本文详细介绍了SIGSEGV和SIGBUS两种信号的含义和触发条件。SIGSEGV通常发生在程序尝试访问非法内存区域或试图写入只读内存时，而SIGBUS则指示了无效地址的访问，可能是由于指针对齐问题导致。理解这些错误有助于开发者诊断和修复程序中的内存问题。
Macro: int SIGSEGV
This signal is generated when a program tries to read or write outside the memory that is allocated for it, or to write memory that can only be read. (Actually, the signals only occur when the program goes far enough outside to be detected by the system’s memory protection mechanism.) The name is an abbreviation for “segmentation violation”.
Common ways of getting a SIGSEGV condition include dereferencing a null or uninitialized pointer, or when you use a pointer to step through an array, but fail to check for the end of the array. It varies among systems whether dereferencing a null pointer generates SIGSEGV or SIGBUS.
Macro: int SIGBUS
This signal is generated when an invalid pointer is dereferenced. Like SIGSEGV, this signal is typically the result of dereferencing an uninitialized pointer. The difference between the two is that SIGSEGV indicates an invalid access to valid memory, while SIGBUS indicates an access to an invalid address. In particular, SIGBUS signals often result from dereferencing a misaligned pointer, such as referring to a four-word integer at an address not divisible by four. (Each kind of computer has its own requirements for address alignment.)
The name of this signal is an abbreviation for “bus error”.
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