chiark / gitweb /
man: Add a note about what environment variables are available by default
[elogind.git] / man / systemd.exec.xml
index eff75d033a8d43ace7c374a37b8907e6d18d5b53..ff8b812ef44087ab47278cde43bcc83e3614952a 100644 (file)
@@ -1,4 +1,3 @@
-<?xml version='1.0'?> <!--*-nxml-*-->
 <?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?>
 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
 
         <refnamediv>
                 <refname>systemd.exec</refname>
-                <refpurpose>systemd execution environment configuration</refpurpose>
+                <refpurpose>Execution environment configuration</refpurpose>
         </refnamediv>
 
         <refsynopsisdiv>
-                <para><filename>systemd.service</filename>,
-                <filename>systemd.socket</filename>,
-                <filename>systemd.mount</filename>,
-                <filename>systemd.swap</filename></para>
+                <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>
         </refsynopsisdiv>
 
         <refsect1>
                 files, and
                 <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>
+                <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                 and
                 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                 for more information on the specific unit
                 configuration files. The execution specific
                 configuration options are configured in the [Service],
-                [Socket], [Mount] resp. [Swap] section, depending on the unit
+                [Socket], [Mount], or [Swap] sections, depending on the unit
                 type.</para>
+
+                <para>Processes started by the system systemd instance
+                are executed in a clean environment in which only the
+                <varname>$PATH</varname> and <varname>$LANG</varname>
+                variables are set by default. In order to add
+                additional variables, see the
+                <varname>Environment=</varname> and
+                <varname>EnvironmentFile=</varname> options below. To
+                specify variables globally, see
+                <varname>DefaultEnvironment=</varname> in
+                <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+                or the kernel option
+                <varname>systemd.setenv=</varname> in
+                <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>. Processes
+                started by the user systemd instances inherit all
+                environment variables from the user systemd instance,
+                and have <varname>$HOME</varname>,
+                <varname>$USER</varname>,
+                <varname>$XDG_RUNTIME_DIR</varname> defined, among
+                others. In addition, <varname>$MANAGERPID</varname>
+                contains the PID of the user systemd instance.</para>
         </refsect1>
 
         <refsect1>
                 <title>Options</title>
 
-                <variablelist>
+                <variablelist class='unit-directives'>
 
                         <varlistentry>
                                 <term><varname>WorkingDirectory=</varname></term>
 
                                 <listitem><para>Takes an absolute
                                 directory path. Sets the working
-                                directory for executed
-                                processes.</para></listitem>
+                                directory for executed processes. If
+                                not set defaults to the root directory
+                                when systemd is running as a system
+                                instance and the respective user's
+                                home directory if run as
+                                user.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <term><varname>Group=</varname></term>
 
                                 <listitem><para>Sets the Unix user
-                                resp. group the processes are executed
-                                as. Takes a single user resp. group
+                                or group that the processes are executed
+                                as, respectively. Takes a single user or group
                                 name or ID as argument. If no group is
-                                set the default group of the user is
+                                set, the default group of the user is
                                 chosen.</para></listitem>
                         </varlistentry>
 
 
                                 <listitem><para>Sets the supplementary
                                 Unix groups the processes are executed
-                                as. This takes a space separated list
+                                as. This takes a space-separated list
                                 of group names or IDs. This option may
                                 be specified more than once in which
                                 case all listed groups are set as
-                                supplementary groups. This option does
-                                not override but extends the list of
-                                supplementary groups configured in the
-                                system group database for the
+                                supplementary groups. When the empty
+                                string is assigned the list of
+                                supplementary groups is reset, and all
+                                assignments prior to this one will
+                                have no effect. In any way, this
+                                option does not override, but extends
+                                the list of supplementary groups
+                                configured in the system group
+                                database for the
                                 user.</para></listitem>
                         </varlistentry>
 
                                 for this process) and 1000 (to make
                                 killing of this process under memory
                                 pressure very likely). See <ulink
-                                url="http://www.kernel.org/doc/Documentation/filesystems/proc.txt">proc.txt</ulink>
+                                url="https://www.kernel.org/doc/Documentation/filesystems/proc.txt">proc.txt</ulink>
                                 for details.</para></listitem>
                         </varlistentry>
 
