container() > 0)
                return 0;

        /* When started as PID1, the kernel uses /dev/console for our stdios and uses TERM=linux whatever the
         * backend device used by the console. We try to make a better guess here since some consoles might
         * not have support for color mode for example.
         *
         * However if TERM was configured through the kernel command line then leave it alone. */
        _cleanup_free_ char *term = NULL;
        r = proc_cmdline_get_key("TERM", 0, &term);
        if (r < 0)
                return r;
        if (r > 0) {
                /* If we pick up $TERM, then also pick up $COLORTERM, $NO_COLOR */
                FOREACH_STRING(v, "COLORTERM", "NO_COLOR") {
                        _cleanup_free_ char *vv = NULL;
                        r = proc_cmdline_get_key(v, 0, &vv);
                        if (r < 0)
                                return r;
                        if (r > 0 && setenv(v, vv, /* overwrite= */ true) < 0)
                                return -errno;
                }
        } else {
                /* If no $TERM is set then look for the per-tty variable instead */
                r = proc_cmdline_get_key("systemd.tty.term.console", 0, &term);
                if (r < 0)
                        return r;
        }

        if (!term)
                (void) query_term_for_tty("/dev/console", &term);

        if (setenv("TERM", term ?: FALLBACK_TERM, /* overwrite= */ true) < 0)
                return -errno;

        /* The kernels sets HOME=/ for init. Let's undo this. */
        if (path_equal(getenv("HOME"), "/"))
                assert_se(unsetenv("HOME") == 0);

        return 0;
}

static int become_shutdown(int objective, int retval) {
        static const char* const table[_MANAGER_OBJECTIVE_MAX] = {
                [MANAGER_EXIT]     = "exit",
                [MANAGER_REBOOT]   = "reboot",
                [MANAGER_POWEROFF] = "poweroff",
                [MANAGER_HALT]     = "halt",
                [MANAGER_KEXEC]    = "kexec",
        };

        char timeout[STRLEN("--timeout=") + DECIMAL_STR_MAX(usec_t) + STRLEN("us")],
             exit_code[STRLEN("--exit-code=") + DECIMAL_STR_MAX(uint8_t)];

        _cleanup_strv_free_ char **env_block = NULL;
        _cleanup_free_ char *max_log_levels = NULL;
        usec_t watchdog_timer = 0;
        int r;

        assert(objective >= 0 && objective < _MANAGER_OBJECTIVE_MAX);
        assert(table[objective]);

        xsprintf(timeout, "--timeout=%" PRI_USEC "us", arg_defaults.timeout_stop_usec);

        const char* command_line[11] = {
                SYSTEMD_SHUTDOWN_BINARY_PATH,
                table[objective],
                timeout,
                /* Note that the last position is a terminator and must contain NULL. */
        };
        size_t pos = 3;

        assert(command_line[pos-1]);
        assert(!command_line[pos]);

        (void) log_max_levels_to_string(log_get_max_level(), &max_log_levels);

        if (max_log_levels) {
                command_line[pos++] = "--log-level";
                command_line[pos++] = max_log_levels;
        }

        switch (log_get_target()) {

        case LOG_TARGET_KMSG:
        case LOG_TARGET_JOURNAL_OR_KMSG:
        case LOG_TARGET_SYSLOG_OR_KMSG:
                command_line[pos++] = "--log-target=kmsg";
                break;

        case LOG_TARGET_NULL:
                command_line[pos++] = "--log-target=null";
                break;

        case LOG_TARGET_CONSOLE:
        default:
                command_line[pos++] = "--log-target=console";
        };

        if (log_get_show_color())
                command_line[pos++] = "--log-color";

        if (log_get_show_location())
                command_line[pos++] = "--log-location";

        if (log_get_show_time())
                command_line[pos++] = "--log-time";

        xsprintf(exit_code, "--exit-code=%d", retval);
        command_line[pos++] = exit_code;

        assert(pos < ELEMENTSOF(command_line));

        /* The watchdog: */

        if (objective == MANAGER_REBOOT)
                watchdog_timer = arg_reboot_watchdog;
        else if (objective == MANAGER_KEXEC)
                watchdog_timer = arg_kexec_watchdog;

        /* If we reboot or kexec let's set the shutdown watchdog and tell the
         * shutdown binary to repeatedly ping it.
         * Disable the pretimeout watchdog, as we do not support it from the shutdown binary. */
        (void) watchdog_setup_pretimeout(0);
        (void) watchdog_setup_pretimeout_governor(NULL);
        r = watchdog_setup(watchdog_timer);
        watchdog_close(/* disarm= */ r < 0);

        /* The environment block: */

        env_block = strv_copy(environ);

        /* Tell the binary how often to ping, ignore failure */
        (void) strv_extendf(&env_block, "WATCHDOG_USEC="USEC_FMT, watchdog_timer);

        /* Make sure that tools that look for $WATCHDOG_USEC (and might get started by the exitrd) don't get
         * confused by the variable, because the sd_watchdog_enabled() protocol uses the same variable for
         * the same purposes. */
        (void) strv_extendf(&env_block, "WATCHDOG_PID=" PID_FMT, getpid_cached());

        if (arg_watchdog_device)
                (void) strv_extendf(&env_block, "WATCHDOG_DEVICE=%s", arg_watchdog_device);

        (void) write_boot_or_shutdown_osc("shutdown");

        execve(SYSTEMD_SHUTDOWN_BINARY_PATH, (char **) command_line, env_block);
        return -errno;
}

static void initialize_clock_timewarp(void) {
        int r;

        /* This is called very early on, before we parse the kernel command line or otherwise figure out why
         * we are running, but only once. */

        if (clock_is_localtime(NULL) > 0) {
                int min;

                /* The very first call of settimeofday() also does a time warp in the kernel.
                 *
                 * In the rtc-in-local time mode, we set the kernel's timezone, and rely on external tools to
                 * take care of maintaining the RTC and do all adjustments. This matches the behavior of
                 * Windows, which leaves the RTC alone if the registry tells that the RTC runs in UTC.
                 */
                r = clock_set_timezone(&min);
                if (r < 0)
                        log_error_errno(r, "Failed to apply local time delta, ignoring: %m");
                else
                        log_info("RTC configured in localtime, applying delta of %i minutes to system time.", min);

        } else if (!in_initrd())
                /*
                 * Do a dummy very first call to seal the kernel's time warp magic.
                 *
                 * Do not call this from inside the initrd. The initrd might not carry /etc/adjtime with
                 * LOCAL, but the real system could be set up that way. In such case, we need to delay the
                 * time-warp or the sealing until we reach the real system.
                 *
                 * Do no set the kernel's timezone. The concept of local time cannot be supported reliably,
                 * the time will jump or be incorrect at every daylight saving time change. All kernel local
                 * time concepts will be treated as UTC that way.
                 */
                (void) clock_reset_timewarp();
}

static void apply_clock_update(void) {
        /* This is called later than clock_apply_epoch(), i.e. after we have parsed
         * configuration files/kernel command line and such. */

        if (arg_clock_usec == 0)
                return;

        if (getpid_cached() != 1)
                return;

        if (clock_settime(CLOCK_REALTIME, TIMESPEC_STORE(arg_clock_usec)) < 0)
                log_error_errno(errno, "Failed to set system clock to time specified on kernel command line: %m");
        else
                log_info("Set system clock to %s, as specified on the kernel command line.",
                         FORMAT_TIMESTAMP(arg_clock_usec));
}

static void cmdline_take_random_seed(void) {
        size_t suggested;
        int r;

        if (arg_random_seed_size == 0)
                return;

        if (getpid_cached() != 1)
                return;

        assert(arg_random_seed);
        suggested = random_pool_size();

        if (arg_random_seed_size < suggested)
                log_warning("Random seed specified on kernel command line has size %zu, but %zu bytes required to fill entropy pool.",
                            arg_random_seed_size, suggested);

        r = random_write_entropy(-1, arg_random_seed, arg_random_seed_size, true);
        if (r < 0) {
                log_warning_errno(r, "Failed to credit entropy specified on kernel command line, ignoring: %m");
                return;
        }

        log_notice("Successfully credited entropy passed on kernel command line.\n"
                   "Note that the seed provided this way is accessible to unprivileged programs. "
                   "This functionality should not be used outside of testing environments.");
}

static void initialize_coredump(bool skip_setup) {
        if (getpid_cached() != 1)
                return;

        /* Don't limit the core dump size, so that coredump handlers such as systemd-coredump (which honour
         * the limit) will process core dumps for system services by default. */
        if (setrlimit(RLIMIT_CORE, &RLIMIT_MAKE_CONST(RLIM_INFINITY)) < 0)
                log_warning_errno(errno, "Failed to set RLIMIT_CORE: %m");

