Quoting Cedric Le Goater ([EMAIL PROTECTED]): > > >> hmm, I'm wondering how this is going to work for a process which > >> would have unshared its device (pts) namespace. How are we going > >> to link the pts living in different namespaces if the stdios of the > >> hijacked process is using them ? like in the case of a shell, which > >> is certainly something we would like to hijacked. > >> > >> it looks like a challenge for me. maybe I'm wrong. > > > > Might be a problem, but tough to address that until we actually > > have a dev ns or devpts ns and established semantics. > > > > Note the filestruct comes from current, not the hijack target, so > > presumably we can work around the tty issue in any case by > > keeping an open file across the hijack? > > > > For instance, use the attached modified version of hijack.c > > which puts a writeable fd for /tmp/helloworld in fd 5, then > > does hijack, then from the resulting shell do > > > > echo ab >&5 > > > > So we should easily be able to work around it. > > yes. it should. > > > Or am i missing something? > > I guess we need to work a little more on the pts/device namespace > to see how it interacts. > > >>> The effect is a sort of namespace enter. The following program > >>> uses sys_hijack to 'enter' all namespaces of the specified pid. > >>> For instance in one terminal, do > >>> > >>> mount -t cgroup -ons /cgroup > >>> hostname > >>> qemu > >>> ns_exec -u /bin/sh > >>> hostname serge > >>> echo $$ > >>> 1073 > >>> cat /proc/$$/cgroup > >>> ns:/node_1073 > >> Is there a reason to have the 'node_' prefix ? couldn't we just > >> use $pid ? > > > > Good question. It's just how the ns-cgroup does it... If you want to > > send in a patch to change that, I'll ack it. > > just below. > > I gave a quick look to the ns subsystem and didn't see how the node_$pid > was destroyed. do we have to do a rmdir ? > > Thanks, > > > C. > > Signed-off-by: Cedric Le Goater <[EMAIL PROTECTED]>
Thanks. Acked-by: Serge Hallyn <[EMAIL PROTECTED]> > --- > kernel/cgroup.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Index: 2.6.23-mm1/kernel/cgroup.c > =================================================================== > --- 2.6.23-mm1.orig/kernel/cgroup.c > +++ 2.6.23-mm1/kernel/cgroup.c > @@ -2604,7 +2604,7 @@ int cgroup_clone(struct task_struct *tsk > cg = tsk->cgroups; > parent = task_cgroup(tsk, subsys->subsys_id); > > - snprintf(nodename, MAX_CGROUP_TYPE_NAMELEN, "node_%d", tsk->pid); > + snprintf(nodename, MAX_CGROUP_TYPE_NAMELEN, "%d", tsk->pid); > > /* Pin the hierarchy */ > atomic_inc(&parent->root->sb->s_active); _______________________________________________ Containers mailing list [EMAIL PROTECTED] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
