X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fperlasm%2Fx86_64-xlate.pl;h=645be9184d96853b5012aea5fc008327bc489abe;hp=131109d84950ebf74f04de9c46b76e16e62d84e1;hb=c47aea8af1e28e46e1ad5e2e7468b49fec3f4f29;hpb=e81695205edc4f5391f6a6d82e17f0062c1c4cea diff --git a/crypto/perlasm/x86_64-xlate.pl b/crypto/perlasm/x86_64-xlate.pl index 131109d849..645be9184d 100755 --- a/crypto/perlasm/x86_64-xlate.pl +++ b/crypto/perlasm/x86_64-xlate.pl @@ -1,4 +1,11 @@ -#!/usr/bin/env perl +#! /usr/bin/env perl +# Copyright 2005-2016 The OpenSSL Project Authors. All Rights Reserved. +# +# Licensed under the OpenSSL license (the "License"). You may not use +# this file except in compliance with the License. You can obtain a copy +# in the file LICENSE in the source distribution or at +# https://www.openssl.org/source/license.html + # Ascetic x86_64 AT&T to MASM/NASM assembler translator by . # @@ -44,28 +51,24 @@ # 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. To support legacy code a synthetic directive, .picmeup, -# is implemented. It puts address of the *next* instruction into -# target register, e.g.: -# -# .picmeup %rax -# lea .Label-.(%rax),%rax +# 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 $flavour; } -{ my ($stddev,$stdino,@junk)=stat(STDOUT); - my ($outdev,$outino,@junk)=stat($output); - - open STDOUT,">$output" || die "can't open $output: $!" - if ($stddev!=$outdev || $stdino!=$outino); -} +open STDOUT,">$output" || die "can't open $output: $!" + if (defined($output)); my $gas=1; $gas=0 if ($output =~ /\.asm$/); my $elf=1; $elf=0 if (!$gas); @@ -80,7 +83,10 @@ my $PTR=" PTR"; my $nasmref=2.03; my $nasm=0; -if ($flavour eq "mingw64") { $gas=1; $elf=0; $win64=1; $prefix="_"; } +if ($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\$"; $PTR=""; } @@ -89,7 +95,7 @@ elsif (!$gas) { $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 || $masm)); + die "no assembler found on %PATH%" if (!($nasm || $masm)); $win64=1; $elf=0; $decor="\$L\$"; @@ -101,21 +107,28 @@ my %globals; { package opcode; # pick up opcodes sub re { - my $self = shift; # single instance in enough... - local *line = shift; - undef $ret; + my ($class, $line) = @_; + my $self = {}; + my $ret; - if ($line =~ /^([a-z][a-z0-9]*)/i) { + if ($$line =~ /^([a-z][a-z0-9]*)/i) { + bless $self,$class; $self->{op} = $1; $ret = $self; - $line = substr($line,@+[0]); $line =~ s/^\s+//; + $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; undef $self->{sz}; - if ($self->{op} =~ /^(movz)b.*/) { # movz is pain... + if ($self->{op} =~ /^(movz)x?([bw]).*/) { # movz is pain... $self->{op} = $1; - $self->{sz} = "b"; + $self->{sz} = $2; } elsif ($self->{op} =~ /call|jmp/) { - $self->{sz} = "" + $self->{sz} = ""; + } elsif ($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; @@ -124,8 +137,7 @@ my %globals; $ret; } sub size { - my $self = shift; - my $sz = shift; + my ($self, $sz) = @_; $self->{sz} = $sz if (defined($sz) && !defined($self->{sz})); $self->{sz}; } @@ -134,7 +146,7 @@ my %globals; if ($gas) { if ($self->{op} eq "movz") { # movz is pain... sprintf "%s%s%s",$self->{op},$self->{sz},shift; - } elsif ($self->{op} =~ /^set/) { + } elsif ($self->{op} =~ /^set/) { "$self->{op}"; } elsif ($self->{op} eq "ret") { my $epilogue = ""; @@ -153,82 +165,96 @@ my %globals; if ($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"; + $self->{op} = "mov rdi,QWORD$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} = "ALIGN\t8\n\tDQ"; - } + $self->{op} = "\tDQ"; + } $self->{op}; } } sub mnemonic { - my $self=shift; - my $op=shift; + my ($self, $op) = @_; $self->{op}=$op if (defined($op)); $self->{op}; } } { package const; # pick up constants, which start with $ sub re { - my $self = shift; # single instance in enough... - local *line = shift; - undef $ret; + my ($class, $line) = @_; + my $self = {}; + my $ret; - if ($line =~ /^\$([^,]+)/) { + if ($$line =~ /^\$([^,]+)/) { + bless $self, $class; $self->{value} = $1; $ret = $self; - $line = substr($line,@+[0]); $line =~ s/^\s+//; + $$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} - $self->{value} =~ s/(?{value} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg; + my $value = $self->{value}; + no warnings; # oct might complain about overflow, ignore here... + $value =~ s/(?{value} = $value; + } sprintf "\$%s",$self->{value}; } else { - $self->{value} =~ s/(0b[0-1]+)/oct($1)/eig; - $self->{value} =~ s/0x([0-9a-f]+)/0$1h/ig if ($masm); - sprintf "%s",$self->{value}; + 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 $self = shift; # single instance in enough... - local *line = shift; - undef $ret; + my ($class, $line, $opcode) = @_; + my $self = {}; + my $ret; - # optional * ---vvv--- appears in indirect jmp/call - if ($line =~ /^(\*?)([^\(,]*)\(([%\w,]+)\)/) { + # 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+//; + $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; if ($win64 && $self->{label} =~ s/\@GOTPCREL//) { - die if (opcode->mnemonic() ne "mov"); - opcode->mnemonic("lea"); + 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 = shift; - my $sz = shift; + my ($self, $sz) = @_; $self->{label} =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; $self->{label} =~ s/\.L/$decor/g; @@ -239,63 +265,91 @@ my %globals; $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/(?{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) { - # Solaris /usr/ccs/bin/as can't handle multiplications - # in $self->{label} - $self->{label} =~ s/(?{label} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg; $self->{label} =~ s/^___imp_/__imp__/ if ($flavour eq "mingw64"); if (defined($self->{index})) { - sprintf "%s%s(%%%s,%%%s,%d)",$self->{asterisk}, - $self->{label},$self->{base}, - $self->{index},$self->{scale}; + 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)", $self->{asterisk},$self->{label},$self->{base}; + sprintf "%s%s(%%%s)%s", $self->{asterisk},$self->{label}, + $self->{base},$self->{opmask}; } } else { - %szmap = ( b=>"BYTE$PTR", w=>"WORD$PTR", l=>"DWORD$PTR", q=>"QWORD$PTR" ); - $self->{label} =~ s/\./\$/g; - $self->{label} =~ s/0x([0-9a-f]+)/0$1h/ig; + $self->{label} =~ s/(?{label} = "($self->{label})" if ($self->{label} =~ /[\*\+\-\/]/); - $sz="q" if ($self->{asterisk}); + + 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]",$szmap{$sz}, + sprintf "%s[%s%s*%d%s]%s",$szmap{$sz}, $self->{label}?"$self->{label}+":"", $self->{index},$self->{scale}, - $self->{base}; + $self->{base}?"