diff -rup systemd-228/src/basic/io-util.c systemd-228-new/src/basic/io-util.c
--- systemd-228/src/basic/io-util.c	2015-11-17 23:59:06.000000000 -0800
+++ systemd-228-new/src/basic/io-util.c	2019-01-16 11:15:29.889275944 -0800
@@ -23,6 +23,7 @@
 #include <unistd.h>
 
 #include "io-util.h"
+#include "string-util.h"
 
 int flush_fd(int fd) {
         struct pollfd pollfd = {
@@ -259,3 +260,20 @@ ssize_t sparse_write(int fd, const void
 
         return q - (const uint8_t*) p;
 }
+
+char* set_iovec_string_field(struct iovec *iovec, unsigned int *n_iovec, const char *field, const char *value) {
+        char *x;
+
+        x = strappend(field, value);
+        if (x)
+                iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(x);
+        return x;
+}
+
+char* set_iovec_field_free(struct iovec *iovec, unsigned int *n_iovec, const char *field, char *value) {
+        char *x;
+
+        x = set_iovec_string_field(iovec, n_iovec, field, value);
+        free(value);
+        return x;
+}
diff -rup systemd-228/src/basic/io-util.h systemd-228-new/src/basic/io-util.h
--- systemd-228/src/basic/io-util.h	2015-11-17 23:59:06.000000000 -0800
+++ systemd-228-new/src/basic/io-util.h	2019-01-16 11:15:29.889275944 -0800
@@ -47,6 +47,14 @@ ssize_t sparse_write(int fd, const void
                 _i->iov_len = strlen(_s);       \
         } while(false)
 
+#define IOVEC_INIT(base, len) { .iov_base = (base), .iov_len = (len) }
+#define IOVEC_MAKE(base, len) (struct iovec) IOVEC_INIT(base, len)
+#define IOVEC_INIT_STRING(string) IOVEC_INIT((char*) string, strlen(string))
+#define IOVEC_MAKE_STRING(string) (struct iovec) IOVEC_INIT_STRING(string)
+
+char* set_iovec_string_field(struct iovec *iovec, unsigned int *n_iovec, const char *field, const char *value);
+char* set_iovec_field_free(struct iovec *iovec, unsigned int *n_iovec, const char *field, char *value);
+
 static inline size_t IOVEC_TOTAL_SIZE(const struct iovec *i, unsigned n) {
         unsigned j;
         size_t r = 0;
diff -rup systemd-228/src/journal/coredump.c systemd-228-new/src/journal/coredump.c
--- systemd-228/src/journal/coredump.c	2015-11-17 23:59:06.000000000 -0800
+++ systemd-228-new/src/journal/coredump.c	2019-01-16 11:21:27.779910457 -0800
@@ -537,28 +537,16 @@ static int compose_open_fds(pid_t pid, c
 }
 
 int main(int argc, char* argv[]) {
-
-        /* The small core field we allocate on the stack, to keep things simple */
-        char
-                *core_pid = NULL, *core_uid = NULL, *core_gid = NULL, *core_signal = NULL,
-                *core_session = NULL, *core_exe = NULL, *core_comm = NULL, *core_cmdline = NULL,
-                *core_cgroup = NULL, *core_cwd = NULL, *core_root = NULL, *core_unit = NULL,
-                *core_slice = NULL;
-
-        /* The larger ones we allocate on the heap */
-        _cleanup_free_ char
-                *core_timestamp = NULL,  *core_message = NULL, *coredump_data = NULL, *core_owner_uid = NULL,
-                *core_open_fds = NULL, *core_proc_status = NULL, *core_proc_maps = NULL, *core_proc_limits = NULL,
-                *core_proc_cgroup = NULL, *core_environ = NULL;
-
-        _cleanup_free_ char *exe = NULL, *comm = NULL, *filename = NULL;
+        _cleanup_free_ char *core_timestamp = NULL, *core_owner_uid = NULL, *coredump_data = NULL;
+        _cleanup_free_ char *exe = NULL, *comm = NULL, *filename = NULL, *core_message = NULL;
         const char *info[_INFO_LEN];
 
