Merging upstream version 256.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 150 insertions, 94 deletions

diff --git a/src/userdb/20-systemd-userdb.conf.in b/src/userdb/20-systemd-userdb.conf.in
new file mode 100644
index 0000000..031fc3a
--- /dev/null
+++ b/src/userdb/20-systemd-userdb.conf.in
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# Make sure SSH authorized keys recorded in user records can be consumed by SSH
+#
+AuthorizedKeysCommand {{BINDIR}}/userdbctl ssh-authorized-keys %u
+AuthorizedKeysCommandUser root
diff --git a/src/userdb/meson.build b/src/userdb/meson.build
index 2d701c8..413f2be 100644
--- a/src/userdb/meson.build
+++ b/src/userdb/meson.build
@@ -23,3 +23,20 @@ executables += [
                 'dependencies' : threads,
         },
 ]
+
+if conf.get('ENABLE_SSH_USERDB_CONFIG') == 1
+        custom_target(
+                '20-systemd-userdb.conf',
+                input : '20-systemd-userdb.conf.in',
+                output : '20-systemd-userdb.conf',
+                command : [jinja2_cmdline, '@INPUT@', '@OUTPUT@'],
+                install : true,
+                install_dir : sshdconfdir.startswith('/usr/') ? sshdconfdir : libexecdir / 'sshd_config.d')
+
+        if not sshdconfdir.startswith('/usr/')
+                install_emptydir(sshdconfdir)
+
+                meson.add_install_script(sh, '-c',
+                        ln_s.format(libexecdir / 'sshd_config.d' / '20-systemd-userdb.conf', sshdconfdir / '20-systemd-userdb.conf'))
+        endif
+endif
diff --git a/src/userdb/userdbctl.c b/src/userdb/userdbctl.c
index 238a71d..1718419 100644
--- a/src/userdb/userdbctl.c
+++ b/src/userdb/userdbctl.c
@@ -169,24 +169,24 @@ static const struct {
         },
 };
 
-static int table_add_uid_boundaries(Table *table, const UidRange *p) {
+static int table_add_uid_boundaries(Table *table, const UIDRange *p) {
         int r;
 
         assert(table);
 
-        for (size_t i = 0; i < ELEMENTSOF(uid_range_table); i++) {
+        FOREACH_ELEMENT(i, uid_range_table) {
                 _cleanup_free_ char *name = NULL, *comment = NULL;
 
-                if (!uid_range_covers(p, uid_range_table[i].first, uid_range_table[i].last - uid_range_table[i].first + 1))
+                if (!uid_range_covers(p, i->first, i->last - i->first + 1))
                         continue;
 
                 name = strjoin(special_glyph(SPECIAL_GLYPH_ARROW_DOWN),
-                               " begin ", uid_range_table[i].name, " users ",
+                               " begin ", i->name, " users ",
                                special_glyph(SPECIAL_GLYPH_ARROW_DOWN));
                 if (!name)
                         return log_oom();
 
-                comment = strjoin("First ", uid_range_table[i].name, " user");
+                comment = strjoin("First ", i->name, " user");
                 if (!comment)
                         return log_oom();
 
@@ -195,9 +195,9 @@ static int table_add_uid_boundaries(Table *table, const UidRange *p) {
                                 TABLE_STRING, special_glyph(SPECIAL_GLYPH_TREE_TOP),
                                 TABLE_STRING, name,
                                 TABLE_SET_COLOR, ansi_grey(),
-                                TABLE_STRING, user_disposition_to_string(uid_range_table[i].disposition),
+                                TABLE_STRING, user_disposition_to_string(i->disposition),
                                 TABLE_SET_COLOR, ansi_grey(),
-                                TABLE_UID, uid_range_table[i].first,
+                                TABLE_UID, i->first,
                                 TABLE_SET_COLOR, ansi_grey(),
                                 TABLE_EMPTY,
                                 TABLE_STRING, comment,
@@ -210,13 +210,13 @@ static int table_add_uid_boundaries(Table *table, const UidRange *p) {
 
                 free(name);
                 name = strjoin(special_glyph(SPECIAL_GLYPH_ARROW_UP),
-                               " end ", uid_range_table[i].name, " users ",
+                               " end ", i->name, " users ",
                                special_glyph(SPECIAL_GLYPH_ARROW_UP));
                 if (!name)
                         return log_oom();
 
                 free(comment);
-                comment = strjoin("Last ", uid_range_table[i].name, " user");
+                comment = strjoin("Last ", i->name, " user");
                 if (!comment)
                         return log_oom();
 
