EXC_BAD_ACCESS中的code = 1和code = 2有什么区别? [英] what's the difference between code=1 and code=2 in EXC_BAD_ACCESS?

问题描述

我收到EXC_BAD_ACCESS错误的代码= 1或代码= 2.我想知道code = 1和code = 2有什么区别?

I am receiving code=1 or code=2 for EXC_BAD_ACCESS error. I am wondering what's the difference between code=1 and code=2?

推荐答案

代码= 1是KERN_INVALID_ADDRESS，代码= 2是KERN_PROTECTION_FAILURE.两者都是 技术说明TN2123 CrashReporter" 中的解释:

Code = 1 is KERN_INVALID_ADDRESS and code = 2 is KERN_PROTECTION_FAILURE. Both are explained in the "Technical Note TN2123 CrashReporter":

最常见的异常形式是:

The most common forms of exception are:

• EXC_BAD_ACCESS/KERN_INVALID_ADDRESS —这是由线程引起的 访问未映射的内存.它可能是由数据访问触发的 或取指令；线程状态部分介绍了如何 分辨出差异.
• EXC_BAD_ACCESS/KERN_PROTECTION_FAILURE —这是 由试图写入只读内存的线程引起的.这是 总是由数据访问引起的.

• EXC_BAD_ACCESS/KERN_INVALID_ADDRESS — This is caused by the thread accessing unmapped memory. It may be triggered by either a data access or an instruction fetch; the Thread State section describes how to tell the difference.
• EXC_BAD_ACCESS/KERN_PROTECTION_FAILURE — This is caused by the thread trying to write to read-only memory. This is always caused by a data access.

代码在 <mach/kern_return.h> :

#define KERN_INVALID_ADDRESS            1
                /* Specified address is not currently valid.
                 */

#define KERN_PROTECTION_FAILURE         2
                /* Specified memory is valid, but does not permit the
                 * required forms of access.
                 */

和 <mach/exception_types.h> 记录该代码 对于EXC_BAD_ACCESS是kern_return_t:

and in <mach/exception_types.h> it is documented that the code for a EXC_BAD_ACCESS is a kern_return_t:

#define EXC_BAD_ACCESS          1       /* Could not access memory */
                /* Code contains kern_return_t describing error. */
                /* Subcode contains bad memory address. */

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