         _cleanup_close_ int coredump_fd = -1;
 
         struct iovec iovec[26];
         uint64_t coredump_size;
-        int r, j = 0;
+        int r;
+        unsigned n_iovec = 0;
         uid_t uid, owner_uid;
         gid_t gid;
         pid_t pid;
@@ -645,151 +633,101 @@ int main(int argc, char* argv[]) {
                         goto finish;
                 }
 
-                core_unit = strjoina("COREDUMP_UNIT=", t);
-                free(t);
+                if (!set_iovec_field_free(iovec, &n_iovec, "COREDUMP_UNIT=", t))
+                        return log_oom();
 
         } else if (cg_pid_get_user_unit(pid, &t) >= 0) {
-                core_unit = strjoina("COREDUMP_USER_UNIT=", t);
-                free(t);
+                if (!set_iovec_field_free(iovec, &n_iovec, "COREDUMP_USER_UNIT=", t))
+                        return log_oom();
         }
 
-        if (core_unit)
-                IOVEC_SET_STRING(iovec[j++], core_unit);
-
         /* OK, now we know it's not the journal, hence we can make use
          * of it now. */
         log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
         log_open();
 
-        core_pid = strjoina("COREDUMP_PID=", info[INFO_PID]);
-        IOVEC_SET_STRING(iovec[j++], core_pid);
-
-        core_uid = strjoina("COREDUMP_UID=", info[INFO_UID]);
-        IOVEC_SET_STRING(iovec[j++], core_uid);
-
-        core_gid = strjoina("COREDUMP_GID=", info[INFO_GID]);
-        IOVEC_SET_STRING(iovec[j++], core_gid);
-
-        core_signal = strjoina("COREDUMP_SIGNAL=", info[INFO_SIGNAL]);
-        IOVEC_SET_STRING(iovec[j++], core_signal);
+        if (!set_iovec_string_field(iovec, &n_iovec, "COREDUMP_PID=", info[INFO_PID]))
+                return log_oom();
+        if (!set_iovec_string_field(iovec, &n_iovec, "COREDUMP_UID=", info[INFO_UID]))
+                return log_oom();
+        if (!set_iovec_string_field(iovec, &n_iovec, "COREDUMP_GID=", info[INFO_GID]))
+                return log_oom();
+        if (!set_iovec_string_field(iovec, &n_iovec, "COREDUMP_SIGNAL=", info[INFO_SIGNAL]))
+                return log_oom();
 
         if (sd_pid_get_session(pid, &t) >= 0) {
-                core_session = strjoina("COREDUMP_SESSION=", t);
-                free(t);
-
-                IOVEC_SET_STRING(iovec[j++], core_session);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_SESSION=", t);
         }
 
         if (sd_pid_get_owner_uid(pid, &owner_uid) >= 0) {
                 r = asprintf(&core_owner_uid,
                              "COREDUMP_OWNER_UID=" UID_FMT, owner_uid);
                 if (r > 0)
-                        IOVEC_SET_STRING(iovec[j++], core_owner_uid);
+                        IOVEC_SET_STRING(iovec[n_iovec++], core_owner_uid);
         }
 
         if (sd_pid_get_slice(pid, &t) >= 0) {
-                core_slice = strjoina("COREDUMP_SLICE=", t);
-                free(t);
-
-                IOVEC_SET_STRING(iovec[j++], core_slice);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_SLICE=", t);
         }
 
-        if (comm) {
-                core_comm = strjoina("COREDUMP_COMM=", comm);
-                IOVEC_SET_STRING(iovec[j++], core_comm);
+        if (comm && !set_iovec_string_field(iovec, &n_iovec, "COREDUMP_COMM=",  comm)) {
+                return log_oom();
         }
 