@@ -225,9 +225,9 @@ static int table_add_uid_boundaries(Table *table, const UidRange *p) {
                                 TABLE_STRING, special_glyph(SPECIAL_GLYPH_TREE_RIGHT),
                                 TABLE_STRING, name,
                                 TABLE_SET_COLOR, ansi_grey(),
-                                TABLE_STRING, user_disposition_to_string(uid_range_table[i].disposition),
+                                TABLE_STRING, user_disposition_to_string(i->disposition),
                                 TABLE_SET_COLOR, ansi_grey(),
-                                TABLE_UID, uid_range_table[i].last,
+                                TABLE_UID, i->last,
                                 TABLE_SET_COLOR, ansi_grey(),
                                 TABLE_EMPTY,
                                 TABLE_STRING, comment,
@@ -301,7 +301,7 @@ static int add_unavailable_uid(Table *table, uid_t start, uid_t end) {
 
 static int table_add_uid_map(
                 Table *table,
-                const UidRange *p,
+                const UIDRange *p,
                 int (*add_unavailable)(Table *t, uid_t start, uid_t end)) {
 
         uid_t focus = 0;
@@ -313,9 +313,7 @@ static int table_add_uid_map(
         if (!p)
                 return 0;
 
-        for (size_t i = 0; p && i < p->n_entries; i++) {
-                UidRangeEntry *x = p->entries + i;
-
+        FOREACH_ARRAY(x, p->entries, p->n_entries) {
                 if (focus < x->start) {
                         r = add_unavailable(table, focus, x->start-1);
                         if (r < 0)
@@ -428,10 +426,10 @@ static int display_user(int argc, char *argv[], void *userdata) {
         }
 
         if (table) {
-                _cleanup_(uid_range_freep) UidRange *uid_range = NULL;
+                _cleanup_(uid_range_freep) UIDRange *uid_range = NULL;
                 int boundary_lines, uid_map_lines;
 
-                r = uid_range_load_userns(&uid_range, "/proc/self/uid_map");
+                r = uid_range_load_userns(/* path = */ NULL, UID_RANGE_USERNS_INSIDE, &uid_range);
                 if (r < 0)
                         log_debug_errno(r, "Failed to load /proc/self/uid_map, ignoring: %m");
 
@@ -443,7 +441,7 @@ static int display_user(int argc, char *argv[], void *userdata) {
                 if (uid_map_lines < 0)
                         return uid_map_lines;
 
-                if (table_get_rows(table) > 1) {
+                if (!table_isempty(table)) {
                         r = table_print_with_pager(table, arg_json_format_flags, arg_pager_flags, arg_legend);
                         if (r < 0)
                                 return table_log_print_error(r);
@@ -529,25 +527,24 @@ static int show_group(GroupRecord *gr, Table *table) {
         return 0;
 }
 
-static int table_add_gid_boundaries(Table *table, const UidRange *p) {
+static int table_add_gid_boundaries(Table *table, const UIDRange *p) {
         int r;
 
         assert(table);
 
-        for (size_t i = 0; i < ELEMENTSOF(uid_range_table); i++) {
+        FOREACH_ELEMENT(i, uid_range_table) {
                 _cleanup_free_ char *name = NULL, *comment = NULL;
 
-                if (!uid_range_covers(p, uid_range_table[i].first,
-                                      uid_range_table[i].last - uid_range_table[i].first + 1))
+                if (!uid_range_covers(p, i->first, i->last - i->first + 1))
                         continue;
 
                 name = strjoin(special_glyph(SPECIAL_GLYPH_ARROW_DOWN),
-                               " begin ", uid_range_table[i].name, " groups ",
+                               " begin ", i->name, " groups ",
                                special_glyph(SPECIAL_GLYPH_ARROW_DOWN));
                 if (!name)
                         return log_oom();
 