+$self->{base}":"", + $self->{opmask}; } elsif ($self->{base} eq "rip") { sprintf "%s[%s]",$szmap{$sz},$self->{label}; } else { - sprintf "%s[%s%s]",$szmap{$sz}, + sprintf "%s[%s%s]%s", $szmap{$sz}, $self->{label}?"$self->{label}+":"", - $self->{base}; + $self->{base},$self->{opmask}; } } } } { package register; # pick up registers, which start with %. sub re { - my $class = shift; # muliple instances... + my ($class, $line, $opcode) = @_; my $self = {}; - local *line = shift; - undef $ret; + my $ret; - # optional * ---vvv--- appears in indirect jmp/call - if ($line =~ /^(\*?)%(\w+)/) { + # 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+//; + $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; } $ret; } sub size { my $self = shift; - undef $ret; + my $ret; if ($self->{value} =~ /^r[\d]+b$/i) { $ret="b"; } elsif ($self->{value} =~ /^r[\d]+w$/i) { $ret="w"; } @@ -310,20 +364,24 @@ my %globals; } sub out { my $self = shift; - if ($gas) { sprintf "%s%%%s",$self->{asterisk},$self->{value}; } - else { $self->{value}; } + if ($gas) { sprintf "%s%%%s%s", $self->{asterisk}, + $self->{value}, + $self->{opmask}; } + else { $self->{opmask} =~ s/%(k[0-7])/$1/; + $self->{value}.$self->{opmask}; } } } { package label; # pick up labels, which end with : sub re { - my $self = shift; # single instance is enough... - local *line = shift; - undef $ret; + my ($class, $line) = @_; + my $self = {}; + my $ret; - if ($line =~ /(^[\.\w]+)\:/) { + if ($$line =~ /(^[\.\w]+)\:/) { + bless $self,$class; $self->{value} = $1; $ret = $self; - $line = substr($line,@+[0]); $line =~ s/^\s+//; + $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; $self->{value} =~ s/^\.L/$decor/; } @@ -334,9 +392,8 @@ my %globals; if ($gas) { my $func = ($globals{$self->{value}} or $self->{value}) . ":"; - if ($win64 && - $current_function->{name} eq $self->{value} && - $current_function->{abi} eq "svr4") { + if ($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"; @@ -353,14 +410,15 @@ my %globals; } $func; } elsif ($self->{value} ne "$current_function->{name}") { - $self->{value} .= ":" if ($masm && $ret!~m/^\$/); + # 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"; + $func .= " mov QWORD$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); @@ -371,8 +429,8 @@ my %globals; $func .= " mov rsi,rdx\n" if ($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); + $func .= " mov r8,QWORD$PTR\[40+rsp\]\n" if ($narg>4); + $func .= " mov r9,QWORD$PTR\[48+rsp\]\n" if ($narg>5); $func .= "\n"; } else { "$current_function->{name}". @@ -380,67 +438,294 @@ my %globals; } } } -{ package expr; # pick up expressioins +{ package expr; # pick up expressions sub re { - my $self = shift; # single instance is enough... - local *line = shift; - undef $ret; + my ($class, $line, $opcode) = @_; + my $self = {}; + my $ret; - if ($line =~ /(^[^,]+)/) { + if ($$line =~ /(^[^,]+)/) { + bless $self,$class; $self->{value} = $1; $ret = $self; - $line = substr($line,@+[0]); $line =~ s/^\s+//; + $$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 && opcode->mnemonic()=~m/^j/) { + 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 avaiable 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 significat 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 $self = shift; # single instance is enough... - local *line = shift; - undef $ret; + my ($class, $line) = @_; + my $self = {}; + my $ret; my $dir; - my %opcode = # lea 2f-1f(%rip),%dst; 1: nop; 2: - ( "%rax"=>0x01058d48, "%rcx"=>0x010d8d48, - "%rdx"=>0x01158d48, "%rbx"=>0x011d8d48, - "%rsp"=>0x01258d48, "%rbp"=>0x012d8d48, - "%rsi"=>0x01358d48, "%rdi"=>0x013d8d48, - "%r8" =>0x01058d4c, "%r9" =>0x010d8d4c, - "%r10"=>0x01158d4c, "%r11"=>0x011d8d4c, - "%r12"=>0x01258d4c, "%r13"=>0x012d8d4c, - "%r14"=>0x01358d4c, "%r15"=>0x013d8d4c ); - - if ($line =~ /^\s*(\.