Commit fa4fb8b8 authored by Michael Biebl's avatar Michael Biebl

core: If the start command vanishes during runtime don't hit an assert

This can happen when the configuration is changed and reloaded while we
are executing a service. Let's not hit an assert in this case.

Closes: #856985
parent 81ac2f2a
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 21 Oct 2016 12:27:46 +0200
Subject: core: if the start command vanishes during runtime don't hit an
assert
This can happen when the configuration is changed and reloaded while we are
executing a service. Let's not hit an assert in this case.
Fixes: #4444
(cherry picked from commit 47fffb3530af3e3ad4048570611685635fde062e)
---
src/core/service.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/src/core/service.c b/src/core/service.c
index 2ffb2aa..eb05a75 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -1346,7 +1346,15 @@ static void service_enter_start(Service *s) {
}
if (!c) {
- assert(s->type == SERVICE_ONESHOT);
+ if (s->type != SERVICE_ONESHOT) {
+ /* There's no command line configured for the main command? Hmm, that is strange. This can only
+ * happen if the configuration changes at runtime. In this case, let's enter a failure
+ * state. */
+ log_error_unit(UNIT(s)->id, "There's no 'start' task anymore we could start: %m");
+ r = -ENXIO;
+ goto fail;
+ }
+
service_enter_start_post(s);
return;
}
......@@ -171,6 +171,8 @@ core-rework-logic-to-determine-when-we-decide-to-add-auto.patch
systemctl-fix-argument-handling-when-invoked-as-shutdown.patch
systemctl-when-reading-legacy-t-argument-for-shutdown-don.patch
bus-fix-bus_print_property-to-use-int-for-booleans.patch
service-allow-services-of-Type-oneshot-that-specify-no-Ex.patch
core-if-the-start-command-vanishes-during-runtime-don-t-h.patch
## Debian specific patches:
Add-back-support-for-Debian-specific-config-files.patch
......
From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 21 Aug 2014 18:50:42 +0200
Subject: service: allow services of Type=oneshot that specify no ExecStart=
commands
This is useful for services that simply want to run something on
shutdown, but not at bootup. They should only set ExecStop= but leave
ExecStart= unset.
(cherry picked from commit 96fb8242cc1ef6b0e28f6c86a4f57950095dd7f1)
---
man/systemd.service.xml | 44 +++++++++++++++++++++++++++-----------------
src/core/service.c | 39 +++++++++++++++++++++++++++++----------
2 files changed, 56 insertions(+), 27 deletions(-)
diff --git a/man/systemd.service.xml b/man/systemd.service.xml
index b169716..1423084 100644
--- a/man/systemd.service.xml
+++ b/man/systemd.service.xml
@@ -139,9 +139,10 @@
<para>If set to
<option>simple</option> (the default
- value if neither
+ if neither
<varname>Type=</varname> nor
- <varname>BusName=</varname> are
+ <varname>BusName=</varname>, but
+ <varname>ExecStart=</varname> are
specified), it is expected that the
process configured with
<varname>ExecStart=</varname> is the
@@ -177,13 +178,17 @@
exits.</para>
<para>Behavior of
- <option>oneshot</option> is similar
- to <option>simple</option>; however,
- it is expected that the process has to
+ <option>oneshot</option> is similar to
+ <option>simple</option>; however, it
+ is expected that the process has to
exit before systemd starts follow-up
units. <varname>RemainAfterExit=</varname>
is particularly useful for this type
- of service.</para>
+ of service. This is the implied
+ default if neither
+ <varname>Type=</varname> or
+ <varname>ExecStart=</varname> are
+ specified.</para>
<para>Behavior of
<option>dbus</option> is similar to
@@ -313,22 +318,27 @@
<para>When <varname>Type</varname> is
not <option>oneshot</option>, only one
- command may be given. When
+ command may and must be given. When
<varname>Type=oneshot</varname> is
- used, more than one command may be