-        if (exe) {
-                core_exe = strjoina("COREDUMP_EXE=", exe);
-                IOVEC_SET_STRING(iovec[j++], core_exe);
+        if (exe && !set_iovec_string_field(iovec, &n_iovec, "COREDUMP_EXE=", exe)) {
+                return log_oom();
         }
 
         if (get_process_cmdline(pid, 0, false, &t) >= 0) {
-                core_cmdline = strjoina("COREDUMP_CMDLINE=", t);
-                free(t);
-
-                IOVEC_SET_STRING(iovec[j++], core_cmdline);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_CMDLINE=", t);
         }
 
         if (cg_pid_get_path_shifted(pid, NULL, &t) >= 0) {
-                core_cgroup = strjoina("COREDUMP_CGROUP=", t);
-                free(t);
-
-                IOVEC_SET_STRING(iovec[j++], core_cgroup);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_CGROUP=", t);
         }
 
         if (compose_open_fds(pid, &t) >= 0) {
-                core_open_fds = strappend("COREDUMP_OPEN_FDS=", t);
-                free(t);
-
-                if (core_open_fds)
-                        IOVEC_SET_STRING(iovec[j++], core_open_fds);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_OPEN_FDS=", t);
         }
 
         p = procfs_file_alloca(pid, "status");
         if (read_full_file(p, &t, NULL) >= 0) {
-                core_proc_status = strappend("COREDUMP_PROC_STATUS=", t);
-                free(t);
-
-                if (core_proc_status)
-                        IOVEC_SET_STRING(iovec[j++], core_proc_status);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_PROC_STATUS=", t);
         }
 
         p = procfs_file_alloca(pid, "maps");
         if (read_full_file(p, &t, NULL) >= 0) {
-                core_proc_maps = strappend("COREDUMP_PROC_MAPS=", t);
-                free(t);
-
-                if (core_proc_maps)
-                        IOVEC_SET_STRING(iovec[j++], core_proc_maps);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_PROC_MAPS=", t);
         }
 
         p = procfs_file_alloca(pid, "limits");
         if (read_full_file(p, &t, NULL) >= 0) {
-                core_proc_limits = strappend("COREDUMP_PROC_LIMITS=", t);
-                free(t);
-
-                if (core_proc_limits)
-                        IOVEC_SET_STRING(iovec[j++], core_proc_limits);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_PROC_LIMITS=", t);
         }
 
         p = procfs_file_alloca(pid, "cgroup");
         if (read_full_file(p, &t, NULL) >=0) {
-                core_proc_cgroup = strappend("COREDUMP_PROC_CGROUP=", t);
-                free(t);
-
-                if (core_proc_cgroup)
-                        IOVEC_SET_STRING(iovec[j++], core_proc_cgroup);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_PROC_CGROUP=", t);
         }
 
         if (get_process_cwd(pid, &t) >= 0) {
-                core_cwd = strjoina("COREDUMP_CWD=", t);
-                free(t);
-
-                IOVEC_SET_STRING(iovec[j++], core_cwd);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_CWD=", t);
         }
 
         if (get_process_root(pid, &t) >= 0) {
-                core_root = strjoina("COREDUMP_ROOT=", t);
-                free(t);
-
-                IOVEC_SET_STRING(iovec[j++], core_root);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_ROOT=", t);
         }
 
         if (get_process_environ(pid, &t) >= 0) {
-                core_environ = strappend("COREDUMP_ENVIRON=", t);
-                free(t);
-
-                if (core_environ)
-                        IOVEC_SET_STRING(iovec[j++], core_environ);
+                set_iovec_field_free(iovec, &n_iovec, "COREDUMP_ENVIRON=", t);
         }
 
         core_timestamp = strjoin("COREDUMP_TIMESTAMP=", info[INFO_TIMESTAMP], "000000", NULL);
         if (core_timestamp)
-                IOVEC_SET_STRING(iovec[j++], core_timestamp);
+                IOVEC_SET_STRING(iovec[n_iovec++], core_timestamp);
 
-        IOVEC_SET_STRING(iovec[j++], "MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1");
-        IOVEC_SET_STRING(iovec[j++], "PRIORITY=2");
+        IOVEC_SET_STRING(iovec[n_iovec++], "MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1");
+        IOVEC_SET_STRING(iovec[n_iovec++], "PRIORITY=2");
 