        /* But at the same time, turn off the core_pattern logic by default, so that no coredumps are stored
         * until the systemd-coredump tool is enabled via sysctl. However it can be changed via the kernel
         * command line later so core dumps can still be generated during early startup and in initrd. */
        if (!skip_setup)
                disable_coredumps();
}

static void initialize_core_pattern(bool skip_setup) {
        int r;

        if (skip_setup || !arg_early_core_pattern)
                return;

        if (getpid_cached() != 1)
                return;

        r = write_string_file("/proc/sys/kernel/core_pattern", arg_early_core_pattern, WRITE_STRING_FILE_DISABLE_BUFFER);
        if (r < 0)
                log_warning_errno(r, "Failed to write '%s' to /proc/sys/kernel/core_pattern, ignoring: %m",
                                  arg_early_core_pattern);
}

static void apply_protect_system(bool skip_setup) {
        int r;

        if (skip_setup || getpid_cached() != 1 || arg_protect_system == 0)
                return;

        if (arg_protect_system < 0 && !in_initrd()) {
                log_debug("ProtectSystem=auto selected, but not running in an initrd, skipping.");
                return;
        }

        r = make_mount_point("/usr");
        if (r < 0) {
                log_warning_errno(r, "Failed to make /usr/ a mount point, ignoring: %m");
                return;
        }

        if (mount_nofollow_verbose(
                        LOG_WARNING,
                        /* what= */ NULL,
                        "/usr",
                        /* fstype= */ NULL,
                        MS_BIND|MS_REMOUNT|MS_RDONLY,
                        /* options= */ NULL) < 0)
                return;

        log_info("Successfully made /usr/ read-only.");
}

static void update_cpu_affinity(bool skip_setup) {
        _cleanup_free_ char *mask = NULL;

        if (skip_setup || !arg_cpu_affinity.set)
                return;

        assert(arg_cpu_affinity.allocated > 0);

        mask = cpu_set_to_range_string(&arg_cpu_affinity);
        log_debug("Setting CPU affinity to {%s}.", strnull(mask));

        if (sched_setaffinity(0, arg_cpu_affinity.allocated, arg_cpu_affinity.set) < 0)
                log_warning_errno(errno, "Failed to set CPU affinity, ignoring: %m");
}

static void update_numa_policy(bool skip_setup) {
        int r;
        _cleanup_free_ char *nodes = NULL;
        const char * policy = NULL;

        if (skip_setup || !mpol_is_valid(numa_policy_get_type(&arg_numa_policy)))
                return;

        if (DEBUG_LOGGING) {
                policy = mpol_to_string(numa_policy_get_type(&arg_numa_policy));
                nodes = cpu_set_to_range_string(&arg_numa_policy.nodes);
                log_debug("Setting NUMA policy to %s, with nodes {%s}.", strnull(policy), strnull(nodes));
        }

        r = apply_numa_policy(&arg_numa_policy);
        if (r == -EOPNOTSUPP)
                log_debug_errno(r, "NUMA support not available, ignoring.");
        else if (r < 0)
                log_warning_errno(r, "Failed to set NUMA memory policy, ignoring: %m");
}

static void filter_args(
                const char* dst[],
                size_t *dst_index,
                char **src,
                int argc) {

        assert(dst);
        assert(dst_index);

        /* Copy some filtered arguments into the dst array from src. */
        for (int i = 1; i < argc; i++) {
                if (STR_IN_SET(src[i],
                               "--switched-root",
                               "--system",
                               "--user"))
                        continue;

                if (startswith(src[i], "--deserialize="))
                        continue;
                if (streq(src[i], "--deserialize")) {
                        i++;                            /* Skip the argument too */
                        continue;
                }

                /* Skip target unit designators. We already acted upon this information and have queued
                 * appropriate jobs. We don't want to redo all this after reexecution. */
                if (startswith(src[i], "--unit="))
                        continue;
                if (streq(src[i], "--unit")) {
                        i++;                            /* Skip the argument too */
                        continue;
                }

                /* Seems we have a good old option. Let's pass it over to the new instance. */
                dst[(*dst_index)++] = src[i];
        }
}

static void finish_remaining_processes(ManagerObjective objective) {
        assert(objective >= 0 && objective < _MANAGER_OBJECTIVE_MAX);

        /* Kill all remaining processes from the initrd, but don't wait for them, so that we can handle the
         * SIGCHLD for them after deserializing. */
        if (IN_SET(objective, MANAGER_SWITCH_ROOT, MANAGER_SOFT_REBOOT))
                broadcast_signal(SIGTERM, /* wait_for_exit= */ false, /* send_sighup= */ true, arg_defaults.timeout_stop_usec);

        /* On soft reboot really make sure nothing is left. Note that this will skip cgroups
         * of units that were configured with SurviveFinalKillSignal=yes. */
        if (objective == MANAGER_SOFT_REBOOT)
                broadcast_signal(SIGKILL, /* wait_for_exit= */ false, /* send_sighup= */ false, arg_defaults.timeout_stop_usec);
}

static void reduce_vt(ManagerObjective objective) {
        int r;

        if (objective != MANAGER_SOFT_REBOOT)
                return;

        /* Switches back to VT 1, and releases all other VTs, in an attempt to return to a situation similar
         * to how it was during the original kernel initialization. This is important because if some random
         * TTY is in foreground, /dev/console will end up pointing to it, where the future init system will
         * then write its status output to, but where it probably shouldn't be writing to. */

        r = chvt(1);
        if (r < 0)
                log_debug_errno(r, "Failed to switch to VT TTY 1, ignoring: %m");

        _cleanup_close_ int tty0_fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
        if (tty0_fd < 0)
                return (void) log_debug_errno(tty0_fd, "Failed to open '/dev/tty0', ignoring: %m");

        for (int ttynr = 2; ttynr <= VTNR_MAX; ttynr++)
                if (ioctl(tty0_fd, VT_DISALLOCATE, ttynr) < 0)
                        log_debug_errno(errno, "Failed to disallocate VT TTY %i, ignoring: %m", ttynr);
                else
                        log_debug("Successfully disallocated VT TTY %i.", ttynr);
}

static int do_reexecute(
                ManagerObjective objective,
                int argc,
                char* argv[],
                const struct rlimit *saved_rlimit_nofile,
                const struct rlimit *saved_rlimit_memlock,
                FDSet *fds,
                const char *switch_root_dir,
                const char *switch_root_init,
                uint64_t saved_capability_ambient_set,
                const char **ret_error_message) {

        size_t i, args_size;
        const char **args;
        int r;

        assert(IN_SET(objective, MANAGER_REEXECUTE, MANAGER_SWITCH_ROOT, MANAGER_SOFT_REBOOT));
        assert(argc >= 0);
        assert(saved_rlimit_nofile);
        assert(saved_rlimit_memlock);
        assert(ret_error_message);

        /* Close and disarm the watchdog, so that the new instance can reinitialize it, but the machine
         * doesn't get rebooted while we do that. */
        watchdog_close(/* disarm= */ true);

        if (!switch_root_dir && objective == MANAGER_SOFT_REBOOT) {
                /* If no switch root dir is specified, then check if /run/nextroot/ qualifies and use that */
                r = path_is_os_tree("/run/nextroot");
                if (r < 0 && r != -ENOENT)
                        log_debug_errno(r, "Failed to determine if /run/nextroot/ is a valid OS tree, ignoring: %m");
                else if (r > 0)
                        switch_root_dir = "/run/nextroot";
        }

        if (switch_root_dir) {
                /* If we're supposed to switch root, preemptively check the existence of a usable init.
                 * Otherwise the system might end up in a completely undebuggable state afterwards. */
                if (switch_root_init) {
                        r = chase_and_access(switch_root_init, switch_root_dir, CHASE_PREFIX_ROOT, X_OK, /* ret_path= */ NULL);
                        if (r < 0)
                                log_warning_errno(r, "Failed to chase configured init %s/%s: %m",
                                                  switch_root_dir, switch_root_init);
                } else {
                        r = chase_and_access(SYSTEMD_BINARY_PATH, switch_root_dir, CHASE_PREFIX_ROOT, X_OK, /* ret_path= */ NULL);
                        if (r < 0)
                                log_debug_errno(r, "Failed to chase our own binary %s/%s: %m",
                                                switch_root_dir, SYSTEMD_BINARY_PATH);
                }

                if (r < 0) {
                        r = chase_and_access("/sbin/init", switch_root_dir, CHASE_PREFIX_ROOT, X_OK, /* ret_path= */ NULL);
                        if (r < 0) {
                                *ret_error_message = "Switch root target contains no usable init";
                                return log_error_errno(r, "Failed to chase %s/sbin/init", switch_root_dir);
                        }
                }
        }

