0x2e2e2e2e in GDB backtrace?

I've got a SIGSEGV I'm trying to track down in my code, but I'm getting strange backtraces like this out of GDB:

#1  0x00407d15 in print_banner (msg=0x2e2e2e2e <Address 0x2e2e2e2e out of bounds>)
    at ../include/test_util.hh:20
#2  0x2e2e2e2e in ?? ()
#3  0x2e2e2e2e in ?? ()
#4  0x2e2e2e2e in ?? ()
#5  0x2e2e2e2e in ?? ()
#6  0x2e2e2e2e in ?? ()
#7  0x2e2e2e2e in ?? ()
#8  0x2e2e2e2e in ?? ()
#9  0x2e2e2e2e in ?? ()
#10 0x2e2e2e2e in ?? ()
#11 0x2e2e2e2e in ?? ()
#12 0x2e2e2e2e in ?? ()
#13 0x2e2e2e2e in ?? ()
#14 0x2e2e2e2e in ?? ()
#15 0x2e2e2e2e in ?? ()
#16 0x2e2e2e2e in ?? ()
#17 0x2e2e2e2e in ?? ()
#18 0x2e2e2e2e in ?? ()
#19 0x2e2e2e2e in ?? ()
#20 0x2e2e2e2e in ?? ()
#21 0x2e2e2e2e in ?? ()
#22 0x2e2e2e2e in ?? ()
#23 0x2e2e2e2e in ?? ()
#24 0x2e2e2e2e in ?? ()
#25 0x2e2e2e2e in ?? ()
#26 0x2e2e2e2e in ?? ()
#27 0x2e2e2e2e in ?? ()
#28 0x2e2e2e2e in ?? ()
#29 0x2e2e2e2e in ?? ()
#30 0x2e2e2e2e in ?? ()
#31 0x2e2e2e2e in ?? ()
#32 0x2e2e2e2e in ?? ()
#33 0x2e2e2e2e in ?? ()
#34 0x2e2e2e2e in ?? ()
#35 0x2e2e2e2e in ?? ()
#开发者_StackOverflow36 0x2e2e2e2e in ?? ()
#37 0x2e2e2e2e in ?? ()
#38 0x2e2e2e2e in ?? ()
#39 0x2e2e2e2e in ?? ()
#40 0x2e2e2e2e in ?? ()
#41 0x2e2e2e2e in ?? ()
#42 0x2e2e2e2e in ?? ()
#43 0x2e2e2e2e in ?? ()
#44 0x2e2e2e2e in ?? ()
#45 0x2e2e2e2e in ?? ()
#46 0x2e2e2e2e in ?? ()
#47 0x2e2e2e2e in ?? ()
#48 0x2e2e2e2e in ?? ()

Which isn't very help other than to tell me that print_banner is getting 0x2e2e2e2e as it's msg parameter (const char*), where are all these values coming from, is GDB trying to tell me something specific here?

You get this when you've corrupted the stack, and overwritten stuff that gdb needs. Sounds like you've overflown a buffer with a bunch of "...." characters.

Tools like valgrind can more easily help you diagnose such problems.