diff --git a/src/libsystemd/sd-bus/bus-control.c b/src/libsystemd/sd-bus/bus-control.c
index ca31807f70..fa4c28174d 100644
--- a/src/libsystemd/sd-bus/bus-control.c
+++ b/src/libsystemd/sd-bus/bus-control.c
@@ -423,9 +423,24 @@ static int bus_populate_creds_from_items(
                                 c->mask |= SD_BUS_CREDS_TID;
                         }
 
-                        if (mask & SD_BUS_CREDS_PPID && item->pids.ppid > 0) {
-                                c->ppid = (pid_t) item->pids.ppid;
-                                c->mask |= SD_BUS_CREDS_PPID;
+                        if (mask & SD_BUS_CREDS_PPID) {
+                                if (item->pids.ppid > 0) {
+                                        c->ppid = (pid_t) item->pids.ppid;
+                                        c->mask |= SD_BUS_CREDS_PPID;
+                                } else if (item->pids.pid == 1) {
+                                        /* The structure doesn't
+                                         * really distuingish the case
+                                         * where a process has no
+                                         * parent and where we don't
+                                         * know it because it could
+                                         * not be translated due to
+                                         * namespaces. However, we
+                                         * know that PID 1 has no
+                                         * parent process, hence let's
+                                         * patch that in, manually. */
+                                        c->ppid = 0;
+                                        c->mask |= SD_BUS_CREDS_PPID;
+                                }
                         }
 
                         break;
@@ -565,12 +580,12 @@ static int bus_populate_creds_from_items(
                         break;
 
                 case KDBUS_ITEM_AUDIT:
-                        if (mask & SD_BUS_CREDS_AUDIT_SESSION_ID && (uint32_t) item->audit.sessionid != (uint32_t) -1) {
+                        if (mask & SD_BUS_CREDS_AUDIT_SESSION_ID) {
                                 c->audit_session_id = (uint32_t) item->audit.sessionid;
                                 c->mask |= SD_BUS_CREDS_AUDIT_SESSION_ID;
                         }
 
-                        if (mask & SD_BUS_CREDS_AUDIT_LOGIN_UID && (uid_t) item->audit.loginuid != UID_INVALID) {
+                        if (mask & SD_BUS_CREDS_AUDIT_LOGIN_UID) {
                                 c->audit_login_uid = (uid_t) item->audit.loginuid;
                                 c->mask |= SD_BUS_CREDS_AUDIT_LOGIN_UID;
                         }
diff --git a/src/libsystemd/sd-bus/bus-creds.c b/src/libsystemd/sd-bus/bus-creds.c
index 8d02885d3b..ed9bf5293b 100644
--- a/src/libsystemd/sd-bus/bus-creds.c
+++ b/src/libsystemd/sd-bus/bus-creds.c
@@ -302,6 +302,12 @@ _public_ int sd_bus_creds_get_ppid(sd_bus_creds *c, pid_t *ppid) {
         if (!(c->mask & SD_BUS_CREDS_PPID))
                 return -ENODATA;
 
+        /* PID 1 has no parent process. Let's distuingish the case of
+         * not knowing and not having a parent process by the returned
+         * error code. */
+        if (c->ppid == 0)
+                return -ENXIO;
+
         *ppid = c->ppid;
         return 0;
 }
@@ -360,7 +366,9 @@ _public_ int sd_bus_creds_get_exe(sd_bus_creds *c, const char **ret) {
         if (!(c->mask & SD_BUS_CREDS_EXE))
                 return -ENODATA;
 
-        assert(c->exe);
+        if (!c->exe)
+                return -ENXIO;
+
         *ret = c->exe;
         return 0;
 }
@@ -510,8 +518,8 @@ _public_ int sd_bus_creds_get_cmdline(sd_bus_creds *c, char ***cmdline) {
         if (!(c->mask & SD_BUS_CREDS_CMDLINE))
                 return -ENODATA;
 
-        assert_return(c->cmdline, -ESRCH);
-        assert(c->cmdline);
+        if (!c->cmdline)
+                return -ENXIO;
 
         if (!c->cmdline_array) {
                 c->cmdline_array = strv_parse_nulstr(c->cmdline, c->cmdline_size);
@@ -530,6 +538,9 @@ _public_ int sd_bus_creds_get_audit_session_id(sd_bus_creds *c, uint32_t *sessio
         if (!(c->mask & SD_BUS_CREDS_AUDIT_SESSION_ID))
                 return -ENODATA;
 
