This signal is raised when your program accesses memory in an invalid way. This signal by default causes your program to terminate and dump core. Bus Errors often occur when you access unaligned memory on a machine that doesn't support unaligned memory accesses. It can also occur if you access mmap(2)'d memory beyond the end of the file but within the region of the mmap(2).
Also, interestingly this can occur if the OS cannot map a page in the middle of a mmap(2) for some reason. This can occur due to disk errors, or perhaps an nfs share going away.
