core: introduce new KillMode=mixed which sends SIGTERM only to the main process,...

This should fix some race with terminating systemd --user, where the
system systemd instance might race against the user systemd instance
when sending SIGTERM.

diff --git a/man/systemd.kill.xml b/man/systemd.kill.xml
index 1b10fba9d53d22b9b7b7f5ca0dbd4075a8561923..a4009aa38a8f86c1bb1a9726c17cd4f43320547c 100644 (file)
--- a/man/systemd.kill.xml
+++ b/man/systemd.kill.xml
@@ -44,39 +44,44 @@
 
         <refnamediv>
                 <refname>systemd.kill</refname>
 
         <refnamediv>
                 <refname>systemd.kill</refname>

-                <refpurpose>Kill environment configuration</refpurpose>
+                <refpurpose>Process killing procedure
+                configuration</refpurpose>

         </refnamediv>
 
         <refsynopsisdiv>
                 <para><filename><replaceable>service</replaceable>.service</filename>,
                 <filename><replaceable>socket</replaceable>.socket</filename>,
                 <filename><replaceable>mount</replaceable>.mount</filename>,
         </refnamediv>
 
         <refsynopsisdiv>
                 <para><filename><replaceable>service</replaceable>.service</filename>,
                 <filename><replaceable>socket</replaceable>.socket</filename>,
                 <filename><replaceable>mount</replaceable>.mount</filename>,

-                <filename><replaceable>swap</replaceable>.swap</filename></para>
+                <filename><replaceable>swap</replaceable>.swap</filename>,
+                <filename><replaceable>scope</replaceable>.scope</filename></para>

         </refsynopsisdiv>
 
         <refsect1>
                 <title>Description</title>
 
                 <para>Unit configuration files for services, sockets,
         </refsynopsisdiv>
 
         <refsect1>
                 <title>Description</title>
 
                 <para>Unit configuration files for services, sockets,

-                mount points and swap devices share a subset of
-                configuration options which define the process killing
-                parameters of spawned processes.</para>
+                mount points, swap devices and scopes share a subset
+                of configuration options which define the
+                killing procedure of processes belonging to the unit.</para>

 
                 <para>This man page lists the configuration options
 
                 <para>This man page lists the configuration options

-                shared by these four unit types. See
+                shared by these five unit types. See

                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>

-                for the common options of all unit configuration
-                files, and
+                for the common options shared by all unit
+                configuration files, and

                 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

-                <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>
-                and
+                <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

                 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>

-                for more information on the specific unit
-                configuration files. The execution specific
+                and
+                <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+                for more information on the configuration file options
+                specific to each unit type.</para>
+
+                <para>The kill procedure

                 configuration options are configured in the [Service],
                 configuration options are configured in the [Service],

-                [Socket], [Mount], or [Swap] section, depending on the unit
-                type.</para>
+                [Socket], [Mount] or [Swap] section, depending on the
+                unit type.</para>

         </refsect1>
 
         <refsect1>
         </refsect1>
 
         <refsect1>


@@ -87,32 +92,40 @@
                         <varlistentry>
                                 <term><varname>KillMode=</varname></term>
                                 <listitem><para>Specifies how
                         <varlistentry>
                                 <term><varname>KillMode=</varname></term>
                                 <listitem><para>Specifies how

-                                processes of this service shall be
+                                processes of this unit shall be

                                 killed. One of
                                 <option>control-group</option>,
                                 <option>process</option>,
                                 killed. One of
                                 <option>control-group</option>,
                                 <option>process</option>,

+                                <option>mixed</option>,

                                 <option>none</option>.</para>
 
                                 <para>If set to
                                 <option>control-group</option>, all
                                 remaining processes in the control
                                 <option>none</option>.</para>
 
                                 <para>If set to
                                 <option>control-group</option>, all
                                 remaining processes in the control

-                                group of this unit will be terminated
-                                on unit stop (for services: after the
+                                group of this unit will be killed on
+                                unit stop (for services: after the

                                 stop command is executed, as
                                 configured with
                                 <varname>ExecStop=</varname>). If set
                                 to <option>process</option>, only the
                                 main process itself is killed. If set
                                 stop command is executed, as
                                 configured with
                                 <varname>ExecStop=</varname>). If set
                                 to <option>process</option>, only the
                                 main process itself is killed. If set

-                                to <option>none</option>, no process is
+                                to <option>mixed</option> the
+                                <constant>SIGTERM</constant> signal
+                                (see below) is sent to the main
+                                process while the subsequent
+                                <constant>SIGKILL</constant> signal
+                                (see below) is sent to all remaining
+                                processes of the unit's control
+                                group. If set to
+                                <option>none</option>, no process is

                                 killed. In this case only the stop
                                 killed. In this case only the stop

-                                command will be executed on unit
-                                stop, but no process be killed
+                                command will be executed on unit stop,
+                                but no process be killed

                                 otherwise. Processes remaining alive
                                 after stop are left in their control
                                 group and the control group continues
                                 to exist after stop unless it is
                                 otherwise. Processes remaining alive
                                 after stop are left in their control
                                 group and the control group continues
                                 to exist after stop unless it is

-                                empty. Defaults to
-                                <option>control-group</option>.</para>
+                                empty.</para>

