Re: stuck on ghak100 testsuite script

On Sun, Nov 11, 2018 at 11:36 PM Richard Guy Briggs <rgb(a)redhat.com&gt; wrote: > On 2018-11-11 17:24, Ondrej Mosnacek wrote: > > Hi Richard, > > On Fri, Nov 9, 2018 at 11:04 PM Richard Guy Briggs <rgb(a)redhat.com&gt; wrote: > > > Hi Paul, Ondrej, > > > > > > I've got a couple of patches with two different approaches to address > > > ghak100: > > > https://github.com/linux-audit/audit-kernel/issues/100 > > > > > > The patches work, but I've not posted them yet because I wanted to > > > update the audit-testsuite first to consistently test it. > > > > > > I've written a test to automate the regression test to add to > > > audit-testsuite based on the reproducer recipe provided in ghak100. The > > > procedure in the description of ghak100 works, but I'm having some > > > trouble with the script. In particular, it is hanging the script on the > > > "kill 'SIGSTOP' $pid_fuse" line. Once it hangs, the main script, the > > > test subscript and both backgrounded processes (fuse and umount) are > > > still hanging around. > > > > > > Here's the script: > > > https://github.com/linux-audit/audit-testsuite/compare/master...rgbriggs:... > > > > > > Do either of you have any insight why this might be happenning and how > > > to fix or work around it? > > > > > > A couple of minor notes: > > > - The $pid_fuse += 1 is necessary since it forks from the PID reported > > > to the shell. > > > > I don't understand... why do you expect the forked PID to be exactly > > one higher? This doesn't seem to be the case in general: > > > > $ (echo $$; exec bash -c 'echo $$' &) > > 10995 > > 13693 > > I was not happy with this hack, but this was the most expedient way to > try to get a first attempt working... I suppose a better way might be > to spawn the client which forks, then use something like pgrep to find > all the instances and eliminate the PID that was returned by the launch. How about something like: system("cd $basedir/$clientdir; mkfifo /tmp/fifo; sh -c 'echo $$ > /tmp/fifo; exec ./$client -f -s $tmpdir' & cat /tmp/fifo"); That should always give you the right PID. You just need to tweak it to create the FIFO as a temporary file and clean it up afterwards. It is more complicated, but should be reliable.

> As far as I can tell, I was hitting the right task since hitting the > wrong or non-existant task didn't hang the test. Yes, when I fork from a fresh shell, I also get the forked PID one greater practically every time, so that will be a different problem... I didn't look at the hang problem yet, I will try it later in the afternoon. > > > - The SIGSTOP is necessary to simulate the hung filesystem. > > > > > > - RGB > > > > Ondrej Mosnacek <omosnace at redhat dot com> > > - RGB Ondrej Mosnacek <omosnace at redhat dot com>