diff options
Diffstat (limited to 'src/crypto/zinc/perlasm/x86_64-xlate.pl')
| -rw-r--r-- | src/crypto/zinc/perlasm/x86_64-xlate.pl | 1442 |
1 files changed, 0 insertions, 1442 deletions
diff --git a/src/crypto/zinc/perlasm/x86_64-xlate.pl b/src/crypto/zinc/perlasm/x86_64-xlate.pl deleted file mode 100644 index 0fe1516..0000000 --- a/src/crypto/zinc/perlasm/x86_64-xlate.pl +++ /dev/null @@ -1,1442 +0,0 @@ -#!/usr/bin/env perl -# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause -# -# Copyright (C) 2017-2018 Samuel Neves <sneves@dei.uc.pt>. All Rights Reserved. -# Copyright (C) 2006-2017 CRYPTOGAMS by <appro@openssl.org>. All Rights Reserved. -# -# This code is taken from the OpenSSL project but the author, Andy Polyakov, -# has relicensed it under the licenses specified in the SPDX header above. -# The original headers, including the original license headers, are -# included below for completeness. -# -# ==================================================================== -# Written by Andy Polyakov <appro@openssl.org> for the OpenSSL -# project. The module is, however, dual licensed under OpenSSL and -# CRYPTOGAMS licenses depending on where you obtain it. For further -# details see http://www.openssl.org/~appro/cryptogams/. -# ==================================================================== -# -# Ascetic x86_64 AT&T to MASM/NASM assembler translator by <appro>. -# -# Why AT&T to MASM and not vice versa? Several reasons. Because AT&T -# format is way easier to parse. Because it's simpler to "gear" from -# Unix ABI to Windows one [see cross-reference "card" at the end of -# file]. Because Linux targets were available first... -# -# In addition the script also "distills" code suitable for GNU -# assembler, so that it can be compiled with more rigid assemblers, -# such as Solaris /usr/ccs/bin/as. -# -# This translator is not designed to convert *arbitrary* assembler -# code from AT&T format to MASM one. It's designed to convert just -# enough to provide for dual-ABI OpenSSL modules development... -# There *are* limitations and you might have to modify your assembler -# code or this script to achieve the desired result... -# -# Currently recognized limitations: -# -# - can't use multiple ops per line; -# -# Dual-ABI styling rules. -# -# 1. Adhere to Unix register and stack layout [see cross-reference -# ABI "card" at the end for explanation]. -# 2. Forget about "red zone," stick to more traditional blended -# stack frame allocation. If volatile storage is actually required -# that is. If not, just leave the stack as is. -# 3. Functions tagged with ".type name,@function" get crafted with -# unified Win64 prologue and epilogue automatically. If you want -# to take care of ABI differences yourself, tag functions as -# ".type name,@abi-omnipotent" instead. -# 4. To optimize the Win64 prologue you can specify number of input -# arguments as ".type name,@function,N." Keep in mind that if N is -# larger than 6, then you *have to* write "abi-omnipotent" code, -# because >6 cases can't be addressed with unified prologue. -# 5. Name local labels as .L*, do *not* use dynamic labels such as 1: -# (sorry about latter). -# 6. Don't use [or hand-code with .byte] "rep ret." "ret" mnemonic is -# required to identify the spots, where to inject Win64 epilogue! -# But on the pros, it's then prefixed with rep automatically:-) -# 7. Stick to explicit ip-relative addressing. If you have to use -# GOTPCREL addressing, stick to mov symbol@GOTPCREL(%rip),%r??. -# Both are recognized and translated to proper Win64 addressing -# modes. -# -# 8. In order to provide for structured exception handling unified -# Win64 prologue copies %rsp value to %rax. For further details -# see SEH paragraph at the end. -# 9. .init segment is allowed to contain calls to functions only. -# a. If function accepts more than 4 arguments *and* >4th argument -# is declared as non 64-bit value, do clear its upper part. - - -use strict; - -my $flavour = shift; -my $output = shift; -if ($flavour =~ /\./) { $output = $flavour; undef $flavour; } - -open STDOUT,">$output" || die "can't open $output: $!" - if (defined($output)); - -my $kernel=0; $kernel=1 if ($flavour =~ /linux/); -my $gas=1; $gas=0 if ($output =~ /\.asm$/); -my $elf=1; $elf=0 if (!$gas); -my $win64=0; -my $prefix=""; -my $decor=".L"; - -my $masmref=8 + 50727*2**-32; # 8.00.50727 shipped with VS2005 -my $masm=0; -my $PTR=" PTR"; - -my $nasmref=2.03; -my $nasm=0; - -if ($flavour eq "mingw64") { $gas=1; $elf=0; $win64=1; - $prefix=`echo __USER_LABEL_PREFIX__ | $ENV{CC} -E -P -`; - $prefix =~ s|\R$||; # Better chomp - } -elsif ($flavour eq "macosx") { $gas=1; $elf=0; $prefix="_"; $decor="L\$"; } -elsif ($flavour eq "masm") { $gas=0; $elf=0; $masm=$masmref; $win64=1; $decor="\$L\$"; } -elsif ($flavour eq "nasm") { $gas=0; $elf=0; $nasm=$nasmref; $win64=1; $decor="\$L\$"; $PTR=""; } -elsif (!$gas) -{ if ($ENV{ASM} =~ m/nasm/ && `nasm -v` =~ m/version ([0-9]+)\.([0-9]+)/i) - { $nasm = $1 + $2*0.01; $PTR=""; } - elsif (`ml64 2>&1` =~ m/Version ([0-9]+)\.([0-9]+)(\.([0-9]+))?/) - { $masm = $1 + $2*2**-16 + $4*2**-32; } - die "no assembler found on %PATH%" if (!($nasm || $masm)); - $win64=1; - $elf=0; - $decor="\$L\$"; -} - -my $current_segment; -my $current_function; -my %globals; - -{ package opcode; # pick up opcodes - sub re { - my ($class, $line) = @_; - my $self = {}; - my $ret; - - if ($$line =~ /^([a-z][a-z0-9]*)/i) { - bless $self,$class; - $self->{op} = $1; - $ret = $self; - $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; - - undef $self->{sz}; - if ($self->{op} =~ /^(movz)x?