diff options
Diffstat (limited to 'man')
| -rw-r--r-- | man/systemctl.xml | 80 | ||||
| -rw-r--r-- | man/systemd.exec.xml | 89 | ||||
| -rw-r--r-- | man/systemd.resource-control.xml | 4 |
3 files changed, 127 insertions, 46 deletions
diff --git a/man/systemctl.xml b/man/systemctl.xml index 2288f65d16..914af929c8 100644 --- a/man/systemctl.xml +++ b/man/systemctl.xml @@ -481,19 +481,16 @@ <para>When used with <command>enable</command>, overwrite any existing conflicting symlinks.</para> - <para>When used with <command>halt</command>, - <command>poweroff</command>, <command>reboot</command> or - <command>kexec</command>, execute the selected operation - without shutting down all units. However, all processes will - be killed forcibly and all file systems are unmounted or - remounted read-only. This is hence a drastic but relatively - safe option to request an immediate reboot. If - <option>--force</option> is specified twice for these - operations, they will be executed immediately without - terminating any processes or unmounting any file - systems. Warning: specifying <option>--force</option> twice - with any of these operations might result in data - loss.</para> + <para>When used with <command>halt</command>, <command>poweroff</command>, <command>reboot</command> or + <command>kexec</command>, execute the selected operation without shutting down all units. However, all + processes will be killed forcibly and all file systems are unmounted or remounted read-only. This is hence a + drastic but relatively safe option to request an immediate reboot. If <option>--force</option> is specified + twice for these operations (with the exception of <command>kexec</command>), they will be executed + immediately, without terminating any processes or unmounting any file systems. Warning: specifying + <option>--force</option> twice with any of these operations might result in data loss. Note that when + <option>--force</option> is specified twice the selected operation is executed by + <command>systemctl</command> itself, and the system manager is not contacted. This means the command should + succeed even when the system manager hangs or crashed.</para> </listitem> </varlistentry> @@ -1602,48 +1599,45 @@ kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service <term><command>halt</command></term> <listitem> - <para>Shut down and halt the system. This is mostly equivalent to - <command>start halt.target --job-mode=replace-irreversibly</command>, but also - prints a wall message to all users. If combined with - <option>--force</option>, shutdown of all running services is - skipped, however all processes are killed and all file - systems are unmounted or mounted read-only, immediately - followed by the system halt. If <option>--force</option> is - specified twice, the operation is immediately executed - without terminating any processes or unmounting any file - systems. This may result in data loss.</para> + <para>Shut down and halt the system. This is mostly equivalent to <command>start halt.target + --job-mode=replace-irreversibly</command>, but also prints a wall message to all users. If combined with + <option>--force</option>, shutdown of all running services is skipped, however all processes are killed and + all file systems are unmounted or mounted read-only, immediately followed by the system halt. If + <option>--force</option> is specified twice, the operation is immediately executed without terminating any + processes or unmounting any file systems. This may result in data loss. Note that when + <option>--force</option> is specified twice the halt operation is executed by + <command>systemctl</command> itself, and the system manager is not contacted. This means the command should + succeed even when the system manager hangs or crashed.</para> </listitem> </varlistentry> <varlistentry> <term><command>poweroff</command></term> <listitem> - <para>Shut down and power-off the system. This is mostly - equivalent to <command>start poweroff.target --job-mode=replace-irreversibly</command>, - but also prints a wall message to all users. If combined with - <option>--force</option>, shutdown of all running services is - skipped, however all processes are killed and all file - systems are unmounted or mounted read-only, immediately - followed by the powering off. If <option>--force</option> is - specified twice, the operation is immediately executed - without terminating any processes or unmounting any file - systems. This may result in data loss.</para> + <para>Shut down and power-off the system. This is mostly equivalent to <command>start poweroff.target + --job-mode=replace-irreversibly</command>, but also prints a wall message to all users. If combined with + <option>--force</option>, shutdown of all running services is skipped, however all processes are killed and + all file systems are unmounted or mounted read-only, immediately followed by the powering off. If + <option>--force</option> is specified twice, the operation is immediately executed without terminating any + processes or unmounting any file systems. This may result in data loss. Note that when + <option>--force</option> is specified twice the power-off operation is executed by + <command>systemctl</command> itself, and the system manager is not contacted. This means the command should + succeed even when the system manager hangs or crashed.</para> </listitem> </varlistentry> <varlistentry> <term><command>reboot <optional><replaceable>arg</replaceable></optional></command></term> <listitem> - <para>Shut down and reboot the system. This is mostly - equivalent to <command>start reboot.target --job-mode=replace-irreversibly</command>, - but also prints a wall message to all users. If combined with - <option>--force</option>, shutdown of all running services is - skipped, however all processes are killed and all file - systems are unmounted or mounted read-only, immediately - followed by the reboot. If <option>--force</option> is - specified twice, the operation is immediately executed - without terminating any processes or unmounting any file - systems. This may result in data loss.