        /* Reset RLIMIT_NOFILE + RLIMIT_MEMLOCK back to the kernel defaults, so that the new systemd can pass
         * the kernel default to its child processes */
        if (saved_rlimit_nofile->rlim_cur != 0)
                (void) setrlimit(RLIMIT_NOFILE, saved_rlimit_nofile);
        if (saved_rlimit_memlock->rlim_cur != RLIM_INFINITY)
                (void) setrlimit(RLIMIT_MEMLOCK, saved_rlimit_memlock);

        finish_remaining_processes(objective);
        reduce_vt(objective);

        if (switch_root_dir) {
                r = switch_root(/* new_root= */ switch_root_dir,
                                /* old_root_after= */ NULL,
                                /* flags= */ (objective == MANAGER_SWITCH_ROOT ? SWITCH_ROOT_DESTROY_OLD_ROOT : 0) |
                                             (objective == MANAGER_SOFT_REBOOT ? 0 : SWITCH_ROOT_RECURSIVE_RUN));
                if (r < 0)
                        log_error_errno(r, "Failed to switch root, trying to continue: %m");
        }

        r = capability_ambient_set_apply(saved_capability_ambient_set, /* also_inherit= */ false);
        if (r < 0)
                log_warning_errno(r, "Failed to apply the starting ambient set, ignoring: %m");

        args_size = argc + 5;
        args = newa(const char*, args_size);

        if (!switch_root_init) {
                char sfd[STRLEN("--deserialize=") + DECIMAL_STR_MAX(int)];

                /* First try to spawn ourselves with the right path, and with full serialization. We do this
                 * only if the user didn't specify an explicit init to spawn. */

                assert(arg_serialization);
                assert(fds);

                xsprintf(sfd, "--deserialize=%i", fileno(arg_serialization));

                i = 1;         /* Leave args[0] empty for now. */

                /* Put our stuff first to make sure it always gets parsed in case
                 * we get weird stuff from the kernel cmdline (like --) */
                if (IN_SET(objective, MANAGER_SWITCH_ROOT, MANAGER_SOFT_REBOOT))
                        args[i++] = "--switched-root";
                args[i++] = runtime_scope_cmdline_option_to_string(arg_runtime_scope);
                args[i++] = sfd;

                filter_args(args, &i, argv, argc);

                args[i++] = NULL;

                assert(i <= args_size);

                /*
                 * We want valgrind to print its memory usage summary before reexecution. Valgrind won't do
                 * this is on its own on exec(), but it will do it on exit(). Hence, to ensure we get a
                 * summary here, fork() off a child, let it exit() cleanly, so that it prints the summary,
                 * and wait() for it in the parent, before proceeding into the exec().
                 */
                valgrind_summary_hack();

                args[0] = SYSTEMD_BINARY_PATH;
                (void) execv(args[0], (char* const*) args);

                if (objective == MANAGER_REEXECUTE) {
                        *ret_error_message = "Failed to execute our own binary";
                        return log_error_errno(errno, "Failed to execute our own binary %s: %m", args[0]);
                }

                log_debug_errno(errno, "Failed to execute our own binary %s, trying fallback: %m", args[0]);
        }

        /* Try the fallback, if there is any, without any serialization. We pass the original argv[] and
         * envp[]. (Well, modulo the ordering changes due to getopt() in argv[], and some cleanups in envp[],
         * but let's hope that doesn't matter.) */

        arg_serialization = safe_fclose(arg_serialization);
        fds = fdset_free(fds);

        /* Drop /run/systemd directory. Some of its content can be used as a flag indicating that systemd is
         * the init system but we might be replacing it with something different. If systemd is used again it
         * will recreate the directory and its content anyway. */
        r = rm_rf("/run/systemd.pre-switch-root", REMOVE_ROOT|REMOVE_MISSING_OK);
        if (r < 0)
                log_warning_errno(r, "Failed to prepare /run/systemd.pre-switch-root/, ignoring: %m");

        r = RET_NERRNO(rename("/run/systemd", "/run/systemd.pre-switch-root"));
        if (r < 0)
                log_warning_errno(r, "Failed to move /run/systemd/ to /run/systemd.pre-switch-root/, ignoring: %m");

        /* Reopen the console */
        (void) make_console_stdio();

        i = 1;         /* Leave args[0] empty for now. */
        for (int j = 1; j <= argc; j++)
                args[i++] = argv[j];
        assert(i <= args_size);

        /* Re-enable any blocked signals, especially important if we switch from initrd to init=... */
        (void) reset_all_signal_handlers();
        (void) reset_signal_mask();
        (void) rlimit_nofile_safe();

        if (switch_root_init) {
                args[0] = switch_root_init;
                (void) execve(args[0], (char* const*) args, saved_env);
                log_warning_errno(errno, "Failed to execute configured init %s, trying fallback: %m", args[0]);
        }

        args[0] = "/sbin/init";
        (void) execv(args[0], (char* const*) args);
        r = -errno;
        *ret_error_message = "Failed to execute /sbin/init";

        if (r == -ENOENT) {
                manager_status_printf(NULL, STATUS_TYPE_EMERGENCY,
                                      ANSI_HIGHLIGHT_RED "  !!  " ANSI_NORMAL,
                                      "%s", *ret_error_message);

                log_warning_errno(r, "No /sbin/init, trying fallback shell");

                args[0] = "/bin/sh";
                args[1] = NULL;
                (void) execve(args[0], (char* const*) args, saved_env);
                r = -errno;
                *ret_error_message = "Failed to execute fallback shell";
        }

        return log_error_errno(r, "%s, giving up: %m", *ret_error_message);
}

static int invoke_main_loop(
                Manager *m,
                const struct rlimit *saved_rlimit_nofile,
                const struct rlimit *saved_rlimit_memlock,
                int *ret_retval,                   /* Return parameters relevant for shutting down */
                FDSet **ret_fds,                   /* Return parameters for reexecuting */
                char **ret_switch_root_dir,        /* … */
                char **ret_switch_root_init,       /* … */
                const char **ret_error_message) {

        int r;

        assert(m);
        assert(saved_rlimit_nofile);
        assert(saved_rlimit_memlock);
        assert(ret_retval);
        assert(ret_fds);
        assert(ret_switch_root_dir);
        assert(ret_switch_root_init);
        assert(ret_error_message);

        for (;;) {
                int objective = manager_loop(m);
                if (objective < 0) {
                        *ret_error_message = "Failed to run main loop";
                        return log_struct_errno(LOG_EMERG, objective,
                                                LOG_MESSAGE("Failed to run main loop: %m"),
                                                LOG_MESSAGE_ID(SD_MESSAGE_CORE_MAINLOOP_FAILED_STR));
                }

                /* Ensure shutdown timestamp is taken even when bypassing the job engine */
                if (IN_SET(objective,
                           MANAGER_SOFT_REBOOT,
                           MANAGER_REBOOT,
                           MANAGER_KEXEC,
                           MANAGER_HALT,
                           MANAGER_POWEROFF) &&
                    !dual_timestamp_is_set(m->timestamps + MANAGER_TIMESTAMP_SHUTDOWN_START))
                        dual_timestamp_now(m->timestamps + MANAGER_TIMESTAMP_SHUTDOWN_START);

                switch (objective) {

                case MANAGER_RELOAD: {
                        LogTarget saved_log_target;
                        int saved_log_level;

                        manager_send_reloading(m);

                        log_info("Reloading...");

                        /* First, save any overridden log level/target, then parse the configuration file,
                         * which might change the log level to new settings. */

                        saved_log_level = m->log_level_overridden ? log_get_max_level() : -1;
                        saved_log_target = m->log_target_overridden ? log_get_target() : _LOG_TARGET_INVALID;

                        (void) parse_configuration(saved_rlimit_nofile, saved_rlimit_memlock);

                        set_manager_defaults(m);
                        set_manager_settings(m);

                        update_cpu_affinity(false);
                        update_numa_policy(false);

                        if (saved_log_level >= 0)
                                manager_override_log_level(m, saved_log_level);
                        if (saved_log_target >= 0)
                                manager_override_log_target(m, saved_log_target);

                        if (manager_reload(m) < 0)
                                /* Reloading failed before the point of no return.
                                 * Let's continue running as if nothing happened. */
                                m->objective = MANAGER_OK;
                        else
                                log_info("Reloading finished in " USEC_FMT " ms.",
                                         usec_sub_unsigned(now(CLOCK_MONOTONIC), m->timestamps[MANAGER_TIMESTAMP_UNITS_LOAD].monotonic) / USEC_PER_MSEC);

                        continue;
                }

                case MANAGER_REEXECUTE:

                        manager_send_reloading(m); /* From the perspective of the manager calling us this is
                                                    * pretty much the same as a reload */

                        r = prepare_reexecute(m, &arg_serialization, ret_fds, false);
                        if (r < 0) {
                                *ret_error_message = "Failed to prepare for reexecution";
                                return r;
                        }

                        log_notice("Reexecuting.");

                        *ret_retval = EXIT_FAILURE;
                        *ret_switch_root_dir = *ret_switch_root_init = NULL;

                        return objective;

                case MANAGER_SWITCH_ROOT:

                        manager_send_reloading(m); /* From the perspective of the manager calling us this is
                                                    * pretty much the same as a reload */

                        manager_set_switching_root(m, true);

                        if (!m->switch_root_init) {
                                r = prepare_reexecute(m, &arg_serialization, ret_fds, true);
                                if (r < 0) {
                                        *ret_error_message = "Failed to prepare for reexecution";
                                        return r;
                                }
                        } else
                                *ret_fds = NULL;

                        log_notice("Switching root.");