 
                                 <listitem><para>Sets the CPU
                                 scheduling priority for executed
-                                processes. Takes an integer between 1
-                                (lowest priority) and 99 (highest
-                                priority). The available priority
+                                processes. The available priority
                                 range depends on the selected CPU
-                                scheduling policy (see above). See
-                                <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
-                                for details.</para></listitem>
+                                scheduling policy (see above). For
+                                real-time scheduling policies an
+                                integer between 1 (lowest priority)
+                                and 99 (highest priority) can be used.
+                                See <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+                                for details.
+                                </para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <listitem><para>Controls the CPU
                                 affinity of the executed
                                 processes. Takes a space-separated
-                                list of CPU indexes. See
+                                list of CPU indexes. This option may
+                                be specified more than once in which
+                                case the specificed CPU affinity masks
+                                are merged. If the empty string is
+                                assigned the mask is reset, all
+                                assignments prior to this will have no
+                                effect. See
                                 <citerefentry><refentrytitle>sched_setaffinity</refentrytitle><manvolnum>2</manvolnum></citerefentry>
                                 for details.</para></listitem>
                         </varlistentry>
                                 in which case all listed variables
                                 will be set. If the same variable is
                                 set twice the later setting will
-                                override the earlier setting. See
+                                override the earlier setting. If the
+                                empty string is assigned to this
+                                option the list of environment
+                                variables is reset, all prior
+                                assignments have no effect.
+                                Variable expansion is not performed
+                                inside the strings, however, specifier
+                                expansion is possible. $ character has
+                                no special meaning.
+                                If you need to assign a value containing spaces
+                                to a variable, use double quotes (")
+                                for the assignment.</para>
+
+                                <para>Example:
+                                <programlisting>Environment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"</programlisting>
+                                gives three variables <literal>VAR1</literal>,
+                                <literal>VAR2</literal>, <literal>VAR3</literal>.
+                                </para>
+
+                                <para>
+                                See
                                 <citerefentry><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
-                                for details.</para></listitem>
+                                for details about environment variables.</para></listitem>
                         </varlistentry>
                         <varlistentry>
                                 <term><varname>EnvironmentFile=</varname></term>
                                 <varname>Environment=</varname> but
                                 reads the environment variables from a
                                 text file. The text file should
-                                contain new-line separated variable
+                                contain new-line-separated variable
                                 assignments. Empty lines and lines
                                 starting with ; or # will be ignored,
-                                which may be used for commenting. The
-                                parser strips leading and
-                                trailing whitespace from the values
+                                which may be used for commenting. A line
+                                ending with a backslash will be concatenated
+                                with the following one, allowing multiline variable
+                                definitions. The parser strips leading
+                                and trailing whitespace from the values
                                 of assignments, unless you use
-                                double quotes (").
-                                The
-                                argument passed should be an absolute
-                                file name, optionally prefixed with
-                                "-", which indicates that if the file
-                                does not exist it won't be read and no
-                                error or warning message is
-                                logged. The files listed with this
+                                double quotes (").</para>
+
+                                <para>The argument passed should be an
+                                absolute filename or wildcard
+                                expression, optionally prefixed with
+                                <literal>-</literal>, which indicates
+                                that if the file does not exist, it
+                                will not be read and no error or warning
+                                message is logged.  This option may be
+                                specified more than once in which case
+                                all specified files are read. If the
+                                empty string is assigned to this
+                                option the list of file to read is
+                                reset, all prior assignments have no
+                                effect.</para>
+
+                                <para>The files listed with this
                                 directive will be read shortly before
                                 the process is executed. Settings from
                                 these files override settings made
                                 these files the files will be read in
                                 the order they are specified and the
                                 later setting will override the
-                                earlier setting. </para></listitem>
+                                earlier setting.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 with
                                 <option>DefaultStandardOutput=</option>
                                 in
-                                <citerefentry><refentrytitle>systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                                <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                                 which defaults to
                                 <option>journal</option>.</para></listitem>
                         </varlistentry>
                                 setting defaults to the value set with
                                 <option>DefaultStandardError=</option>
                                 in
-                                <citerefentry><refentrytitle>systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                                <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                                 which defaults to
                                 <option>inherit</option>.</para></listitem>
                         </varlistentry>
                         </varlistentry>
                         <varlistentry>
                                 <term><varname>TTYVTDisallocate=</varname></term>
-                                <listitem><para>If the the terminal
+                                <listitem><para>If the terminal
                                 device specified with
                                 <varname>TTYPath=</varname> is a
                                 virtual console terminal try to
                                 argument. If true and
                                 <varname>StandardOutput=</varname> or
                                 <varname>StandardError=</varname> are
-                                set to <option>syslog</option> or
-                                <option>kmsg</option> log lines
+                                set to <option>syslog</option>,
+                                <option>kmsg</option> or
+                                <option>journal</option>, log lines
                                 written by the executed process that
                                 are prefixed with a log level will be
                                 passed on to syslog with this log
                                 capability bounding set for the
                                 executed process. See
                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
-                                for details. Takes a whitespace
-                                separated list of capability names as
-                                read by
-                                <citerefentry><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+                                for details. Takes a whitespace-separated
+                                list of capability names as read by
+                                <citerefentry><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                                e.g. <constant>CAP_SYS_ADMIN</constant>,
+                                <constant>CAP_DAC_OVERRIDE</constant>,
+                                <constant>CAP_SYS_PTRACE</constant>.
                                 Capabilities listed will be included
                                 in the bounding set, all others are
                                 removed. If the list of capabilities
-                                is prefixed with ~ all but the listed
-                                capabilities will be included, the
-                                effect of the assignment
-                                inverted. Note that this option also
-                                effects the respective capabilities in
-                                the effective, permitted and
-                                inheritable capability sets, on top of
-                                what <varname>Capabilities=</varname>
+                                is prefixed with <literal>~</literal>
+                                all but the listed capabilities will
+                                be included, the effect of the
+                                assignment inverted. Note that this
+                                option also affects the respective
+                                capabilities in the effective,
+                                permitted and inheritable capability
+                                sets, on top of what
+                                <varname>Capabilities=</varname>
                                 does. If this option is not used the
                                 capability bounding set is not
                                 modified on process execution, hence
                                 no limits on the capabilities of the
-                                process are
-                                enforced.</para></listitem>
+                                process are enforced. This option may
+                                appear more than once in which case
+                                the bounding sets are merged. If the
+                                empty string is assigned to this
+                                option the bounding set is reset to
+                                the empty capability set, and all
+                                prior settings have no effect. If set
+                                to <literal>~</literal> (without any
+                                further argument) the bounding set is
+                                reset to the full set of available
+                                capabilities, also undoing any
+                                previous settings.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <option>no-setuid-fixup</option>,
                                 <option>no-setuid-fixup-locked</option>,
                                 <option>noroot</option> and/or
-                                <option>noroot-locked</option>.
-                                </para></listitem>
+                                <option>noroot-locked</option>. This
+                                option may appear more than once in
+                                which case the secure bits are
+                                ORed. If the empty string is assigned
+                                to this option the bits are reset to
+                                0.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 setting.</para></listitem>
                         </varlistentry>
 
