/*
* Copyright 2019, Jérôme Duval, jerome.duval@gmail.com.
* Copyright 2008, Ingo Weinhold, ingo_weinhold@gmx.de.
* Distributed under the terms of the MIT License.
*/
#include <asm_defs.h>
call_stub:
// push arguments on the stack
push %r9
push %r8
push %rcx
push %rdx
push %rsi
push %rdi
// pointer to ourself
lea call_stub(%rip), %rdi
// pointer to first argument
mov %rsp, %rsi
// call the wrapper function
movq (call_stub_callback_address - call_stub)(%rdi), %rax
call *%rax
// returns a pointer to the actual function
// restore arguments before calling
pop %rdi
pop %rsi
pop %rdx
pop %rcx
pop %r8
pop %r9
jmp *%rax
.align 8
call_stub_callback_address:
.long 0
call_stub_end:
// size_t arch_call_stub_size()
FUNCTION(arch_call_stub_size):
movq $(call_stub_end - call_stub), %rax
ret
FUNCTION_END(arch_call_stub_size)
// void arch_init_call_stub(void* stub,
// void* (*callback)(const void* stub, const void* args),
// void* function)
FUNCTION(arch_init_call_stub):
push %rbp
movq %rsp, %rbp
push %rsi
push %rdi
// copy the stub
movq $(call_stub_end - call_stub), %rdx
lea call_stub(%rip), %rsi
call memcpy@plt
// set the callback address in the stub
pop %rdi
pop %rsi
movq %rsi, (call_stub_callback_address - call_stub)(%rdi)
movq %rbp, %rsp
pop %rbp
ret
FUNCTION_END(arch_init_call_stub)
