libucontext/arch/x86_64/getcontext.S

49 lines
1.3 KiB
ArmAsm

/*
* Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* This software is provided 'as is' and without any warranty, express or
* implied. In no event shall the authors be liable for any damages arising
* from the use of this software.
*/
.globl __getcontext;
__getcontext:
/* copy all of the current registers into the ucontext structure */
movq %r8, 40(%rdi)
movq %r9, 48(%rdi)
movq %r10, 56(%rdi)
movq %r11, 64(%rdi)
movq %r12, 72(%rdi)
movq %r13, 80(%rdi)
movq %r14, 88(%rdi)
movq %r15, 96(%rdi)
movq %rdi, 104(%rdi)
movq %rbp, 112(%rdi)
movq %rsi, 120(%rdi)
movq %rbx, 128(%rdi)
movq %rdx, 136(%rdi)
movq $1, 144(%rdi) /* $1 is %rax */
movq %rcx, 152(%rdi)
/* the first argument on the stack is the jump target (%rip), so we store it in the RIP
register in the ucontext structure. */
movq (%rsp), %rcx
movq %rcx, 168(%rdi)
/* finally take the stack pointer address (%rsp) offsetting by 8 to skip over the jump
target. */
leaq 8(%rsp), %rcx
movq %rcx, 160(%rdi)
/* we're all done here, return 0 */
xorl %eax, %eax
ret
.weak getcontext;
getcontext = __getcontext;