                        *ret_retval = EXIT_FAILURE;

                        /* Steal the switch root parameters */
                        *ret_switch_root_dir = TAKE_PTR(m->switch_root);
                        *ret_switch_root_init = TAKE_PTR(m->switch_root_init);

                        return objective;

                case MANAGER_SOFT_REBOOT:
                        manager_send_reloading(m);
                        manager_set_switching_root(m, true);

                        r = prepare_reexecute(m, &arg_serialization, ret_fds, /* switching_root= */ true);
                        if (r < 0) {
                                *ret_error_message = "Failed to prepare for reexecution";
                                return r;
                        }

                        log_notice("Soft-rebooting.");

                        *ret_retval = EXIT_FAILURE;
                        *ret_switch_root_dir = TAKE_PTR(m->switch_root);
                        *ret_switch_root_init = NULL;

                        return objective;

                case MANAGER_EXIT:
                        if (MANAGER_IS_USER(m)) {
                                log_debug("Exit.");

                                *ret_retval = m->return_value;
                                *ret_fds = NULL;
                                *ret_switch_root_dir = *ret_switch_root_init = NULL;

                                return objective;
                        }

                        _fallthrough_;
                case MANAGER_REBOOT:
                case MANAGER_POWEROFF:
                case MANAGER_HALT:
                case MANAGER_KEXEC: {
                        log_notice("Shutting down.");

                        *ret_retval = m->return_value;
                        *ret_fds = NULL;
                        *ret_switch_root_dir = *ret_switch_root_init = NULL;

                        return objective;
                }

                default:
                        assert_not_reached();
                }
        }
}

static void log_execution_mode(bool *ret_first_boot) {
        bool first_boot = false;
        int r;

        assert(ret_first_boot);

        switch (arg_runtime_scope) {

        case RUNTIME_SCOPE_SYSTEM: {
                struct utsname uts;
                int v;

                log_info("systemd " GIT_VERSION " running in %ssystem mode (%s)",
                         arg_action == ACTION_TEST ? "test " : "",
                         systemd_features);

                v = detect_virtualization();
                if (v > 0)
                        log_info("Detected virtualization %s.", virtualization_to_string(v));

                v = detect_confidential_virtualization();
                if (v > 0)
                        log_info("Detected confidential virtualization %s.", confidential_virtualization_to_string(v));

                log_info("Detected architecture %s.", architecture_to_string(uname_architecture()));

                if (in_initrd())
                        log_info("Running in initrd.");
                else {
                        _cleanup_free_ char *id_text = NULL;

                        /* Let's check whether we are in first boot. First, check if an override was
                         * specified on the kernel command line. If yes, we honour that. */

                        r = proc_cmdline_get_bool("systemd.condition_first_boot", /* flags= */ 0, &first_boot);
                        if (r < 0)
                                log_debug_errno(r, "Failed to parse systemd.condition_first_boot= kernel command line argument, ignoring: %m");

                        if (r > 0)
                                log_full(first_boot ? LOG_INFO : LOG_DEBUG,
                                         "Kernel command line argument says we are %s first boot.",
                                         first_boot ? "in" : "not in");
                        else {
                                /* Second, perform autodetection. We use /etc/machine-id as flag file for
                                 * this: If it is missing or contains the value "uninitialized", this is the
                                 * first boot. In other cases, it is not. This allows container managers and
                                 * installers to provision a couple of files in /etc but still permit the
                                 * first-boot initialization to occur. If the container manager wants to
                                 * provision the machine ID it should pass $container_uuid to PID 1. */

                                r = read_one_line_file("/etc/machine-id", &id_text);
                                if (r < 0 || streq(id_text, "uninitialized")) {
                                        if (r < 0 && r != -ENOENT)
                                                log_warning_errno(r, "Unexpected error while reading /etc/machine-id, assuming first boot: %m");

                                        first_boot = true;
                                        log_info("Detected first boot.");
                                } else
                                        log_debug("Detected initialized system, this is not the first boot.");
                        }
                }

                assert_se(uname(&uts) >= 0);

                if (strverscmp_improved(uts.release, KERNEL_BASELINE_VERSION) < 0)
                        log_warning("Warning! Reported kernel version %s is older than systemd's required baseline kernel version %s. "
                                    "Your mileage may vary.", uts.release, KERNEL_BASELINE_VERSION);
                else
                        log_debug("Kernel version %s, our baseline is %s", uts.release, KERNEL_BASELINE_VERSION);

                break;
        }

        case RUNTIME_SCOPE_USER:
                if (DEBUG_LOGGING) {
                        _cleanup_free_ char *t = NULL;

                        t = uid_to_name(getuid());
                        log_debug("systemd " GIT_VERSION " running in %suser mode for user " UID_FMT "/%s. (%s)",
                                  arg_action == ACTION_TEST ? " test" : "",
                                  getuid(), strna(t), systemd_features);
                }

                break;

        default:
                assert_not_reached();
        }

        *ret_first_boot = first_boot;
}

static int initialize_runtime(
                bool skip_setup,
                bool first_boot,
                struct rlimit *saved_rlimit_nofile,
                struct rlimit *saved_rlimit_memlock,
                uint64_t *saved_ambient_set,
                const char **ret_error_message) {

        int r;

        assert(saved_ambient_set);
        assert(ret_error_message);

        /* Sets up various runtime parameters. Many of these initializations are conditionalized:
         *
         * - Some only apply to --system instances
         * - Some only apply to --user instances
         * - Some only apply when we first start up, but not when we reexecute
         */

        if (arg_action != ACTION_RUN)
                return 0;

        update_cpu_affinity(skip_setup);
        update_numa_policy(skip_setup);

        switch (arg_runtime_scope) {

        case RUNTIME_SCOPE_SYSTEM:
                /* Make sure we leave a core dump without panicking the kernel. */
                install_crash_handler();

                if (!skip_setup) {
                        /* Check that /usr/ is either on the same file system as / or mounted already. */
                        if (dir_is_empty("/usr", /* ignore_hidden_or_backup= */ true) > 0) {
                                *ret_error_message = "Refusing to run in unsupported environment where /usr/ is not populated";
                                return -ENOEXEC;
                        }

                        /* Pull credentials from various sources into a common credential directory (we do
                         * this here, before setting up the machine ID, so that we can use credential info
                         * for setting up the machine ID) */
                        (void) import_credentials();

                        (void) os_release_status();
                        (void) machine_id_setup(/* root= */ NULL, arg_machine_id,
                                                (first_boot ? MACHINE_ID_SETUP_FORCE_TRANSIENT : 0) |
                                                (arg_machine_id_from_firmware ? MACHINE_ID_SETUP_FORCE_FIRMWARE : 0),
                                                /* ret= */ NULL);
                        (void) hostname_setup(/* really= */ true);
                        (void) loopback_setup();

                        bump_unix_max_dgram_qlen();
                        bump_file_max_and_nr_open();

                        write_container_id();

                        (void) write_boot_or_shutdown_osc("boot");

                        /* Copy os-release to the propagate directory, so that we update it for services running
                         * under RootDirectory=/RootImage= when we do a soft reboot. */
                        r = setup_os_release(RUNTIME_SCOPE_SYSTEM);
                        if (r < 0)
                                log_warning_errno(r, "Failed to copy os-release for propagation, ignoring: %m");
                }

                r = watchdog_set_device(arg_watchdog_device);
                if (r < 0)
                        log_warning_errno(r, "Failed to set watchdog device to %s, ignoring: %m", arg_watchdog_device);

                if (!cap_test_all(arg_capability_bounding_set)) {
                        r = capability_bounding_set_drop_usermode(arg_capability_bounding_set);
                        if (r < 0) {
                                *ret_error_message = "Failed to drop capability bounding set of usermode helpers";
                                return log_struct_errno(LOG_EMERG, r,
                                                        LOG_MESSAGE("Failed to drop capability bounding set of usermode helpers: %m"),
                                                        LOG_MESSAGE_ID(SD_MESSAGE_CORE_CAPABILITY_BOUNDING_USER_STR));
                        }

                        r = capability_bounding_set_drop(arg_capability_bounding_set, true);
                        if (r < 0) {
                                *ret_error_message = "Failed to drop capability bounding set";
                                return log_struct_errno(LOG_EMERG, r,
                                                        LOG_MESSAGE("Failed to drop capability bounding set: %m"),
                                                        LOG_MESSAGE_ID(SD_MESSAGE_CORE_CAPABILITY_BOUNDING_STR));
                        }
                }

                if (arg_no_new_privs) {
                        if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) {
                                *ret_error_message = "Failed to disable new privileges";
                                return log_struct_errno(LOG_EMERG, errno,
                                                        LOG_MESSAGE("Failed to disable new privileges: %m"),
                                                        LOG_MESSAGE_ID(SD_MESSAGE_CORE_DISABLE_PRIVILEGES_STR));
                        }
                }

                break;

        case RUNTIME_SCOPE_USER: {
                _cleanup_free_ char *p = NULL;