-                comment = strjoin("First ", uid_range_table[i].name, " group");
+                comment = strjoin("First ", i->name, " group");
                 if (!comment)
                         return log_oom();
 
@@ -556,9 +553,9 @@ static int table_add_gid_boundaries(Table *table, const UidRange *p) {
                                 TABLE_STRING, special_glyph(SPECIAL_GLYPH_TREE_TOP),
                                 TABLE_STRING, name,
                                 TABLE_SET_COLOR, ansi_grey(),
-                                TABLE_STRING, user_disposition_to_string(uid_range_table[i].disposition),
+                                TABLE_STRING, user_disposition_to_string(i->disposition),
                                 TABLE_SET_COLOR, ansi_grey(),
-                                TABLE_GID, uid_range_table[i].first,
+                                TABLE_GID, i->first,
                                 TABLE_SET_COLOR, ansi_grey(),
                                 TABLE_STRING, comment,
                                 TABLE_SET_COLOR, ansi_grey(),
@@ -568,13 +565,13 @@ static int table_add_gid_boundaries(Table *table, const UidRange *p) {
 
                 free(name);
                 name = strjoin(special_glyph(SPECIAL_GLYPH_ARROW_UP),
-                               " end ", uid_range_table[i].name, " groups ",
+                               " end ", i->name, " groups ",
                                special_glyph(SPECIAL_GLYPH_ARROW_UP));
                 if (!name)
                         return log_oom();
 
                 free(comment);
-                comment = strjoin("Last ", uid_range_table[i].name, " group");
+                comment = strjoin("Last ", i->name, " group");
                 if (!comment)
                         return log_oom();
 
@@ -583,9 +580,9 @@ static int table_add_gid_boundaries(Table *table, const UidRange *p) {
                                 TABLE_STRING, special_glyph(SPECIAL_GLYPH_TREE_RIGHT),
                                 TABLE_STRING, name,
                                 TABLE_SET_COLOR, ansi_grey(),
-                                TABLE_STRING, user_disposition_to_string(uid_range_table[i].disposition),
+                                TABLE_STRING, user_disposition_to_string(i->disposition),
                                 TABLE_SET_COLOR, ansi_grey(),
-                                TABLE_GID, uid_range_table[i].last,
+                                TABLE_GID, i->last,
                                 TABLE_SET_COLOR, ansi_grey(),
                                 TABLE_STRING, comment,
                                 TABLE_SET_COLOR, ansi_grey(),
@@ -732,10 +729,10 @@ static int display_group(int argc, char *argv[], void *userdata) {
         }
 
         if (table) {
-                _cleanup_(uid_range_freep) UidRange *gid_range = NULL;
+                _cleanup_(uid_range_freep) UIDRange *gid_range = NULL;
                 int boundary_lines, gid_map_lines;
 
-                r = uid_range_load_userns(&gid_range, "/proc/self/gid_map");
+                r = uid_range_load_userns(/* path = */ NULL, GID_RANGE_USERNS_INSIDE, &gid_range);
                 if (r < 0)
                         log_debug_errno(r, "Failed to load /proc/self/gid_map, ignoring: %m");
 
@@ -747,7 +744,7 @@ static int display_group(int argc, char *argv[], void *userdata) {
                 if (gid_map_lines < 0)
                         return gid_map_lines;
 
-                if (table_get_rows(table) > 1) {
+                if (!table_isempty(table)) {
                         r = table_print_with_pager(table, arg_json_format_flags, arg_pager_flags, arg_legend);
                         if (r < 0)
                                 return table_log_print_error(r);
@@ -895,17 +892,17 @@ static int display_memberships(int argc, char *argv[], void *userdata) {
         }
 
         if (table) {
-                if (table_get_rows(table) > 1) {
+                if (!table_isempty(table)) {
                         r = table_print_with_pager(table, arg_json_format_flags, arg_pager_flags, arg_legend);
                         if (r < 0)
                                 return table_log_print_error(r);
                 }
 
                 if (arg_legend) {
-                        if (table_get_rows(table) > 1)
-                                printf("\n%zu memberships listed.\n", table_get_rows(table) - 1);
-                        else
+                        if (table_isempty(table))
                                 printf("No memberships.\n");
+                        else
+                                printf("\n%zu memberships listed.\n", table_get_rows(table) - 1);
                 }
         }
 
