subprocess exit status 255, but nsjail exit with 55 about nsjail HOT 6 CLOSED

or exit 100 will be reported as exit 0 ?

https://github.com/google/nsjail/blob/master/subproc.cc#L322

and seems strange about here too
https://github.com/google/nsjail/blob/master/subproc.cc#L334

from nsjail.

Hi,

I don't think so, the following should catch it

				if (rv == 0 && WEXITSTATUS(status) != 0) {
					rv = 1;
				}

as for the signal value, it's maximally 127, so it'll be 227, which is good exit value IMO.

In any case, I tested it

$ ./nsjail -q --chroot / -- /bin/sh -c 'exit 99'
$ echo $?
99
$ ./nsjail -q --chroot / -- /bin/sh -c 'exit 100'
$ echo $?
1
$ ./nsjail -q --chroot / -- /bin/sh -c 'exit 101'
$ echo $?
1

from nsjail.

ah, I didn't check it that.

anyway, I'm surprised we got exit status 55, which nsjail logs exit with 255.
why it takes mod 100 ? not 0x100 ?

from nsjail.

We need to represent signal exits somehow. And the only accessible to us values are 0-255.

We can definitely change something, but this is how more-or-less bash works.

Though, it simply exits with 128+signal in case of signal.

I can replicate this behavior if you think it's better

$ /bin/sh -c 'exit 137'
$ echo $?
137
$ /bin/sh -c 'kill -9 $$'
Killed
$ echo $?
137
$ /bin/sh -c 'exit 255'
$ echo $?
255

from nsjail.

Done in ffd8360

from nsjail.

lgtm

from nsjail.