1#! /usr/bin/env perl 2# Copyright 2005-2016 The OpenSSL Project Authors. All Rights Reserved. 3# 4# Licensed under the OpenSSL license (the "License"). You may not use 5# this file except in compliance with the License. You can obtain a copy 6# in the file LICENSE in the source distribution or at 7# https://www.openssl.org/source/license.html 8 9 10# Ascetic x86_64 AT&T to MASM/NASM assembler translator by <appro>. 11# 12# Why AT&T to MASM and not vice versa? Several reasons. Because AT&T 13# format is way easier to parse. Because it's simpler to "gear" from 14# Unix ABI to Windows one [see cross-reference "card" at the end of 15# file]. Because Linux targets were available first... 16# 17# In addition the script also "distills" code suitable for GNU 18# assembler, so that it can be compiled with more rigid assemblers, 19# such as Solaris /usr/ccs/bin/as. 20# 21# This translator is not designed to convert *arbitrary* assembler 22# code from AT&T format to MASM one. It's designed to convert just 23# enough to provide for dual-ABI OpenSSL modules development... 24# There *are* limitations and you might have to modify your assembler 25# code or this script to achieve the desired result... 26# 27# Currently recognized limitations: 28# 29# - can't use multiple ops per line; 30# 31# Dual-ABI styling rules. 32# 33# 1. Adhere to Unix register and stack layout [see cross-reference 34# ABI "card" at the end for explanation]. 35# 2. Forget about "red zone," stick to more traditional blended 36# stack frame allocation. If volatile storage is actually required 37# that is. If not, just leave the stack as is. 38# 3. Functions tagged with ".type name,@function" get crafted with 39# unified Win64 prologue and epilogue automatically. If you want 40# to take care of ABI differences yourself, tag functions as 41# ".type name,@abi-omnipotent" instead. 42# 4. To optimize the Win64 prologue you can specify number of input 43# arguments as ".type name,@function,N." Keep in mind that if N is 44# larger than 6, then you *have to* write "abi-omnipotent" code, 45# because >6 cases can't be addressed with unified prologue. 46# 5. Name local labels as .L*, do *not* use dynamic labels such as 1: 47# (sorry about latter). 48# 6. Don't use [or hand-code with .byte] "rep ret." "ret" mnemonic is 49# required to identify the spots, where to inject Win64 epilogue! 50# But on the pros, it's then prefixed with rep automatically:-) 51# 7. Stick to explicit ip-relative addressing. If you have to use 52# GOTPCREL addressing, stick to mov symbol@GOTPCREL(%rip),%r??. 53# Both are recognized and translated to proper Win64 addressing 54# modes. 55# 56# 8. In order to provide for structured exception handling unified 57# Win64 prologue copies %rsp value to %rax. For further details 58# see SEH paragraph at the end. 59# 9. .init segment is allowed to contain calls to functions only. 60# a. If function accepts more than 4 arguments *and* >4th argument 61# is declared as non 64-bit value, do clear its upper part. 62 63 64use strict; 65 66my $flavour = shift; 67my $output = shift; 68if ($flavour =~ /\./) { $output = $flavour; undef $flavour; } 69 70open STDOUT,">$output" || die "can't open $output: $!" 71 if (defined($output)); 72 73my $gas=1; $gas=0 if ($output =~ /\.asm$/); 74my $elf=1; $elf=0 if (!$gas); 75my $win64=0; 76my $prefix=""; 77my $decor=".L"; 78 79my $masmref=8 + 50727*2**-32; # 8.00.50727 shipped with VS2005 80my $masm=0; 81my $PTR=" PTR"; 82 83my $nasmref=2.03; 84my $nasm=0; 85 86if ($flavour eq "mingw64") { $gas=1; $elf=0; $win64=1; 87 # TODO(davidben): Before supporting the 88 # mingw64 perlasm flavour, do away with this 89 # environment variable check. 