signal-util: fix typo

Noticed by @behrmann: https://github.com/systemd/systemd/pull/20156#discussion_r667451006

TODO

@@ -1019,10 +1019,6 @@ Features:
 
 * bootctl,sd-boot: actually honour the "architecture" key
 
-* sd-boot: add service that automatically runs "bootctl update" on every boot,
-  in a graceful way, so that updated /usr trees automatically propagate into
-  updated boot loaders on reboot.
-
 * bootctl:
   - teach it to prepare an ESP wholesale, i.e. with mkfs.vfat invocation
   - teach it to copy in unified kernel images and maybe type #1 boot loader spec entries from host

man/bootctl.xml

@@ -233,8 +233,9 @@
 
       <varlistentry>
         <term><option>--graceful</option></term>
-        <listitem><para>Ignore failure when the EFI System Partition cannot be found, or when EFI variables
-        cannot be written. Currently only applies to random seed operations.</para></listitem>
+        <listitem><para>Ignore failure when the EFI System Partition cannot be found, when EFI variables
+        cannot be written, or a different or newer boot loader is already installed. Currently only applies
+        to random seed and update operations.</para></listitem>
       </varlistentry>
 
       <varlistentry>

presets/90-systemd.preset

@@ -22,6 +22,7 @@ enable systemd-resolved.service
 enable systemd-homed.service
 enable systemd-userdbd.socket
 enable systemd-pstore.service
+enable systemd-boot-update.service
 
 disable console-getty.service
 disable debug-shell.service

src/basic/signal-util.c

@@ -265,7 +265,7 @@ int pop_pending_signal_internal(int sig, ...) {
         if (sigemptyset(&ss) < 0)
                 return -errno;
 
-        /* Add first signal (if the signal is zero, we'll silently skip it, to make it easiert to build
+        /* Add first signal (if the signal is zero, we'll silently skip it, to make it easier to build
          * parameter lists where some element are sometimes off, similar to how sigset_add_many_ap() handles
          * this.) */
         if (sig > 0 && sigaddset(&ss, sig) < 0)

src/boot/bootctl.c

@@ -65,6 +65,7 @@ static const char *arg_dollar_boot_path(void) {
 
 static int acquire_esp(
                 bool unprivileged_mode,
+                bool graceful,
                 uint32_t *ret_part,
                 uint64_t *ret_pstart,
                 uint64_t *ret_psize,
@@ -80,10 +81,14 @@ static int acquire_esp(
          * this). */
 
         r = find_esp_and_warn(arg_esp_path, unprivileged_mode, &np, ret_part, ret_pstart, ret_psize, ret_uuid);
-        if (r == -ENOKEY)
+        if (r == -ENOKEY) {
+                if (graceful)
+                        return log_info_errno(r, "Couldn't find EFI system partition, skipping.");
+
                 return log_error_errno(r,
                                        "Couldn't find EFI system partition. It is recommended to mount it to /boot or /efi.\n"
                                        "Alternatively, use --esp-path= to specify path to mount point.");
+        }
         if (r < 0)
                 return r;
 
@@ -500,7 +505,7 @@ static int version_check(int fd_from, const char *from, int fd_to, const char *t
         if (r < 0)
                 return r;
         if (r == 0)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                return log_notice_errno(SYNTHETIC_ERRNO(EREMOTE),
                                        "Source file \"%s\" does not carry version information!",
                                        from);
 
@@ -508,12 +513,15 @@ static int version_check(int fd_from, const char *from, int fd_to, const char *t
         if (r < 0)
                 return r;
         if (r == 0 || compare_product(a, b) != 0)
-                return log_notice_errno(SYNTHETIC_ERRNO(EEXIST),
+                return log_notice_errno(SYNTHETIC_ERRNO(EREMOTE),
                                         "Skipping \"%s\", since it's owned by another boot loader.",
                                         to);
 
-        if (compare_version(a, b) < 0)
-                return log_warning_errno(SYNTHETIC_ERRNO(ESTALE), "Skipping \"%s\", since a newer boot loader version exists already.", to);
+        r = compare_version(a, b);
+        if (r < 0)
+                return log_warning_errno(SYNTHETIC_ERRNO(ESTALE), "Skipping \"%s\", since newer boot loader version in place already.", to);
+        else if (r == 0)
+                return log_info_errno(SYNTHETIC_ERRNO(ESTALE), "Skipping \"%s\", since same boot loader version in place already.", to);
 
         return 0;
 }
@@ -665,6 +673,10 @@ static int install_binaries(const char *esp_path, bool force) {
                         continue;
 
                 k = copy_one_file(esp_path, de->d_name, force);
+                /* Don't propagate an error code if no update necessary, installed version already equal or
+                 * newer version, or other boot loader in place. */
+                if (arg_graceful && IN_SET(k, -ESTALE, -EREMOTE))
+                        continue;
                 if (k < 0 && r == 0)
                         r = k;
         }
@@ -1243,7 +1255,7 @@ static int verb_status(int argc, char *argv[], void *userdata) {
         sd_id128_t esp_uuid = SD_ID128_NULL, xbootldr_uuid = SD_ID128_NULL;
         int r, k;
 
