QEMU中Segmentation fault (core dumped)

Segmentation fault, often abbreviated as SIGSEGV or segfault, is a common error in the execution of programs on systems that use memory management techniques like paging or segmentation. In QEMU (Quick Emulator), which is a dynamic binary translator and an emulator, a segmentation fault occurs when a program tries to access memory that it's not allowed to, typically due to one of the following reasons:

1. Dereferencing a null or uninitialized pointer: If a pointer points to an invalid memory location, accessing the memory it references will trigger a segmentation fault.

2. Out-of-bounds array access: Attempting to access an index beyond the valid range of an array can lead to a segfault.

3. Writing to read-only memory: If a program tries to modify memory marked as read-only, QEMU will catch this and report a segmentation fault.

4. Invalid memory mapping: If QEMU encounters an attempt to access memory that is not mapped correctly or has been unmapped, it will generate a segfault.

When a segmentation fault occurs in QEMU, the affected program typically terminates abruptly, and the system may generate a core dump, which is a snapshot of the program's memory state at the time of the error. This information can be useful for debugging, as it allows developers to analyze the exact cause of the crash.