+        if (c->audit_session_id == AUDIT_SESSION_INVALID)
+                return -ENXIO;
+
         *sessionid = c->audit_session_id;
         return 0;
 }
@@ -541,6 +552,9 @@ _public_ int sd_bus_creds_get_audit_login_uid(sd_bus_creds *c, uid_t *uid) {
         if (!(c->mask & SD_BUS_CREDS_AUDIT_LOGIN_UID))
                 return -ENODATA;
 
+        if (c->audit_login_uid == UID_INVALID)
+                return -ENXIO;
+
         *uid = c->audit_login_uid;
         return 0;
 }
@@ -552,6 +566,9 @@ _public_ int sd_bus_creds_get_tty(sd_bus_creds *c, const char **ret) {
         if (!(c->mask & SD_BUS_CREDS_TTY))
                 return -ENODATA;
 
+        if (!c->tty)
+                return -ENXIO;
+
         *ret = c->tty;
         return 0;
 }
@@ -787,8 +804,10 @@ int bus_creds_add_more(sd_bus_creds *c, uint64_t mask, pid_t pid, pid_t tid) {
                                                         if (r < 0)
                                                                 return r;
 
-                                                        c->mask |= SD_BUS_CREDS_PPID;
-                                                }
+                                                } else
+                                                        c->ppid = 0;
+
+                                                c->mask |= SD_BUS_CREDS_PPID;
                                                 continue;
                                         }
                                 }
@@ -941,7 +960,17 @@ int bus_creds_add_more(sd_bus_creds *c, uint64_t mask, pid_t pid, pid_t tid) {
 
         if (missing & SD_BUS_CREDS_EXE) {
                 r = get_process_exe(pid, &c->exe);
-                if (r < 0) {
+                if (r == -ESRCH) {
+                        /* Unfortunately we cannot really distuingish
+                         * the case here where the process does not
+                         * exist, and /proc/$PID/exe being unreadable
+                         * because $PID is a kernel thread. Hence,
+                         * assume it is a kernel thread, and rely on
+                         * that this case is caught with a later
+                         * call. */
+                        c->exe = NULL;
+                        c->mask |= SD_BUS_CREDS_EXE;
+                } else if (r < 0) {
                         if (r != -EPERM && r != -EACCES)
                                 return r;
                 } else
@@ -953,17 +982,18 @@ int bus_creds_add_more(sd_bus_creds *c, uint64_t mask, pid_t pid, pid_t tid) {
 
                 p = procfs_file_alloca(pid, "cmdline");
                 r = read_full_file(p, &c->cmdline, &c->cmdline_size);
+                if (r == -ENOENT)
+                        return -ESRCH;
                 if (r < 0) {
-                        if (r == -ENOENT)
-                                return -ESRCH;
                         if (r != -EPERM && r != -EACCES)
                                 return r;
                 } else {
                         if (c->cmdline_size == 0) {
                                 free(c->cmdline);
                                 c->cmdline = NULL;
-                        } else
-                                c->mask |= SD_BUS_CREDS_CMDLINE;
+                        }
+
+                        c->mask |= SD_BUS_CREDS_CMDLINE;
                 }
         }
 
@@ -974,9 +1004,9 @@ int bus_creds_add_more(sd_bus_creds *c, uint64_t mask, pid_t pid, pid_t tid) {
                         return -ENOMEM;
 
                 r = read_one_line_file(p, &c->tid_comm);
+                if (r == -ENOENT)
+                        return -ESRCH;
                 if (r < 0) {
-                        if (r == -ENOENT)
-                                return -ESRCH;
                         if (r != -EPERM && r != -EACCES)
                                 return r;
                 } else
@@ -1005,8 +1035,12 @@ int bus_creds_add_more(sd_bus_creds *c, uint64_t mask, pid_t pid, pid_t tid) {
 
         if (missing & SD_BUS_CREDS_AUDIT_SESSION_ID) {
                 r = audit_session_from_pid(pid, &c->audit_session_id);
-                if (r < 0) {
-                        if (r != -EOPNOTSUPP && r != -ENXIO && r != -ENOENT && r != -EPERM && r != -EACCES)
+                if (r == -ENXIO) {
+                        /* ENXIO means: no audit session id assigned */
+                        c->audit_session_id = AUDIT_SESSION_INVALID;
+                        c->mask |= SD_BUS_CREDS_AUDIT_SESSION_ID;
+                } else if (r < 0) {
+                        if (r != -EOPNOTSUPP && r != -ENOENT && r != -EPERM && r != -EACCES)
                                 return r;
                 } else
                         c->mask |= SD_BUS_CREDS_AUDIT_SESSION_ID;
@@ -1014,8 +1048,12 @@ int bus_creds_add_more(sd_bus_creds *c, uint64_t mask, pid_t pid, pid_t tid) {
 
