Early Draft: Add parameter to check if files are mapped in processes not part of the recording.

[bernhardu]

In its current state it just calls lsof with the pids inside the the recording excluded.

It would show the mapping that caused the issue in #3417,
but the others are probably just read-only mappings due to /proc/pid/maps.

$ rr record --lsof -n atril sshfs/home/benutzer/test2.pdfrr: Saving execution to trace directory `/home/bernhard/data/entwicklung/2022/rr/rr-recordings/atril-14'.
Warning: /usr/lib/x86_64-linux-gnu/gconv/gconv-modules.cache seems to be mapped by a process outside of the recording. Diversions might happen when replaying this trace.
Warning: /home/bernhard/.cache/fontconfig/a6050266-6adb-4e1c-8a1d-f55d18a3f9c3-le64.cache-7 seems to be mapped by a process outside of the recording. Diversions might happen when replaying this trace.
Warning: /run/user/1000/dconf/user seems to be mapped by a process outside of the recording. Diversions might happen when replaying this trace.
Warning: /home/bernhard/.local/share/mime/mime.cache seems to be mapped by a process outside of the recording. Diversions might happen when replaying this trace.
Warning: /usr/local/share/mime/mime.cache seems to be mapped by a process outside of the recording. Diversions might happen when replaying this trace.
Warning: /usr/share/mime/mime.cache seems to be mapped by a process outside of the recording. Diversions might happen when replaying this trace.
Warning: /home/bernhard/.local/share/gvfs-metadata/root seems to be mapped by a process outside of the recording. Diversions might happen when replaying this trace.
Warning: /home/bernhard/.local/share/gvfs-metadata/root-5c301c7a.log seems to be mapped by a process outside of the recording. Diversions might happen when replaying this trace.
...

[bernhardu]

The call to system() might be ugly to dangerous. lsof seems to want in the long term to make it available as library.
Would the license allow it?

[rocallahan]

This would be a cool feature to have but rather than calling lsof I think we would want to reimplement the functionality by scanning /proc/.../maps.