([bw]).*/) { # movz is pain... - $self->{op} = $1; - $self->{sz} = $2; - } elsif ($self->{op} =~ /call|jmp/) { - $self->{sz} = ""; - } elsif ($self->{op} =~ /^p/ && $' !~ /^(ush|op|insrw)/) { # SSEn - $self->{sz} = ""; - } elsif ($self->{op} =~ /^[vk]/) { # VEX or k* such as kmov - $self->{sz} = ""; - } elsif ($self->{op} =~ /mov[dq]/ && $$line =~ /%xmm/) { - $self->{sz} = ""; - } elsif ($self->{op} =~ /([a-z]{3,})([qlwb])$/) { - $self->{op} = $1; - $self->{sz} = $2; - } - } - $ret; - } - sub size { - my ($self, $sz) = @_; - $self->{sz} = $sz if (defined($sz) && !defined($self->{sz})); - $self->{sz}; - } - sub out { - my $self = shift; - if ($gas) { - if ($self->{op} eq "movz") { # movz is pain... - sprintf "%s%s%s",$self->{op},$self->{sz},shift; - } elsif ($self->{op} =~ /^set/) { - "$self->{op}"; - } elsif ($self->{op} eq "ret") { - my $epilogue = ""; - if ($win64 && $current_function->{abi} eq "svr4") { - $epilogue = "movq 8(%rsp),%rdi\n\t" . - "movq 16(%rsp),%rsi\n\t"; - } - $epilogue . "ret"; - } elsif ($self->{op} eq "call" && !$elf && $current_segment eq ".init") { - ".p2align\t3\n\t.quad"; - } else { - "$self->{op}$self->{sz}"; - } - } else { - $self->{op} =~ s/^movz/movzx/; - if ($self->{op} eq "ret") { - $self->{op} = ""; - if ($win64 && $current_function->{abi} eq "svr4") { - $self->{op} = "mov rdi,QWORD$PTR\[8+rsp\]\t;WIN64 epilogue\n\t". - "mov rsi,QWORD$PTR\[16+rsp\]\n\t"; - } - $self->{op} .= "DB\t0F3h,0C3h\t\t;repret"; - } elsif ($self->{op} =~ /^(pop|push)f/) { - $self->{op} .= $self->{sz}; - } elsif ($self->{op} eq "call" && $current_segment eq ".CRT\$XCU") { - $self->{op} = "\tDQ"; - } - $self->{op}; - } - } - sub mnemonic { - my ($self, $op) = @_; - $self->{op}=$op if (defined($op)); - $self->{op}; - } -} -{ package const; # pick up constants, which start with $ - sub re { - my ($class, $line) = @_; - my $self = {}; - my $ret; - - if ($$line =~ /^\$([^,]+)/) { - bless $self, $class; - $self->{value} = $1; - $ret = $self; - $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; - } - $ret; - } - sub out { - my $self = shift; - - $self->{value} =~ s/\b(0b[0-1]+)/oct($1)/eig; - if ($gas) { - # Solaris /usr/ccs/bin/as can't handle multiplications - # in $self->{value} - my $value = $self->{value}; - no warnings; # oct might complain about overflow, ignore here... - $value =~ s/(?<![\w\$\.])(0x?[0-9a-f]+)/oct($1)/egi; - if ($value =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg) { - $self->{value} = $value; - } - sprintf "\$%s",$self->{value}; - } else { - my $value = $self->{value}; - $value =~ s/0x([0-9a-f]+)/0$1h/ig if ($masm); - sprintf "%s",$value; - } - } -} -{ package ea; # pick up effective addresses: expr(%reg,%reg,scale) - - my %szmap = ( b=>"BYTE$PTR", w=>"WORD$PTR", - l=>"DWORD$PTR", d=>"DWORD$PTR", - q=>"QWORD$PTR", o=>"OWORD$PTR", - x=>"XMMWORD$PTR", y=>"YMMWORD$PTR", - z=>"ZMMWORD$PTR" ) if (!$gas); - - sub re { - my ($class, $line, $opcode) = @_; - my $self = {}; - my $ret; - - # optional * ----vvv--- appears in indirect jmp/call - if ($$line =~ /^(\*?)([^\(,]*)\(([%\w,]+)\)((?:{[^}]+})*)/) { - bless $self, $class; - $self->{asterisk} = $1; - $self->{label} = $2; - ($self->{base},$self->{index},$self->{scale})=split(/,/,$3); - $self->{scale} = 1 if (!defined($self->{scale})); - $self->{opmask} = $4; - $ret = $self; - $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; - - if ($win64 && $self->{label} =~ s/\@GOTPCREL//) { - die if ($opcode->mnemonic() ne "mov"); - $opcode->mnemonic("lea"); - } - $self->{base} =~ s/^%//; - $self->{index} =~ s/^%// if (defined($self->{index})); - $self->{opcode} = $opcode; - } - $ret; - } - sub size {} - sub out { - my ($self, $sz) = @_; - - $self->{label} =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; - $self->{label} =~ s/\.L/$decor/g; - - # Silently convert all EAs to 64-bit. This is required for - # elder GNU assembler and results in more compact code, - # *but* most importantly AES module depends on this feature! - $self->{index} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/; - $self->{base} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/; - - # Solaris /usr/ccs/bin/as can't handle multiplications - # in $self->{label}... - use integer; - $self->{label} =~ s/(?<![\w\$\.])(0x?[0-9a-f]+)/oct($1)/egi; - $self->{label} =~ s/\b([0-9]+\s*[\*\/\%]\s*[0-9]+)\b/eval($1)/eg; - - # Some assemblers insist on signed presentation of 32-bit - # offsets, but sign extension is a tricky business in perl... - if ((1<<31)<<1) { - $self->{label} =~ s/\b([0-9]+)\b/$1<<32>>32/eg; - } else { - $self->{label} =~ s/\b([0-9]+)\b/$1>>0/eg; - } - - # if base register is %rbp or %r13, see if it's possible to - # flip base and index registers [for better performance] - if (!$self->{label} && $self->{index} && $self->{scale}==1 && - $self->{base} =~ /(rbp|r13)/) { - $self->{base} = $self->{index}; $self->{index} = $1; - } - - if ($gas) { - $self->{label} =~ s/^___imp_/__imp__/ if ($flavour eq "mingw64"); - - if (defined($self->{index})) { - sprintf "%s%s(%s,%%%s,%d)%s", - $self->{asterisk},$self->{label}, - $self->{base}?"%$self->{base}":"", - $self->{index},$self->{scale}, - $self->{opmask}; - } else { - sprintf "%s%s(%%%s)%s", $self->{asterisk},$self->{label}, - $self->{base},$self->{opmask}; - } - } else { - $self->{label} =~ s/\./\$/g; - $self->{label} =~ s/(?