- specified. Multiple command lines may
- be concatenated in a single directive
- by separating them with semicolons
- (these semicolons must be passed as
- separate words). Alternatively, this
- directive may be specified more than
- once with the same effect.
- Lone semicolons may be escaped as
+ used, none or more than one command
+ may be specified. Multiple command
+ lines may be concatenated in a single
+ directive by separating them with
+ semicolons (these semicolons must be
+ passed as separate
+ words). Alternatively, this directive
+ may be specified more than once with
+ the same effect. Lone semicolons may
+ be escaped as
<literal>\;</literal>. If the empty
string is assigned to this option, the
list of commands to start is reset,
prior assignments of this option will
- have no effect.</para>
+ have no effect. If no
+ <varname>ExecStart=</varname> is
+ specified, then the service must have
+ <varname>RemainAfterExit=yes</varname>
+ set.</para>
<para>Each command line is split on
whitespace, with the first item being
diff --git a/src/core/service.c b/src/core/service.c
index e60757b..2ffb2aa 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -319,14 +319,23 @@ static int service_verify(Service *s) {
if (UNIT(s)->load_state != UNIT_LOADED)
return 0;
- if (!s->exec_command[SERVICE_EXEC_START]) {
- log_error_unit(UNIT(s)->id, "%s lacks ExecStart setting. Refusing.", UNIT(s)->id);
+ if (!s->exec_command[SERVICE_EXEC_START] && !s->exec_command[SERVICE_EXEC_STOP]) {
+ log_error_unit(UNIT(s)->id, "%s lacks both ExecStart= and ExecStop= setting. Refusing.", UNIT(s)->id);
return -EINVAL;
}
- if (s->type != SERVICE_ONESHOT &&
- s->exec_command[SERVICE_EXEC_START]->command_next) {
- log_error_unit(UNIT(s)->id, "%s has more than one ExecStart setting, which is only allowed for Type=oneshot services. Refusing.", UNIT(s)->id);
+ if (s->type != SERVICE_ONESHOT && !s->exec_command[SERVICE_EXEC_START]) {
+ log_error_unit(UNIT(s)->id, "%s has no ExecStart= setting, which is only allowed for Type=oneshot services. Refusing.", UNIT(s)->id);
+ return -EINVAL;
+ }
+
+ if (!s->remain_after_exit && !s->exec_command[SERVICE_EXEC_START]) {
+ log_error_unit(UNIT(s)->id, "%s has no ExecStart= setting, which is only allowed for RemainAfterExit=yes services. Refusing.", UNIT(s)->id);
+ return -EINVAL;
+ }
+
+ if (s->type != SERVICE_ONESHOT && s->exec_command[SERVICE_EXEC_START]->command_next) {
+ log_error_unit(UNIT(s)->id, "%s has more than one ExecStart= setting, which is only allowed for Type=oneshot services. Refusing.", UNIT(s)->id);
return -EINVAL;
}
@@ -418,8 +427,15 @@ static int service_load(Unit *u) {
if (r < 0)
return r;
- if (s->type == _SERVICE_TYPE_INVALID)
- s->type = s->bus_name ? SERVICE_DBUS : SERVICE_SIMPLE;
+ if (s->type == _SERVICE_TYPE_INVALID) {
+ /* Figure out a type automatically */
+ if (s->bus_name)
+ s->type = SERVICE_DBUS;
+ else if (s->exec_command[SERVICE_EXEC_START])
+ s->type = SERVICE_SIMPLE;
+ else
+ s->type = SERVICE_ONESHOT;
+ }
/* Oneshot services have disabled start timeout by default */
if (s->type == SERVICE_ONESHOT && !s->start_timeout_defined)
@@ -1309,9 +1325,6 @@ static void service_enter_start(Service *s) {
assert(s);
- assert(s->exec_command[SERVICE_EXEC_START]);
- assert(!s->exec_command[SERVICE_EXEC_START]->command_next || s->type == SERVICE_ONESHOT);
-
service_unwatch_control_pid(s);
service_unwatch_main_pid(s);
@@ -1332,6 +1345,12 @@ static void service_enter_start(Service *s) {
c = s->main_command = s->exec_command[SERVICE_EXEC_START];
}
+ if (!c) {
+ assert(s->type == SERVICE_ONESHOT);
+ service_enter_start_post(s);
+ return;
+ }
+
r = service_spawn(s,
c,
IN_SET(s->type, SERVICE_FORKING, SERVICE_DBUS, SERVICE_NOTIFY, SERVICE_ONESHOT) ? s->timeout_start_usec : 0,
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