I tried to add nanosleep() for 20 seconds to forked child setting breakpoint on next line after nanosleep() and then to attach with gdb. After attaching it stops inside of nanosleep(), when continuing it crashes. I don't understand what happens here. Any ideas ?
That should've worked. Can you try again after turning PaX mprotect off: sysctl -w security.pax.mprotect.enabled=0 -RVP