my programm crashed with some possible error in memory allocation. I had thought there should be a core file, with which I can use gdb to find the bug. But unfortunately, there is no such file. Anybody can give me some hints?  thanks a lot. (by "segmentation fault", there is a core dumped, by "bus error" also, but not by bad_alloc).
error message:
terminate called after throwing an instance of 'std::bad_alloc'
  what():  St9bad_alloc

root@OpenWrt:~# ulimit -a
time(seconds)        unlimited
file(blocks)         unlimited
data(kbytes)         unlimited
stack(kbytes)        8192
coredump(blocks)     unlimited
memory(kbytes)       unlimited
locked memory(kbytes) unlimited
process              256
nofiles              1024
vmemory(kbytes)      unlimited
locks                unlimited