-        r = acquire_esp(geteuid() != 0, NULL, NULL, NULL, &esp_uuid);
+        r = acquire_esp(/* unprivileged_mode= */ geteuid() != 0, /* graceful= */ false, NULL, NULL, NULL, &esp_uuid);
         if (arg_print_esp_path) {
                 if (r == -EACCES) /* If we couldn't acquire the ESP path, log about access errors (which is the only
                                    * error the find_esp_and_warn() won't log on its own) */
@@ -1254,7 +1266,7 @@ static int verb_status(int argc, char *argv[], void *userdata) {
                 puts(arg_esp_path);
         }
 
-        r = acquire_xbootldr(geteuid() != 0, &xbootldr_uuid);
+        r = acquire_xbootldr(/* unprivileged_mode= */ geteuid() != 0, &xbootldr_uuid);
         if (arg_print_dollar_boot_path) {
                 if (r == -EACCES)
                         return log_error_errno(r, "Failed to determine XBOOTLDR location: %m");
@@ -1402,13 +1414,13 @@ static int verb_list(int argc, char *argv[], void *userdata) {
          * off logging about access errors and turn off potentially privileged device probing. Here we're interested in
          * the latter but not the former, hence request the mode, and log about EACCES. */
 
-        r = acquire_esp(geteuid() != 0, NULL, NULL, NULL, NULL);
+        r = acquire_esp(/* unprivileged_mode= */ geteuid() != 0, /* graceful= */ false, NULL, NULL, NULL, NULL);
         if (r == -EACCES) /* We really need the ESP path for this call, hence also log about access errors */
                 return log_error_errno(r, "Failed to determine ESP: %m");
         if (r < 0)
                 return r;
 
-        r = acquire_xbootldr(geteuid() != 0, NULL);
+        r = acquire_xbootldr(/* unprivileged_mode= */ geteuid() != 0, NULL);
         if (r == -EACCES)
                 return log_error_errno(r, "Failed to determine XBOOTLDR partition: %m");
         if (r < 0)
@@ -1600,21 +1612,24 @@ static int verb_install(int argc, char *argv[], void *userdata) {
         sd_id128_t uuid = SD_ID128_NULL;
         uint64_t pstart = 0, psize = 0;
         uint32_t part = 0;
-        bool install;
+        bool install, graceful;
         int r;
 
-        r = acquire_esp(false, &part, &pstart, &psize, &uuid);
+        install = streq(argv[0], "install");
+        graceful = !install && arg_graceful; /* support graceful mode for updates */
+
+        r = acquire_esp(/* unprivileged_mode= */ false, graceful, &part, &pstart, &psize, &uuid);
+        if (graceful && r == -ENOKEY)
+                return 0; /* If --graceful is specified and we can't find an ESP, handle this cleanly */
         if (r < 0)
                 return r;
 
-        r = acquire_xbootldr(false, NULL);
+        r = acquire_xbootldr(/* unprivileged_mode= */ false, NULL);
         if (r < 0)
                 return r;
 
         settle_make_machine_id_directory();
 
-        install = streq(argv[0], "install");
-
         RUN_WITH_UMASK(0002) {
                 if (install) {
                         /* Don't create any of these directories when we are just updating. When we update
@@ -1663,11 +1678,11 @@ static int verb_remove(int argc, char *argv[], void *userdata) {
         sd_id128_t uuid = SD_ID128_NULL;
         int r, q;
 
-        r = acquire_esp(false, NULL, NULL, NULL, &uuid);
+        r = acquire_esp(/* unprivileged_mode= */ false, /* graceful= */ false, NULL, NULL, NULL, &uuid);
         if (r < 0)
                 return r;
 
-        r = acquire_xbootldr(false, NULL);
+        r = acquire_xbootldr(/* unprivileged_mode= */ false, NULL);
         if (r < 0)
                 return r;
 
@@ -1726,7 +1741,7 @@ static int verb_is_installed(int argc, char *argv[], void *userdata) {
         _cleanup_free_ char *p = NULL;
         int r;
 
-        r = acquire_esp(false, NULL, NULL, NULL, NULL);
+        r = acquire_esp(/* privileged_mode= */ false, /* graceful= */ false, NULL, NULL, NULL, NULL);
         if (r < 0)
                 return r;
 

units/systemd-boot-update.service

@@ -0,0 +1,24 @@
+#  SPDX-License-Identifier: LGPL-2.1-or-later
+#
+#  This file is part of systemd.
+#
+#  systemd is free software; you can redistribute it and/or modify it
+#  under the terms of the GNU Lesser General Public License as published by
+#  the Free Software Foundation; either version 2.1 of the License, or
+#  (at your option) any later version.
+
+[Unit]
+Description=Automatic Boot Loader Update
+Documentation=man:bootctl(1)
+DefaultDependencies=no
+Conflicts=shutdown.target
+After=local-fs.target
+Before=sysinit.target shutdown.target systemd-update-done.service
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=bootctl --no-variables --graceful update
+
+[Install]
+WantedBy=sysinit.target