<![\w\$\.])0x([0-9a-f]+)/0$1h/ig; - $self->{label} = "($self->{label})" if ($self->{label} =~ /[\*\+\-\/]/); - - my $mnemonic = $self->{opcode}->mnemonic(); - ($self->{asterisk}) && ($sz="q") || - ($mnemonic =~ /^v?mov([qd])$/) && ($sz=$1) || - ($mnemonic =~ /^v?pinsr([qdwb])$/) && ($sz=$1) || - ($mnemonic =~ /^vpbroadcast([qdwb])$/) && ($sz=$1) || - ($mnemonic =~ /^v(?!perm)[a-z]+[fi]128$/) && ($sz="x"); - - $self->{opmask} =~ s/%(k[0-7])/$1/; - - if (defined($self->{index})) { - sprintf "%s[%s%s*%d%s]%s",$szmap{$sz}, - $self->{label}?"$self->{label}+":"", - $self->{index},$self->{scale}, - $self->{base}?"+$self->{base}":"", - $self->{opmask}; - } elsif ($self->{base} eq "rip") { - sprintf "%s[%s]",$szmap{$sz},$self->{label}; - } else { - sprintf "%s[%s%s]%s", $szmap{$sz}, - $self->{label}?"$self->{label}+":"", - $self->{base},$self->{opmask}; - } - } - } -} -{ package register; # pick up registers, which start with %. - sub re { - my ($class, $line, $opcode) = @_; - my $self = {}; - my $ret; - - # optional * ----vvv--- appears in indirect jmp/call - if ($$line =~ /^(\*?)%(\w+)((?:{[^}]+})*)/) { - bless $self,$class; - $self->{asterisk} = $1; - $self->{value} = $2; - $self->{opmask} = $3; - $opcode->size($self->size()); - $ret = $self; - $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; - } - $ret; - } - sub size { - my $self = shift; - my $ret; - - if ($self->{value} =~ /^r[\d]+b$/i) { $ret="b"; } - elsif ($self->{value} =~ /^r[\d]+w$/i) { $ret="w"; } - elsif ($self->{value} =~ /^r[\d]+d$/i) { $ret="l"; } - elsif ($self->{value} =~ /^r[\w]+$/i) { $ret="q"; } - elsif ($self->{value} =~ /^[a-d][hl]$/i){ $ret="b"; } - elsif ($self->{value} =~ /^[\w]{2}l$/i) { $ret="b"; } - elsif ($self->{value} =~ /^[\w]{2}$/i) { $ret="w"; } - elsif ($self->{value} =~ /^e[a-z]{2}$/i){ $ret="l"; } - - $ret; - } - sub out { - my $self = shift; - if ($gas) { sprintf "%s%%%s%s", $self->{asterisk}, - $self->{value}, - $self->{opmask}; } - else { $self->{opmask} =~ s/%(k[0-7])/$1/; - $self->{value}.$self->{opmask}; } - } -} -{ package label; # pick up labels, which end with : - sub re { - my ($class, $line) = @_; - my $self = {}; - my $ret; - - if ($$line =~ /(^[\.\w]+)\:/) { - bless $self,$class; - $self->{value} = $1; - $ret = $self; - $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; - - $self->{value} =~ s/^\.L/$decor/; - } - $ret; - } - sub out { - my $self = shift; - - if ($gas) { - my $func = ($globals{$self->{value}} or $self->{value}) . ":"; - if ($win64 && $current_function->{name} eq $self->{value} - && $current_function->{abi} eq "svr4") { - $func .= "\n"; - $func .= " movq %rdi,8(%rsp)\n"; - $func .= " movq %rsi,16(%rsp)\n"; - $func .= " movq %rsp,%rax\n"; - $func .= "${decor}SEH_begin_$current_function->{name}:\n"; - my $narg = $current_function->{narg}; - $narg=6 if (!defined($narg)); - $func .= " movq %rcx,%rdi\n" if ($narg>0); - $func .= " movq %rdx,%rsi\n" if ($narg>1); - $func .= " movq %r8,%rdx\n" if ($narg>2); - $func .= " movq %r9,%rcx\n" if ($narg>3); - $func .= " movq 40(%rsp),%r8\n" if ($narg>4); - $func .= " movq 48(%rsp),%r9\n" if ($narg>5); - } - $func; - } elsif ($self->{value} ne "$current_function->{name}") { - # Make all labels in masm global. - $self->{value} .= ":" if ($masm); - $self->{value} . ":"; - } elsif ($win64 && $current_function->{abi} eq "svr4") { - my $func = "$current_function->{name}" . - ($nasm ? ":" : "\tPROC $current_function->{scope}") . - "\n"; - $func .= " mov QWORD$PTR\[8+rsp\],rdi\t;WIN64 prologue\n"; - $func .= " mov QWORD$PTR\[16+rsp\],rsi\n"; - $func .= " mov rax,rsp\n"; - $func .= "${decor}SEH_begin_$current_function->{name}:"; - $func .= ":" if ($masm); - $func .= "\n"; - my $narg = $current_function->{narg}; - $narg=6 if (!defined($narg)); - $func .= " mov rdi,rcx\n" if ($narg>0); - $func .= " mov rsi,rdx\n" if ($narg>1); - $func .= " mov rdx,r8\n" if ($narg>2); - $func .= " mov rcx,r9\n" if ($narg>3); - $func .= " mov r8,QWORD$PTR\[40+rsp\]\n" if ($narg>4); - $func .= " mov r9,QWORD$PTR\[48+rsp\]\n" if ($narg>5); - $func .= "\n"; - } else { - "$current_function->{name}". - ($nasm ? ":" : "\tPROC $current_function->{scope}"); - } - } -} -{ package expr; # pick up expressions - sub re { - my ($class, $line, $opcode) = @_; - my $self = {}; - my $ret; - - if ($$line =~ /(^[^,]+)/) { - bless $self,$class; - $self->{value} = $1; - $ret = $self; - $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; - - $self->{value} =~ s/\@PLT// if (!$elf); - $self->{value} =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; - $self->{value} =~ s/\.L/$decor/g; - $self->{opcode} = $opcode; - } - $ret; - } - sub out { - my $self = shift; - if ($nasm && $self->{opcode}->mnemonic()=~m/^j(?![re]cxz)/) { - "NEAR ".$self->{value}; - } else { - $self->{value}; - } - } -} -{ package cfi_directive; - # CFI directives annotate instructions that are significant for - # stack unwinding procedure compliant with DWARF specification, - # see http://dwarfstd.org/. Besides naturally expected for this - # script platform-specific filtering function, this module adds - # three auxiliary synthetic directives not recognized by [GNU] - # assembler: - # - # - .cfi_push to annotate push instructions in prologue, which - # translates to .cfi_adjust_cfa_offset (if needed) and - # .cfi_offset; - # - .cfi_pop to annotate pop instructions in epilogue, which - # translates to .cfi_adjust_cfa_offset (if needed) and - # .cfi_restore; - # - [and most notably] .cfi_cfa_expression which encodes - # DW_CFA_def_cfa_expression and passes it to .cfi_escape as - # byte vector; - # - # CFA expressions were introduced in