Goto a specific Address in C

问题:

How can I JMP to a specific address in C?

I want to use

goto 0x10080000

This is not working, is there other way I can change the address of Program Counter??

回答1:

You can cast the address to a function pointer and then jump into:

((void (*)(void))0x10008000)();

To make it a bit more clear:

typedef void (*func_t)(void);
...
((func_t)0x10008000)();

But this is a function, the compiler will emit a branch instruction that expect to return (then is up to you to make your function return or not). Also notice that the compiler will produce a code that expect to find a C function at the given address, about how the function arguments are given and returned.

If you need to emit a branch instruction without return you need to use inline assembly.

回答2:

In GCC you can use computed goto. I didn't try it myself, but it should work like this:

void *address = 0x10080000;
...
goto *address;

回答3:

Inline assembly instruction should work too:

asm("jump 0x10080000");