         /* Vacuum before we write anything again */
         coredump_vacuum(-1, arg_keep_free, arg_max_use);
@@ -811,7 +749,7 @@ int main(int argc, char* argv[]) {
                 const char *coredump_filename;
 
                 coredump_filename = strjoina("COREDUMP_FILENAME=", filename);
-                IOVEC_SET_STRING(iovec[j++], coredump_filename);
+                IOVEC_SET_STRING(iovec[n_iovec++], coredump_filename);
         }
 
         /* Vacuum again, but exclude the coredump we just created */
@@ -849,7 +787,7 @@ int main(int argc, char* argv[]) {
 log:
         core_message = strjoin("MESSAGE=Process ", info[INFO_PID], " (", comm, ") of user ", info[INFO_UID], " dumped core.", NULL);
         if (core_message)
-                IOVEC_SET_STRING(iovec[j++], core_message);
+                IOVEC_SET_STRING(iovec[n_iovec++], core_message);
 
         /* Optionally store the entire coredump in the journal */
         if (IN_SET(arg_storage, COREDUMP_STORAGE_JOURNAL, COREDUMP_STORAGE_BOTH) &&
@@ -860,13 +798,13 @@ log:
 
                 r = allocate_journal_field(coredump_fd, (size_t) coredump_size, &coredump_data, &sz);
                 if (r >= 0) {
-                        iovec[j].iov_base = coredump_data;
-                        iovec[j].iov_len = sz;
-                        j++;
+                        iovec[n_iovec].iov_base = coredump_data;
+                        iovec[n_iovec].iov_len = sz;
+                        n_iovec++;
                 }
         }
 
-        r = sd_journal_sendv(iovec, j);
+        r = sd_journal_sendv(iovec, n_iovec);
         if (r < 0)
                 log_error_errno(r, "Failed to log coredump: %m");
 
diff -rup systemd-228/src/journal/journald-server.c systemd-228-new/src/journal/journald-server.c
--- systemd-228/src/journal/journald-server.c	2015-11-17 23:59:06.000000000 -0800
+++ systemd-228-new/src/journal/journald-server.c	2019-01-16 11:15:29.889275944 -0800
@@ -579,6 +579,7 @@ static void dispatch_message_real(
                 o_uid[sizeof("OBJECT_UID=") + DECIMAL_STR_MAX(uid_t)],
                 o_gid[sizeof("OBJECT_GID=") + DECIMAL_STR_MAX(gid_t)],
                 o_owner_uid[sizeof("OBJECT_SYSTEMD_OWNER_UID=") + DECIMAL_STR_MAX(uid_t)];
+        _cleanup_free_ char *cmdline1 = NULL, *cmdline2 = NULL;
         uid_t object_uid;
         gid_t object_gid;
         char *x;
@@ -629,9 +630,9 @@ static void dispatch_message_real(
 
                 r = get_process_cmdline(ucred->pid, 0, false, &t);
                 if (r >= 0) {
-                        x = strjoina("_CMDLINE=", t);
-                        free(t);
-                        IOVEC_SET_STRING(iovec[n++], x);
+                        /* At most _SC_ARG_MAX (2MB usually), which is too much to put on stack.
+                         * Let's use a heap allocation for this one. */
+                        cmdline1 = set_iovec_field_free(iovec, &n, "_CMDLINE=", t);
                 }
 
                 r = get_process_capeff(ucred->pid, &t);
@@ -757,9 +758,7 @@ static void dispatch_message_real(
 
                 r = get_process_cmdline(object_pid, 0, false, &t);
                 if (r >= 0) {
-                        x = strjoina("OBJECT_CMDLINE=", t);
-                        free(t);
-                        IOVEC_SET_STRING(iovec[n++], x);
+                        cmdline2 = set_iovec_field_free(iovec, &n, "OBJECT_CMDLINE=", t);
                 }
 
 #ifdef HAVE_AUDIT