DWARF specification version - # 3 and describe how to deduce CFA, Canonical Frame Address. This - # becomes handy if your stack frame is variable and you can't - # spare register for [previous] frame pointer. Suggested directive - # syntax is made-up mix of DWARF operator suffixes [subset of] - # and references to registers with optional bias. Following example - # describes offloaded *original* stack pointer at specific offset - # from *current* stack pointer: - # - # .cfi_cfa_expression %rsp+40,deref,+8 - # - # Final +8 has everything to do with the fact that CFA is defined - # as reference to top of caller's stack, and on x86_64 call to - # subroutine pushes 8-byte return address. In other words original - # stack pointer upon entry to a subroutine is 8 bytes off from CFA. - - # Below constants are taken from "DWARF Expressions" section of the - # DWARF specification, section is numbered 7.7 in versions 3 and 4. - my %DW_OP_simple = ( # no-arg operators, mapped directly - deref => 0x06, dup => 0x12, - drop => 0x13, over => 0x14, - pick => 0x15, swap => 0x16, - rot => 0x17, xderef => 0x18, - - abs => 0x19, and => 0x1a, - div => 0x1b, minus => 0x1c, - mod => 0x1d, mul => 0x1e, - neg => 0x1f, not => 0x20, - or => 0x21, plus => 0x22, - shl => 0x24, shr => 0x25, - shra => 0x26, xor => 0x27, - ); - - my %DW_OP_complex = ( # used in specific subroutines - constu => 0x10, # uleb128 - consts => 0x11, # sleb128 - plus_uconst => 0x23, # uleb128 - lit0 => 0x30, # add 0-31 to opcode - reg0 => 0x50, # add 0-31 to opcode - breg0 => 0x70, # add 0-31 to opcole, sleb128 - regx => 0x90, # uleb28 - fbreg => 0x91, # sleb128 - bregx => 0x92, # uleb128, sleb128 - piece => 0x93, # uleb128 - ); - - # Following constants are defined in x86_64 ABI supplement, for - # example available at https://www.uclibc.org/docs/psABI-x86_64.pdf, - # see section 3.7 "Stack Unwind Algorithm". - my %DW_reg_idx = ( - "%rax"=>0, "%rdx"=>1, "%rcx"=>2, "%rbx"=>3, - "%rsi"=>4, "%rdi"=>5, "%rbp"=>6, "%rsp"=>7, - "%r8" =>8, "%r9" =>9, "%r10"=>10, "%r11"=>11, - "%r12"=>12, "%r13"=>13, "%r14"=>14, "%r15"=>15 - ); - - my ($cfa_reg, $cfa_rsp); - - # [us]leb128 format is variable-length integer representation base - # 2^128, with most significant bit of each byte being 0 denoting - # *last* most significant digit. See "Variable Length Data" in the - # DWARF specification, numbered 7.6 at least in versions 3 and 4. - sub sleb128 { - use integer; # get right shift extend sign - - my $val = shift; - my $sign = ($val < 0) ? -1 : 0; - my @ret = (); - - while(1) { - push @ret, $val&0x7f; - - # see if remaining bits are same and equal to most - # significant bit of the current digit, if so, it's - # last digit... - last if (($val>>6) == $sign); - - @ret[-1] |= 0x80; - $val >>= 7; - } - - return @ret; - } - sub uleb128 { - my $val = shift; - my @ret = (); - - while(1) { - push @ret, $val&0x7f; - - # see if it's last significant digit... - last if (($val >>= 7) == 0); - - @ret[-1] |= 0x80; - } - - return @ret; - } - sub const { - my $val = shift; - - if ($val >= 0 && $val < 32) { - return ($DW_OP_complex{lit0}+$val); - } - return ($DW_OP_complex{consts}, sleb128($val)); - } - sub reg { - my $val = shift; - - return if ($val !~ m/^(%r\w+)(?:([\+\-])((?:0x)?[0-9a-f]+))?/); - - my $reg = $DW_reg_idx{$1}; - my $off = eval ("0 $2 $3"); - - return (($DW_OP_complex{breg0} + $reg), sleb128($off)); - # Yes, we use DW_OP_bregX+0 to push register value and not - # DW_OP_regX, because latter would require even DW_OP_piece, - # which would be a waste under the circumstances. If you have - # to use DWP_OP_reg, use "regx:N"... - } - sub cfa_expression { - my $line = shift; - my @ret; - - foreach my $token (split(/,\s*/,$line)) { - if ($token =~ /^%r/) { - push @ret,reg($token); - } elsif ($token =~ /((?:0x)?[0-9a-f]+)\((%r\w+)\)/) { - push @ret,reg("$2+$1"); - } elsif ($token =~ /(\w+):(\-?(?:0x)?[0-9a-f]+)(U?)/i) { - my $i = 1*eval($2); - push @ret,$DW_OP_complex{$1}, ($3 ? uleb128($i) : sleb128($i)); - } elsif (my $i = 1*eval($token) or $token eq "0") { - if ($token =~ /^\+/) { - push @ret,$DW_OP_complex{plus_uconst},uleb128($i); - } else { - push @ret,const($i); - } - } else { - push @ret,$DW_OP_simple{$token}; - } - } - - # Finally we return DW_CFA_def_cfa_expression, 15, followed by - # length of the expression and of course the expression itself. - return (15,scalar(@ret),@ret); - } - sub re { - my ($class, $line) = @_; - my $self = {}; - my $ret; - - if ($$line =~ s/^\s*\.cfi_(\w+)\s*//) { - bless $self,$class; - $ret = $self; - undef $self->{value}; - my $dir = $1; - - SWITCH: for ($dir) { - # What is $cfa_rsp? Effectively it's difference between %rsp - # value and current CFA, Canonical Frame Address, which is - # why it starts with -8. Recall that CFA is top of caller's - # stack... - /startproc/ && do { ($cfa_reg, $cfa_rsp) = ("%rsp", -8); last; }; - /endproc/ && do { ($cfa_reg, $cfa_rsp) = ("%rsp", 0); last; }; - /def_cfa_register/ - && do { $cfa_reg = $$line; last; }; - /def_cfa_offset/ - && do { $cfa_rsp = -1*eval($$line) if ($cfa_reg eq "%rsp"); - last; - }; - /adjust_cfa_offset/ - && do { $cfa_rsp -= 1*eval($$line) if ($cfa_reg eq "%rsp"); - last; - }; - /def_cfa/ && do { if ($$line =~ /(%r\w+)\s*,\s*(.+)/) { - $cfa_reg = $1; - $cfa_rsp = -1*eval($2) if ($cfa_reg eq "%rsp"); - } - last; - }; - /push/ && do { $dir = undef; - $cfa_rsp -= 8; - if ($cfa_reg eq "%rsp") { - $self->{value} = ".cfi_adjust_cfa_offset\t8\n"; - } - $self->{value} .