         if (missing & SD_BUS_CREDS_AUDIT_LOGIN_UID) {
                 r = audit_loginuid_from_pid(pid, &c->audit_login_uid);
-                if (r < 0) {
-                        if (r != -EOPNOTSUPP && r != -ENXIO && r != -ENOENT && r != -EPERM && r != -EACCES)
+                if (r == -ENXIO) {
+                        /* ENXIO means: no audit login uid assigned */
+                        c->audit_login_uid = UID_INVALID;
+                        c->mask |= SD_BUS_CREDS_AUDIT_LOGIN_UID;
+                } else if (r < 0) {
+                        if (r != -EOPNOTSUPP && r != -ENOENT && r != -EPERM && r != -EACCES)
                                 return r;
                 } else
                         c->mask |= SD_BUS_CREDS_AUDIT_LOGIN_UID;
@@ -1023,13 +1061,28 @@ int bus_creds_add_more(sd_bus_creds *c, uint64_t mask, pid_t pid, pid_t tid) {
 
         if (missing & SD_BUS_CREDS_TTY) {
                 r = get_ctty(pid, NULL, &c->tty);
-                if (r < 0) {
+                if (r == -ENXIO) {
+                        /* ENXIO means: process has no controlling TTY */
+                        c->tty = NULL;
+                        c->mask |= SD_BUS_CREDS_TTY;
+                } else if (r < 0) {
                         if (r != -EPERM && r != -EACCES && r != -ENOENT)
                                 return r;
                 } else
                         c->mask |= SD_BUS_CREDS_TTY;
         }
 
+        /* In case only the exe path was to be read we cannot
+         * distuingish the case where the exe path was unreadable
+         * because the process was a kernel thread, or when the
+         * process didn't exist at all. Hence, let's do a final check,
+         * to be sure. */
+        if (!pid_is_alive(pid))
+                return -ESRCH;
+
+        if (tid > 0 && tid != pid && !pid_is_unwaited(tid))
+                return -ESRCH;
+
         c->augmented = missing & c->mask;
 
         return 0;
@@ -1112,14 +1165,22 @@ int bus_creds_extend_by_pid(sd_bus_creds *c, uint64_t mask, sd_bus_creds **ret)
         }
 
         if (c->mask & mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS) {
-                n->supplementary_gids = newdup(gid_t, c->supplementary_gids, c->n_supplementary_gids);
-                if (!n->supplementary_gids)
-                        return -ENOMEM;
-                n->n_supplementary_gids = c->n_supplementary_gids;
+                if (c->supplementary_gids) {
+                        n->supplementary_gids = newdup(gid_t, c->supplementary_gids, c->n_supplementary_gids);
+                        if (!n->supplementary_gids)
+                                return -ENOMEM;
+                        n->n_supplementary_gids = c->n_supplementary_gids;
+                } else {
+                        n->supplementary_gids = NULL;
+                        n->n_supplementary_gids = 0;
+                }
+
                 n->mask |= SD_BUS_CREDS_SUPPLEMENTARY_GIDS;
         }
 
         if (c->mask & mask & SD_BUS_CREDS_COMM) {
+                assert(c->comm);
+
                 n->comm = strdup(c->comm);
                 if (!n->comm)
                         return -ENOMEM;
@@ -1128,6 +1189,8 @@ int bus_creds_extend_by_pid(sd_bus_creds *c, uint64_t mask, sd_bus_creds **ret)
         }
 
         if (c->mask & mask & SD_BUS_CREDS_TID_COMM) {
+                assert(c->tid_comm);
+
                 n->tid_comm = strdup(c->tid_comm);
                 if (!n->tid_comm)
                         return -ENOMEM;
@@ -1136,23 +1199,34 @@ int bus_creds_extend_by_pid(sd_bus_creds *c, uint64_t mask, sd_bus_creds **ret)
         }
 
         if (c->mask & mask & SD_BUS_CREDS_EXE) {
-                n->exe = strdup(c->exe);
-                if (!n->exe)
-                        return -ENOMEM;
+                if (c->exe) {
+                        n->exe = strdup(c->exe);
+                        if (!n->exe)
+                                return -ENOMEM;
+                } else
+                        n->exe = NULL;
 
                 n->mask |= SD_BUS_CREDS_EXE;
         }
 
         if (c->mask & mask & SD_BUS_CREDS_CMDLINE) {
-                n->cmdline = memdup(c->cmdline, c->cmdline_size);
-                if (!n->cmdline)
-                        return -ENOMEM;
+                if (c->cmdline) {
+                        n->cmdline = memdup(c->cmdline, c->cmdline_size);
+                        if (!n->cmdline)
+                                return -ENOMEM;
+
+                        n->cmdline_size = c->cmdline_size;
+                } else {
+                        n->cmdline = NULL;
+                        n->cmdline_size = 0;
+                }
 
