On Thu, Jul 7, 2011 at 16:33, MK <m...@cognitivedissonance.ca> wrote: > I have a mod_perl based module running a service on an openVZ slice. > It was working fine for a few weeks, but when I went to use it today I > get delivered an empty page and in the apache error.log: > > child exit signal Illegal instruction (4) > > Which AFAIK is a very strange thing (SIGILL); actual perl errors are > usually explicit, and passed on from the interpreter. To make sure the > problem wasn't in my code, I replaced the module with a one liner: > > sub handler { > return SERVER_ERROR; > } > > Same thing. Ie, suddenly perl modules are working. I did not compile > apache or mod_perl myself. > > Anyone have any ideas about how I can solve this or debug it further? > I have been playing around with small max stack sizes (ulimit -s 256), > but resetting that to 8192 and restarting apache did not alleviate the > problem.
I'm not sure if this is the right mailing list for you but if you want to debug Apache, start it in single-process mode (`httpd -X`) and attach `gdb` to it. That may be only nominally useful if your Apache is compiled without debug symbols (unless you get a kick out of stepping through assembly code).