\w+)/) { + + # chain-call to cfi_directive + $ret = cfi_directive->re($line) and return $ret; + + if ($$line =~ /^\s*(\.\w+)/) { + bless $self,$class; $dir = $1; $ret = $self; undef $self->{value}; - $line = substr($line,@+[0]); $line =~ s/^\s+//; + $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; SWITCH: for ($dir) { - /\.picmeup/ && do { if ($line =~ /(%r[\w]+)/i) { - $dir="\t.long"; - $line=sprintf "0x%x,0x90000000",$opcode{$1}; - } - last; - }; /\.global|\.globl|\.extern/ - && do { $globals{$line} = $prefix . $line; - $line = $globals{$line} if ($prefix); + && do { $globals{$$line} = $prefix . $$line; + $$line = $globals{$$line} if ($prefix); last; }; - /\.type/ && do { ($sym,$type,$narg) = split(',',$line); + /\.type/ && do { my ($sym,$type,$narg) = split(',',$$line); if ($type eq "\@function") { undef $current_function; $current_function->{name} = $sym; @@ -452,25 +737,25 @@ my %globals; $current_function->{name} = $sym; $current_function->{scope} = defined($globals{$sym})?"PUBLIC":"PRIVATE"; } - $line =~ s/\@abi\-omnipotent/\@function/; - $line =~ s/\@function.*/\@function/; + $$line =~ s/\@abi\-omnipotent/\@function/; + $$line =~ s/\@function.*/\@function/; last; }; - /\.asciz/ && do { if ($line =~ /^"(.*)"$/) { + /\.asciz/ && do { if ($$line =~ /^"(.*)"$/) { $dir = ".byte"; - $line = join(",",unpack("C*",$1),0); + $$line = join(",",unpack("C*",$1),0); } last; }; /\.rva|\.long|\.quad/ - && do { $line =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; - $line =~ s/\.L/$decor/g; + && do { $$line =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; + $$line =~ s/\.L/$decor/g; last; }; } if ($gas) { - $self->{value} = $dir . "\t" . $line; + $self->{value} = $dir . "\t" . $$line; if ($dir =~ /\.extern/) { $self->{value} = ""; # swallow extern @@ -479,7 +764,7 @@ my %globals; $self->{value} = ".def\t" . ($globals{$1} or $1) . ";\t" . (defined($globals{$1})?".scl 2;":".scl 3;") . "\t.type 32;\t.endef" - if ($win64 && $line =~ /([^,]+),\@function/); + if ($win64 && $$line =~ /([^,]+),\@function/); } elsif (!$elf && $dir =~ /\.size/) { $self->{value} = ""; if (defined($current_function)) { @@ -488,17 +773,23 @@ my %globals; undef $current_function; } } elsif (!$elf && $dir =~ /\.align/) { - $self->{value} = ".p2align\t" . (log($line)/log(2)); + $self->{value} = ".p2align\t" . (log($$line)/log(2)); } elsif ($dir eq ".section") { - $current_segment=$line; + $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$$line"; + $self->{value} =~ s|,([0-9]+),([0-9]+)$|",$1,".log($2)/log(2)|e if ($flavour eq "macosx"); } - $line = ""; + $$line = ""; return $self; } @@ -511,7 +802,7 @@ my %globals; $v="$current_segment\tENDS\n" if ($current_segment); $current_segment = ".text\$"; $v.="$current_segment\tSEGMENT "; - $v.=$masm>=$masmref ? "ALIGN(64)" : "PAGE"; + $v.=$masm>=$masmref ? "ALIGN(256)" : "PAGE"; $v.