chiark / gitweb /
docs: typos in loginctl.xml
[elogind.git] / man / systemd.exec.xml
index eff75d033a8d43ace7c374a37b8907e6d18d5b53..7ab9b5c1ed6824c07d6a71158af87c45ad7ac33b 100644 (file)
@@ -44,7 +44,7 @@
 
         <refnamediv>
                 <refname>systemd.exec</refname>
-                <refpurpose>systemd execution environment configuration</refpurpose>
+                <refpurpose>Execution environment configuration</refpurpose>
         </refnamediv>
 
         <refsynopsisdiv>
 
                                 <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>
                         </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
 
                                 <listitem><para>Set a specific control
                                 group attribute for executed
-                                processes, and (if needed) add the the
+                                processes, and (if needed) add the
                                 executed processes to a cgroup in the
                                 hierarchy of the controller the
                                 attribute belongs to. Takes two
                                 <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
+                                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>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>
+                                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
                                 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 SIGSYS 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 don't
+                                need to be listed
+                                explicitly.</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>
                   </para>
         </refsect1>