= ".cfi_offset\t$$line,$cfa_rsp"; - last; - }; - /pop/ && do { $dir = undef; - $cfa_rsp += 8; - if ($cfa_reg eq "%rsp") { - $self->{value} = ".cfi_adjust_cfa_offset\t-8\n"; - } - $self->{value} .= ".cfi_restore\t$$line"; - last; - }; - /cfa_expression/ - && do { $dir = undef; - $self->{value} = ".cfi_escape\t" . - join(",", map(sprintf("0x%02x", $_), - cfa_expression($$line))); - last; - }; - } - - $self->{value} = ".cfi_$dir\t$$line" if ($dir); - - $$line = ""; - } - - return $ret; - } - sub out { - my $self = shift; - return ($elf ? $self->{value} : undef); - } -} -{ package directive; # pick up directives, which start with . - sub re { - my ($class, $line) = @_; - my $self = {}; - my $ret; - my $dir; - - # chain-call to cfi_directive - $ret = cfi_directive->re($line) and return $ret; - - if ($$line =~ /^\s*(\.\w+)/) { - bless $self,$class; - $dir = $1; - $ret = $self; - undef $self->{value}; - $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; - - SWITCH: for ($dir) { - /\.global|\.globl|\.extern/ - && do { $globals{$$line} = $prefix . $$line; - $$line = $globals{$$line} if ($prefix); - last; - }; - /\.type/ && do { my ($sym,$type,$narg) = split(',',$$line); - if ($type eq "\@function") { - undef $current_function; - $current_function->{name} = $sym; - $current_function->{abi} = "svr4"; - $current_function->{narg} = $narg; - $current_function->{scope} = defined($globals{$sym})?"PUBLIC":"PRIVATE"; - } elsif ($type eq "\@abi-omnipotent") { - undef $current_function; - $current_function->{name} = $sym; - $current_function->{scope} = defined($globals{$sym})?"PUBLIC":"PRIVATE"; - } - $$line =~ s/\@abi\-omnipotent/\@function/; - $$line =~ s/\@function.*/\@function/; - last; - }; - /\.asciz/ && do { if ($$line =~ /^"(.*)"$/) { - $dir = ".byte"; - $$line = join(",",unpack("C*",$1),0); - } - last; - }; - /\.rva|\.long|\.quad/ - && do { $$line =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; - $$line =~ s/\.L/$decor/g; - last; - }; - } - - if ($gas) { - $self->{value} = $dir . "\t" . $$line; - - if ($dir =~ /\.extern/) { - $self->{value} = ""; # swallow extern - } elsif (!$elf && $dir =~ /\.type/) { - $self->{value} = ""; - $self->{value} = ".def\t" . ($globals{$1} or $1) . ";\t" . - (defined($globals{$1})?".scl 2;":".scl 3;") . - "\t.type 32;\t.endef" - if ($win64 && $$line =~ /([^,]+),\@function/); - } elsif (!$elf && $dir =~ /\.size/) { - $self->{value} = ""; - if (defined($current_function)) { - $self->{value} .= "${decor}SEH_end_$current_function->{name}:" - if ($win64 && $current_function->{abi} eq "svr4"); - undef $current_function; - } - } elsif (!$elf && $dir =~ /\.align/) { - $self->{value} = ".p2align\t" . (log($$line)/log(2)); - } elsif ($dir eq ".section") { - $current_segment=$$line; - if (!$elf && $current_segment eq ".init") { - if ($flavour eq "macosx") { $self->{value} = ".mod_init_func"; } - elsif ($flavour eq "mingw64") { $self->{value} = ".section\t.ctors"; } - } - } elsif ($dir =~ /\.(text|data)/) { - $current_segment=".$1"; - } elsif ($dir =~ /\.hidden/) { - if ($flavour eq "macosx") { $self->{value} = ".private_extern\t$prefix$$line"; } - elsif ($flavour eq "mingw64") { $self->{value} = ""; } - } elsif ($dir =~ /\.comm/) { - $self->{value} = "$dir\t$prefix$$line"; - $self->{value} =~ s|,([0-9]+),([0-9]+)$|",$1,".log($2)/log(2)|e if ($flavour eq "macosx"); - } - $$line = ""; - return $self; - } - - # non-gas case or nasm/masm - SWITCH: for ($dir) { - /\.text/ && do { my $v=undef; - if ($nasm) { - $v="section .text code align=64\n"; - } else { - $v="$current_segment\tENDS\n" if ($current_segment); - $current_segment = ".text\$"; - $v.="$current_segment\tSEGMENT "; - $v.=$masm>=$masmref ? "ALIGN(256)" : "PAGE"; - $v.=" 'CODE'"; - } - $self->{value} = $v; - last; - }; - /\.data/ && do { my $v=undef; - if ($nasm) { - $v="section .data data align=8\n"; - } else { - $v="$current_segment\tENDS\n" if ($current_segment); - $current_segment = "_DATA"; - $v.="$current_segment\tSEGMENT"; - } - $self->{value} = $v; - last; - }; - /\.section/ && do { my $v=undef; - $$line =~ s/([^,]*).*/$1/; - $$line = ".CRT\$XCU" if ($$line eq ".init"); - if ($nasm) { - $v="section $$line"; - if ($$line=~/\.([px])data/) { - $v.=" rdata align="; - $v.=$1 eq "p"? 4 : 8; - } elsif ($$line=~/\.CRT\$/i) { - $v.=" rdata align=8"; - } - } else { - $v="$current_segment\tENDS\n" if ($current_segment); - $v.="$$line\tSEGMENT"; - if ($$line=~/\.([px])data/) { - $v.=" READONLY"; - $v.=" ALIGN(".($1 eq "p" ? 4 : 8).")" if ($masm>=$masmref); - } elsif ($$line=~/\.CRT\$/i) { - $v.=" READONLY "; - $v.=$masm>=$masmref ? "ALIGN(8)" : "DWORD"; - } - } - $current_segment = $$line; - $self->{value} = $v; - last; - }; - /\.extern/ && do { $self->{value} = "EXTERN\t".$$line; - $self->{value} .= ":NEAR" if ($masm); - last; - }; - /\.globl|.global/ - && do { $self->{value} = $masm?"PUBLIC":"global"; - $self->{value} .= "\t".$$line; - last; - }; - /\.size/ && do { if (defined($current_function)) { - undef $self->{value}; - if ($current_function->{abi} eq "svr4") { - $self->{value}="${decor}SEH_end_$current_function->{name}:"; - $self->{value}.=":\n" if($masm); - } - $self->{value}.="$current_function->{name}\tENDP" if($masm && $current_function->{name}); - undef $current_function; - } - last; - }; - /\.align/ && do { my $max = ($masm && $masm>=$masmref) ? 256 : 4096; - $self->{value} = "ALIGN\t".($$line>$max?$max:$$line); - last; - }; - /\.(value|long|rva|quad)/ - && do { my $sz = substr($1,0,1); - my @arr = split(/,\s*/,$$line); - my $last = pop(@arr); - my $conv = sub { my $var=shift; - $var=~s/^(0b[0-1]+)/oct($1)/eig; - $var=~s/^0x([0-9a-f]+)/0$1h/ig if ($masm); - if ($sz eq "D" && ($current_segment=~/.