/*--------------------------------------------------------------------*/
/*--- A minimal setjmp/longjmp implementation. m_libcsetjmp.c ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Valgrind, a dynamic binary instrumentation
framework.
Copyright (C) 2010-2011 Mozilla Inc
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; either version 2 of the
License, or (at your option) any later version.
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., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file COPYING.
*/
/* Contributed by Julian Seward <jseward@acm.org> */
#include "pub_core_basics.h"
#include "pub_core_libcsetjmp.h" /* self */
/* See include/pub_tool_libcsetjmp.h for background and rationale. */
/* The alternative implementations are for ppc{32,64}-linux and
{amd64,x86}-{linux,darwin}. See #259977. That leaves only
{arm,s390x}-linux using the gcc builtins now.
*/
/* ------------ ppc32-linux ------------ */
#if defined(VGP_ppc32_linux)
__asm__(
".text" "\n"
"" "\n"
".global VG_MINIMAL_SETJMP" "\n" // r3 = jmp_buf
"VG_MINIMAL_SETJMP:" "\n"
" stw 0, 0(3)" "\n"
" stw 1, 4(3)" "\n"
" stw 2, 8(3)" "\n"
" stw 3, 12(3)" "\n"
" stw 4, 16(3)" "\n"
" stw 5, 20(3)" "\n"
" stw 6, 24(3)" "\n"
" stw 7, 28(3)" "\n"
" stw 8, 32(3)" "\n"
" stw 9, 36(3)" "\n"
" stw 10, 40(3)" "\n"
" stw 11, 44(3)" "\n"
" stw 12, 48(3)" "\n"
" stw 13, 52(3)" "\n"
" stw 14, 56(3)" "\n"
" stw 15, 60(3)" "\n"
" stw 16, 64(3)" "\n"
" stw 17, 68(3)" "\n"
" stw 18, 72(3)" "\n"
" stw 19, 76(3)" "\n"
" stw 20, 80(3)" "\n"
" stw 21, 84(3)" "\n"
" stw 22, 88(3)" "\n"
" stw 23, 92(3)" "\n"
" stw 24, 96(3)" "\n"
" stw 25, 100(3)" "\n"
" stw 26, 104(3)" "\n"
" stw 27, 108(3)" "\n"
" stw 28, 112(3)" "\n"
" stw 29, 116(3)" "\n"
" stw 30, 120(3)" "\n"
" stw 31, 124(3)" "\n"
// must use a caller-save register here as scratch, hence r4
" mflr 4" "\n"
" stw 4, 128(3)" "\n"
" mfcr 4" "\n"
" stw 4, 132(3)" "\n"
" li 3, 0" "\n"
" blr" "\n"
"" "\n"
".global VG_MINIMAL_LONGJMP" "\n"
"VG_MINIMAL_LONGJMP:" "\n" // r3 = jmp_buf
// do r4 = 1
// and park it in the restore slot for r3 (the ret reg)
" li 4, 1" "\n"
" stw 4, 12(3)" "\n"
// restore everything except r3
// then r3 last of all
// then blr
" lwz 0, 128(3)" "\n"
" mtlr 0" "\n"
" lwz 0, 132(3)" "\n"
" mtcr 0" "\n"
