Eric W. Biederman wrote: > Michael Kerrisk <[EMAIL PROTECTED]> writes: > >> Hello Kirill, >> >> In 2.6.19, your patch to add support for CLONE_NEWIPC was included. Is >> there there some for-userland-programmers documentation of this flag >> somewhere? Would you be able to send some documentation to me (ideally as >> a patch to the clone.2 man page, but otherwise some plain text will do). >> >> If this flag is also supported for unshare(), then could you please send me >> a patch/text for that too? > > In case someone else doesn't do better here is a short summary.
Thanks Eric. That looks to cover a lot of the essentials. Anyone else see something important that should be documented? And a further question: is CLONE_NEWIPC implemented for unshare()? Cheers, Michael > CLONE_NEWIPC creates a new ipc namespace for the new child and all > of it's children. So far CAP_SYS_ADMIN is required. > > An IPC namespace creates a new context for looking up and listing > SYSV IPC shared memory, message queues, and semaphores. Only allowing > finding of SYSV IPC objects in this namespace. > > For most practical purposes two processes in different SYSV IPC > namespaces might as well be on different machines. As they cannot > find each others SYSV IPC resources, and so cannot interact with > each other that way. > > The implementation is essentially just a lookup of the objects > in a different table when doing name to object translation so > there should be no measurable overhead. > > When the last process in a SYSV IPC namespace exits any remaining > objects in that SYSV IPC namespace are destroyed. > > Eric > -- Michael Kerrisk maintainer of Linux man pages Sections 2, 3, 4, 5, and 7 Want to help with man page maintenance? Grab the latest tarball at http://www.kernel.org/pub/linux/docs/manpages/ read the HOWTOHELP file and grep the source files for 'FIXME'. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