[px]data/ || $dir eq ".rva")) - { $var=~s/^([_a-z\$\@][_a-z0-9\$\@]*)/$nasm?"$1 wrt ..imagebase":"imagerel $1"/egi; } - $var; - }; - - $sz =~ tr/bvlrq/BWDDQ/; - $self->{value} = "\tD$sz\t"; - for (@arr) { $self->{value} .= &$conv($_).","; } - $self->{value} .= &$conv($last); - last; - }; - /\.byte/ && do { my @str=split(/,\s*/,$$line); - map(s/(0b[0-1]+)/oct($1)/eig,@str); - map(s/0x([0-9a-f]+)/0$1h/ig,@str) if ($masm); - while ($#str>15) { - $self->{value}.="DB\t" - .join(",",@str[0..15])."\n"; - foreach (0..15) { shift @str; } - } - $self->{value}.="DB\t" - .join(",",@str) if (@str); - last; - }; - /\.comm/ && do { my @str=split(/,\s*/,$$line); - my $v=undef; - if ($nasm) { - $v.="common $prefix@str[0] @str[1]"; - } else { - $v="$current_segment\tENDS\n" if ($current_segment); - $current_segment = "_DATA"; - $v.="$current_segment\tSEGMENT\n"; - $v.="COMM @str[0]:DWORD:".@str[1]/4; - } - $self->{value} = $v; - last; - }; - } - $$line = ""; - } - - $ret; - } - sub out { - my $self = shift; - $self->{value}; - } -} - -# Upon initial x86_64 introduction SSE>2 extensions were not introduced -# yet. In order not to be bothered by tracing exact assembler versions, -# but at the same time to provide a bare security minimum of AES-NI, we -# hard-code some instructions. Extensions past AES-NI on the other hand -# are traced by examining assembler version in individual perlasm -# modules... - -my %regrm = ( "%eax"=>0, "%ecx"=>1, "%edx"=>2, "%ebx"=>3, - "%esp"=>4, "%ebp"=>5, "%esi"=>6, "%edi"=>7 ); - -sub rex { - my $opcode=shift; - my ($dst,$src,$rex)=@_; - - $rex|=0x04 if($dst>=8); - $rex|=0x01 if($src>=8); - push @$opcode,($rex|0x40) if ($rex); -} - -my $movq = sub { # elderly gas can't handle inter-register movq - my $arg = shift; - my @opcode=(0x66); - if ($arg =~ /%xmm([0-9]+),\s*%r(\w+)/) { - my ($src,$dst)=($1,$2); - if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } - rex(\@opcode,$src,$dst,0x8); - push @opcode,0x0f,0x7e; - push @opcode,0xc0|(($src&7)<<3)|($dst&7); # ModR/M - @opcode; - } elsif ($arg =~ /%r(\w+),\s*%xmm([0-9]+)/) { - my ($src,$dst)=($2,$1); - if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } - rex(\@opcode,$src,$dst,0x8); - push @opcode,0x0f,0x6e; - push @opcode,0xc0|(($src&7)<<3)|($dst&7); # ModR/M - @opcode; - } else { - (); - } -}; - -my $pextrd = sub { - if (shift =~ /\$([0-9]+),\s*%xmm([0-9]+),\s*(%\w+)/) { - my @opcode=(0x66); - my $imm=$1; - my $src=$2; - my $dst=$3; - if ($dst =~ /%r([0-9]+)d/) { $dst = $1; } - elsif ($dst =~ /%e/) { $dst = $regrm{$dst}; } - rex(\@opcode,$src,$dst); - push @opcode,0x0f,0x3a,0x16; - push @opcode,0xc0|(($src&7)<<3)|($dst&7); # ModR/M - push @opcode,$imm; - @opcode; - } else { - (); - } -}; - -my $pinsrd = sub { - if (shift =~ /\$([0-9]+),\s*(%\w+),\s*%xmm([0-9]+)/) { - my @opcode=(0x66); - my $imm=$1; - my $src=$2; - my $dst=$3; - if ($src =~ /%r([0-9]+)/) { $src = $1; } - elsif ($src =~ /%e/) { $src = $regrm{$src}; } - rex(\@opcode,$dst,$src); - push @opcode,0x0f,0x3a,0x22; - push @opcode,0xc0|(($dst&7)<<3)|($src&7); # ModR/M - push @opcode,$imm; - @opcode; - } else { - (); - } -}; - -my $pshufb = sub { - if (shift =~ /%xmm([0-9]+),\s*%xmm([0-9]+)/) { - my @opcode=(0x66); - rex(\@opcode,$2,$1); - push @opcode,0x0f,0x38,0x00; - push @opcode,0xc0|($1&7)|(($2&7)<<3); # ModR/M - @opcode; - } else { - (); - } -}; - -my $palignr = sub { - if (shift =~ /\$([0-9]+),\s*%xmm([0-9]+),\s*%xmm([0-9]+)/) { - my @opcode=(0x66); - rex(\@opcode,$3,$2); - push @opcode,0x0f,0x3a,0x0f; - push @opcode,0xc0|($2&7)|(($3&7)<<3); # ModR/M - push @opcode,$1; - @opcode; - } else { - (); - } -}; - -my $pclmulqdq = sub { - if (shift =~ /\$([x0-9a-f]+),\s*%xmm([0-9]+),\s*%xmm([0-9]+)/) { - my @opcode=(0x66); - rex(\@opcode,$3,$2); - push @opcode,0x0f,0x3a,0x44; - push @opcode,0xc0|($2&7)|(($3&7)<<3); # ModR/M - my $c=$1; - push @opcode,$c=~/^0/?oct($c):$c; - @opcode; - } else { - (); - } -}; - -my $rdrand = sub { - if (shift =~ /%[er](\w+)/) { - my @opcode=(); - my $dst=$1; - if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } - rex(\@opcode,0,$dst,8); - push @opcode,0x0f,0xc7,0xf0|($dst&7); - @opcode; - } else { - (); - } -}; - -my $rdseed = sub { - if (shift =~ /%[er](\w+)/) { - my @opcode=(); - my $dst=$1; - if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } - rex(\@opcode,0,$dst,8); - push @opcode,0x0f,0xc7,0xf8|($dst&7); - @opcode; - } else { - (); - } -}; - -# Not all AVX-capable assemblers recognize AMD XOP extension. Since we -# are using only two instructions hand-code them in order to be excused -# from chasing assembler versions... - -sub rxb { - my $opcode=shift; - my ($dst,$src1,$src2,$rxb)=@_; - - $rxb|=0x7<<5; - $rxb&=~(0x04<<5) if($dst>=8); - $rxb&=~(0x01<<5) if($src1>=8); - $rxb&=~(0x02<<5) if($src2>=8); - push @$opcode,$rxb; -} - -my $vprotd = sub { - if (shift =~ /\$([x0-9a-f]+),\s*%xmm([0-9]+),\s*%xmm([0-9]+)/) { - my @opcode=(0x8f); - rxb(\@opcode,$3,$2,-1,0x08); - push @opcode,0x78,0xc2; - push @opcode,0xc0|($2&7)|(($3&7)<<3); # ModR/M - my $c=$1; - push @opcode,$c=~/^0/?oct($c):$c; - @opcode; - } else { - (); - } -}; - -my $vprotq = sub { - if (shift =~ /\$([x0-9a-f]+),\s*%xmm([0-9]+),\s*%xmm([0-9]+)/) { - my @opcode=(0x8f); - rxb(\@opcode,$3,$2,-1,0x08); - push @opcode,0x78,0xc3; - push @opcode,0xc0|($2&7)|(($3&7)<<3); # ModR/M - my $c=$1; - push @opcode,$c=~/^0/?oct($c):$c; - @opcode; - } else { - (); - } -}; - -# Intel Control-flow Enforcement Technology extension. All functions and -# indirect branch targets will have to start with this instruction... - -my $endbranch = sub { - (0xf3,0x0f,0x1e,0xfa); -}; - -######################################################################## - -if ($nasm) { - print <<___; -default rel -%define XMMWORD -%define YMMWORD -%define ZMMWORD -___ -} elsif ($masm) { - print <<___; -OPTION DOTNAME -___ -} -while(defined(my $line=<>)) { - - $line =~ s|\R$||; # Better chomp - - $line =~ s|[#!](?!include)(?!ifdef)(?!endif).