Support additional argument in reboot

reboot syscall can be performed with an additional argument. In some
systems this functionality can be useful to modify the mode of the
next boot performed by the bootloader.

diff --git a/man/systemctl.xml b/man/systemctl.xml
index c7313edcc2bcb1ea57b4c41db2ae983c737d4add..7f1e98f5c5472f84095b345514ffd417b03481d1 100644 (file)
--- a/man/systemctl.xml
+++ b/man/systemctl.xml
@@ -1179,7 +1179,7 @@ kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
           </listitem>
         </varlistentry>
         <varlistentry>
           </listitem>
         </varlistentry>
         <varlistentry>

-          <term><command>reboot</command></term>
+          <term><command>reboot <optional><replaceable>arg</replaceable></optional></command></term>

 
           <listitem>
             <para>Shut down and reboot the system. This is mostly
 
           <listitem>
             <para>Shut down and reboot the system. This is mostly


@@ -1192,6 +1192,16 @@ kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
             specified twice, the operation is immediately executed
             without terminating any processes or unmounting any file
             systems. This may result in data loss.</para>
             specified twice, the operation is immediately executed
             without terminating any processes or unmounting any file
             systems. This may result in data loss.</para>

+
+            <para>If the optional argument
+            <replaceable>arg</replaceable> is given, it will be passed
+            as the optional argument to the
+            <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+            system call. The value is architecture and firmware
+            specific. As an example, <literal>recovery</literal> might
+            be used to trigger system recovery, and
+            <literal>fota</literal> might be used to trigger a
+            <quote>firmware over the air</quote> update.</para>

           </listitem>
         </varlistentry>
         <varlistentry>
           </listitem>
         </varlistentry>
         <varlistentry>

diff --git a/src/core/shutdown.c b/src/core/shutdown.c
index aa9548e2a4700bb567aab34bb56db862902e659e..377c1971a37d130bc9addaf6f639e82a11d37c3d 100644 (file)
--- a/src/core/shutdown.c
+++ b/src/core/shutdown.c
@@ -47,6 +47,7 @@
 #include "watchdog.h"
 #include "killall.h"
 #include "cgroup-util.h"
 #include "watchdog.h"
 #include "killall.h"
 #include "cgroup-util.h"

+#include "def.h"

 
 #define FINALIZE_ATTEMPTS 50
 
 
 #define FINALIZE_ATTEMPTS 50
 


@@ -134,7 +135,7 @@ static int pivot_to_new_root(void) {
 int main(int argc, char *argv[]) {
         bool need_umount = true, need_swapoff = true, need_loop_detach = true, need_dm_detach = true;
         bool in_container, use_watchdog = false;
 int main(int argc, char *argv[]) {
         bool need_umount = true, need_swapoff = true, need_loop_detach = true, need_dm_detach = true;
         bool in_container, use_watchdog = false;

-        _cleanup_free_ char *line = NULL, *cgroup = NULL;
+        _cleanup_free_ char *line = NULL, *cgroup = NULL, *param = NULL;

         char *arguments[3];
         unsigned retries;
         int cmd, r;
         char *arguments[3];
         unsigned retries;
         int cmd, r;


@@ -173,9 +174,11 @@ int main(int argc, char *argv[]) {
 
         in_container = detect_container(NULL) > 0;
 
 
         in_container = detect_container(NULL) > 0;
 

-        if (streq(argv[1], "reboot"))
+        if (streq(argv[1], "reboot")) {

                 cmd = RB_AUTOBOOT;
                 cmd = RB_AUTOBOOT;

-        else if (streq(argv[1], "poweroff"))
+                /* if this fails, that's OK */
+                read_one_line_file(REBOOT_PARAM_FILE, &param);
+        } else if (streq(argv[1], "poweroff"))

                 cmd = RB_POWER_OFF;
         else if (streq(argv[1], "halt"))
                 cmd = RB_HALT_SYSTEM;
                 cmd = RB_POWER_OFF;
         else if (streq(argv[1], "halt"))
                 cmd = RB_HALT_SYSTEM;


@@ -337,7 +340,11 @@ int main(int argc, char *argv[]) {
                 cmd = RB_AUTOBOOT;
         }
 
                 cmd = RB_AUTOBOOT;
         }
 

-        reboot(cmd);
+        if (param)
+                syscall(SYS_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
+                        LINUX_REBOOT_CMD_RESTART2, param);
+        else
+                reboot(cmd);

 
         if (errno == EPERM && in_container) {
                 /* If we are in a container, and we lacked
 
         if (errno == EPERM && in_container) {
                 /* If we are in a container, and we lacked

diff --git a/src/shared/def.h b/src/shared/def.h
index edd0bcf7a42ae98877b7493b9c88edac2dbeda07..46b88a8a49e3040d24455fd5c183f35a1f29ab13 100644 (file)
--- a/src/shared/def.h
+++ b/src/shared/def.h
@@ -38,3 +38,5 @@
 #define LOWERCASE_LETTERS "abcdefghijklmnopqrstuvwxyz"
 #define UPPERCASE_LETTERS "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 #define LETTERS LOWERCASE_LETTERS UPPERCASE_LETTERS
 #define LOWERCASE_LETTERS "abcdefghijklmnopqrstuvwxyz"
 #define UPPERCASE_LETTERS "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 #define LETTERS LOWERCASE_LETTERS UPPERCASE_LETTERS

