cosmopolitan/libc/nexgen32e/slowcall.S

86 lines
3.4 KiB
ArmAsm

/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
This program is free software; you can redistribute it and/or modify │
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License. │
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of │
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software │
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include "libc/macros.h"
#include "libc/notice.inc"
/ Applies no-clobber guarantee to System Five function call.
/
/ - Reentrant
/ - Realigns stack
/ - Doesn't assume red zone
/ - Clobbers nothing (except %rax and flags)
/
/ This function may be called using an stdcall convention. It's
/ useful for files named FOO.hookabi.c and BAR.ncabi.c to make
/ calls into other parts of the system, that don't conform to the
/ same restricted ABI.
/
/ @param six args and fn addr pushed on stack in reverse order
/ @return %rax has function return value, and stack is cleaned up
/ @see libc/shadowargs.hook.c for intended use case
slowcall:
#param %r9 # 0x40 arg6
#param %r8 # 0x38 arg5
#param %rcx # 0x30 arg4
#param %rdx # 0x28 arg3
#param %rsi # 0x20 arg2
#param %rdi # 0x18 arg1
#param %rax # 0x10 call address
#param # 0x08 return address
push %rbp # 0x00 parent frame
mov %rsp,%rbp # ----
push %rdi #-0x08
push %rsi #-0x10
push %rdx #-0x18
push %rcx #-0x20
push %r8 #-0x28
push %r9 #-0x30
push %r10 #-0x38
push %r11 #-0x40
mov 0x10(%rbp),%rax
mov 0x18(%rbp),%rdi
mov 0x20(%rbp),%rsi
mov 0x28(%rbp),%rdx
mov 0x30(%rbp),%rcx
mov 0x38(%rbp),%r8
mov 0x40(%rbp),%r9
and $-16,%rsp
call *%rax
push %rax
mov 0x00(%rbp),%rax
mov %rax,0x38(%rbp)
mov 0x08(%rbp),%rax
mov %rax,0x40(%rbp)
pop %rax
lea -0x40(%rbp),%rsp
pop %r11
pop %r10
pop %r9
pop %r8
pop %rcx
pop %rdx
pop %rsi
pop %rdi
lea 0x38(%rbp),%rsp
pop %rbp
ret
.endfn slowcall,globl
.source __FILE__