                /* Create the runtime directory and place the inaccessible device nodes there, if we run in
                 * user mode. In system mode mount_setup() already did that. */

                r = xdg_user_runtime_dir("/systemd", &p);
                if (r < 0) {
                        *ret_error_message = "$XDG_RUNTIME_DIR is not set";
                        return log_struct_errno(LOG_EMERG, r,
                                                LOG_MESSAGE("Failed to determine $XDG_RUNTIME_DIR path: %m"),
                                                LOG_MESSAGE_ID(SD_MESSAGE_CORE_NO_XDGDIR_PATH_STR));
                }

                if (!skip_setup) {
                        (void) mkdir_p_label(p, 0755);
                        (void) make_inaccessible_nodes(p, UID_INVALID, GID_INVALID);

                        r = setup_os_release(RUNTIME_SCOPE_USER);
                        if (r < 0)
                                log_warning_errno(r, "Failed to copy os-release for propagation, ignoring: %m");
                }

                break;
        }

        default:
                assert_not_reached();
        }

        /* The two operations on the ambient set are meant for a user serssion manager. They do not affect
         * system manager operation, because by default it starts with an empty ambient set.
         *
         * Preserve the ambient set for later use with sd-executor processes. */
        r = capability_get_ambient(saved_ambient_set);
        if (r < 0)
                log_warning_errno(r, "Failed to save ambient capabilities, ignoring: %m");

        /* Clear ambient capabilities, so services do not inherit them implicitly. Dropping them does
         * not affect the permitted and effective sets which are important for the manager itself to
         * operate. */
        r = capability_ambient_set_apply(0, /* also_inherit= */ false);
        if (r < 0)
                log_warning_errno(r, "Failed to reset ambient capability set, ignoring: %m");

        if (arg_timer_slack_nsec != NSEC_INFINITY)
                if (prctl(PR_SET_TIMERSLACK, arg_timer_slack_nsec) < 0)
                        log_warning_errno(errno, "Failed to adjust timer slack, ignoring: %m");

        if (arg_syscall_archs) {
                r = enforce_syscall_archs(arg_syscall_archs);
                if (r < 0) {
                        *ret_error_message = "Failed to set syscall architectures";
                        return r;
                }
        }

        r = make_reaper_process(true);
        if (r < 0)
                log_warning_errno(r, "Failed to make us a subreaper, ignoring: %m");

        /* Bump up RLIMIT_NOFILE for systemd itself */
        (void) bump_rlimit_nofile(saved_rlimit_nofile);
        (void) bump_rlimit_memlock(saved_rlimit_memlock);

        return 0;
}

static int do_queue_default_job(
                Manager *m,
                const char **ret_error_message) {

        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
        const char *unit;
        Job *job;
        Unit *target;
        int r;

        if (arg_default_unit)
                unit = arg_default_unit;
        else if (in_initrd())
                unit = SPECIAL_INITRD_TARGET;
        else
                unit = SPECIAL_DEFAULT_TARGET;

        log_debug("Activating default unit: %s", unit);

        r = manager_load_startable_unit_or_warn(m, unit, NULL, &target);
        if (r < 0 && in_initrd() && !arg_default_unit) {
                /* Fall back to default.target, which we used to always use by default. Only do this if no
                 * explicit configuration was given. */

                log_info("Falling back to %s.", SPECIAL_DEFAULT_TARGET);

                r = manager_load_startable_unit_or_warn(m, SPECIAL_DEFAULT_TARGET, NULL, &target);
        }
        if (r < 0) {
                log_info("Falling back to %s.", SPECIAL_RESCUE_TARGET);

                r = manager_load_startable_unit_or_warn(m, SPECIAL_RESCUE_TARGET, NULL, &target);
                if (r < 0) {
                        *ret_error_message = r == -ERFKILL ? SPECIAL_RESCUE_TARGET " masked"
                                                           : "Failed to load " SPECIAL_RESCUE_TARGET;
                        return r;
                }
        }

        assert(target->load_state == UNIT_LOADED);

        r = manager_add_job(m, JOB_START, target, JOB_ISOLATE, &error, &job);
        if (r == -EPERM) {
                log_debug_errno(r, "Default target could not be isolated, starting instead: %s", bus_error_message(&error, r));

                sd_bus_error_free(&error);

                r = manager_add_job(m, JOB_START, target, JOB_REPLACE, &error, &job);
                if (r < 0) {
                        *ret_error_message = "Failed to start default target";
                        return log_struct_errno(LOG_EMERG, r,
                                                LOG_MESSAGE("Failed to start default target: %s", bus_error_message(&error, r)),
                                                LOG_MESSAGE_ID(SD_MESSAGE_CORE_START_TARGET_FAILED_STR));
                }

        } else if (r < 0) {
                *ret_error_message = "Failed to isolate default target";
                return log_struct_errno(LOG_EMERG, r,
                                        LOG_MESSAGE("Failed to isolate default target: %s", bus_error_message(&error, r)),
                                        LOG_MESSAGE_ID(SD_MESSAGE_CORE_ISOLATE_TARGET_FAILED_STR));
        }

        log_info("Queued %s job for default target %s.",
                 job_type_to_string(job->type), unit_status_string(job->unit, NULL));

        return 0;
}

static void save_rlimits(struct rlimit *saved_rlimit_nofile,
                         struct rlimit *saved_rlimit_memlock) {

        assert(saved_rlimit_nofile);
        assert(saved_rlimit_memlock);

        if (getrlimit(RLIMIT_NOFILE, saved_rlimit_nofile) < 0)
                log_warning_errno(errno, "Reading RLIMIT_NOFILE failed, ignoring: %m");

        if (getrlimit(RLIMIT_MEMLOCK, saved_rlimit_memlock) < 0)
                log_warning_errno(errno, "Reading RLIMIT_MEMLOCK failed, ignoring: %m");
}

static void fallback_rlimit_nofile(const struct rlimit *saved_rlimit_nofile) {
        struct rlimit *rl;

        if (arg_defaults.rlimit[RLIMIT_NOFILE])
                return;

        /* Make sure forked processes get limits based on the original kernel setting */

        rl = newdup(struct rlimit, saved_rlimit_nofile, 1);
        if (!rl) {
                log_oom();
                return;
        }

        /* Bump the hard limit for system services to a substantially higher value. The default
         * hard limit current kernels set is pretty low (4K), mostly for historical
         * reasons. According to kernel developers, the fd handling in recent kernels has been
         * optimized substantially enough, so that we can bump the limit now, without paying too
         * high a price in memory or performance. Note however that we only bump the hard limit,
         * not the soft limit. That's because select() works the way it works, and chokes on fds
         * >= 1024. If we'd bump the soft limit globally, it might accidentally happen to
         * unexpecting programs that they get fds higher than what they can process using
         * select(). By only bumping the hard limit but leaving the low limit as it is we avoid
         * this pitfall:  programs that are written by folks aware of the select() problem in mind
         * (and thus use poll()/epoll instead of select(), the way everybody should) can
         * explicitly opt into high fds by bumping their soft limit beyond 1024, to the hard limit
         * we pass. */
        if (arg_runtime_scope == RUNTIME_SCOPE_SYSTEM)
                rl->rlim_max = MIN((rlim_t) read_nr_open(), MAX(rl->rlim_max, (rlim_t) HIGH_RLIMIT_NOFILE));

        /* If for some reason we were invoked with a soft limit above 1024 (which should never
         * happen!, but who knows what we get passed in from pam_limit when invoked as --user
         * instance), then lower what we pass on to not confuse our children */
        rl->rlim_cur = MIN(rl->rlim_cur, (rlim_t) FD_SETSIZE);

        arg_defaults.rlimit[RLIMIT_NOFILE] = rl;
}

static void fallback_rlimit_memlock(const struct rlimit *saved_rlimit_memlock) {
        struct rlimit *rl;

        /* Pass the original value down to invoked processes */

        if (arg_defaults.rlimit[RLIMIT_MEMLOCK])
                return;

        rl = newdup(struct rlimit, saved_rlimit_memlock, 1);
        if (!rl) {
                log_oom();
                return;
        }

        if (arg_runtime_scope == RUNTIME_SCOPE_SYSTEM)  {
                /* Raise the default limit to 8M also on old kernels and in containers (8M is the kernel
                 * default for this since kernel 5.16) */
                rl->rlim_max = MAX(rl->rlim_max, (rlim_t) DEFAULT_RLIMIT_MEMLOCK);
                rl->rlim_cur = MAX(rl->rlim_cur, (rlim_t) DEFAULT_RLIMIT_MEMLOCK);
        }

        arg_defaults.rlimit[RLIMIT_MEMLOCK] = rl;
}

static void setenv_manager_environment(void) {
        int r;

        STRV_FOREACH(p, arg_manager_environment) {
                log_debug("Setting '%s' in our own environment.", *p);

                r = putenv_dup(*p, true);
                if (r < 0)
                        log_warning_errno(r, "Failed to setenv \"%s\", ignoring: %m", *p);
        }
}

static void reset_arguments(void) {
        /* Frees/resets arg_* variables, with a few exceptions commented below. */

        arg_default_unit = mfree(arg_default_unit);

