I'm going to need a spot of help with this. I have Chromium running under GDB, with surprisingly low overhead (I can browse like normal if I drop the --single-process flag). As far as I could find, the "trap invalid opcode" error reported in syslog is synonymous with a SIGILL, so I set "handle SIGILL stop pass". Unfortunately, the trap errors continue to occur without GDB stopping execution.
Do you know how to set this up to get to a backtrace? Maybe a way of disabling the signal/crash handler?