From 5e68640c5b25b3b682ca8ce92a4a573e8dfba6ae Mon Sep 17 00:00:00 2001

From: Franck Bui <fbui@suse.com>

Date: Thu, 24 Nov 2016 18:52:04 +0100

Subject: [PATCH] core: make sure initrd-switch-root command survives PID1's

 killing spree (#4730)

This is a different way to implement the fix proposed by commit

a4021390fef27f4136497328f suggested by Lennart Poettering.

In this patch we instruct PID1 to not kill "systemctl switch-root" command

started by initrd-switch-root service using the "argv[0][0]='@'" trick.

See: https://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons/ for

more details.

We had to backup argv[0] because argv is modified by dispatch_verb().

(cherry picked from commit acc28e2e3037d689d6481e4664925cf31d4d087b)

Related: #1754053

---

 src/systemctl/systemctl.c | 10 ++++++++++

 1 file changed, 10 insertions(+)

diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c

index f31137787a..f84b92ccbe 100644

--- a/src/systemctl/systemctl.c

+++ b/src/systemctl/systemctl.c

@@ -128,6 +128,7 @@ static const char *arg_kill_who = NULL;

 static int arg_signal = SIGTERM;

 static const char *arg_root = NULL;

 static usec_t arg_when = 0;

+static char *argv_cmdline = NULL;

 static enum action {

         _ACTION_INVALID,

         ACTION_SYSTEMCTL,

@@ -5060,6 +5061,13 @@ static int switch_root(sd_bus *bus, char **args) {

                         init = NULL;

         }

+        /* Instruct PID1 to exclude us from its killing spree applied during

+         * the transition from the initrd to the main system otherwise we would

+         * exit with a failure status even though the switch to the new root

+         * has succeed. */

+        if (in_initrd())

+                argv_cmdline[0] = '@';

+

         log_debug("Switching root - root: %s; init: %s", root, strna(init));

         r = sd_bus_call_method(

@@ -7626,6 +7634,8 @@ int main(int argc, char*argv[]) {

         _cleanup_bus_close_unref_ sd_bus *bus = NULL;

         int r;

+        argv_cmdline = argv[0];

+

         setlocale(LC_ALL, "");

         log_parse_environment();

         log_open();