</para> + <para>Shut down and reboot the system. This is mostly equivalent to <command>start reboot.target + --job-mode=replace-irreversibly</command>, but also prints a wall message to all users. If combined with + <option>--force</option>, shutdown of all running services is skipped, however all processes are killed and + all file systems are unmounted or mounted read-only, immediately followed by the reboot. If + <option>--force</option> is specified twice, the operation is immediately executed without terminating any + processes or unmounting any file systems. This may result in data loss. Note that when + <option>--force</option> is specified twice the reboot operation is executed by + <command>systemctl</command> itself, and the system manager is not contacted. This means the command should + succeed even when the system manager hangs or crashed.</para> <para>If the optional argument <replaceable>arg</replaceable> is given, it will be passed diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml index 4d52982b64..4a3dd14c39 100644 --- a/man/systemd.exec.xml +++ b/man/systemd.exec.xml @@ -1193,7 +1193,78 @@ <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> + will be removed from the set.)</para> + + <para>As the number of possible system + calls is large, predefined sets of system calls are provided. + A set starts with <literal>@</literal> character, followed by + name of the set. + + <table> + <title>Currently predefined system call sets</title> + + <tgroup cols='2'> + <colspec colname='set' /> + <colspec colname='description' /> + <thead> + <row> + <entry>Set</entry> + <entry>Description</entry> + </row> + </thead> + <tbody> + <row> + <entry>@clock</entry> + <entry>System calls for changing the system clock (<function>adjtimex()</function>, + <function>settimeofday()</function>)</entry> + </row> + <row> + <entry>@io-event</entry> + <entry>Event loop use (<function>poll()</function>, <function>select()</function>, + <citerefentry project='man-pages'><refentrytitle>epoll</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <function>eventfd()</function>...)</entry> + </row> + <row> + <entry>@ipc</entry> + <entry>SysV IPC, POSIX Message Queues or other IPC (<citerefentry project='man-pages'><refentrytitle>mq_overview</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>svipc</refentrytitle><manvolnum>7</manvolnum></citerefentry>)</entry> + </row> + <row> + <entry>@module</entry> + <entry>Kernel module control (<function>create_module()</function>, <function>init_module()</function>...)</entry> + </row> + <row> + <entry>@mount</entry> + <entry>File system mounting and unmounting (<function>chroot()</function>, <function>mount()</function>...)</entry> + </row> + <row> + <entry>@network-io</entry> + <entry>Socket I/O (including local AF_UNIX): + <citerefentry project='man-pages'><refentrytitle>socket</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>unix</refentrytitle><manvolnum>7</manvolnum></citerefentry></entry> + </row> + <row> + <entry>@obsolete</entry> + <entry>Unusual, obsolete or unimplemented (<function>fattach()</function>, <function>gtty()</function>, <function>vm86()</function>...)</entry> + </row> + <row> + <entry>@privileged</entry> + <entry>All system calls which need superuser capabilities (<citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>)</entry> + </row> + <row> + <entry>@process</entry> + <entry>Process control, execution, namespaces (<function>execve()</function>, <function>kill()</function>, <citerefentry project='man-pages'><refentrytitle>namespaces</refentrytitle><manvolnum>7</manvolnum></citerefentry>...)</entry> + </row> + <row> + <entry>@raw-io</entry> + <entry>Raw I/O ports (<function>ioperm()</function>, <function>iopl()</function>, <function>pciconfig_read()</function>...)</entry> + </row> + </tbody> + </tgroup> + </table> + + Note, that as new system calls are added to the kernel, additional system calls might be added to the groups + above, so the contents of the sets may change between systemd versions.</para></listitem> </varlistentry> <varlistentry> @@ -1317,6 +1388,22 @@ <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> </varlistentry> + <varlistentry> + <term><varname>MemoryDenyWriteExecute=</varname></term> + + <listitem><para>Takes a boolean argument. If set, attempts to create memory mappings that are writable and + executable at the same time, or to change existing memory mappings to become executable are prohibited. + Specifically, a system call filter is added that rejects + <citerefentry><refentrytitle>mmap</refentrytitle><manvolnum>2</manvolnum></citerefentry> + system calls with both <constant>PROT_EXEC</constant> and <constant>PROT_WRITE</constant> set + and <citerefentry><refentrytitle>mprotect</refentrytitle><manvolnum>2</manvolnum></citerefentry> + system calls with <constant>PROT_EXEC</constant> set. Note that this option is incompatible with programs + that generate program code dynamically at runtime, such as JIT execution engines, or programs compiled making + use of the code "trampoline" feature of various C compilers. This option improves service security, as it makes + harder for software exploits to change running code dynamically. + </para></listitem> + </varlistentry> + </variablelist> </refsect1> diff --git a/man/systemd.resource-control.xml b/man/systemd.resource-control.xml index 570619a743..d4c8fa7091 100644 --- a/man/systemd.resource-control.xml +++ b/man/systemd.resource-control.xml @@ -248,7 +248,7 @@ <para>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, or Terabytes (with the base 1024), respectively. If assigned the - special value <literal>max</literal>, no memory limit is applied. This controls the + special value <literal>infinity</literal>, no memory limit is applied. This controls the <literal>memory.high</literal> control group attribute. For details about this control group attribute, see <ulink url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.</para> @@ -269,7 +269,7 @@ <para>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, or Terabytes (with the base 1024), respectively. If assigned the - special value <literal>max</literal>, no memory limit is applied. This controls the + special value <literal>infinity</literal>, no memory limit is applied. This controls the <literal>memory.max</literal> control group attribute. For details about this control group attribute, see <ulink url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.</para> |