Created attachment 180077 [details]
DTrace script causing problem

Running and stopping a DTrace script, may leave a "ftcleanup" process behind in "DL" state, ps afux output:

root     820   0.0  0.0      0    16  -  DL    1:43PM  0:00.01 [ftcleanup]

Perl scripts (for some reason) notice this and show the following warning afterwards:

WARNING: number of probes fixed does not match the number of defined probes (16 != 18, respectively)
WARNING: some probes might not fire or your program might crash


This is reproducible on 10.3-STABLE and 10.3-RELEASE, and may take two or three attempts if it doesn't occur on the first attempt.


How to reproduce:

1. Execute attached dtracte script.
2. Stop executed dtrace script.
3. Check ps afux for kernel ftcleanup process
4. Repeat above until bug is triggered (2-3 times total should be enough)


Any perl script subsequently will print the following warning on stderr, like this script for example:

```
#!/usr/local/bin/perl
print "Test";
```

WARNING: number of probes fixed does not match the number of defined probes (16 != 18, respectively)
WARNING: some probes might not fire or your program might crash


I can also reproduce this with other dtrace scripts, like this one:
https://gist.github.com/genisd/72db1d98b64d9d7127570fff7d4b89f6


I don't know how big the implications are. One of our automation scripts dies due to the stderr output (it checks on that).