Hi Chen, On Mon, May 26, 2014 at 18:05 +0800, Chen Hanxiao wrote: > We need a direct method of getting the pid inside containers. > If some issues occurred inside a container guest, host user > could not know which process is in trouble just by guest pid: > the users of container guest only knew the pid inside containers. > This will bring obstacle for trouble shooting. > > This patch expands fields of Tgid and Pid: > a) In init_pid_ns, nothing changed; > > b) In one pidns, they will tell the pid inside containers: > Tgid: 1628 9 3 > Pid: 1628 9 3 > ** process id is 1628 in level 0, 9 in level 1, 3 in level 2.
1. It breaks ABI. Any application which does something like "grep pid: | cut -d: -f2" is now broken by the patch. Maybe add a new field like 'Pid-ns', 'PidNS', or 'Pids' and leave the old one for compatibility? 2. Is it OK to show internal pids to unprivileged processes? I cannot see anything obviously dangerous with it, though. > c) If pidns is nested, it depends on which pidns are you in. > Tgid: 9 3 > Pid: 9 3 > ** Views from level 1 for Pid 1628 in host. -- Vasily -- 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/