-                n->cmdline_size = c->cmdline_size;
                 n->mask |= SD_BUS_CREDS_CMDLINE;
         }
 
         if (c->mask & mask & (SD_BUS_CREDS_CGROUP|SD_BUS_CREDS_SESSION|SD_BUS_CREDS_UNIT|SD_BUS_CREDS_USER_UNIT|SD_BUS_CREDS_SLICE|SD_BUS_CREDS_OWNER_UID)) {
+                assert(c->cgroup);
+
                 n->cgroup = strdup(c->cgroup);
                 if (!n->cgroup)
                         return -ENOMEM;
@@ -1165,6 +1239,8 @@ int bus_creds_extend_by_pid(sd_bus_creds *c, uint64_t mask, sd_bus_creds **ret)
         }
 
         if (c->mask & mask & (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS)) {
+                assert(c->capability);
+
                 n->capability = memdup(c->capability, DIV_ROUND_UP(cap_last_cap(), 32U) * 4 * 4);
                 if (!n->capability)
                         return -ENOMEM;
@@ -1173,6 +1249,8 @@ int bus_creds_extend_by_pid(sd_bus_creds *c, uint64_t mask, sd_bus_creds **ret)
         }
 
         if (c->mask & mask & SD_BUS_CREDS_SELINUX_CONTEXT) {
+                assert(c->label);
+
                 n->label = strdup(c->label);
                 if (!n->label)
                         return -ENOMEM;
@@ -1199,6 +1277,8 @@ int bus_creds_extend_by_pid(sd_bus_creds *c, uint64_t mask, sd_bus_creds **ret)
         }
 
         if (c->mask & mask & SD_BUS_CREDS_UNIQUE_NAME) {
+                assert(c->unique_name);
+
                 n->unique_name = strdup(c->unique_name);
                 if (!n->unique_name)
                         return -ENOMEM;
@@ -1206,15 +1286,20 @@ int bus_creds_extend_by_pid(sd_bus_creds *c, uint64_t mask, sd_bus_creds **ret)
         }
 
         if (c->mask & mask & SD_BUS_CREDS_WELL_KNOWN_NAMES) {
-                n->well_known_names = strv_copy(c->well_known_names);
-                if (!n->well_known_names)
-                        return -ENOMEM;
+                if (strv_isempty(c->well_known_names))
+                        n->well_known_names = NULL;
+                else {
+                        n->well_known_names = strv_copy(c->well_known_names);
+                        if (!n->well_known_names)
+                                return -ENOMEM;
+                }
                 n->well_known_names_driver = c->well_known_names_driver;
                 n->well_known_names_local = c->well_known_names_local;
                 n->mask |= SD_BUS_CREDS_WELL_KNOWN_NAMES;
         }
 
         if (c->mask & mask & SD_BUS_CREDS_DESCRIPTION) {
+                assert(c->description);
                 n->description = strdup(c->description);
                 if (!n->description)
                         return -ENOMEM;
diff --git a/src/libsystemd/sd-bus/bus-dump.c b/src/libsystemd/sd-bus/bus-dump.c
index 396bf36f8a..47a5c6b3a8 100644
--- a/src/libsystemd/sd-bus/bus-dump.c
+++ b/src/libsystemd/sd-bus/bus-dump.c
@@ -331,13 +331,11 @@ static void dump_capabilities(
 }
 
 int bus_creds_dump(sd_bus_creds *c, FILE *f, bool terse) {
-        bool audit_sessionid_is_set = false, audit_loginuid_is_set = false;
-        const char *u = NULL, *uu = NULL, *s = NULL, *sl = NULL;
         uid_t owner, audit_loginuid;
         uint32_t audit_sessionid;
         char **cmdline = NULL, **well_known = NULL;
-        const char *prefix, *color, *suffix;
-        int r;
+        const char *prefix, *color, *suffix, *s;
+        int r, q, v, w;
 
         assert(c);
 