" lwz 0, 0(3)" "\n"
" lwz 1, 4(3)" "\n"
" lwz 2, 8(3)" "\n"
// r3 is done at the end
" lwz 4, 16(3)" "\n"
" lwz 5, 20(3)" "\n"
" lwz 6, 24(3)" "\n"
" lwz 7, 28(3)" "\n"
" lwz 8, 32(3)" "\n"
" lwz 9, 36(3)" "\n"
" lwz 10, 40(3)" "\n"
" lwz 11, 44(3)" "\n"
" lwz 12, 48(3)" "\n"
" lwz 13, 52(3)" "\n"
" lwz 14, 56(3)" "\n"
" lwz 15, 60(3)" "\n"
" lwz 16, 64(3)" "\n"
" lwz 17, 68(3)" "\n"
" lwz 18, 72(3)" "\n"
" lwz 19, 76(3)" "\n"
" lwz 20, 80(3)" "\n"
" lwz 21, 84(3)" "\n"
" lwz 22, 88(3)" "\n"
" lwz 23, 92(3)" "\n"
" lwz 24, 96(3)" "\n"
" lwz 25, 100(3)" "\n"
" lwz 26, 104(3)" "\n"
" lwz 27, 108(3)" "\n"
" lwz 28, 112(3)" "\n"
" lwz 29, 116(3)" "\n"
" lwz 30, 120(3)" "\n"
" lwz 31, 124(3)" "\n"
" lwz 3, 12(3)" "\n"
" blr" "\n"
"" "\n"
".previous" "\n"
);
#endif /* VGP_ppc32_linux */
/* ------------ ppc64-linux ------------ */
#if defined(VGP_ppc64_linux)
__asm__(
".section \".toc\",\"aw\"" "\n"
".section \".text\"" "\n"
".align 2" "\n"
".p2align 4,,15" "\n"
".globl VG_MINIMAL_SETJMP" "\n"
".section \".opd\",\"aw\"" "\n"
".align 3" "\n"
"VG_MINIMAL_SETJMP:" "\n"
".quad .L.VG_MINIMAL_SETJMP,.TOC.@tocbase,0" "\n"
".previous" "\n"
".type VG_MINIMAL_SETJMP, @function" "\n"
".L.VG_MINIMAL_SETJMP:" "\n"
" std 0, 0(3)" "\n"
" std 1, 8(3)" "\n"
" std 2, 16(3)" "\n"
" std 3, 24(3)" "\n"
" std 4, 32(3)" "\n"
" std 5, 40(3)" "\n"
" std 6, 48(3)" "\n"
" std 7, 56(3)" "\n"
" std 8, 64(3)" "\n"
" std 9, 72(3)" "\n"
" std 10, 80(3)" "\n"
" std 11, 88(3)" "\n"
" std 12, 96(3)" "\n"
" std 13, 104(3)" "\n"
" std 14, 112(3)" "\n"
" std 15, 120(3)" "\n"
" std 16, 128(3)" "\n"
" std 17, 136(3)" "\n"
" std 18, 144(3)" "\n"
" std 19, 152(3)" "\n"
" std 20, 160(3)" "\n"
" std 21, 168(3)" "\n"
" std 22, 176(3)" "\n"
" std 23, 184(3)" "\n"
" std 24, 192(3)" "\n"
" std 25, 200(3)" "\n"
" std 26, 208(3)" "\n"
" std 27, 216(3)" "\n"
" std 28, 224(3)" "\n"
" std 29, 232(3)" "\n"
" std 30, 240(3)" "\n"
" std 31, 248(3)" "\n"
// must use a caller-save register here as scratch, hence r4
" mflr 4" "\n"
" std 4, 256(3)" "\n"
" mfcr 4" "\n"
" std 4, 264(3)" "\n"
" li 3, 0" "\n"
" blr" "\n"
"" "\n"
".globl VG_MINIMAL_LONGJMP" "\n"
".section \".opd\",\"aw\"" "\n"
".align 3" "\n"
"VG_MINIMAL_LONGJMP:" "\n"
".quad .L.VG_MINIMAL_LONGJMP,.TOC.@tocbase,0" "\n"
