ios常見的crash信號類型

SIGSEGV (Segmentation fault)
訪問了沒有權限的內存地址（系統內存地址等）
Access to an invalid memory address. The address exist, but your program does not have access to it.


SIGBUS (Bus error)
訪問了無效的內存地址
Access to an invalid memory address. The address does not exist, or the alignment is invalid.


SIGABRT
OC和ios系統層面上的crash信號， 比如重複釋放了一個object指針等。


SIGFPE (Floating point exception)
浮點數運算異常
Invalid arithmetic operation. Can be related to integer operations, despite the name.



SIGSEGV和SIGBUS都是屬於硬件層面的信號。