@@ -960,17 +957,17 @@ static int display_services(int argc, char *argv[], void *userdata) {
                         return table_log_add_error(r);
         }
 
-        if (table_get_rows(t) > 1) {
+        if (!table_isempty(t)) {
                 r = table_print_with_pager(t, arg_json_format_flags, arg_pager_flags, arg_legend);
                 if (r < 0)
                         return table_log_print_error(r);
         }
 
         if (arg_legend && arg_output != OUTPUT_JSON) {
-                if (table_get_rows(t) > 1)
-                        printf("\n%zu services listed.\n", table_get_rows(t) - 1);
-                else
+                if (table_isempty(t))
                         printf("No services.\n");
+                else
+                        printf("\n%zu services listed.\n", table_get_rows(t) - 1);
         }
 
         return 0;
diff --git a/src/userdb/userdbd-manager.c b/src/userdb/userdbd-manager.c
index 359c827..5925602 100644
--- a/src/userdb/userdbd-manager.c
+++ b/src/userdb/userdbd-manager.c
@@ -4,6 +4,7 @@
 
 #include "sd-daemon.h"
 
+#include "build-path.h"
 #include "common-signal.h"
 #include "env-util.h"
 #include "fd-util.h"
@@ -14,6 +15,7 @@
 #include "signal-util.h"
 #include "socket-util.h"
 #include "stdio-util.h"
+#include "strv.h"
 #include "umask-util.h"
 #include "userdbd-manager.h"
 
@@ -185,17 +187,19 @@ static int start_one_worker(Manager *m) {
                         _exit(EXIT_FAILURE);
                 }
 
-
                 if (setenv("USERDB_FIXED_WORKER", one_zero(fixed), 1) < 0) {
                         log_error_errno(errno, "Failed to set $USERDB_FIXED_WORKER: %m");
                         _exit(EXIT_FAILURE);
                 }
 
-                /* execl("/home/lennart/projects/systemd/build/systemd-userwork", "systemd-userwork", "xxxxxxxxxxxxxxxx", NULL); /\* With some extra space rename_process() can make use of *\/ */
-                /* execl("/usr/bin/valgrind", "valgrind", "/home/lennart/projects/systemd/build/systemd-userwork", "systemd-userwork", "xxxxxxxxxxxxxxxx", NULL); /\* With some extra space rename_process() can make use of *\/ */
+                r = setenv_systemd_log_level();
+                if (r < 0) {
+                        log_error_errno(r, "Failed to set $SYSTEMD_LOG_LEVEL: %m");
+                        _exit(EXIT_FAILURE);
+                }
 
-                execl(SYSTEMD_USERWORK_PATH, "systemd-userwork", "xxxxxxxxxxxxxxxx", NULL); /* With some extra space rename_process() can make use of */
-                log_error_errno(errno, "Failed start worker process: %m");
+                r = invoke_callout_binary(SYSTEMD_USERWORK_PATH, STRV_MAKE(SYSTEMD_USERWORK_PATH, "xxxxxxxxxxxxxxxx")); /* With some extra space rename_process() can make use of */
+                log_error_errno(r, "Failed start worker process: %m");
                 _exit(EXIT_FAILURE);
         }
 
@@ -265,57 +269,85 @@ static int start_workers(Manager *m, bool explicit_request) {
         return 0;
 }
 
-int manager_startup(Manager *m) {
-        int n, r;
+static int manager_make_listen_socket(Manager *m) {
+        static const union sockaddr_union sockaddr = {
+                .un.sun_family = AF_UNIX,
+                .un.sun_path = "/run/systemd/userdb/io.systemd.Multiplexer",
+        };
+        int r;
 
         assert(m);
-        assert(m->listen_fd < 0);
 
