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iosmemoryarminstructions

The memory copy from text segment is not the same with the original

In iOS, I copy memory use the code below:

memcpy(code, oriAddress  , 100);

where oriAddress point to text segment(a funtion's address). My problem is ,the memory in oriAddress is not the same with in code. How this happen?

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Before the arm instruction ldrh execute, the value pointed by 0x2a305ad4 is 0xb5f0. But after ldrh execute,the value of r0 is not 0xb5f0.

Solution

  • It’s my fault. I set a BreakPoint to the address,And lldb change the value pointed by the address. So the value is the BreakPoint code.