-                        <varlistentry>
-                                <term><varname>ControlGroup=</varname></term>
-
-                                <listitem><para>Controls the control
-                                groups the executed processes shall be
-                                made members of. Takes a
-                                space-separated list of cgroup
-                                identifiers. A cgroup identifier has a
-                                format like
-                                <filename>cpu:/foo/bar</filename>,
-                                where "cpu" identifies the kernel
-                                control group controller used, and
-                                <filename>/foo/bar</filename> is the
-                                control group path. The controller
-                                name and ":" may be omitted in which
-                                case the named systemd control group
-                                hierarchy is implied. Alternatively,
-                                the path and ":" may be omitted, in
-                                which case the default control group
-                                path for this unit is implied. This
-                                option may be used to place executed
-                                processes in arbitrary groups in
-                                arbitrary hierarchies -- which can be
-                                configured externally with additional
-                                execution limits. By default systemd
-                                will place all executed processes in
-                                separate per-unit control groups
-                                (named after the unit) in the systemd
-                                named hierarchy. Since every process
-                                can be in one group per hierarchy only
-                                overriding the control group path in
-                                the named systemd hierarchy will
-                                disable automatic placement in the
-                                default group. This option is
-                                primarily intended to place executed
-                                processes in specific paths in
-                                specific kernel controller
-                                hierarchies. It is however not
-                                recommended to manipulate the service
-                                control group path in the systemd
-                                named hierarchy. For details about
-                                control groups see <ulink
-                                url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>.</para></listitem>
-                        </varlistentry>
-
-                        <varlistentry>
-                                <term><varname>ControlGroupModify=</varname></term>
-                                <listitem><para>Takes a boolean
-                                argument. If true, the control groups
-                                created for this unit will be owned by
-                                the user specified with
-                                <varname>User=</varname> (and the
-                                appropriate group), and he/she can create
-                                subgroups as well as add processes to
-                                the group.</para></listitem>
-                        </varlistentry>
-
-                        <varlistentry>
-                                <term><varname>ControlGroupPersistent=</varname></term>
-                                <listitem><para>Takes a boolean
-                                argument. If true, the control groups
-                                created for this unit will be marked
-                                to be persistent, i.e. systemd will
-                                not remove them when stopping the
-                                unit. The default is false, meaning
-                                that the control groups will be
-                                removed when the unit is stopped. For
-                                details about the semantics of this
-                                logic see <ulink
-                                url="http://www.freedesktop.org/wiki/Software/systemd/PaxControlGroups">PaxControlGroups</ulink>.</para></listitem>
-                        </varlistentry>
-
-                        <varlistentry>
-                                <term><varname>ControlGroupAttribute=</varname></term>
-
-                                <listitem><para>Set a specific control
-                                group attribute for executed
-                                processes, and (if needed) add the the
-                                executed processes to a cgroup in the
-                                hierarchy of the controller the
-                                attribute belongs to. Takes two
-                                space-separated arguments: the
-                                attribute name (syntax is
-                                <literal>cpu.shares</literal> where
-                                <literal>cpu</literal> refers to a
-                                specific controller and
-                                <literal>shares</literal> to the
-                                attribute name), and the attribute
-                                value. Example:
-                                <literal>ControlGroupAttribute=cpu.shares
-                                512</literal>. If this option is used
-                                for an attribute that belongs to a
-                                kernel controller hierarchy the unit
-                                is not already configured to be added
-                                to (for example via the
-                                <literal>ControlGroup=</literal>
-                                option) then the unit will be added to
-                                the controller and the default unit
-                                cgroup path is implied. Thus, using
-                                <varname>ControlGroupAttribute=</varname>
-                                is in most case sufficient to make use
-                                of control group enforcements,
-                                explicit
-                                <varname>ControlGroup=</varname> are
-                                only necessary in case the implied
-                                default control group path for a
-                                service is not desirable. For details
-                                about control group attributes see
-                                <ulink
-                                url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>. This
-                                option may appear more than once, in
-                                order to set multiple control group
-                                attributes.</para></listitem>
-                        </varlistentry>
-
-                        <varlistentry>
-                                <term><varname>CPUShares=</varname></term>
-
-                                <listitem><para>Assign the specified