-        n = sd_listen_fds(false);
+        if (m->listen_fd >= 0)
+                return 0;
+
+        r = mkdir_p("/run/systemd/userdb", 0755);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /run/systemd/userdb: %m");
+
+        m->listen_fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
+        if (m->listen_fd < 0)
+                return log_error_errno(errno, "Failed to bind on socket: %m");
+
+        (void) sockaddr_un_unlink(&sockaddr.un);
+
+        WITH_UMASK(0000)
+                if (bind(m->listen_fd, &sockaddr.sa, SOCKADDR_UN_LEN(sockaddr.un)) < 0)
+                        return log_error_errno(errno, "Failed to bind socket: %m");
+
+        FOREACH_STRING(alias,
+                       "/run/systemd/userdb/io.systemd.NameServiceSwitch",
+                       "/run/systemd/userdb/io.systemd.DropIn") {
+
+                r = symlink_idempotent("io.systemd.Multiplexer", alias, /* make_relative= */ false);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to symlink '%s': %m", alias);
+        }
+
+        if (listen(m->listen_fd, SOMAXCONN_DELUXE) < 0)
+                return log_error_errno(errno, "Failed to listen on socket: %m");
+
+        return 1;
+}
+
+static int manager_scan_listen_fds(Manager *m) {
+        int n;
+
+        assert(m);
+
+        n = sd_listen_fds(/* unset_environment= */ true);
         if (n < 0)
                 return log_error_errno(n, "Failed to determine number of passed file descriptors: %m");
         if (n > 1)
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Expected one listening fd, got %i.", n);
         if (n == 1)
                 m->listen_fd = SD_LISTEN_FDS_START;
-        else {
-                static const union sockaddr_union sockaddr = {
-                        .un.sun_family = AF_UNIX,
-                        .un.sun_path = "/run/systemd/userdb/io.systemd.Multiplexer",
-                };
-
-                r = mkdir_p("/run/systemd/userdb", 0755);
-                if (r < 0)
-                        return log_error_errno(r, "Failed to create /run/systemd/userdb: %m");
-
-                m->listen_fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
-                if (m->listen_fd < 0)
-                        return log_error_errno(errno, "Failed to bind on socket: %m");
 
-                (void) sockaddr_un_unlink(&sockaddr.un);
+        return 0;
+}
 
-                WITH_UMASK(0000)
-                        if (bind(m->listen_fd, &sockaddr.sa, SOCKADDR_UN_LEN(sockaddr.un)) < 0)
-                                return log_error_errno(errno, "Failed to bind socket: %m");
+int manager_startup(Manager *m) {
+        int r;
 
-                r = symlink_idempotent("io.systemd.Multiplexer",
-                                       "/run/systemd/userdb/io.systemd.NameServiceSwitch", false);
-                if (r < 0)
-                        return log_error_errno(r, "Failed to bind io.systemd.Multiplexer: %m");
+        assert(m);
+        assert(m->listen_fd < 0);
 
-                r = symlink_idempotent("io.systemd.Multiplexer",
-                                       "/run/systemd/userdb/io.systemd.DropIn", false);
-                if (r < 0)
-                        return log_error_errno(r, "Failed to bind io.systemd.Multiplexer: %m");
+        r = manager_scan_listen_fds(m);
+        if (r < 0)
+                return r;
 
-                if (listen(m->listen_fd, SOMAXCONN_DELUXE) < 0)
-                        return log_error_errno(errno, "Failed to listen on socket: %m");
-        }
+        r = manager_make_listen_socket(m);
+        if (r < 0)
+                return r;
 
         /* Let's make sure every accept() call on this socket times out after 25s. This allows workers to be
          * GC'ed on idle */
         if (setsockopt(m->listen_fd, SOL_SOCKET, SO_RCVTIMEO, TIMEVAL_STORE(LISTEN_TIMEOUT_USEC), sizeof(struct timeval)) < 0)
                 return log_error_errno(errno, "Failed to se SO_RCVTIMEO: %m");
 