=" 'CODE'"; } $self->{value} = $v; @@ -529,33 +820,38 @@ my %globals; last; }; /\.section/ && do { my $v=undef; - $line =~ s/([^,]*).*/$1/; - $line = ".CRT\$XCU" if ($line eq ".init"); + $$line =~ s/([^,]*).*/$1/; + $$line = ".CRT\$XCU" if ($$line eq ".init"); if ($nasm) { - $v="section $line"; - if ($line=~/\.([px])data/) { + $v="section $$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.="$$line\tSEGMENT"; + if ($$line=~/\.([px])data/) { $v.=" READONLY"; $v.=" ALIGN(".($1 eq "p" ? 4 : 8).")" if ($masm>=$masmref); + } elsif ($$line=~/\.CRT\$/i) { + $v.=" READONLY "; + $v.=$masm>=$masmref ? "ALIGN(8)" : "DWORD"; } } - $current_segment = $line; + $current_segment = $$line; $self->{value} = $v; last; }; - /\.extern/ && do { $self->{value} = "EXTERN\t".$line; + /\.extern/ && do { $self->{value} = "EXTERN\t".$$line; $self->{value} .= ":NEAR" if ($masm); last; }; /\.globl|.global/ && do { $self->{value} = $masm?"PUBLIC":"global"; - $self->{value} .= "\t".$line; + $self->{value} .= "\t".$$line; last; }; /\.size/ && do { if (defined($current_function)) { @@ -564,23 +860,26 @@ my %globals; $self->{value}="${decor}SEH_end_$current_function->{name}:"; $self->{value}.=":\n" if($masm); } - $self->{value}.="$current_function->{name}\tENDP" if($masm); + $self->{value}.="$current_function->{name}\tENDP" if($masm && $current_function->{name}); undef $current_function; } last; }; - /\.align/ && do { $self->{value} = "ALIGN\t".$line; 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($1,0,1); - my @arr = split(',',$line); + my @arr = split(/,\s*/,$$line); my $last = pop(@arr); my $conv = sub { my $var=shift; - $var=~s/(0b[0-1]+)/oct($1)/eig; - $var=~s/0x([0-9a-f]+)/0$1h/ig if ($masm); + $var=~s/^(0b[0-1]+)/oct($1)/eig; + $var=~s/^0x([0-9a-f]+)/0$1h/ig if ($masm); if ($sz eq "D" && ($current_segment=~/.[px]data/ || $dir eq ".rva")) { $var=~s/([_a-z\$\@][_a-z0-9\$\@]*)/$nasm?"$1 wrt ..imagebase":"imagerel $1"/egi; } $var; - }; + }; $sz =~ tr/bvlrq/BWDDQ/; $self->{value} = "\tD$sz\t"; @@ -588,9 +887,9 @@ my %globals; $self->{value} .= &$conv($last); last; }; - /\.byte/ && do { my @str=split(",",$line); + /\.byte/ && do { my @str=split(/,\s*/,$$line); map(s/(0b[0-1]+)/oct($1)/eig,@str); - map(s/0x([0-9a-f]+)/0$1h/ig,@str) if ($masm); + map(s/0x([0-9a-f]+)/0$1h/ig,@str) if ($masm); while ($#str>15) { $self->{value}.="DB\t" .join(",",@str[0..15])."\n"; @@ -600,8 +899,21 @@ my %globals; .join(",",@str) if (@str); last; }; + /\.comm/ && do { my @str=split(/,\s*/,$$line); + my $v=undef; + if ($nasm) { + $v.="common $prefix@str[0] @str[1]"; + } else { + $v="$current_segment\tENDS\n" if ($current_segment); + $current_segment = "_DATA"; + $v.="$current_segment\tSEGMENT\n"; + $v.="COMM @str[0]:DWORD:".@str[1]/4; + } + $self->{value} = $v; + last; + }; } - $line = ""; + $$line = ""; } $ret; @@ -612,60 +924,272 @@ my %globals; } } +# 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 ($masm) { print <<___; OPTION DOTNAME ___ } -while($line=<>) { +while(defined(my $line=<>)) { - chomp($line); + $line =~ s|\R$||; # Better chomp $line =~ s|[#!].*$||; # 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(); } - undef $label; - undef $opcode; - undef $sz; - undef @args; + if (my $directive=directive->re(\$line)) { + printf "%s",$directive->out(); + } elsif (my $opcode=opcode->re(\$line)) { + my $asm = eval("\$".