在linux中，当发生中断或异常时，如果CUrrent Privilege Level (CPL) 的权限低于Description Privilege Level (DPL)。一般保护将被提升！但是在这种情况下，一般保护故障的作用是什么？请帮我！
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The processor does not permit transfer of execution to an exception or interrupt-handler procedure in a less privileged code segment than the CPL. An attempt to violate this rule results in a general-protection exception (#GP). more on that(http://www.lpthe.jussieu.fr/~talon/pentium3.pdf)
Inside the kernel each exception is handled by a specific exception handler, which usually sends a Unix signal to the process that caused the exception.
In our case : the kernel will generate a signal SIGSEV.
The exception handler in this case is general_protection( ) (https://github.com/torvalds/linux/blob/master/arch/x86/include/asm/traps.h)
EDIT : in this link you can get a great explanation about how the kernel compare DPL, CPL and RPL:
http://duartes.org/gustavo/blog/post/cpu-rings-privilege-and-protection
Another good link:
于 2012-08-16T10:30:57.817 回答