@@ -362,8 +360,12 @@ int bus_creds_dump(sd_bus_creds *c, FILE *f, bool terse) {
                 fprintf(f, "%sPID=%s"PID_FMT"%s", prefix, color, c->pid, suffix);
         if (c->mask & SD_BUS_CREDS_TID)
                 fprintf(f, "%sTID=%s"PID_FMT"%s", prefix, color, c->tid, suffix);
-        if (c->mask & SD_BUS_CREDS_PPID)
-                fprintf(f, "%sPPID=%s"PID_FMT"%s", prefix, color, c->ppid, suffix);
+        if (c->mask & SD_BUS_CREDS_PPID) {
+                if (c->ppid == 0)
+                        fprintf(f, "%sPPID=%sn/a%s", prefix, color, suffix);
+                else
+                        fprintf(f, "%sPPID=%s"PID_FMT"%s", prefix, color, c->ppid, suffix);
+        }
         if (c->mask & SD_BUS_CREDS_TTY)
                 fprintf(f, "%sTTY=%s%s%s", prefix, color, strna(c->tty), suffix);
 
@@ -409,12 +411,13 @@ int bus_creds_dump(sd_bus_creds *c, FILE *f, bool terse) {
         if (c->mask & SD_BUS_CREDS_TID_COMM)
                 fprintf(f, "%sTIDComm=%s%s%s", prefix, color, c->tid_comm, suffix);
         if (c->mask & SD_BUS_CREDS_EXE)
-                fprintf(f, "%sExe=%s%s%s", prefix, color, c->exe, suffix);
+                fprintf(f, "%sExe=%s%s%s", prefix, color, strna(c->exe), suffix);
 
         if (terse && (c->mask & (SD_BUS_CREDS_EXE|SD_BUS_CREDS_COMM|SD_BUS_CREDS_TID_COMM)))
                 fputs("\n", f);
 
-        if (sd_bus_creds_get_cmdline(c, &cmdline) >= 0) {
+        r = sd_bus_creds_get_cmdline(c, &cmdline);
+        if (r >= 0) {
                 char **i;
 
                 fprintf(f, "%sCommandLine=%s", prefix, color);
@@ -426,7 +429,8 @@ int bus_creds_dump(sd_bus_creds *c, FILE *f, bool terse) {
                 }
 
                 fprintf(f, "%s", suffix);
-        }
+        } else if (r != -ENODATA)
+                fprintf(f, "%sCommandLine=%sn/a%s", prefix, color, suffix);
 
         if (c->mask & SD_BUS_CREDS_SELINUX_CONTEXT)
                 fprintf(f, "%sLabel=%s%s%s", prefix, color, c->label, suffix);
@@ -438,32 +442,38 @@ int bus_creds_dump(sd_bus_creds *c, FILE *f, bool terse) {
 
         if (c->mask & SD_BUS_CREDS_CGROUP)
                 fprintf(f, "%sCGroup=%s%s%s", prefix, color, c->cgroup, suffix);
-        (void) sd_bus_creds_get_unit(c, &u);
-        if (u)
-                fprintf(f, "%sUnit=%s%s%s", prefix, color, u, suffix);
-        (void) sd_bus_creds_get_user_unit(c, &uu);
-        if (uu)
-                fprintf(f, "%sUserUnit=%s%s%s", prefix, color, uu, suffix);
-        (void) sd_bus_creds_get_slice(c, &sl);
-        if (sl)
-                fprintf(f, "%sSlice=%s%s%s", prefix, color, sl, suffix);
-        (void) sd_bus_creds_get_session(c, &s);
-        if (s)
-                fprintf(f, "%sSession=%s%s%s", prefix, color, s, suffix);
+        s = NULL;
+        r = sd_bus_creds_get_unit(c, &s);
+        if (r != -ENODATA)
+                fprintf(f, "%sUnit=%s%s%s", prefix, color, strna(s), suffix);
+        s = NULL;
+        q = sd_bus_creds_get_user_unit(c, &s);
+        if (q != -ENODATA)
+                fprintf(f, "%sUserUnit=%s%s%s", prefix, color, strna(s), suffix);
+        s = NULL;
+        v = sd_bus_creds_get_slice(c, &s);
+        if (v != -ENODATA)
+                fprintf(f, "%sSlice=%s%s%s", prefix, color, strna(s), suffix);
+        s = NULL;
+        w = sd_bus_creds_get_session(c, &s);
+        if (w != -ENODATA)
+                fprintf(f, "%sSession=%s%s%s", prefix, color, strna(s), suffix);
 
-        if (terse && ((c->mask & SD_BUS_CREDS_CGROUP) || u || uu || sl || s))
+        if (terse && ((c->mask & SD_BUS_CREDS_CGROUP) || r != -ENODATA || q != -ENODATA || v != -ENODATA || w != -ENODATA))
                 fputs("\n", f);
 