".previous" "\n"
".type VG_MINIMAL_LONGJMP, @function" "\n"
".L.VG_MINIMAL_LONGJMP:" "\n"
// do r4 = 1
// and park it in the restore slot for r3 (the ret reg)
" li 4, 1" "\n"
" std 4, 24(3)" "\n"
// restore everything except r3
// then r3 last of all
// then blr
" ld 0, 256(3)" "\n"
" mtlr 0" "\n"
" ld 0, 264(3)" "\n"
" mtcr 0" "\n"
" ld 0, 0(3)" "\n"
" ld 1, 8(3)" "\n"
" ld 2, 16(3)" "\n"
// r3 is done at the end
" ld 4, 32(3)" "\n"
" ld 5, 40(3)" "\n"
" ld 6, 48(3)" "\n"
" ld 7, 56(3)" "\n"
" ld 8, 64(3)" "\n"
" ld 9, 72(3)" "\n"
" ld 10, 80(3)" "\n"
" ld 11, 88(3)" "\n"
" ld 12, 96(3)" "\n"
" ld 13, 104(3)" "\n"
" ld 14, 112(3)" "\n"
" ld 15, 120(3)" "\n"
" ld 16, 128(3)" "\n"
" ld 17, 136(3)" "\n"
" ld 18, 144(3)" "\n"
" ld 19, 152(3)" "\n"
" ld 20, 160(3)" "\n"
" ld 21, 168(3)" "\n"
" ld 22, 176(3)" "\n"
" ld 23, 184(3)" "\n"
" ld 24, 192(3)" "\n"
" ld 25, 200(3)" "\n"
" ld 26, 208(3)" "\n"
" ld 27, 216(3)" "\n"
" ld 28, 224(3)" "\n"
" ld 29, 232(3)" "\n"
" ld 30, 240(3)" "\n"
" ld 31, 248(3)" "\n"
" ld 3, 24(3)" "\n"
" blr" "\n"
"" "\n"
".previous" "\n"
".previous" "\n"
);
#endif /* VGP_ppc64_linux */
/* ------------ amd64-{linux,darwin} ------------ */
#if defined(VGP_amd64_linux) || defined(VGP_amd64_darwin)
__asm__(
".text" "\n"
"" "\n"
#if defined(VGP_amd64_linux)
".global VG_MINIMAL_SETJMP" "\n" // rdi = jmp_buf
"VG_MINIMAL_SETJMP:" "\n"
#elif defined(VGP_amd64_darwin)
".globl _VG_MINIMAL_SETJMP" "\n" // rdi = jmp_buf
"_VG_MINIMAL_SETJMP:" "\n"
#else
# error "Huh?"
#endif
" movq %rax, 0(%rdi)" "\n"
" movq %rbx, 8(%rdi)" "\n"
" movq %rcx, 16(%rdi)" "\n"
" movq %rdx, 24(%rdi)" "\n"
" movq %rdi, 32(%rdi)" "\n"
" movq %rsi, 40(%rdi)" "\n"
" movq %rbp, 48(%rdi)" "\n"
" movq %rsp, 56(%rdi)" "\n"
" movq %r8, 64(%rdi)" "\n"
" movq %r9, 72(%rdi)" "\n"
" movq %r10, 80(%rdi)" "\n"
" movq %r11, 88(%rdi)" "\n"
" movq %r12, 96(%rdi)" "\n"
" movq %r13, 104(%rdi)" "\n"
" movq %r14, 112(%rdi)" "\n"
" movq %r15, 120(%rdi)" "\n"
// store the return address
" movq 0(%rsp), %rax" "\n"
" movq %rax, 128(%rdi)" "\n"
// and return zero
" movq $0, %rax" "\n"
" ret" "\n"
"" "\n"
#if defined(VGP_amd64_linux)
".global VG_MINIMAL_LONGJMP" "\n"
"VG_MINIMAL_LONGJMP:" "\n" // rdi = jmp_buf
#elif defined(VGP_amd64_darwin)
".globl _VG_MINIMAL_LONGJMP" "\n"
