waitpid() on the child process when changing namespaces

waitpid() on the child process when changing namespaces

This allows upstart to wait for the process as if it was the same one called.
Otherwise, we lose the process id and upstart assumes everything is over.
"expect fork" does not handle this properly.


TEST=manual check: /sbin/minijail --namespace-vfs -- /bin/bash -c 'sleep 1'
BUG=none

[Chris Masone, 2010-03-31 03:51:20]

http://codereview.chromium.org/1570004/diff/3001/4001
File src/platform/minijail/env.cc (right):

http://codereview.chromium.org/1570004/diff/3001/4001#newcode213
src/platform/minijail/env.cc:213: _exit(WEXITSTATUS(status));
I believe that, if the process dies as a result of a signal, you'll lose that
info this way.  It's often useful to know if something aborted or segv'd or
what...

[Chris Masone, 2010-04-01 00:44:46]

LGTM

[Will Drewry, 2010-04-01 14:34:51]

New version is up that propagates the signal # and/or the exit code. All else
fails, it just bails with a value of 1.

http://codereview.chromium.org/1570004/diff/3001/4001
File src/platform/minijail/env.cc (right):

http://codereview.chromium.org/1570004/diff/3001/4001#newcode213
src/platform/minijail/env.cc:213: _exit(WEXITSTATUS(status));
On 2010/03/31 03:51:20, cmasone wrote:
> I believe that, if the process dies as a result of a signal, you'll lose that
> info this way.  It's often useful to know if something aborted or segv'd or
> what...


Ah yeah - that was sloppy of me. I'll push up a new version soon.

[Will Drewry, 2010-04-01 14:35:18]

On 2010/04/01 00:44:46, cmasone wrote:
> LGTM


Missed that you saw the fix already - thanks!