        /* arg_runtime_scope — ignore */

        arg_dump_core = true;
        arg_crash_chvt = -1;
        arg_crash_shell = false;
        arg_crash_action = CRASH_FREEZE;
        arg_confirm_spawn = mfree(arg_confirm_spawn);
        arg_show_status = _SHOW_STATUS_INVALID;
        arg_status_unit_format = STATUS_UNIT_FORMAT_DEFAULT;
        arg_switched_root = false;
        arg_pager_flags = 0;
        arg_service_watchdogs = true;

        unit_defaults_done(&arg_defaults);
        unit_defaults_init(&arg_defaults, arg_runtime_scope);

        arg_runtime_watchdog = 0;
        arg_reboot_watchdog = 10 * USEC_PER_MINUTE;
        arg_kexec_watchdog = 0;
        arg_pretimeout_watchdog = 0;
        arg_early_core_pattern = mfree(arg_early_core_pattern);
        arg_watchdog_device = mfree(arg_watchdog_device);
        arg_watchdog_pretimeout_governor = mfree(arg_watchdog_pretimeout_governor);

        arg_default_environment = strv_free(arg_default_environment);
        arg_manager_environment = strv_free(arg_manager_environment);

        arg_capability_bounding_set = CAP_MASK_ALL;
        arg_no_new_privs = false;
        arg_protect_system = -1;
        arg_timer_slack_nsec = NSEC_INFINITY;

        arg_syscall_archs = set_free(arg_syscall_archs);

        /* arg_serialization — ignore */

        arg_machine_id = (sd_id128_t) {};
        arg_cad_burst_action = EMERGENCY_ACTION_REBOOT_FORCE;

        cpu_set_done(&arg_cpu_affinity);
        numa_policy_reset(&arg_numa_policy);

        arg_random_seed = mfree(arg_random_seed);
        arg_random_seed_size = 0;
        arg_clock_usec = 0;

        arg_reload_limit_interval_sec = 0;
        arg_reload_limit_burst = 0;
}

static void determine_default_oom_score_adjust(void) {
        int r, a, b;

        /* Run our services at slightly higher OOM score than ourselves. But let's be conservative here, and
         * do this only if we don't run as root (i.e. only if we are run in user mode, for an unprivileged
         * user). */

        if (arg_defaults.oom_score_adjust_set)
                return;

        if (getuid() == 0)
                return;

        r = get_oom_score_adjust(&a);
        if (r < 0)
                return (void) log_warning_errno(r, "Failed to determine current OOM score adjustment value, ignoring: %m");

        assert_cc(100 <= OOM_SCORE_ADJ_MAX);
        b = saturate_add(a, 100, OOM_SCORE_ADJ_MAX);

        if (a == b)
                return;

        arg_defaults.oom_score_adjust = b;
        arg_defaults.oom_score_adjust_set = true;
}

static int parse_configuration(const struct rlimit *saved_rlimit_nofile,
                               const struct rlimit *saved_rlimit_memlock) {
        int r;

        assert(saved_rlimit_nofile);
        assert(saved_rlimit_memlock);

        /* Assign configuration defaults */
        reset_arguments();

        r = parse_config_file();
        if (r < 0)
                log_warning_errno(r, "Failed to parse config file, ignoring: %m");

        if (arg_runtime_scope == RUNTIME_SCOPE_SYSTEM) {
                r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
        }

        /* Initialize the show status setting if it hasn't been explicitly set yet */
        if (arg_show_status == _SHOW_STATUS_INVALID)
                arg_show_status = SHOW_STATUS_YES;

        /* Push variables into the manager environment block */
        setenv_manager_environment();

        /* Parse log environment variables to take into account any new environment variables.
         * Note that this also parses bits from the kernel command line, including "debug". */
        log_parse_environment();

        /* Initialize some default rlimits for services if they haven't been configured */
        fallback_rlimit_nofile(saved_rlimit_nofile);
        fallback_rlimit_memlock(saved_rlimit_memlock);

        /* Slightly raise the OOM score for our services if we are running for unprivileged users. */
        determine_default_oom_score_adjust();

        return 0;
}

static int safety_checks(void) {

        if (getpid_cached() == 1 &&
            arg_action != ACTION_RUN)
                return log_error_errno(SYNTHETIC_ERRNO(EPERM),
                                       "Unsupported execution mode while PID 1.");

        if (getpid_cached() == 1 &&
            arg_runtime_scope == RUNTIME_SCOPE_USER)
                return log_error_errno(SYNTHETIC_ERRNO(EPERM),
                                       "Can't run --user mode as PID 1.");

        if (arg_action == ACTION_RUN &&
            arg_runtime_scope == RUNTIME_SCOPE_SYSTEM &&
            getpid_cached() != 1)
                return log_error_errno(SYNTHETIC_ERRNO(EPERM),
                                       "Can't run system mode unless PID 1.");

        if (arg_action == ACTION_TEST &&
            geteuid() == 0)
                return log_error_errno(SYNTHETIC_ERRNO(EPERM),
                                       "Don't run test mode as root.");

        switch (arg_runtime_scope) {

        case RUNTIME_SCOPE_USER:

                if (arg_action == ACTION_RUN &&
                    sd_booted() <= 0)
                        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                               "Trying to run as user instance, but the system has not been booted with systemd.");

                if (arg_action == ACTION_RUN &&
                    !getenv("XDG_RUNTIME_DIR"))
                        return log_error_errno(SYNTHETIC_ERRNO(EUNATCH),
                                               "Trying to run as user instance, but $XDG_RUNTIME_DIR is not set.");

                break;

        case RUNTIME_SCOPE_SYSTEM:
                if (arg_action == ACTION_RUN &&
                    running_in_chroot() > 0)
                        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                               "Cannot be run in a chroot() environment.");
                break;

        default:
                assert_not_reached();
        }

        return 0;
}

static int initialize_security(
                bool *loaded_policy,
                dual_timestamp *security_start_timestamp,
                dual_timestamp *security_finish_timestamp,
                const char **ret_error_message) {

        int r;

        assert(loaded_policy);
        assert(security_start_timestamp);
        assert(security_finish_timestamp);
        assert(ret_error_message);

        dual_timestamp_now(security_start_timestamp);

        r = mac_selinux_setup(loaded_policy);
        if (r < 0) {
                *ret_error_message = "Failed to load SELinux policy";
                return r;
        }

        r = mac_smack_setup(loaded_policy);
        if (r < 0) {
                *ret_error_message = "Failed to load SMACK policy";
                return r;
        }

        r = mac_apparmor_setup();
        if (r < 0) {
                *ret_error_message = "Failed to load AppArmor policy";
                return r;
        }

        r = ima_setup();
        if (r < 0) {
                *ret_error_message = "Failed to load IMA policy";
                return r;
        }

        r = ipe_setup();
        if (r < 0) {
                *ret_error_message = "Failed to load IPE policy";
                return r;
        }

        dual_timestamp_now(security_finish_timestamp);
        return 0;
}

static int collect_fds(FDSet **ret_fds, const char **ret_error_message) {
        int r;

        assert(ret_fds);
        assert(ret_error_message);

        /* Pick up all fds passed to us. We apply a filter here: we only take the fds that have O_CLOEXEC
         * off. All fds passed via execve() to us must have O_CLOEXEC off, and our own code and dependencies
         * should be clean enough to set O_CLOEXEC universally. Thus checking the bit should be a safe
         * mechanism to distinguish passed in fds from our own.
         *
         * Why bother? Some subsystems we initialize early, specifically selinux might keep fds open in our
         * process behind our back. We should not take possession of that (and then accidentally close
         * it). SELinux thankfully sets O_CLOEXEC on its fds, so this test should work. */
        r = fdset_new_fill(/* filter_cloexec= */ 0, ret_fds);
        if (r < 0) {
                *ret_error_message = "Failed to allocate fd set";
                return log_struct_errno(LOG_EMERG, r,
                                        LOG_MESSAGE("Failed to allocate fd set: %m"),
                                        LOG_MESSAGE_ID(SD_MESSAGE_CORE_FD_SET_FAILED_STR));
        }

        /* The serialization fd should have O_CLOEXEC turned on already, let's verify that we didn't pick it up here */
        assert_se(!arg_serialization || !fdset_contains(*ret_fds, fileno(arg_serialization)));

        return 0;
}

static void setup_console_terminal(bool skip_setup) {

        if (arg_runtime_scope != RUNTIME_SCOPE_SYSTEM)
                return;

        /* If we are init, we connect stdin/stdout/stderr to /dev/null and make sure we don't have a
         * controlling tty. */
        terminal_detach_session();

        /* Reset the console, but only if this is really init and we are freshly booted */
        if (!skip_setup)
                (void) console_setup();
}

static bool early_skip_setup_check(int argc, char *argv[]) {
        bool found_deserialize = false;

