summaryrefslogtreecommitdiff
path: root/man/systemd.exec.xml
diff options
context:
space:
mode:
Diffstat (limited to 'man/systemd.exec.xml')
-rw-r--r--man/systemd.exec.xml38
1 files changed, 14 insertions, 24 deletions
diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml
index 11029ca186..e7d8bb23a4 100644
--- a/man/systemd.exec.xml
+++ b/man/systemd.exec.xml
@@ -1255,30 +1255,20 @@
<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 processes 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 running in
- user mode, or in system mode, but without the
- <constant>CAP_SYS_ADMIN</constant> capability (e.g. setting
- <varname>User=nobody</varname>),
- <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. This does not affect commands prefixed with <literal>+</literal>.</para>
+ <listitem><para>Takes a space-separated list of system call names. If this setting is used, all system calls
+ executed by the unit processes 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 running in user mode, or in system mode, but without the <constant>CAP_SYS_ADMIN</constant>
+ capability (e.g. setting <varname>User=nobody</varname>), <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>exit</function>, <function>exit_group</function>, <function>getrlimit</function>,
+ <function>rt_sigreturn</function>, <function>sigreturn</function> system calls and the system calls for
+ querying time and sleeping 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. This does not affect commands prefixed with
+ <literal>+</literal>.</para>
<para>If you specify both types of this option (i.e.
whitelisting and blacklisting), the first encountered will