[Valgrind-users] Signal handlers not being called under valgrind

[Jonathan B. <jbe...@ci...>]

First posted this question on irc, but noticed that was intended to be a dev channel, so moving here as it seems the proper forum.
I'm hitting an odd problem running a program (fwknopd) under valgrind.  We have signal handlers for several of the typical signals, including sigint, and they work as expected when running without valgrind.
When running under valgrind and leak-check=full, I am getting "Process terminating with default action of signal 2 (SIGINT)"
Same story for sigusr1 and sigusr2, even though handlers are in place.  I've tried --vex-iropt-register-updates=allregs-at-each-insn, but this doesn't seem to reliably fix the issue.
What's even more odd is that on some runs, a given signal handler will work as expected, almost randomly switching.  I have yet to get all 3 to work correctly at once.
Handler code is at https://github.com/mrash/fwknop/blob/master/server/sig_handler.c if interested.  Any hints welcome.  One element I find very strange is that sighup works perfectly every time, even though its handler is declared in exactly the same way.

Thanks!
Jonathan Bennett