*$||; # get rid of asm-style comments... - $line =~ s|/\*.*\*/||; # ... and C-style comments... - $line =~ s|^\s+||; # ... and skip white spaces in beginning - $line =~ s|\s+$||; # ... and at the end - - if (my $label=label->re(\$line)) { print $label->out(); } - - if (my $directive=directive->re(\$line)) { - printf "%s",$directive->out(); - } elsif (my $opcode=opcode->re(\$line)) { - my $asm = eval("\$".$opcode->mnemonic()); - - if ((ref($asm) eq 'CODE') && scalar(my @bytes=&$asm($line))) { - print $gas?".byte\t":"DB\t",join(',',@bytes),"\n"; - next; - } - - my @args; - ARGUMENT: while (1) { - my $arg; - - ($arg=register->re(\$line, $opcode))|| - ($arg=const->re(\$line)) || - ($arg=ea->re(\$line, $opcode)) || - ($arg=expr->re(\$line, $opcode)) || - last ARGUMENT; - - push @args,$arg; - - last ARGUMENT if ($line !~ /^,/); - - $line =~ s/^,\s*//; - } # ARGUMENT: - - if ($#args>=0) { - my $insn; - my $sz=$opcode->size(); - - if ($gas) { - $insn = $opcode->out($#args>=1?$args[$#args]->size():$sz); - @args = map($_->out($sz),@args); - printf "\t%s\t%s",$insn,join(",",@args); - } else { - $insn = $opcode->out(); - foreach (@args) { - my $arg = $_->out(); - # $insn.=$sz compensates for movq, pinsrw, ... - if ($arg =~ /^xmm[0-9]+$/) { $insn.=$sz; $sz="x" if(!$sz); last; } - if ($arg =~ /^ymm[0-9]+$/) { $insn.=$sz; $sz="y" if(!$sz); last; } - if ($arg =~ /^zmm[0-9]+$/) { $insn.=$sz; $sz="z" if(!$sz); last; } - if ($arg =~ /^mm[0-9]+$/) { $insn.=$sz; $sz="q" if(!$sz); last; } - } - @args = reverse(@args); - undef $sz if ($nasm && $opcode->mnemonic() eq "lea"); - printf "\t%s\t%s",$insn,join(",",map($_->out($sz),@args)); - } - } else { - printf "\t%s",$opcode->out(); - } - } - - print $line,"\n"; -} - -print "\n$current_segment\tENDS\n" if ($current_segment && $masm); -print "END\n" if ($masm); - -close STDOUT; - -################################################# -# Cross-reference x86_64 ABI "card" -# -# Unix Win64 -# %rax * * -# %rbx - - -# %rcx #4 #1 -# %rdx #3 #2 -# %rsi #2 - -# %rdi #1 - -# %rbp - - -# %rsp - - -# %r8 #5 #3 -# %r9 #6 #4 -# %r10 * * -# %r11 * * -# %r12 - - -# %r13 - - -# %r14 - - -# %r15 - - -# -# (*) volatile register -# (-) preserved by callee -# (#) Nth argument, volatile -# -# In Unix terms top of stack is argument transfer area for arguments -# which could not be accommodated in registers. Or in other words 7th -# [integer] argument resides at 8(%rsp) upon function entry point. -# 128 bytes above %rsp constitute a "red zone" which is not touched -# by signal handlers and can be used as temporal storage without -# allocating a frame. -# -# In Win64 terms N*8 bytes on top of stack is argument transfer area, -# which belongs to/can be overwritten by callee. N is the number of -# arguments passed to callee, *but* not less than 4! This means that -# upon function entry point 5th argument resides at 40(%rsp), as well -# as that 32 bytes from 8(%rsp) can always be used as temporal -# storage [without allocating a frame]. One can actually argue that -# one can assume a "red zone" above stack pointer under Win64 as well. -# Point is that at apparently no occasion Windows kernel would alter -# the area above user stack pointer in true asynchronous manner... -# -# All the above means that if assembler programmer adheres to Unix -# register and stack layout, but disregards the "red zone" existence, -# it's possible to use following prologue and epilogue to "gear" from -# Unix to Win64 ABI in leaf functions with not more than 6 arguments. -# -# omnipotent_function: -# ifdef WIN64 -# movq %rdi,8(%rsp) -# movq %rsi,16(%rsp) -# movq %rcx,%rdi ; if 1st argument is actually present -# movq %rdx,%rsi ; if 2nd argument is actually ... -# movq %r8,%rdx ; if 3rd argument is ... -# movq %r9,%rcx ; if 4th argument ... -# movq 40(%rsp),%r8 ; if 5th ... -# movq 48(%rsp),%r9 ; if 6th ... -# endif -# ... -# ifdef WIN64 -# movq 8(%rsp),%rdi -# movq 16(%rsp),%rsi -# endif -# ret -# -################################################# -# Win64 SEH, Structured Exception Handling. -# -# Unlike on Unix systems(*) lack of Win64 stack unwinding information -# has undesired side-effect at run-time: if an exception is raised in -# assembler subroutine such as those in question (basically we're -# referring to segmentation violations caused by malformed input -# parameters), the application is briskly terminated without invoking -# any exception handlers, most notably without generating memory dump -# or any user notification whatsoever. This poses a problem. It's -# possible to address it by registering custom language-specific -# handler that would restore processor context to the state at -# subroutine entry point and return "exception is not handled, keep -# unwinding" code. Writing such handler can be a challenge... But it's -# doable, though requires certain coding convention. Consider following -# snippet: -# -# .type function,@function -# function: -# movq %rsp,%rax # copy rsp to volatile register -# pushq %r15 # save non-volatile registers -# pushq %rbx -# pushq %rbp -# movq %rsp,%r11 -# subq %rdi,%r11 # prepare [variable] stack frame -# andq $-64,%r11 -# movq %rax,0(%r11) # check for exceptions -# movq %r11,%rsp # allocate [variable] stack frame -# movq %rax,0(%rsp) # save original rsp value -# magic_point: -# ... -# movq 0(%rsp),%rcx # pull original rsp value -# movq -24(%rcx),%rbp # restore non-volatile registers -# movq -16(%rcx),%rbx -# movq -8(%rcx),%r15 -# movq %rcx,%rsp # restore original rsp -# magic_epilogue: -# ret -# .size function,.