-        if (sd_bus_creds_get_audit_login_uid(c, &audit_loginuid) >= 0) {
-                audit_loginuid_is_set = true;
+        r = sd_bus_creds_get_audit_login_uid(c, &audit_loginuid);
+        if (r >= 0)
                 fprintf(f, "%sAuditLoginUID=%s"UID_FMT"%s", prefix, color, audit_loginuid, suffix);
-        }
-        if (sd_bus_creds_get_audit_session_id(c, &audit_sessionid) >= 0) {
-                audit_sessionid_is_set = true;
+        else if (r != -ENODATA)
+                fprintf(f, "%sAuditLoginUID=%sn/a%s", prefix, color, suffix);
+        q = sd_bus_creds_get_audit_session_id(c, &audit_sessionid);
+        if (q >= 0)
                 fprintf(f, "%sAuditSessionID=%s%"PRIu32"%s", prefix, color, audit_sessionid, suffix);
-        }
+        else if (q != -ENODATA)
+                fprintf(f, "%sAuditSessionID=%sn/a%s", prefix, color, suffix);
 
-        if (terse && (audit_loginuid_is_set || audit_sessionid_is_set))
+        if (terse && (r != -ENODATA || q != -ENODATA))
                 fputs("\n", f);
 
         if (c->mask & SD_BUS_CREDS_UNIQUE_NAME)
diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c
index a8c04b98a9..556b5eb704 100644
--- a/src/libsystemd/sd-bus/bus-kernel.c
+++ b/src/libsystemd/sd-bus/bus-kernel.c
@@ -598,6 +598,9 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
                         if (d->pids.ppid > 0) {
                                 m->creds.ppid = (pid_t) d->pids.ppid;
                                 m->creds.mask |= SD_BUS_CREDS_PPID & bus->creds_mask;
+                        } else if (d->pids.pid == 1) {
+                                m->creds.ppid = 0;
+                                m->creds.mask |= SD_BUS_CREDS_PPID & bus->creds_mask;
                         }
 
                         break;
@@ -686,15 +689,11 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
                         break;
 
                 case KDBUS_ITEM_AUDIT:
-                        if ((uint32_t) d->audit.sessionid != (uint32_t) -1) {
-                                m->creds.audit_session_id = (uint32_t) d->audit.sessionid;
-                                m->creds.mask |= SD_BUS_CREDS_AUDIT_SESSION_ID & bus->creds_mask;
-                        }
+                        m->creds.audit_session_id = (uint32_t) d->audit.sessionid;
+                        m->creds.mask |= SD_BUS_CREDS_AUDIT_SESSION_ID & bus->creds_mask;
 
-                        if ((uid_t) d->audit.loginuid != UID_INVALID) {
-                                m->creds.audit_login_uid = (uid_t) d->audit.loginuid;
-                                m->creds.mask |= SD_BUS_CREDS_AUDIT_LOGIN_UID & bus->creds_mask;
-                        }
+                        m->creds.audit_login_uid = (uid_t) d->audit.loginuid;
+                        m->creds.mask |= SD_BUS_CREDS_AUDIT_LOGIN_UID & bus->creds_mask;
                         break;
 
                 case KDBUS_ITEM_CAPS:
diff --git a/src/shared/audit.c b/src/shared/audit.c
index 84181d3321..54148fcf18 100644
--- a/src/shared/audit.c
+++ b/src/shared/audit.c
@@ -46,7 +46,7 @@ int audit_session_from_pid(pid_t pid, uint32_t *id) {
         if (r < 0)
                 return r;
 
-        if (u == (uint32_t) -1 || u <= 0)
+        if (u == AUDIT_SESSION_INVALID || u <= 0)
                 return -ENXIO;
 
         *id = u;
diff --git a/src/shared/audit.h b/src/shared/audit.h
index 781866ae1c..6de331c73e 100644
--- a/src/shared/audit.h
+++ b/src/shared/audit.h
@@ -25,6 +25,7 @@
 #include <stdbool.h>
 #include <sys/types.h>
 
+#define AUDIT_SESSION_INVALID ((uint32_t) -1)
 
 int audit_session_from_pid(pid_t pid, uint32_t *id);
 int audit_loginuid_from_pid(pid_t pid, uid_t *uid);
diff --git a/src/shared/cgroup-util.c b/src/shared/cgroup-util.c
index 5b04702ac2..7521b8b5f9 100644
--- a/src/shared/cgroup-util.c
+++ b/src/shared/cgroup-util.c
@@ -1150,7 +1150,7 @@ int cg_path_decode_unit(const char *cgroup, char **unit){
         c = cg_unescape(c);
 
         if (!unit_name_is_valid(c, TEMPLATE_INVALID))
-                return -EINVAL;
+                return -ENXIO;
 
         s = strdup(c);
         if (!s)
@@ -1258,7 +1258,7 @@ int cg_path_get_user_unit(const char *path, char **unit) {
         if (!t)
                 t = skip_user_manager(e);
         if (!t)
-                return -ENOENT;
+                return -ENXIO;
 