-                                overall CPU time shares to the
-                                processes executed. Takes an integer
-                                value. This controls the
-                                <literal>cpu.shares</literal> control
-                                group attribute, which defaults to
-                                1024. For details about this control
-                                group attribute see <ulink
-                                url="http://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.</para></listitem>
-                        </varlistentry>
-
-                        <varlistentry>
-                                <term><varname>MemoryLimit=</varname></term>
-                                <term><varname>MemorySoftLimit=</varname></term>
-
-                                <listitem><para>Limit the overall memory usage
-                                of the executed processes to a certain
-                                size. Takes a memory size in bytes. If
-                                the value is suffixed with K, M, G or
-                                T the specified memory size is parsed
-                                as Kilobytes, Megabytes, Gigabytes,
-                                resp. Terabytes (to the base
-                                1024). This controls the
-                                <literal>memory.limit_in_bytes</literal>
-                                and
-                                <literal>memory.soft_limit_in_bytes</literal>
-                                control group attributes. For details
-                                about these control group attributes
-                                see <ulink
-                                url="http://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>.</para></listitem>
-                        </varlistentry>
-
-                        <varlistentry>
-                                <term><varname>DeviceAllow=</varname></term>
-                                <term><varname>DeviceDeny=</varname></term>
-
-                                <listitem><para>Control access to
-                                specific device nodes by the executed processes. Takes two
-                                space separated strings: a device node
-                                path (such as
-                                <filename>/dev/null</filename>)
-                                followed by a combination of r, w, m
-                                to control reading, writing resp.
-                                creating of the specific device node
-                                by the unit. This controls the
-                                <literal>devices.allow</literal>
-                                and
-                                <literal>devices.deny</literal>
-                                control group attributes. For details
-                                about these control group attributes
-                                see <ulink
-                                url="http://www.kernel.org/doc/Documentation/cgroups/devices.txt">devices.txt</ulink>.</para></listitem>
-                        </varlistentry>
-
-                        <varlistentry>
-                                <term><varname>BlockIOWeight=</varname></term>
-
-                                <listitem><para>Set the default or
-                                per-device overall block IO weight
-                                value for the executed
-                                processes. Takes either a single
-                                weight value (between 10 and 1000) to
-                                set the default block IO weight, or a
-                                space separated pair of a file path
-                                and a weight value to specify the
-                                device specific weight value (Example:
-                                "/dev/sda 500"). The file path may be
-                                specified as path to a block device
-                                node or as any other file in which
-                                case the backing block device of the
-                                file system of the file is
-                                determined. This controls the
-                                <literal>blkio.weight</literal> and
-                                <literal>blkio.weight_device</literal>
-                                control group attributes, which
-                                default to 1000. Use this option
-                                multiple times to set weights for
-                                multiple devices. For details about
-                                these control group attributes see
-                                <ulink
-                                url="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para></listitem>
-                        </varlistentry>
-
-                        <varlistentry>
-                                <term><varname>BlockIOReadBandwidth=</varname></term>
-                                <term><varname>BlockIOWriteBandwidth=</varname></term>
-
-                                <listitem><para>Set the per-device
-                                overall block IO bandwidth limit for
-                                the executed processes. Takes a space
-                                separated pair of a file path and a
-                                bandwidth value (in bytes per second)
-                                to specify the device specific
-                                bandwidth. The file path may be
-                                specified as path to a block device
-                                node or as any other file in which
-                                case the backing block device of the
-                                file system of the file is determined.
-                                If the bandwidth is suffixed with K, M,
-                                G, or T the specified bandwidth is
-                                parsed as Kilobytes, Megabytes,
-                                Gigabytes, resp. Terabytes (Example:
-                                "/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0
-                                5M"). This controls the
-                                <literal>blkio.read_bps_device</literal>
-                                and
-                                <literal>blkio.write_bps_device</literal>
-                                control group attributes. Use this
-                                option multiple times to set bandwidth
-                                limits for multiple devices. For
-                                details about these control group
-                                attributes see <ulink
-                                url="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para></listitem>
-                        </varlistentry>
-
                         <varlistentry>
                                 <term><varname>ReadWriteDirectories=</varname></term>
                                 <term><varname>ReadOnlyDirectories=</varname></term>
                                 <term><varname>InaccessibleDirectories=</varname></term>
 