 
                                 <para>Processes will first be
                                 terminated via
 
                                 <para>Processes will first be
                                 terminated via


@@ -133,14 +146,24 @@
                                 option). See
                                 <citerefentry><refentrytitle>kill</refentrytitle><manvolnum>2</manvolnum></citerefentry>
                                 for more
                                 option). See
                                 <citerefentry><refentrytitle>kill</refentrytitle><manvolnum>2</manvolnum></citerefentry>
                                 for more

-                                information.</para></listitem>
+                                information.</para>
+
+                                <para>Defaults to
+                                <option>control-group</option>.</para></listitem>

                         </varlistentry>
 
                         <varlistentry>
                                 <term><varname>KillSignal=</varname></term>
                                 <listitem><para>Specifies which signal
                         </varlistentry>
 
                         <varlistentry>
                                 <term><varname>KillSignal=</varname></term>
                                 <listitem><para>Specifies which signal

-                                to use when killing a
-                                service. Defaults to <constant>SIGTERM</constant>.
+                                to use when killing a service. This
+                                controls the signal that is sent as
+                                first step of shutting down a unit
+                                (see above), and is usually followed
+                                by <constant>SIGKILL</constant> (see
+                                above and below). For a list of valid
+                                signals, see
+                                <citerefentry><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>. Defaults
+                                to <constant>SIGTERM</constant>.

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


@@ -184,7 +207,9 @@
                           <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                           <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                           <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                           <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                           <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                           <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

-                          <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+                          <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+                          <citerefentry><refentrytitle>kill</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
+                          <citerefentry><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>

                   </para>
         </refsect1>
 
                   </para>
         </refsect1>
 

diff --git a/src/core/kill.c b/src/core/kill.c
index ea947c23ae04a3787e21b8377f5cd9fdf5c079d3..4271346511ecfa8d010a51e508f4e71323494da4 100644 (file)
--- a/src/core/kill.c
+++ b/src/core/kill.c
@@ -52,6 +52,7 @@ void kill_context_dump(KillContext *c, FILE *f, const char *prefix) {
 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
         [KILL_CONTROL_GROUP] = "control-group",
         [KILL_PROCESS] = "process",
 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
         [KILL_CONTROL_GROUP] = "control-group",
         [KILL_PROCESS] = "process",

+        [KILL_MIXED] = "mixed",

         [KILL_NONE] = "none"
 };
 
         [KILL_NONE] = "none"
 };
 

diff --git a/src/core/kill.h b/src/core/kill.h
index 41773f07aeac18bd4c23f50dbf085229281c166d..d5f125fa41aebf1610ac4f870b6f196bad0b11c8 100644 (file)
--- a/src/core/kill.h
+++ b/src/core/kill.h
@@ -32,6 +32,7 @@ typedef enum KillMode {
         /* The kill mode is a property of a unit. */
         KILL_CONTROL_GROUP = 0,
         KILL_PROCESS,
         /* The kill mode is a property of a unit. */
         KILL_CONTROL_GROUP = 0,
         KILL_PROCESS,

+        KILL_MIXED,

         KILL_NONE,
         _KILL_MODE_MAX,
         _KILL_MODE_INVALID = -1
         KILL_NONE,
         _KILL_MODE_MAX,
         _KILL_MODE_INVALID = -1

diff --git a/src/core/unit.c b/src/core/unit.c
index e5ea994e5473a20cf47c355cad13649ad1d77e85..0ad679ba622f6154f742a9cacee2a794c1872a24 100644 (file)
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -2966,7 +2966,7 @@ int unit_kill_context(
                 }
         }
 
                 }
         }
 

-        if (c->kill_mode == KILL_CONTROL_GROUP && u->cgroup_path) {
+        if ((c->kill_mode == KILL_CONTROL_GROUP || (c->kill_mode == KILL_MIXED && sigkill)) && u->cgroup_path) {

                 _cleanup_set_free_ Set *pid_set = NULL;
 
                 /* Exclude the main/control pids from being killed via the cgroup */
                 _cleanup_set_free_ Set *pid_set = NULL;
 
                 /* Exclude the main/control pids from being killed via the cgroup */


@@ -2980,6 +2980,7 @@ int unit_kill_context(
                                 log_warning_unit(u->id, "Failed to kill control group: %s", strerror(-r));
                 } else if (r > 0) {
                         wait_for_exit = true;
                                 log_warning_unit(u->id, "Failed to kill control group: %s", strerror(-r));
                 } else if (r > 0) {
                         wait_for_exit = true;

+

                         if (c->send_sighup) {
                                 set_free(pid_set);
 
                         if (c->send_sighup) {
                                 set_free(pid_set);
 

diff --git a/units/user@.service.in b/units/user@.service.in
index bfc9b709d2c09918523aa7e3336b6a5095c3e5d8..8091ce1a0ba6bb4d3ebf56d00dc426e7df4e3a88 100644 (file)
--- a/units/user@.service.in
+++ b/units/user@.service.in
@@ -15,3 +15,4 @@ PAMName=systemd-user
 Type=notify
 ExecStart=-@rootlibexecdir@/systemd --user
 Slice=user-%i.slice
 Type=notify
 ExecStart=-@rootlibexecdir@/systemd --user
 Slice=user-%i.slice

+KillMode=mixed