PR_SET_CHILD_SUBREAPER actually requires a non-zero argument to `prctl`
in order to work..!
Now, this used to work just fine (and currently works in most places)
because when we use a libc that doesn't know about
PR_SET_CHILD_SUBREAPER, it doesn't do anything about the second argument
passed to `pctrl`, so we end up sending some junk in as the second
argument. What we send appears to be completely random and as such seems
very unlikely to be zero, and so things appear to work (e.g. the tests
all pass, etc.).
However, using a libc that does know about this argument (e.g. Ubuntu
Xenial), things *don't* work because the second argument is
automatically set to 0 when we don't provide one.
This probably went unnoticed for a while considering that `tini-static`
isn't affected (it's built on Trusty), and that this mode isn't enabled
by default in the first place.
Also adding a test in run_build.sh to ensure that the pre-processed
license is always up to date with the actual license file.
To recreate: `xxd -i LICENSE > src/license.h`
This changes the execve exit status for the child process to be inline
with standard exit status codes for common execve failures.
I don't think this breaks any backwards compat with existing tini users
because it is still returning a non zero exit status but with correct
codes providing more information why it failed.
- Don't mention options that don't exist in Usage.
- Don't include a log prefix when NO_ARGS is set.
- Turn up the default verbosity to FATAL when NO_ARGS is set.
- Expose verbosity via an ENV var for debugging.
The reaping test assumes that all the `sleep` processes on the system
are created by us, which is an incorrect assumption, and creates
problems now that we run in a more "complete" system in CI (i.e. not in
a minimal container).
This solves the issue by not assuming that random sleep processes are
related to us: instead, we look at whether these processes are in our
process group.
This also includes a little clean up of the reaping stage 1.
Right now, the packages are hard-coded to report the amd64 architecture.
I'm not sure they'll be used or needed, so for now let's ignore and skip
them.
This adds 1k of weight to the resulting binary, which is reasonable
(it's less than 5% for the smaller non-static binary), but alleviates
legitimate user concern that the license requires being included when
Tini is redistributed.