                                 <listitem><para>Sets up a new
-                                file-system name space for executed
+                                file system namespace for executed
                                 processes. These options may be used
                                 to limit access a process might have
-                                to the main file-system
+                                to the main file system
                                 hierarchy. Each setting takes a
                                 space-separated list of absolute
                                 directory paths. Directories listed in
                                 usual file access controls would
                                 permit this. Directories listed in
                                 <varname>InaccessibleDirectories=</varname>
-                                will be made inaccessible for processes
-                                inside the namespace. Note that
-                                restricting access with these options
-                                does not extend to submounts of a
-                                directory. You must list submounts
-                                separately in these settings to
-                                ensure the same limited access. These
-                                options may be specified more than
-                                once in which case all directories
-                                listed will have limited access from
-                                within the
-                                namespace.</para></listitem>
+                                will be made inaccessible for
+                                processes inside the namespace. Note
+                                that restricting access with these
+                                options does not extend to submounts
+                                of a directory. You must list
+                                submounts separately in these settings
+                                to ensure the same limited
+                                access. These options may be specified
+                                more than once in which case all
+                                directories listed will have limited
+                                access from within the namespace. If
+                                the empty string is assigned to this
+                                option the specific list is reset, and
+                                all prior assignments have no
+                                effect.</para>
+                                <para>Paths in
+                                <varname>ReadOnlyDirectories=</varname>
+                                and
+                                <varname>InaccessibleDirectories=</varname>
+                                may be prefixed with
+                                <literal>-</literal>, in which case
+                                they will be ignored when they do not
+                                exist.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <listitem><para>Takes a boolean
                                 argument. If true sets up a new file
                                 system namespace for the executed
-                                processes and mounts a private
-                                <filename>/tmp</filename> directory
-                                inside it, that is not shared by
+                                processes and mounts private
+                                <filename>/tmp</filename> and
+                                <filename>/var/tmp</filename> directories
+                                inside it, that are not shared by
                                 processes outside of the
                                 namespace. This is useful to secure
                                 access to temporary files of the
                                 process, but makes sharing between
                                 processes via
-                                <filename>/tmp</filename>
-                                impossible. Defaults to
+                                <filename>/tmp</filename> or
+                                <filename>/var/tmp</filename>
+                                impossible. All temporary data created
+                                by service will be removed after service
+                                is stopped. Defaults to
                                 false.</para></listitem>
                         </varlistentry>
 
