doc: detail what "UID" is

[elogind.git] / man / systemd.exec.xml

diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml
index 0c6ca5acfb347212eef790704ab64202f249ec17..a9e54cb03b1d573368dc3feb371212238a5c00d7 100644 (file)
--- a/man/systemd.exec.xml
+++ b/man/systemd.exec.xml
@@ -472,9 +472,9 @@
                         <varlistentry>
                                 <term><varname>StandardError=</varname></term>
                                 <listitem><para>Controls where file
                         <varlistentry>
                                 <term><varname>StandardError=</varname></term>
                                 <listitem><para>Controls where file

-                                descriptor 2 (STDERR) of the executed
-                                processes is connected to. The
-                                available options are identical to
+                                descriptor 2 (standard error) of the
+                                executed processes is connected to.
+                                The available options are identical to

                                 those of
                                 <varname>StandardOutput=</varname>,
                                 with one exception: if set to
                                 those of
                                 <varname>StandardOutput=</varname>,
                                 with one exception: if set to


@@ -491,8 +491,8 @@
                         <varlistentry>
                                 <term><varname>TTYPath=</varname></term>
                                 <listitem><para>Sets the terminal
                         <varlistentry>
                                 <term><varname>TTYPath=</varname></term>
                                 <listitem><para>Sets the terminal

-                                device node to use if standard input,
-                                output or stderr are connected to a
+                                device node to use if standard input, output,
+                                or error are connected to a

                                 TTY (see above). Defaults to
                                 <filename>/dev/console</filename>.</para></listitem>
                         </varlistentry>
                                 TTY (see above). Defaults to
                                 <filename>/dev/console</filename>.</para></listitem>
                         </varlistentry>


@@ -1001,7 +1001,7 @@
                                 list of system call
                                 names. If this setting is used, all
                                 system calls executed by the unit
                                 list of system call
                                 names. If this setting is used, all
                                 system calls executed by the unit

-                                process except for the listed ones
+                                processes except for the listed ones

                                 will result in immediate process
                                 termination with the
                                 <constant>SIGSYS</constant> signal
                                 will result in immediate process
                                 termination with the
                                 <constant>SIGSYS</constant> signal


@@ -1031,21 +1031,95 @@
                                 prior assignments will have no
                                 effect.</para>
 
                                 prior assignments will have no
                                 effect.</para>
 

-                                <para>If you specify both types of this option
-                                (i.e. whitelisting and blacklisting) the first
-                                encountered will take precedence and will
-                                dictate the default action (termination
-                                or approval of a system call). Then the
-                                next occurrences of this option will add or
-                                delete the listed system calls from the set
-                                of the filtered system calls, depending of
-                                its type and the default action (e.g. You
-                                have started with a whitelisting of <function>
-                                read</function> and <function>write</function>
-                                and right after it add a blacklisting of
-                                <function>write</function>, then <function>
-                                write</function> will be removed from the set)
+                                <para>If you specify both types of
+                                this option (i.e. whitelisting and
+                                blacklisting) the first encountered
+                                will take precedence and will dictate
+                                the default action (termination or
+                                approval of a system call). Then the
+                                next occurrences of this option will
+                                add or delete the listed system calls
+                                from the set of the filtered system
+                                calls, depending of its type and the
+                                default action (e.g. You have started
+                                with a whitelisting of
+                                <function>read</function> and
+                                <function>write</function> and right
+                                after it add a blacklisting of
+                                <function>write</function>, then
+                                <function>write</function> will be
+                                removed from the set).

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

+
+                                <para>Note that setting
+                                <varname>SystemCallFilter=</varname>
+                                implies a
+                                <varname>SystemCallArchitectures=</varname>
+                                setting of <literal>native</literal>
+                                (see below), unless that option is
+                                configured otherwise.</para>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><varname>SystemCallErrorNumber=</varname></term>
+
+                                <listitem><para>Takes an
+                                <literal>errno</literal> error number
+                                name to return when the system call
+                                filter configured with
+                                <varname>SystemCallFilter=</varname>
+                                is triggered, instead of terminating
+                                the process immediately. Takes an
+                                error name such as
+                                <literal>EPERM</literal>,
+                                <literal>EACCES</literal> or
+                                <literal>EUCLEAN</literal>. When this
+                                setting is not used, or when the empty
+                                string is assigned the process will be
+                                terminated immediately when the filter
+                                is triggered.</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><varname>SystemCallArchitectures=</varname></term>
+
+                                <listitem><para>Takes a space
+                                separated list of architecture
+                                identifiers to include in the system
+                                call filter. The known architecture
+                                identifiers are
+                                <literal>x86</literal>,
+                                <literal>x86-64</literal>,
+                                <literal>x32</literal>,
+                                <literal>arm</literal> as well as the
+                                special identifier
+                                <literal>native</literal>. Only system
+                                calls of the specified architectures
+                                will be permitted to processes of this
+                                unit. This is an effective way to
+                                disable compatibility with non-native
+                                architectures for processes, for
+                                example to prohibit execution of 32bit
+                                x86 binaries on 64bit x86-64
+                                systems. The special
+                                <literal>native</literal> identifier
+                                implicitly maps to the native
+                                architecture of the system (or more
+                                strictly: to the architecture the
+                                system manager is compiled for). Note
+                                that setting this option to a
+                                non-empty list implies that
+                                <literal>native</literal> is included
+                                too. By default this option is set to
+                                the empty list, i.e. no architecture
+                                system call filtering is applied. Note
+                                that configuring a system call filter
+                                with
+                                <varname>SystemCallFilter=</varname>
+                                (above) implies a
+                                <literal>native</literal> architecture
+                                list, unless configured
+                                otherwise.</para></listitem>

                         </varlistentry>
 
                 </variablelist>
                         </varlistentry>
 
                 </variablelist>