[Ltrace-devel] Tracing multi-threaded processes

[Petr Machata]

pmachata at redhat.com writes:

> For some reason, attaching to running multi-threaded task doesn't work
> (this was one of the first things that I fixed, but apparently it got
> broken in the meantime), so that's what I'll be doing next.

This is now fixed.  During detaching the process that ltrace attached to
previously, the process is occasionally SIGSEGVed or SIGTRAPed.  I don't
understand why that is happening, but it turns out it's not a regression
at all.  Both current master and an ancient and heavily patched version
of ltrace that's currently in Fedora exhibit this behavior.  The detach
works sometimes, which hopefully means that the underlying code is
essentially sound, just hitting some weird race or something.

The current code is on the branch pmachata/threads.  I still intend to
clean up the history and still need to verify that it works on platforms
other than x86_64.

Thanks,
PM