         /* ... and skip more slices if there are any */
         e = skip_slices(t);
@@ -1318,17 +1318,17 @@ int cg_path_get_session(const char *path, char **session) {
 
         n = strchrnul(e, '/');
         if (e == n)
-                return -ENOENT;
+                return -ENXIO;
 
         s = strndupa(e, n - e);
         s = cg_unescape(s);
 
         x = startswith(s, "session-");
         if (!x)
-                return -ENOENT;
+                return -ENXIO;
         y = endswith(x, ".scope");
         if (!y || x == y)
-                return -ENOENT;
+                return -ENXIO;
 
         if (session) {
                 char *r;
@@ -1369,17 +1369,17 @@ int cg_path_get_owner_uid(const char *path, uid_t *uid) {
 
         start = startswith(slice, "user-");
         if (!start)
-                return -ENOENT;
+                return -ENXIO;
         end = endswith(slice, ".slice");
         if (!end)
-                return -ENOENT;
+                return -ENXIO;
 
         s = strndupa(start, end - start);
         if (!s)
-                return -ENOENT;
+                return -ENXIO;
 
         if (parse_uid(s, &u) < 0)
-                return -EIO;
+                return -ENXIO;
 
         if (uid)
                 *uid = u;
@@ -1415,7 +1415,7 @@ int cg_path_get_slice(const char *p, char **slice) {
                         char *s;
 
                         if (!e)
-                                return -ENOENT;
+                                return -ENXIO;
 
                         s = strndup(e, m);
                         if (!s)
diff --git a/src/shared/terminal-util.c b/src/shared/terminal-util.c
index f5b6590993..042b88f222 100644
--- a/src/shared/terminal-util.c
+++ b/src/shared/terminal-util.c
@@ -1009,7 +1009,7 @@ int get_ctty_devnr(pid_t pid, dev_t *d) {
                 return -EIO;
 
         if (major(ttynr) == 0 && minor(ttynr) == 0)
-                return -ENOENT;
+                return -ENXIO;
 
         if (d)
                 *d = (dev_t) ttynr;
diff --git a/src/test/test-cgroup-util.c b/src/test/test-cgroup-util.c
index aca4f868a1..fff9ec22cf 100644
--- a/src/test/test-cgroup-util.c
+++ b/src/test/test-cgroup-util.c
@@ -40,11 +40,11 @@ static void test_path_decode_unit(void) {
         check_p_d_u("getty@tty2.service", 0, "getty@tty2.service");
         check_p_d_u("getty@tty2.service/", 0, "getty@tty2.service");
         check_p_d_u("getty@tty2.service/xxx", 0, "getty@tty2.service");
-        check_p_d_u("getty@.service/", -EINVAL, NULL);
-        check_p_d_u("getty@.service", -EINVAL, NULL);
+        check_p_d_u("getty@.service/", -ENXIO, NULL);
+        check_p_d_u("getty@.service", -ENXIO, NULL);
         check_p_d_u("getty.service", 0, "getty.service");
-        check_p_d_u("getty", -EINVAL, NULL);
-        check_p_d_u("getty/waldo", -EINVAL, NULL);
+        check_p_d_u("getty", -ENXIO, NULL);
+        check_p_d_u("getty/waldo", -ENXIO, NULL);
         check_p_d_u("_cpu.service", 0, "cpu.service");
 }
 
@@ -64,12 +64,12 @@ static void test_path_get_unit(void) {
         check_p_g_u("/system.slice/getty@tty5.service/aaa/bbb", 0, "getty@tty5.service");
         check_p_g_u("/system.slice/getty@tty5.service/", 0, "getty@tty5.service");
         check_p_g_u("/system.slice/getty@tty6.service/tty5", 0, "getty@tty6.service");
-        check_p_g_u("sadfdsafsda", -EINVAL, NULL);
-        check_p_g_u("/system.slice/getty####@tty6.service/xxx", -EINVAL, NULL);
+        check_p_g_u("sadfdsafsda", -ENXIO, NULL);
+        check_p_g_u("/system.slice/getty####@tty6.service/xxx", -ENXIO, NULL);
         check_p_g_u("/system.slice/system-waldo.slice/foobar.service/sdfdsaf", 0, "foobar.service");
         check_p_g_u("/system.slice/system-waldo.slice/_cpu.service/sdfdsaf", 0, "cpu.service");
         check_p_g_u("/user.slice/user-1000.slice/user@1000.service/server.service", 0, "user@1000.service");
-        check_p_g_u("/user.slice/user-1000.slice/user@.service/server.service", -EINVAL, NULL);
+        check_p_g_u("/user.slice/user-1000.slice/user@.service/server.service", -ENXIO, NULL);
 }
 
