diff options
Diffstat (limited to 'man')
| -rw-r--r-- | man/systemd.exec.xml | 60 |
1 files changed, 32 insertions, 28 deletions
diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml index bf82326096..bcedebd5bb 100644 --- a/man/systemd.exec.xml +++ b/man/systemd.exec.xml @@ -160,14 +160,14 @@ use. However, UID/GIDs are recycled after a unit is terminated. Care should be taken that any processes running as part of a unit for which dynamic users/groups are enabled do not leave files or directories owned by these users/groups around, as a different unit might get the same UID/GID assigned later on, and thus gain access to - these files or directories. If <varname>DynamicUser=</varname> is enabled, <varname>PrivateTmp=</varname> is - implied. This ensures that the lifetime of temporary files created by the executed processes is bound to the - runtime of the service, and hence the lifetime of the dynamic user/group. Since <filename>/tmp</filename> and - <filename>/var/tmp</filename> are usually the only world-writable directories on a system this ensures that a - unit making use of dynamic user/group allocation cannot leave files around after unit termination. Use - <varname>RuntimeDirectory=</varname> (see below) in order to assign a writable runtime directory to a service, - owned by the dynamic user/group and removed automatically when the unit is terminated. Defaults to - off.</para></listitem> + these files or directories. If <varname>DynamicUser=</varname> is enabled, <varname>RemoveIPC=</varname> and + <varname>PrivateTmp=</varname> are implied. This ensures that the lifetime of IPC objects and temporary files + created by the executed processes is bound to the runtime of the service, and hence the lifetime of the dynamic + user/group. Since <filename>/tmp</filename> and <filename>/var/tmp</filename> are usually the only + world-writable directories on a system this ensures that a unit making use of dynamic user/group allocation + cannot leave files around after unit termination. Use <varname>RuntimeDirectory=</varname> (see below) in order + to assign a writable runtime directory to a service, owned by the dynamic user/group and removed automatically + when the unit is terminated. Defaults to off.</para></listitem> </varlistentry> <varlistentry> @@ -186,6 +186,18 @@ </varlistentry> <varlistentry> + <term><varname>RemoveIPC=</varname></term> + + <listitem><para>Takes a boolean parameter. If set, all System V and POSIX IPC objects owned by the user and + group the processes of this unit are run as are removed when the unit is stopped. This setting only has an + effect if at least one of <varname>User=</varname>, <varname>Group=</varname> and + <varname>DynamicUser=</varname> are used. It has no effect on IPC objects owned by the root user. Specifically, + this removes System V semaphores, as well as System V and POSIX shared memory segments and message queues. If + multiple units use the same user or group the IPC objects are removed when the last of these units is + stopped. This setting is implied if <varname>DynamicUser=</varname> is set.</para></listitem> + </varlistentry> + + <varlistentry> <term><varname>Nice=</varname></term> <listitem><para>Sets the default nice level (scheduling @@ -920,27 +932,19 @@ <varlistentry> <term><varname>PrivateTmp=</varname></term> - <listitem><para>Takes a boolean argument. If true, sets up a - new file system namespace for the executed processes and - mounts private <filename>/tmp</filename> and - <filename>/var/tmp</filename> directories inside it that is - 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> - or <filename>/var/tmp</filename> impossible. If this is - enabled, all temporary files created by a service in these - directories will be removed after the service is stopped. - Defaults to false. It is possible to run two or more units - within the same private <filename>/tmp</filename> and - <filename>/var/tmp</filename> namespace by using the + <listitem><para>Takes a boolean argument. If true, sets up a new file system namespace for the executed + processes and mounts private <filename>/tmp</filename> and <filename>/var/tmp</filename> directories inside it + that is 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> or <filename>/var/tmp</filename> + impossible. If this is enabled, all temporary files created by a service in these directories will be removed + after the service is stopped. Defaults to false. It is possible to run two or more units within the same + private <filename>/tmp</filename> and <filename>/var/tmp</filename> namespace by using the <varname>JoinsNamespaceOf=</varname> directive, see - <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> - for details. Note that using this setting will disconnect - propagation of mounts from the service to the host - (propagation in the opposite direction continues to work). - This means that this setting may not be used for services - which shall be able to install mount points in the main mount - namespace.</para></listitem> + <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for + details. Note that using this setting will disconnect propagation of mounts from the service to the host + (propagation in the opposite direction continues to work). This means that this setting may not be used for + services which shall be able to install mount points in the main mount namespace. This setting is implied if + <varname>DynamicUser=</varname> is set.</para></listitem> </varlistentry> <varlistentry> |