        /* Determine if this is a reexecution or normal bootup. We do the full command line parsing much
         * later, so let's just have a quick peek here. Note that if we have switched root, do all the
         * special setup things anyway, even if in that case we also do deserialization. */

        for (int i = 1; i < argc; i++)
                if (streq(argv[i], "--switched-root"))
                        return false; /* If we switched root, don't skip the setup. */
                else if (startswith(argv[i], "--deserialize=") || streq(argv[i], "--deserialize"))
                        found_deserialize = true;

        return found_deserialize; /* When we are deserializing, then we are reexecuting, hence avoid the extensive setup */
}

static int save_env(void) {
        char **l;

        l = strv_copy(environ);
        if (!l)
                return log_oom();

        strv_free_and_replace(saved_env, l);
        return 0;
}

int main(int argc, char *argv[]) {
        dual_timestamp
                initrd_timestamp = DUAL_TIMESTAMP_NULL,
                userspace_timestamp = DUAL_TIMESTAMP_NULL,
                kernel_timestamp = DUAL_TIMESTAMP_NULL,
                security_start_timestamp = DUAL_TIMESTAMP_NULL,
                security_finish_timestamp = DUAL_TIMESTAMP_NULL;
        struct rlimit saved_rlimit_nofile = RLIMIT_MAKE_CONST(0),
                saved_rlimit_memlock = RLIMIT_MAKE_CONST(RLIM_INFINITY); /* The original rlimits we passed
                                                                          * in. Note we use different values
                                                                          * for the two that indicate whether
                                                                          * these fields are initialized! */
        bool skip_setup, loaded_policy = false, queue_default_job = false, first_boot = false;
        char *switch_root_dir = NULL, *switch_root_init = NULL;
        usec_t before_startup, after_startup;
        static char systemd[] = "systemd";
        const char *error_message = NULL;
        uint64_t saved_ambient_set = 0;
        int r, retval = EXIT_FAILURE;
        Manager *m = NULL;
        FDSet *fds = NULL;

        assert_se(argc > 0 && !isempty(argv[0]));

        /* Take timestamps early on */
        dual_timestamp_from_monotonic(&kernel_timestamp, 0);
        dual_timestamp_now(&userspace_timestamp);

        /* Figure out whether we need to do initialize the system, or if we already did that because we are
         * reexecuting. */
        skip_setup = early_skip_setup_check(argc, argv);

        /* If we get started via the /sbin/init symlink then we are called 'init'. After a subsequent
         * reexecution we are then called 'systemd'. That is confusing, hence let's call us systemd
         * right-away. */
        program_invocation_short_name = systemd;
        (void) prctl(PR_SET_NAME, systemd);

        /* Save the original command line */
        save_argc_argv(argc, argv);

        /* Save the original environment as we might need to restore it if we're requested to execute another
         * system manager later. */
        r = save_env();
        if (r < 0) {
                error_message = "Failed to copy environment block";
                goto finish;
        }

        /* Make sure that if the user says "syslog" we actually log to the journal. */
        log_set_upgrade_syslog_to_journal(true);

        if (getpid_cached() == 1) {
                /* When we run as PID 1 force system mode */
                arg_runtime_scope = RUNTIME_SCOPE_SYSTEM;

                /* Disable the umask logic */
                umask(0);

                /* Make sure that at least initially we do not ever log to journald/syslogd, because it might
                 * not be activated yet (even though the log socket for it exists). */
                log_set_prohibit_ipc(true);

                /* Always reopen /dev/console when running as PID 1 or one of its pre-execve() children. This
                 * is important so that we never end up logging to any foreign stderr, for example if we have
                 * to log in a child process right before execve()'ing the actual binary, at a point in time
                 * where socket activation stderr/stdout area already set up. */
                log_set_always_reopen_console(true);

                if (detect_container() <= 0) {

                        /* Running outside of a container as PID 1 */
                        log_set_target_and_open(LOG_TARGET_KMSG);

                        if (in_initrd())
                                initrd_timestamp = userspace_timestamp;

                        if (!skip_setup) {
                                r = mount_setup_early();
                                if (r < 0) {
                                        error_message = "Failed to mount early API filesystems";
                                        goto finish;
                                }
                        }

                        /* We might have just mounted /proc, so let's try to parse the kernel
                         * command line log arguments immediately. */
                        log_parse_environment();

                        /* Let's open the log backend a second time, in case the first time didn't
                         * work. Quite possibly we have mounted /dev just now, so /dev/kmsg became
                         * available, and it previously wasn't. */
                        log_open();

                        if (!skip_setup) {
                                disable_printk_ratelimit();

                                r = initialize_security(
                                                &loaded_policy,
                                                &security_start_timestamp,
                                                &security_finish_timestamp,
                                                &error_message);
                                if (r < 0)
                                        goto finish;
                        }

                        r = mac_init();
                        if (r < 0) {
                                error_message = "Failed to initialize MAC support";
                                goto finish;
                        }

                        if (!skip_setup)
                                initialize_clock_timewarp();

                        clock_apply_epoch(/* allow_backwards= */ !skip_setup);

                        /* Set the default for later on, but don't actually open the logs like this for
                         * now. Note that if we are transitioning from the initrd there might still be
                         * journal fd open, and we shouldn't attempt opening that before we parsed
                         * /proc/cmdline which might redirect output elsewhere. */
                        log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);

                } else {
                        /* Running inside a container, as PID 1 */
                        log_set_target_and_open(LOG_TARGET_CONSOLE);

                        /* For later on, see above... */
                        log_set_target(LOG_TARGET_JOURNAL);

                        /* clear the kernel timestamp, because we are in a container */
                        kernel_timestamp = DUAL_TIMESTAMP_NULL;
                }

                initialize_coredump(skip_setup);

                r = fixup_environment();
                if (r < 0) {
                        log_struct_errno(LOG_EMERG, r,
                                         LOG_MESSAGE("Failed to fix up PID 1 environment: %m"),
                                         LOG_MESSAGE_ID(SD_MESSAGE_CORE_PID1_ENVIRONMENT_STR));
                        error_message = "Failed to fix up PID1 environment";
                        goto finish;
                }

                /* Try to figure out if we can use colors with the console. No need to do that for user
                 * instances since they never log into the console. */
                log_show_color(colors_enabled());

                r = make_null_stdio();
                if (r < 0)
                        log_warning_errno(r, "Failed to redirect standard streams to /dev/null, ignoring: %m");

                /* Load the kernel modules early. */
                if (!skip_setup)
                        (void) kmod_setup();

                /* Mount /proc, /sys and friends, so that /proc/cmdline and /proc/$PID/fd is available. */
                r = mount_setup(loaded_policy, skip_setup);
                if (r < 0) {
                        error_message = "Failed to mount API filesystems";
                        goto finish;
                }

                /* The efivarfs is now mounted, let's lock down the system token. */
                lock_down_efi_variables();
        } else {
                /* Running as user instance */
                arg_runtime_scope = RUNTIME_SCOPE_USER;
                log_set_always_reopen_console(true);
                log_set_target_and_open(LOG_TARGET_AUTO);

                /* clear the kernel timestamp, because we are not PID 1 */
                kernel_timestamp = DUAL_TIMESTAMP_NULL;

                r = mac_init();
                if (r < 0) {
                        error_message = "Failed to initialize MAC support";
                        goto finish;
                }
        }

        /* Save the original RLIMIT_NOFILE/RLIMIT_MEMLOCK so that we can reset it later when
         * transitioning from the initrd to the main systemd or suchlike. */
        save_rlimits(&saved_rlimit_nofile, &saved_rlimit_memlock);

        /* Reset all signal handlers. */
        (void) reset_all_signal_handlers();
        (void) ignore_signals(SIGNALS_IGNORE);

        (void) parse_configuration(&saved_rlimit_nofile, &saved_rlimit_memlock);

        r = parse_argv(argc, argv);
        if (r < 0) {
                error_message = "Failed to parse command line arguments";
                goto finish;
        }

        r = safety_checks();
        if (r < 0)
                goto finish;

        if (IN_SET(arg_action, ACTION_TEST, ACTION_HELP, ACTION_DUMP_CONFIGURATION_ITEMS, ACTION_DUMP_BUS_PROPERTIES, ACTION_BUS_INTROSPECT))
                pager_open(arg_pager_flags);

        if (arg_action != ACTION_RUN)
                skip_setup = true;

        if (arg_action == ACTION_HELP) {
                retval = help() < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
                goto finish;
        } else if (arg_action == ACTION_VERSION) {
                retval = version();
                goto finish;
        } else if (arg_action == ACTION_DUMP_CONFIGURATION_ITEMS) {
                unit_dump_config_items(stdout);
                retval = EXIT_SUCCESS;
                goto finish;
        } else if (arg_action == ACTION_DUMP_BUS_PROPERTIES) {
                dump_bus_properties(stdout);
                retval = EXIT_SUCCESS;
                goto finish;
        } else if (arg_action == ACTION_BUS_INTROSPECT) {
                r = bus_manager_introspect_implementations(stdout, arg_bus_introspect);
                retval = r >= 0 ? EXIT_SUCCESS : EXIT_FAILURE;
                goto finish;
        }

        assert_se(IN_SET(arg_action, ACTION_RUN, ACTION_TEST));