$opcode->mnemonic()); - if ($label=label->re(\$line)) { print $label->out(); } + if ((ref($asm) eq 'CODE') && scalar(my @bytes=&$asm($line))) { + print $gas?".byte\t":"DB\t",join(',',@bytes),"\n"; + next; + } - if (directive->re(\$line)) { - printf "%s",directive->out(); - } elsif ($opcode=opcode->re(\$line)) { ARGUMENT: while (1) { - my $arg; + my @args; + ARGUMENT: while (1) { + my $arg; - if ($arg=register->re(\$line)) { opcode->size($arg->size()); } - elsif ($arg=const->re(\$line)) { } - elsif ($arg=ea->re(\$line)) { } - elsif ($arg=expr->re(\$line)) { } - else { last ARGUMENT; } + ($arg=register->re(\$line, $opcode))|| + ($arg=const->re(\$line)) || + ($arg=ea->re(\$line, $opcode)) || + ($arg=expr->re(\$line, $opcode)) || + last ARGUMENT; - push @args,$arg; + push @args,$arg; - last ARGUMENT if ($line !~ /^,/); + last ARGUMENT if ($line !~ /^,/); - $line =~ s/^,\s*//; + $line =~ s/^,\s*//; } # ARGUMENT: - $sz=opcode->size(); - if ($#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)); } - printf "\t%s\t%s",$insn,join(",",map($_->out($sz),@args)); } else { printf "\t%s",$opcode->out(); } @@ -699,13 +1223,13 @@ close STDOUT; # %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 accomodated in registers. Or in other words 7th +# 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 @@ -722,7 +1246,7 @@ close STDOUT; # 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" existense, +# 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. # @@ -780,6 +1304,7 @@ close STDOUT; # movq -16(%rcx),%rbx # movq -8(%rcx),%r15 # movq %rcx,%rsp # restore original rsp +# magic_epilogue: # ret # .size function,.-function # @@ -792,11 +1317,16 @@ close STDOUT; # EXCEPTION_DISPOSITION handler (EXCEPTION_RECORD *rec,ULONG64 frame, # CONTEXT *context,DISPATCHER_CONTEXT *disp) # { ULONG64 *rsp = (ULONG64 *)context->Rax; -# if (context->Rip >= magic_point) -# { rsp = ((ULONG64 **)context->Rsp)[0]; -# context->Rbp = rsp[-3]; -# context->Rbx = rsp[-2]; -# context->R15 = rsp[-1]; +# 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]; @@ -831,6 +1361,7 @@ close STDOUT; # CONTEXT.R14 232 # CONTEXT.R15 240 # CONTEXT.Rip 248 +# CONTEXT.Xmm6 512 # sizeof(CONTEXT) 1232 # DISPATCHER_CONTEXT.ControlPc 0 # DISPATCHER_CONTEXT.ImageBase 8 @@ -868,7 +1399,7 @@ close STDOUT; # .rva .LSEH_end_function # .rva function_unwind_info # -# Reference to functon_unwind_info from .xdata segment is the anchor. +# 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. @@ -887,13 +1418,12 @@ close STDOUT; # instruction and reflecting it in finer grade unwind logic in handler. # After all, isn't it why it's called *language-specific* handler... # -# Attentive reader can notice that exceptions would be mishandled in -# auto-generated "gear" epilogue. Well, exception effectively can't -# occur there, because if memory area used by it was subject to -# segmentation violation, then it would be raised upon call to the -# function (and as already mentioned be accounted to caller, which is -# not a problem). If you're still not comfortable, then define tail -# "magic point" just prior ret instruction and have handler treat it... +# 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