Problem with passing variable/register arguments to function

[programdev218]

Description

Whenever I try to call a function with a register argument, I get the NotImplementedError exception. Based on the error code, I'm assuming that this is because gadgets like jmp rax for function calls are not supported.

This code

rop.func_call('mprotect', ('rax', 0x1000, 0x7))

causes this exception

NotImplementedError: currently only support jmp_mem type func_jmp_gadgets!

[Kyle-Kyle]

If you'd like to utilize a register as an argument directly, we actually support it. Just not in this syntax (I'd like to though, so I'll leave this issue open until I finish the refactor).
Anyway, the correct syntax is:

rop.func_call('mprotect', (0x41414141, 0x1000, 0x7), preserve_regs={'rdi'})

And the 0x41414141 will be ignored. (it doesn't need to be 0x41414141, whatever is there in rdi will be ignored)

I agree the current syntax is not intuitive, that's why I'd like to refactor this part soon.

[Kyle-Kyle]

And example looks like this:

[ins] In [3]: rop.func_call("prepare_kernel_cred", (0x41414141, 0x42424242), preserve_regs={'rdi'}).pp()
0xffffffff81489752: pop rsi; ret 
                    0x42424242
0xffffffff8114d660: <prepare_kernel_cred>
                    <BV64 next_pc_4280_64>