        /* Move out of the way, so that we won't block unmounts */
        assert_se(chdir("/") == 0);

        if (arg_action == ACTION_RUN) {
                if (!skip_setup) {
                        /* Apply the systemd.clock_usec= kernel command line switch */
                        apply_clock_update();

                        /* Apply random seed from kernel command line */
                        cmdline_take_random_seed();
                }

                /* A core pattern might have been specified via the cmdline. */
                initialize_core_pattern(skip_setup);

                /* Make /usr/ read-only */
                apply_protect_system(skip_setup);

                /* Close logging fds, in order not to confuse collecting passed fds and terminal logic below */
                log_close();

                /* Remember open file descriptors for later deserialization */
                r = collect_fds(&fds, &error_message);
                if (r < 0)
                        goto finish;

                /* Give up any control of the console, but make sure its initialized. */
                setup_console_terminal(skip_setup);

                /* Open the logging devices, if possible and necessary */
                log_open();
        }

        log_execution_mode(&first_boot);

        r = cg_has_legacy();
        if (r < 0) {
                error_message = "Failed to check cgroup hierarchy";
                goto finish;
        }
        if (r > 0) {
                r = log_full_errno(LOG_EMERG, SYNTHETIC_ERRNO(EPROTO),
                                   "Detected cgroup v1 hierarchy at /sys/fs/cgroup/, which is no longer supported by current version of systemd.\n"
                                   "Please instruct your initrd to mount cgroup v2 (unified) hierarchy,\n"
                                   "possibly by removing any stale kernel command line options, such as:\n"
                                   "  systemd.legacy_systemd_cgroup_controller=1\n"
                                   "  systemd.unified_cgroup_hierarchy=0");

                error_message = "Detected unsupported legacy cgroup hierarchy, refusing execution";
                goto finish;
        }

        /* Building without libmount is allowed, but if it is compiled in, then we must be able to load it */
        r = dlopen_libmount();
        if (r < 0 && !ERRNO_IS_NEG_NOT_SUPPORTED(r)) {
                error_message = "Failed to load libmount.so";
                goto finish;
        }

        r = initialize_runtime(skip_setup,
                               first_boot,
                               &saved_rlimit_nofile,
                               &saved_rlimit_memlock,
                               &saved_ambient_set,
                               &error_message);
        if (r < 0)
                goto finish;

        r = manager_new(arg_runtime_scope,
                        arg_action == ACTION_TEST ? MANAGER_TEST_FULL : 0,
                        &m);
        if (r < 0) {
                log_struct_errno(LOG_EMERG, r,
                                 LOG_MESSAGE("Failed to allocate manager object: %m"),
                                 LOG_MESSAGE_ID(SD_MESSAGE_CORE_MANAGER_ALLOCATE_STR));
                error_message = "Failed to allocate manager object";
                goto finish;
        }

        m->timestamps[MANAGER_TIMESTAMP_KERNEL] = kernel_timestamp;
        m->timestamps[MANAGER_TIMESTAMP_INITRD] = initrd_timestamp;
        m->timestamps[MANAGER_TIMESTAMP_USERSPACE] = userspace_timestamp;
        m->timestamps[manager_timestamp_initrd_mangle(MANAGER_TIMESTAMP_SECURITY_START)] = security_start_timestamp;
        m->timestamps[manager_timestamp_initrd_mangle(MANAGER_TIMESTAMP_SECURITY_FINISH)] = security_finish_timestamp;

        m->saved_ambient_set = saved_ambient_set;

        set_manager_defaults(m);
        set_manager_settings(m);
        manager_set_first_boot(m, first_boot);
        manager_set_switching_root(m, arg_switched_root);

        /* Remember whether we should queue the default job */
        queue_default_job = !arg_serialization || arg_switched_root;

        before_startup = now(CLOCK_MONOTONIC);

        r = manager_startup(m, arg_serialization, fds, /* root= */ NULL);
        if (r < 0) {
                error_message = "Failed to start up manager";
                goto finish;
        }

        /* This will close all file descriptors that were opened, but not claimed by any unit. */
        fds = fdset_free(fds);
        arg_serialization = safe_fclose(arg_serialization);

        if (queue_default_job) {
                r = do_queue_default_job(m, &error_message);
                if (r < 0)
                        goto finish;
        }

        after_startup = now(CLOCK_MONOTONIC);

        log_full(arg_action == ACTION_TEST ? LOG_INFO : LOG_DEBUG,
                 "Loaded units and determined initial transaction in %s.",
                 FORMAT_TIMESPAN(after_startup - before_startup, 100 * USEC_PER_MSEC));

        if (arg_action == ACTION_TEST) {
                manager_test_summary(m);
                retval = EXIT_SUCCESS;
                goto finish;
        }

        r = invoke_main_loop(m,
                             &saved_rlimit_nofile,
                             &saved_rlimit_memlock,
                             &retval,
                             &fds,
                             &switch_root_dir,
                             &switch_root_init,
                             &error_message);
        /* MANAGER_OK and MANAGER_RELOAD are not expected here. */
        assert(r < 0 || IN_SET(r, MANAGER_REEXECUTE, MANAGER_EXIT) ||
               (arg_runtime_scope == RUNTIME_SCOPE_SYSTEM &&
                IN_SET(r, MANAGER_REBOOT,
                          MANAGER_SOFT_REBOOT,
                          MANAGER_POWEROFF,
                          MANAGER_HALT,
                          MANAGER_KEXEC,
                          MANAGER_SWITCH_ROOT)));

finish:
        pager_close();

        if (m) {
                arg_reboot_watchdog = manager_get_watchdog(m, WATCHDOG_REBOOT);
                arg_kexec_watchdog = manager_get_watchdog(m, WATCHDOG_KEXEC);
                m = manager_free(m);
        }

        mac_selinux_finish();

        if (IN_SET(r, MANAGER_REEXECUTE, MANAGER_SWITCH_ROOT, MANAGER_SOFT_REBOOT))
                r = do_reexecute(r,
                                 argc, argv,
                                 &saved_rlimit_nofile,
                                 &saved_rlimit_memlock,
                                 fds,
                                 switch_root_dir,
                                 switch_root_init,
                                 saved_ambient_set,
                                 &error_message); /* This only returns if reexecution failed */

        arg_serialization = safe_fclose(arg_serialization);
        fds = fdset_free(fds);

        saved_env = strv_free(saved_env);

#if HAVE_VALGRIND_VALGRIND_H
        /* If we are PID 1 and running under valgrind, then let's exit
         * here explicitly. valgrind will only generate nice output on
         * exit(), not on exec(), hence let's do the former not the
         * latter here. */
        if (getpid_cached() == 1 && RUNNING_ON_VALGRIND) {
                /* Cleanup watchdog_device strings for valgrind. We need them
                 * in become_shutdown() so normally we cannot free them yet. */
                watchdog_free_device();
                reset_arguments();
                return retval;
        }
#endif

#if HAS_FEATURE_ADDRESS_SANITIZER
        /* At this stage we most likely don't have stdio/stderr open, so the following
         * LSan check would not print any actionable information and would just crash
         * PID 1. To make this a bit more helpful, let's try to open /dev/console,
         * and if we succeed redirect LSan's report there. */
        if (getpid_cached() == 1) {
                _cleanup_close_ int tty_fd = -EBADF;

                tty_fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
                if (tty_fd >= 0)
                        __sanitizer_set_report_fd((void*) (intptr_t) tty_fd);

                __lsan_do_leak_check();
        }
#endif

        if (r < 0)
                (void) sd_notifyf(/* unset_environment= */ false,
                                  "ERRNO=%i", -r);

        /* Try to invoke the shutdown binary unless we already failed.
         * If we failed above, we want to freeze after finishing cleanup. */
        if (arg_runtime_scope == RUNTIME_SCOPE_SYSTEM &&
            IN_SET(r, MANAGER_EXIT, MANAGER_REBOOT, MANAGER_POWEROFF, MANAGER_HALT, MANAGER_KEXEC)) {
                r = become_shutdown(r, retval);
                log_error_errno(r, "Failed to execute shutdown binary, %s: %m", getpid_cached() == 1 ? "freezing" : "quitting");
                error_message = "Failed to execute shutdown binary";
        }

        /* This is primarily useful when running systemd in a VM, as it provides the user running the VM with
         * a mechanism to pick up systemd's exit status in the VM. */
        (void) sd_notifyf(/* unset_environment= */ false,
                          "EXIT_STATUS=%i", retval);

        watchdog_free_device();
        arg_watchdog_device = mfree(arg_watchdog_device);

        if (getpid_cached() == 1) {
                if (error_message)
                        manager_status_printf(NULL, STATUS_TYPE_EMERGENCY,
                                              ANSI_HIGHLIGHT_RED "!!!!!!" ANSI_NORMAL,
                                              "%s.", error_message);
                freeze_or_exit_or_reboot();
        }

        reset_arguments();
        return retval;
}
