On 01/04/2011 12:02 AM, Mike Heffner wrote: > Hi, > > Is it possible for a process running in a parent PID namespace to map > the PID of a process running in a child's namespace from the > parent->child's namespace? For example, if I span the process "myproc" > with CLONE_NEWPID then a call to getpid() inside myproc will return "1" > whereas in the parent's namespace that process could actually be PID > "23495". I'd like to be able to know that 23495 maps to 1 in the new NS. > Obviously, just mapping the first PID is straightforward since I can > just look at the result of clone(). However, mapping the PIDs of > processes subsequently forked from "myproc" -- in this example -- I > haven't been able to figure out. AFAIK, it is not possible. That would be very nice to show the pid <-> vpid association. The procfs is a good candidate to show these informations. That would makes sense to show the content of /proc/<pid>/status with the pid relatively to the namespace. Let me give an example: Assuming the process '1234' creates a new pid namespace, and the child which is '1' in the new namespace has the real pid '4321'. This one mounts its /proc. If the process '1234' looks at /proc/4321/root/proc/1/status, it sees: ... Tgid: 1 Pid: 1 PPid: 0 ... It could be: ... Tgid: 4321 Pid: 4321 PPid: 1234 ... as the file is inspected from the parent namespace. Of course, if the file is looked from the child namespace context, we will see '1', '1' and '0'. I suppose the patch in the kernel should very small also. Thoughts ? Thanks. -- Daniel Sauf indication contraire ci-dessus: Compagnie IBM France Siège Social : Tour Descartes, 2, avenue Gambetta, La Défense 5, 92400 Courbevoie RCS Nanterre 552 118 465 Forme Sociale : S.A.S. Capital Social : 542.737.118 ? SIREN/SIRET : 552 118 465 02430 _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