-function -# -# The key is that up to magic_point copy of original rsp value remains -# in chosen volatile register and no non-volatile register, except for -# rsp, is modified. While past magic_point rsp remains constant till -# the very end of the function. In this case custom language-specific -# exception handler would look like this: -# -# EXCEPTION_DISPOSITION handler (EXCEPTION_RECORD *rec,ULONG64 frame, -# CONTEXT *context,DISPATCHER_CONTEXT *disp) -# { ULONG64 *rsp = (ULONG64 *)context->Rax; -# ULONG64 rip = context->Rip; -# -# if (rip >= magic_point) -# { rsp = (ULONG64 *)context->Rsp; -# if (rip < magic_epilogue) -# { rsp = (ULONG64 *)rsp[0]; -# context->Rbp = rsp[-3]; -# context->Rbx = rsp[-2]; -# context->R15 = rsp[-1]; -# } -# } -# context->Rsp = (ULONG64)rsp; -# context->Rdi = rsp[1]; -# context->Rsi = rsp[2]; -# -# memcpy (disp->ContextRecord,context,sizeof(CONTEXT)); -# RtlVirtualUnwind(UNW_FLAG_NHANDLER,disp->ImageBase, -# dips->ControlPc,disp->FunctionEntry,disp->ContextRecord, -# &disp->HandlerData,&disp->EstablisherFrame,NULL); -# return ExceptionContinueSearch; -# } -# -# It's appropriate to implement this handler in assembler, directly in -# function's module. In order to do that one has to know members' -# offsets in CONTEXT and DISPATCHER_CONTEXT structures and some constant -# values. Here they are: -# -# CONTEXT.Rax 120 -# CONTEXT.Rcx 128 -# CONTEXT.Rdx 136 -# CONTEXT.Rbx 144 -# CONTEXT.Rsp 152 -# CONTEXT.Rbp 160 -# CONTEXT.Rsi 168 -# CONTEXT.Rdi 176 -# CONTEXT.R8 184 -# CONTEXT.R9 192 -# CONTEXT.R10 200 -# CONTEXT.R11 208 -# CONTEXT.R12 216 -# CONTEXT.R13 224 -# CONTEXT.R14 232 -# CONTEXT.R15 240 -# CONTEXT.Rip 248 -# CONTEXT.Xmm6 512 -# sizeof(CONTEXT) 1232 -# DISPATCHER_CONTEXT.ControlPc 0 -# DISPATCHER_CONTEXT.ImageBase 8 -# DISPATCHER_CONTEXT.FunctionEntry 16 -# DISPATCHER_CONTEXT.EstablisherFrame 24 -# DISPATCHER_CONTEXT.TargetIp 32 -# DISPATCHER_CONTEXT.ContextRecord 40 -# DISPATCHER_CONTEXT.LanguageHandler 48 -# DISPATCHER_CONTEXT.HandlerData 56 -# UNW_FLAG_NHANDLER 0 -# ExceptionContinueSearch 1 -# -# In order to tie the handler to the function one has to compose -# couple of structures: one for .xdata segment and one for .pdata. -# -# UNWIND_INFO structure for .xdata segment would be -# -# function_unwind_info: -# .byte 9,0,0,0 -# .rva handler -# -# This structure designates exception handler for a function with -# zero-length prologue, no stack frame or frame register. -# -# To facilitate composing of .pdata structures, auto-generated "gear" -# prologue copies rsp value to rax and denotes next instruction with -# .LSEH_begin_{function_name} label. This essentially defines the SEH -# styling rule mentioned in the beginning. Position of this label is -# chosen in such manner that possible exceptions raised in the "gear" -# prologue would be accounted to caller and unwound from latter's frame. -# End of function is marked with respective .LSEH_end_{function_name} -# label. To summarize, .pdata segment would contain -# -# .rva .LSEH_begin_function -# .rva .LSEH_end_function -# .rva function_unwind_info -# -# Reference to function_unwind_info from .xdata segment is the anchor. -# In case you wonder why references are 32-bit .rvas and not 64-bit -# .quads. References put into these two segments are required to be -# *relative* to the base address of the current binary module, a.k.a. -# image base. No Win64 module, be it .exe or .dll, can be larger than -# 2GB and thus such relative references can be and are accommodated in -# 32 bits. -# -# Having reviewed the example function code, one can argue that "movq -# %rsp,%rax" above is redundant. It is not! Keep in mind that on Unix -# rax would contain an undefined value. If this "offends" you, use -# another register and refrain from modifying rax till magic_point is -# reached, i.e. as if it was a non-volatile register. If more registers -# are required prior [variable] frame setup is completed, note that -# nobody says that you can have only one "magic point." You can -# "liberate" non-volatile registers by denoting last stack off-load -# instruction and reflecting it in finer grade unwind logic in handler. -# After all, isn't it why it's called *language-specific* handler... -# -# SE handlers are also involved in unwinding stack when executable is -# profiled or debugged. Profiling implies additional limitations that -# are too subtle to discuss here. For now it's sufficient to say that -# in order to simplify handlers one should either a) offload original -# %rsp to stack (like discussed above); or b) if you have a register to -# spare for frame pointer, choose volatile one. -# -# (*) Note that we're talking about run-time, not debug-time. Lack of -# unwind information makes debugging hard on both Windows and -# Unix. "Unlike" refers to the fact that on Unix signal handler -# will always be invoked, core dumped and appropriate exit code -# returned to parent (for user notification). |