-        return start_workers(m, /* explicit_request= */ false);
+        r = start_workers(m, /* explicit_request= */ false);
+        if (r < 0)
+                return r;
+
+        return 0;
 }
diff --git a/src/userdb/userdbd.c b/src/userdb/userdbd.c
index 89ac9c7..cbe4c8e 100644
--- a/src/userdb/userdbd.c
+++ b/src/userdb/userdbd.c
@@ -37,7 +37,7 @@ static int run(int argc, char *argv[]) {
         if (setenv("SYSTEMD_BYPASS_USERDB", "io.systemd.NameServiceSwitch:io.systemd.Multiplexer:io.systemd.DropIn", 1) < 0)
                 return log_error_errno(errno, "Failed to set $SYSTEMD_BYPASS_USERDB: %m");
 
-        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, -1) >= 0);
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD) >= 0);
 
         r = manager_new(&m);
         if (r < 0)
diff --git a/src/userdb/userwork.c b/src/userdb/userwork.c
index b49dbbd..729a9a1 100644
--- a/src/userdb/userwork.c
+++ b/src/userdb/userwork.c
@@ -353,9 +353,9 @@ static int vl_method_get_group_record(Varlink *link, JsonVariant *parameters, Va
 
 static int vl_method_get_memberships(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) {
         static const JsonDispatch dispatch_table[] = {
-                { "userName",  JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, user_name), 0 },
+                { "userName",  JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, user_name),  0 },
                 { "groupName", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, group_name), 0 },
-                { "service",   JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, service),   0 },
+                { "service",   JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, service),    0 },
                 {}
         };
 
@@ -425,16 +425,16 @@ static int vl_method_get_memberships(Varlink *link, JsonVariant *parameters, Var
                                               JSON_BUILD_PAIR("groupName", JSON_BUILD_STRING(last_group_name))));
 }
 
-static int process_connection(VarlinkServer *server, int fd) {
+static int process_connection(VarlinkServer *server, int _fd) {
+        _cleanup_close_ int fd = TAKE_FD(_fd); /* always take possession */
         _cleanup_(varlink_close_unrefp) Varlink *vl = NULL;
         int r;
 
         r = varlink_server_add_connection(server, fd, &vl);
-        if (r < 0) {
-                fd = safe_close(fd);
+        if (r < 0)
                 return log_error_errno(r, "Failed to add connection: %m");
-        }
 
+        TAKE_FD(fd);
         vl = varlink_ref(vl);
 
         for (;;) {
@@ -461,6 +461,7 @@ static int process_connection(VarlinkServer *server, int fd) {
 static int run(int argc, char *argv[]) {
         usec_t start_time, listen_idle_usec, last_busy_usec = USEC_INFINITY;
         _cleanup_(varlink_server_unrefp) VarlinkServer *server = NULL;
+        _cleanup_(pidref_done) PidRef parent = PIDREF_NULL;
         unsigned n_iterations = 0;
         int m, listen_fd, r;
 
@@ -505,6 +506,12 @@ static int run(int argc, char *argv[]) {
         if (r < 0)
                 return log_error_errno(r, "Failed to disable userdb NSS compatibility: %m");
 
+        r = pidref_set_parent(&parent);
+        if (r < 0)
+                return log_error_errno(r, "Failed to acquire pidfd of parent process: %m");
+        if (parent.pid == 1) /* We got reparented away from userdbd? */
+                return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Parent already died, exiting.");
+
         start_time = now(CLOCK_MONOTONIC);
 
         for (;;) {
@@ -554,14 +561,11 @@ static int run(int argc, char *argv[]) {
                                 return log_error_errno(r, "Failed to test for POLLIN on listening socket: %m");
 
                         if (FLAGS_SET(r, POLLIN)) {
-                                pid_t parent;
-
-                                parent = getppid();
-                                if (parent <= 1)
-                                        return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "Parent already died?");
-
-                                if (kill(parent, SIGUSR2) < 0)
-                                        return log_error_errno(errno, "Failed to kill our own parent: %m");
+                                r = pidref_kill(&parent, SIGUSR2);
+                                if (r == -ESRCH)
+                                        return log_error_errno(r, "Parent already died?");
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to send SIGUSR2 signal to parent: %m");
                         }
                 }