"_VG_MINIMAL_LONGJMP:" "\n" // rdi = jmp_buf
#else
# error "Huh?"
#endif
// skip restoring rax; it's pointless
" movq 8(%rdi), %rbx" "\n"
" movq 16(%rdi), %rcx" "\n"
" movq 24(%rdi), %rdx" "\n"
// defer restoring rdi; we still need it
" movq 40(%rdi), %rsi" "\n"
" movq 48(%rdi), %rbp" "\n"
" movq 56(%rdi), %rsp" "\n"
" movq 64(%rdi), %r8" "\n"
" movq 72(%rdi), %r9" "\n"
" movq 80(%rdi), %r10" "\n"
" movq 88(%rdi), %r11" "\n"
" movq 96(%rdi), %r12" "\n"
" movq 104(%rdi), %r13" "\n"
" movq 112(%rdi), %r14" "\n"
" movq 120(%rdi), %r15" "\n"
// restore the return address
" movq 128(%rdi), %rax" "\n"
// restore rdi; this is the last use
" movq 32(%rdi), %rdi" "\n"
// make %rsp look like we really did a return
" addq $8, %rsp" "\n"
// continue at RA of original call. Note: this is a
// nasty trick. We assume that %rax is nonzero, and so the
// caller can differentiate this case from the normal _SETJMP
// return case. If the return address ever is zero, then
// we're hosed; but that seems pretty unlikely given that it
// would mean we'd be executing at the wraparound point of the
// address space.
" jmp *%rax" "\n"
"" "\n"
#if !defined(VGP_amd64_darwin)
".previous" "\n"
#endif
);
#endif /* VGP_amd64_linux || VGP_amd64_darwin */
/* ------------ x86-{linux,darwin} ------------ */
#if defined(VGP_x86_linux) || defined(VGP_x86_darwin)
__asm__(
".text" "\n"
"" "\n"
#if defined(VGP_x86_linux)
".global VG_MINIMAL_SETJMP" "\n" // eax = jmp_buf
"VG_MINIMAL_SETJMP:" "\n"
#elif defined(VGP_x86_darwin)
".globl _VG_MINIMAL_SETJMP" "\n" // eax = jmp_buf
"_VG_MINIMAL_SETJMP:" "\n"
#else
# error "Huh?"
#endif
" movl %eax, 0(%eax)" "\n"
" movl %ebx, 4(%eax)" "\n"
" movl %ecx, 8(%eax)" "\n"
" movl %edx, 12(%eax)" "\n"
" movl %edi, 16(%eax)" "\n"
" movl %esi, 20(%eax)" "\n"
" movl %ebp, 24(%eax)" "\n"
" movl %esp, 28(%eax)" "\n"
// store the return address
" movl 0(%esp), %ebx" "\n"
" movl %ebx, 32(%eax)" "\n"
// un-trash ebx (necessary? i don't know)
" movl 4(%eax), %ebx" "\n"
// and return zero
" movl $0, %eax" "\n"
" ret" "\n"
"" "\n"
#if defined(VGP_x86_linux)
".global VG_MINIMAL_LONGJMP" "\n"
"VG_MINIMAL_LONGJMP:" "\n" // eax = jmp_buf
#elif defined(VGP_x86_darwin)
".globl _VG_MINIMAL_LONGJMP" "\n"
"_VG_MINIMAL_LONGJMP:" "\n" // eax = jmp_buf
#else
# error "Huh?"
#endif
// skip restoring eax; it's pointless
" movl 4(%eax), %ebx" "\n"
" movl 8(%eax), %ecx" "\n"
" movl 12(%eax), %edx" "\n"
" movl 16(%eax), %edi" "\n"
" movl 20(%eax), %esi" "\n"
" movl 24(%eax), %ebp" "\n"
" movl 28(%eax), %esp" "\n"
// restore the return address
" movl 32(%eax), %eax" "\n"
// make %esp look like we really did a return
" addl $4, %esp" "\n"
// continue at RA of original call. Same zero-vs-nonzero
// trick/assumption as documented for the amd64-linux case.
" jmp *%eax" "\n"
"" "\n"
#if !defined(VGP_x86_darwin)
".previous" "\n"
#endif
);
#endif /* VGP_x86_linux || VGP_x86_darwin */
/*--------------------------------------------------------------------*/
/*--- end ---*/
/*--------------------------------------------------------------------*/