X-Git-Url: https://git.openssl.org/?a=blobdiff_plain;f=crypto%2Fperlasm%2Fx86_64-xlate.pl;h=eac21c1c694360181b1a2b5a99eb39714e903f08;hb=95c81f8c8895615b4db0edde8ce5d1e030edd2f9;hp=f050b23f00c1ac3b6e876c5650c5de7a20e4536d;hpb=6a4ea0022c475bbc2c7ad98a6f05f6e2e850575b;p=openssl.git diff --git a/crypto/perlasm/x86_64-xlate.pl b/crypto/perlasm/x86_64-xlate.pl index f050b23f00..eac21c1c69 100755 --- a/crypto/perlasm/x86_64-xlate.pl +++ b/crypto/perlasm/x86_64-xlate.pl @@ -51,12 +51,7 @@ # 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 @@ -100,7 +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\$"; @@ -130,7 +125,7 @@ my %globals; $self->{sz} = ""; } elsif ($self->{op} =~ /^p/ && $' !~ /^(ush|op|insrw)/) { # SSEn $self->{sz} = ""; - } elsif ($self->{op} =~ /^v/) { # VEX + } elsif ($self->{op} =~ /^[vk]/) { # VEX or k* such as kmov $self->{sz} = ""; } elsif ($self->{op} =~ /mov[dq]/ && $$line =~ /%xmm/) { $self->{sz} = ""; @@ -151,7 +146,7 @@ my %globals; if ($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 $epilogue = ""; @@ -170,15 +165,15 @@ my %globals; if ($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} = "\tDQ"; - } + } $self->{op}; } } @@ -210,30 +205,40 @@ my %globals; # 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/(?{value} = $value; } sprintf "\$%s",$self->{value}; } else { - $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 (!$gas); + sub re { my ($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+//; @@ -261,12 +266,21 @@ my %globals; $self->{base} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/; # Solaris /usr/ccs/bin/as can't handle multiplications - # in $self->{label}, new gas requires sign extension... + # in $self->{label}... use integer; $self->{label} =~ s/(?{label} =~ s/\b([0-9]+\s*[\*\/\%]\s*[0-9]+)\b/eval($1)/eg; - $self->{label} =~ s/\b([0-9]+)\b/$1<<32>>32/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; @@ -276,19 +290,16 @@ my %globals; $self->{label} =~ s/^___imp_/__imp__/ if ($flavour eq "mingw64"); if (defined($self->{index})) { - sprintf "%s%s(%s,%%%s,%d)",$self->{asterisk}, - $self->{label}, + sprintf "%s%s(%s,%%%s,%d)%s", + $self->{asterisk},$self->{label}, $self->{base}?"%$self->{base}":"", - $self->{index},$self->{scale}; + $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 { - 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" ); - $self->{label} =~ s/\./\$/g; $self->{label} =~ s/(?{label} = "($self->{label})" if ($self->{label} =~ /[\*\+\-\/]/); @@ -300,17 +311,20 @@ my %globals; ($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->{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}; } } } @@ -322,10 +336,11 @@ my %globals; my $ret; # optional * ----vvv--- appears in indirect jmp/call - if ($$line =~ /^(\*?)%(\w+)/) { + 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+//; @@ -349,8 +364,11 @@ 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 : @@ -374,9 +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"; @@ -400,8 +417,8 @@ my %globals; 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); @@ -412,8 +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}". @@ -421,7 +438,7 @@ my %globals; } } } -{ package expr; # pick up expressioins +{ package expr; # pick up expressions sub re { my ($class, $line, $opcode) = @_; my $self = {}; @@ -449,21 +466,251 @@ my %globals; } } } +{ 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; - 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 ); + + # chain-call to cfi_directive + $ret = cfi_directive->re($line) and return $ret; if ($$line =~ /^\s*(\.\w+)/) { bless $self,$class; @@ -473,12 +720,6 @@ my %globals; $$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 ($prefix); @@ -638,7 +879,7 @@ my %globals; if ($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"; @@ -648,7 +889,7 @@ my %globals; }; /\.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"; @@ -683,6 +924,16 @@ 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)=@_; @@ -692,10 +943,6 @@ sub rex { push @$opcode,($rex|0x40) if ($rex); } -# older gas and ml64 don't handle SSE>2 instructions -my %regrm = ( "%eax"=>0, "%ecx"=>1, "%edx"=>2, "%ebx"=>3, - "%esp"=>4, "%ebp"=>5, "%esi"=>6, "%edi"=>7 ); - my $movq = sub { # elderly gas can't handle inter-register movq my $arg = shift; my @opcode=(0x66); @@ -798,7 +1045,7 @@ my $rdrand = sub { my @opcode=(); my $dst=$1; if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } - rex(\@opcode,0,$1,8); + rex(\@opcode,0,$dst,8); push @opcode,0x0f,0xc7,0xf0|($dst&7); @opcode; } else { @@ -811,7 +1058,7 @@ my $rdseed = sub { my @opcode=(); my $dst=$1; if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } - rex(\@opcode,0,$1,8); + rex(\@opcode,0,$dst,8); push @opcode,0x0f,0xc7,0xf8|($dst&7); @opcode; } else { @@ -819,6 +1066,10 @@ my $rdseed = sub { } }; +# 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)=@_; @@ -858,6 +1109,15 @@ my $vprotq = sub { } }; +# 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 @@ -885,7 +1145,7 @@ while(defined(my $line=<>)) { printf "%s",$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; @@ -963,7 +1223,7 @@ close STDOUT; # %r13 - - # %r14 - - # %r15 - - -# +# # (*) volatile register # (-) preserved by callee # (#) Nth argument, volatile @@ -986,7 +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. # @@ -1044,6 +1304,7 @@ close STDOUT; # movq -16(%rcx),%rbx # movq -8(%rcx),%r15 # movq %rcx,%rsp # restore original rsp +# magic_epilogue: # ret # .size function,.-function # @@ -1056,11 +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]; @@ -1152,16 +1418,15 @@ 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 -# Unix. "Unlike" referes to the fact that on Unix signal handler +# 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).