90 die "mingw64 not supported"; 91 $prefix=`echo __USER_LABEL_PREFIX__ | $ENV{CC} -E -P -`; 92 $prefix =~ s|\R$||; # Better chomp 93 } 94elsif ($flavour eq "macosx") { $gas=1; $elf=0; $prefix="_"; $decor="L\$"; } 95elsif ($flavour eq "masm") { $gas=0; $elf=0; $masm=$masmref; $win64=1; $decor="\$L\$"; } 96elsif ($flavour eq "nasm") { $gas=0; $elf=0; $nasm=$nasmref; $win64=1; $decor="\$L\$"; $PTR=""; } 97elsif (!$gas) { die "unknown flavour $flavour"; } 98 99my $current_segment; 100my $current_function; 101my %globals; 102 103{ package opcode; # pick up opcodes 104 sub re { 105 my ($class, $line) = @_; 106 my $self = {}; 107 my $ret; 108 109 if ($$line =~ /^([a-z][a-z0-9]*)/i) { 110 bless $self,$class; 111 $self->{op} = $1; 112 $ret = $self; 113 $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; 114 115 undef $self->{sz}; 116 if ($self->{op} =~ /^(movz)x?([bw]).*/) { # movz is pain... 117 $self->{op} = $1; 118 $self->{sz} = $2; 119 } elsif ($self->{op} =~ /call|jmp/) { 120 $self->{sz} = ""; 121 } elsif ($self->{op} =~ /^p/ && $' !~ /^(ush|op|insrw)/) { # SSEn 122 $self->{sz} = ""; 123 } elsif ($self->{op} =~ /^[vk]/) { # VEX or k* such as kmov 124 $self->{sz} = ""; 125 } elsif ($self->{op} =~ /mov[dq]/ && $$line =~ /%xmm/) { 126 $self->{sz} = ""; 127 } elsif ($self->{op} =~ /^or([qlwb])$/) { 128 $self->{op} = "or"; 129 $self->{sz} = $1; 130 } elsif ($self->{op} =~ /([a-z]{3,})([qlwb])$/) { 131 $self->{op} = $1; 132 $self->{sz} = $2; 133 } 134 } 135 $ret; 136 } 137 sub size { 138 my ($self, $sz) = @_; 139 $self->{sz} = $sz if (defined($sz) && !defined($self->{sz})); 140 $self->{sz}; 141 } 142 sub out { 143 my $self = shift; 144 if ($gas) { 145 if ($self->{op} eq "movz") { # movz is pain... 146 sprintf "%s%s%s",$self->{op},$self->{sz},shift; 147 } elsif ($self->{op} =~ /^set/) { 148 "$self->{op}"; 149 } elsif ($self->{op} eq "ret") { 150 my $epilogue = ""; 151 if ($win64 && $current_function->{abi} eq "svr4") { 152 $epilogue = "movq 8(%rsp),%rdi\n\t" . 153 "movq 16(%rsp),%rsi\n\t"; 154 } 155 $epilogue . ".byte 0xf3,0xc3"; 156 } elsif ($self->{op} eq "call" && !$elf && $current_segment eq ".init") { 157 ".p2align\t3\n\t.quad"; 158 } else { 159 "$self->{op}$self->{sz}"; 160 } 161 } else { 162 $self->{op} =~ s/^movz/movzx/; 163 if ($self->{op} eq "ret") { 164 $self->{op} = ""; 165 if ($win64 && $current_function->{abi} eq "svr4") { 166 $self->{op} = "mov rdi,QWORD$PTR\[8+rsp\]\t;WIN64 epilogue\n\t". 167 "mov rsi,QWORD$PTR\[16+rsp\]\n\t"; 168 } 169 $self->{op} .= "DB\t0F3h,0C3h\t\t;repret"; 170 } elsif ($self->{op} =~ /^(pop|push)f/) { 171 $self->{op} .= $self->{sz}; 172 } elsif ($self->{op} eq "call" && $current_segment eq ".CRT\$XCU") { 173 $self->{op} = "\tDQ"; 174 } 175 $self->{op}; 176 } 177 } 178 sub mnemonic { 179 my ($self, $op) = @_; 180 $self->{op}=$op if (defined($op)); 181 $self->{op}; 182 } 183} 184{ package const; # pick up constants, which start with $ 185 sub re { 186 my ($class, $line) = @_; 187 my $self = {}; 188 my $ret; 189 190 if ($$line =~ /^\$([^,]+)/) { 191 bless $self, $class; 192 $self->{value} = $1; 193 $ret = $self; 194 $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; 195 } 196 $ret; 197 } 198 sub out { 199 my $self = shift; 200 201 $self->{value} =~ s/\b(0b[0-1]+)/oct($1)/eig; 202 if ($gas) { 203 # Solaris /usr/ccs/bin/as can't handle multiplications 204 # in $self->{value} 205 my $value = $self->{value}; 206 no warnings; # oct might complain about overflow, ignore here... 207 $value =~ s/(?<![\w\$\.])(0x?