 static void check_p_g_u_u(const char *path, int code, const char *result) {
@@ -87,15 +87,15 @@ static void test_path_get_user_unit(void) {
         check_p_g_u_u("/user.slice/user-1000.slice/session-2.scope/waldo.slice/foobar.service", 0, "foobar.service");
         check_p_g_u_u("/user.slice/user-1002.slice/session-2.scope/foobar.service/waldo", 0, "foobar.service");
         check_p_g_u_u("/user.slice/user-1000.slice/session-2.scope/foobar.service/waldo/uuuux", 0, "foobar.service");
-        check_p_g_u_u("/user.slice/user-1000.slice/session-2.scope/waldo/waldo/uuuux", -EINVAL, NULL);
+        check_p_g_u_u("/user.slice/user-1000.slice/session-2.scope/waldo/waldo/uuuux", -ENXIO, NULL);
         check_p_g_u_u("/user.slice/user-1000.slice/session-2.scope/foobar@pie.service/pa/po", 0, "foobar@pie.service");
         check_p_g_u_u("/session-2.scope/foobar@pie.service/pa/po", 0, "foobar@pie.service");
         check_p_g_u_u("/xyz.slice/xyz-waldo.slice/session-77.scope/foobar@pie.service/pa/po", 0, "foobar@pie.service");
-        check_p_g_u_u("/meh.service", -ENOENT, NULL);
+        check_p_g_u_u("/meh.service", -ENXIO, NULL);
         check_p_g_u_u("/session-3.scope/_cpu.service", 0, "cpu.service");
         check_p_g_u_u("/user.slice/user-1000.slice/user@1000.service/server.service", 0, "server.service");
         check_p_g_u_u("/user.slice/user-1000.slice/user@1000.service/foobar.slice/foobar@pie.service", 0, "foobar@pie.service");
-        check_p_g_u_u("/user.slice/user-1000.slice/user@.service/server.service", -ENOENT, NULL);
+        check_p_g_u_u("/user.slice/user-1000.slice/user@.service/server.service", -ENXIO, NULL);
 }
 
 static void check_p_g_s(const char *path, int code, const char *result) {
@@ -108,8 +108,8 @@ static void check_p_g_s(const char *path, int code, const char *result) {
 static void test_path_get_session(void) {
         check_p_g_s("/user.slice/user-1000.slice/session-2.scope/foobar.service", 0, "2");
         check_p_g_s("/session-3.scope", 0, "3");
-        check_p_g_s("/session-.scope", -ENOENT, NULL);
-        check_p_g_s("", -ENOENT, NULL);
+        check_p_g_s("/session-.scope", -ENXIO, NULL);
+        check_p_g_s("", -ENXIO, NULL);
 }
 
 static void check_p_g_o_u(const char *path, int code, uid_t result) {
@@ -122,7 +122,7 @@ static void check_p_g_o_u(const char *path, int code, uid_t result) {
 static void test_path_get_owner_uid(void) {
         check_p_g_o_u("/user.slice/user-1000.slice/session-2.scope/foobar.service", 0, 1000);
         check_p_g_o_u("/user.slice/user-1006.slice", 0, 1006);
-        check_p_g_o_u("", -ENOENT, 0);
+        check_p_g_o_u("", -ENXIO, 0);
 }
 
 static void test_get_paths(void) {
diff --git a/src/test/test-process-util.c b/src/test/test-process-util.c
index 1de100cdae..e4e2efecd5 100644
--- a/src/test/test-process-util.c
+++ b/src/test/test-process-util.c
@@ -44,9 +44,8 @@ static void test_get_process_comm(void) {
         if (stat("/proc/1/comm", &st) == 0) {
                 assert_se(get_process_comm(1, &a) >= 0);
                 log_info("pid1 comm: '%s'", a);
-        } else {
+        } else
                 log_warning("/proc/1/comm does not exist.");
-        }
 
         assert_se(get_process_cmdline(1, 0, true, &c) >= 0);
         log_info("pid1 cmdline: '%s'", c);
@@ -87,7 +86,7 @@ static void test_get_process_comm(void) {
         log_info("self strlen(environ): '%zu'", strlen(env));
 
         if (!detect_container(NULL))
-                assert_se(get_ctty_devnr(1, &h) == -ENOENT);
+                assert_se(get_ctty_devnr(1, &h) == -ENXIO);
 
         getenv_for_pid(1, "PATH", &i);
         log_info("pid1 $PATH: '%s'", strna(i));