[PATCH 0/9] Core pid namespace enhancements

[sukadev at us.ibm.com]

Eric W. Biederman [ebiederm at xmission.com] wrote:
| 
| The following patchset updates the pid namespace infrastructure
| so we don't constantly have to worry if we have been called
| before or after exit_task_namespaces, by using the pid_namespace
| obtained from a processes pid, handles the general case of setting
| si_pid in struct sig_info, changes where we drop signals sent to init,
| and enhances that changes to also work with the per namespace init.
| 
| Thus resolving most of the big gotchas with the current pid namespace
| implementation.
| 
| Eric

The patchset looks good to me.  My only testcase from the previous set
that broke was the case that Oleg pointed out

	- container-init sets a handler for SIGUSR1
	- container-init blocks SIGUSR1
	- a descendant of container-init posts SIGUSR1 to container-init
	- container-init sets SIGUSR1 to SIG_DFL and unblocks and takes the
	  fatal signal.

While that discussion can continue...

<Acked-by>: Sukadev Bhattiprolu <sukadev at us.ibm.com>