+
+#define REBOOT_PARAM_FILE "/run/systemd/reboot-param"

diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index 9d22aad28700ebe1247aaa54ba769b862702a20a..6170cc93d56aa7695621c80eee25b7a902a07a8d 100644 (file)
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -20,6 +20,8 @@
 ***/
 
 #include <sys/reboot.h>
 ***/
 
 #include <sys/reboot.h>

+#include <linux/reboot.h>
+#include <sys/syscall.h>

 #include <stdio.h>
 #include <getopt.h>
 #include <locale.h>
 #include <stdio.h>
 #include <getopt.h>
 #include <locale.h>


@@ -4804,7 +4806,7 @@ static int systemctl_help(void) {
                "  emergency                       Enter system emergency mode\n"
                "  halt                            Shut down and halt the system\n"
                "  poweroff                        Shut down and power-off the system\n"
                "  emergency                       Enter system emergency mode\n"
                "  halt                            Shut down and halt the system\n"
                "  poweroff                        Shut down and power-off the system\n"

-               "  reboot                          Shut down and reboot the system\n"
+               "  reboot [ARG]                    Shut down and reboot the system\n"

                "  kexec                           Shut down and reboot the system with kexec\n"
                "  exit                            Request user instance exit\n"
                "  switch-root [ROOT] [INIT]       Change to a different root file system\n"
                "  kexec                           Shut down and reboot the system with kexec\n"
                "  exit                            Request user instance exit\n"
                "  switch-root [ROOT] [INIT]       Change to a different root file system\n"


@@ -4818,7 +4820,7 @@ static int systemctl_help(void) {
 
 static int halt_help(void) {
 
 
 static int halt_help(void) {
 

-        printf("%s [OPTIONS...]\n\n"
+        printf("%s [OPTIONS...]%s\n\n"

                "%s the system.\n\n"
                "     --help      Show this help\n"
                "     --halt      Halt the machine\n"
                "%s the system.\n\n"
                "     --help      Show this help\n"
                "     --halt      Halt the machine\n"


@@ -4829,6 +4831,7 @@ static int halt_help(void) {
                "  -d --no-wtmp   Don't write wtmp record\n"
                "     --no-wall   Don't send wall message before halt/power-off/reboot\n",
                program_invocation_short_name,
                "  -d --no-wtmp   Don't write wtmp record\n"
                "     --no-wall   Don't send wall message before halt/power-off/reboot\n",
                program_invocation_short_name,

+               arg_action == ACTION_REBOOT   ? " [ARG]" : "",

                arg_action == ACTION_REBOOT   ? "Reboot" :
                arg_action == ACTION_POWEROFF ? "Power off" :
                                                "Halt");
                arg_action == ACTION_REBOOT   ? "Reboot" :
                arg_action == ACTION_POWEROFF ? "Power off" :
                                                "Halt");


@@ -5253,7 +5256,7 @@ static int halt_parse_argv(int argc, char *argv[]) {
                 {}
         };
 
                 {}
         };
 

-        int c, runlevel;
+        int c, r, runlevel;

 
         assert(argc >= 0);
         assert(argv);
 
         assert(argc >= 0);
         assert(argv);


@@ -5311,7 +5314,14 @@ static int halt_parse_argv(int argc, char *argv[]) {
                 }
         }
 
                 }
         }
 

-        if (optind < argc) {
+        if (arg_action == ACTION_REBOOT && argc == optind + 1) {
+                r = write_string_file(REBOOT_PARAM_FILE, argv[optind]);
+                if (r < 0) {
+                        log_error("Failed to write reboot param to "
+                                  REBOOT_PARAM_FILE": %s", strerror(-r));
+                        return r;
+                }
+        } else if (optind < argc) {

                 log_error("Too many arguments.");
                 return -EINVAL;
         }
                 log_error("Too many arguments.");
                 return -EINVAL;
         }


@@ -5944,6 +5954,8 @@ done:
 
 static _noreturn_ void halt_now(enum action a) {
 
 
 static _noreturn_ void halt_now(enum action a) {
 

+        _cleanup_free_ char *param = NULL;
+

        /* Make sure C-A-D is handled by the kernel from this
          * point on... */
         reboot(RB_ENABLE_CAD);
        /* Make sure C-A-D is handled by the kernel from this
          * point on... */
         reboot(RB_ENABLE_CAD);


@@ -5961,8 +5973,14 @@ static _noreturn_ void halt_now(enum action a) {
                 break;
 
         case ACTION_REBOOT:
                 break;
 
         case ACTION_REBOOT:

-                log_info("Rebooting.");
-                reboot(RB_AUTOBOOT);
+                if (read_one_line_file(REBOOT_PARAM_FILE, &param) == 0) {
+                        log_info("Rebooting with arg '%s'.", param);
+                        syscall(SYS_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
+                                LINUX_REBOOT_CMD_RESTART2, param);
+                } else {
+                        log_info("Rebooting.");
+                        reboot(RB_AUTOBOOT);
+                }

                 break;
 
         default:
                 break;
 
         default: