Bus error & Segmentation fault

该信号表示总线错误，通常与SIGSEGV混合。虽然类似（都代表尝试访问无效内存），但当地址不存在或更常见的无效对齐时，会发生SIGBUS 。换句话说，物理地址无效（这与逻辑地址无效的SIGSEGV不同）。

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In computing, a bus error is a fault raised by hardware, notifying an operating system (OS) that a process is trying to access memory that the CPU cannot physically address: an invalid address for the address bus, hence the name.

不合法

In computing, a segmentation fault (often shortened to segfault) or access violation is a fault, or failure condition, raised by hardware with memory protection, notifying an operating system (OS) the software has attempted to access a restricted area of memory (a memory access violation).