                                 <option>shared</option>,
                                 <option>slave</option> or
                                 <option>private</option>, which
-                                control whether namespaces set up with
-                                <varname>ReadWriteDirectories=</varname>,
-                                <varname>ReadOnlyDirectories=</varname>
-                                and
-                                <varname>InaccessibleDirectories=</varname>
-                                receive or propagate new mounts
-                                from/to the main namespace. See
-                                <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>1</manvolnum></citerefentry>
-                                for details. Defaults to
-                                <option>shared</option>, i.e. the new
-                                namespace will both receive new mount
-                                points from the main namespace as well
-                                as propagate new mounts to
-                                it.</para></listitem>
+                                control whether the file system
+                                namespace set up for this unit's
+                                processes will receive or propagate
+                                new mounts. See
+                                <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+                                for details. Default to
+                                <option>shared</option>.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                                 <term><varname>UtmpIdentifier=</varname></term>
 
-                                <listitem><para>Takes a four
+                                <listitem><para>Takes a four
                                 character identifier string for an
                                 utmp/wtmp entry for this service. This
                                 should only be set for services such
                                 <term><varname>IgnoreSIGPIPE=</varname></term>
 
                                 <listitem><para>Takes a boolean
-                                argument. If true causes SIGPIPE to be
+                                argument. If true, causes <constant>SIGPIPE</constant> to be
                                 ignored in the executed
-                                process. Defaults to true, since
-                                SIGPIPE generally is useful only in
+                                process. Defaults to true because
+                                <constant>SIGPIPE</constant> generally is useful only in
                                 shell pipelines.</para></listitem>
                         </varlistentry>
 
+                        <varlistentry>
+                                <term><varname>NoNewPrivileges=</varname></term>
+
+                                <listitem><para>Takes a boolean
+                                argument. If true, ensures that the
+                                service process and all its children
+                                can never gain new privileges. This
+                                option is more powerful than the respective
+                                secure bits flags (see above), as it
+                                also prohibits UID changes of any
+                                kind. This is the simplest, most
+                                effective way to ensure that a process
+                                and its children can never elevate
+                                privileges again.</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><varname>SystemCallFilter=</varname></term>
+
+                                <listitem><para>Takes a space-separated
+                                list of system call
+                                names. If this setting is used, all
+                                system calls executed by the unit
+                                process except for the listed ones
+                                will result in immediate process
+                                termination with the
+                                <constant>SIGSYS</constant> signal
+                                (whitelisting). If the first character
+                                of the list is <literal>~</literal>
+                                the effect is inverted: only the
+                                listed system calls will result in
+                                immediate process termination
+                                (blacklisting). If this option is used
+                                <varname>NoNewPrivileges=yes</varname>
+                                is implied. This feature makes use of
+                                the Secure Computing Mode 2 interfaces
+                                of the kernel ('seccomp filtering')
+                                and is useful for enforcing a minimal
+                                sandboxing environment. Note that the
+                                <function>execve</function>,
+                                <function>rt_sigreturn</function>,
+                                <function>sigreturn</function>,
+                                <function>exit_group</function>,
+                                <function>exit</function> system calls
+                                are implicitly whitelisted and do not
+                                need to be listed explicitly. This
+                                option may be specified more than once
+                                in which case the filter masks are
+                                merged. If the empty string is
+                                assigned the filter is reset, all
+                                prior assignments will have no
+                                effect.</para></listitem>
+                        </varlistentry>
+
                 </variablelist>
         </refsect1>
 
                           <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>,
-                          <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+                          <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                          <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                          <citerefentry><refentrytitle>systemd.cgroup</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                          <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
                   </para>
         </refsect1>