[0-9a-f]+)/oct($1)/egi; 208 if ($value =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg) { 209 $self->{value} = $value; 210 } 211 sprintf "\$%s",$self->{value}; 212 } else { 213 my $value = $self->{value}; 214 $value =~ s/0x([0-9a-f]+)/0$1h/ig if ($masm); 215 sprintf "%s",$value; 216 } 217 } 218} 219{ package ea; # pick up effective addresses: expr(%reg,%reg,scale) 220 221 my %szmap = ( b=>"BYTE$PTR", w=>"WORD$PTR", 222 l=>"DWORD$PTR", d=>"DWORD$PTR", 223 q=>"QWORD$PTR", o=>"OWORD$PTR", 224 x=>"XMMWORD$PTR", y=>"YMMWORD$PTR", 225 z=>"ZMMWORD$PTR" ) if (!$gas); 226 227 sub re { 228 my ($class, $line, $opcode) = @_; 229 my $self = {}; 230 my $ret; 231 232 # optional * ----vvv--- appears in indirect jmp/call 233 if ($$line =~ /^(\*?)([^\(,]*)\(([%\w,]+)\)((?:{[^}]+})*)/) { 234 bless $self, $class; 235 $self->{asterisk} = $1; 236 $self->{label} = $2; 237 ($self->{base},$self->{index},$self->{scale})=split(/,/,$3); 238 $self->{scale} = 1 if (!defined($self->{scale})); 239 $self->{opmask} = $4; 240 $ret = $self; 241 $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; 242 243 if ($win64 && $self->{label} =~ s/\@GOTPCREL//) { 244 die if ($opcode->mnemonic() ne "mov"); 245 $opcode->mnemonic("lea"); 246 } 247 $self->{base} =~ s/^%//; 248 $self->{index} =~ s/^%// if (defined($self->{index})); 249 $self->{opcode} = $opcode; 250 } 251 $ret; 252 } 253 sub size {} 254 sub out { 255 my ($self, $sz) = @_; 256 257 $self->{label} =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; 258 $self->{label} =~ s/\.L/$decor/g; 259 260 # Silently convert all EAs to 64-bit. This is required for 261 # elder GNU assembler and results in more compact code, 262 # *but* most importantly AES module depends on this feature! 263 $self->{index} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/; 264 $self->{base} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/; 265 266 # Solaris /usr/ccs/bin/as can't handle multiplications 267 # in $self->{label}... 268 use integer; 269 $self->{label} =~ s/(?<![\w\$\.])(0x?[0-9a-f]+)/oct($1)/egi; 270 $self->{label} =~ s/\b([0-9]+\s*[\*\/\%]\s*[0-9]+)\b/eval($1)/eg; 271 272 # Some assemblers insist on signed presentation of 32-bit 273 # offsets, but sign extension is a tricky business in perl... 274 if ((1<<31)<<1) { 275 $self->{label} =~ s/\b([0-9]+)\b/$1<<32>>32/eg; 276 } else { 277 $self->{label} =~ s/\b([0-9]+)\b/$1>>0/eg; 278 } 279 280 # if base register is %rbp or %r13, see if it's possible to 281 # flip base and index registers [for better performance] 282 if (!$self->{label} && $self->{index} && $self->{scale}==1 && 283 $self->{base} =~ /(rbp|r13)/) { 284 $self->{base} = $self->{index}; $self->{index} = $1; 285 } 286 287 if ($gas) { 288 $self->{label} =~ s/^___imp_/__imp__/ if ($flavour eq "mingw64"); 289 290 if (defined($self->{index})) { 291 sprintf "%s%s(%s,%%%s,%d)%s", 292 $self->{asterisk},$self->{label}, 293 $self->{base}?"%$self->{base}":"", 294 $self->{index},$self->{scale}, 295 $self->{opmask}; 296 } else { 297 sprintf "%s%s(%%%s)%s", $self->{asterisk},$self->{label}, 298 $self->{base},$self->{opmask}; 299 } 300 } else { 301 $self->{label} =~ s/\./\$/g; 302 $self->{label} =~ s/(?<![\w\$\.])0x([0-9a-f]+)/0$1h/ig; 303 $self->{label} = "($self->{label})" if ($self->{label} =~ /[\*\+\-\/]/); 304 305 my $mnemonic = $self->{opcode}->mnemonic(); 306 ($self->{asterisk}) && ($sz="q") || 307 ($mnemonic =~ /^v?mov([qd])$/) && ($sz=$1) || 308 ($mnemonic =~ /^v?pinsr([qdwb])$/) && ($sz=$1) || 309 ($mnemonic =~ /^vpbroadcast([qdwb])$/) && ($sz=$1) || 310 ($mnemonic =~ /^v(?!perm)[a-z]+[fi]128$/) && ($sz="x"); 311 312 $self->{opmask} =~ s/%(k[0-7])/$1/; 313 314 if (defined($self->{index})) { 315 sprintf "%s[%s%s*%d%s]%s",$szmap{$sz}, 316 $self->{label}?"$self->{label}+":"", 317 $self->{index},$self->{scale}, 318 $self->{base}?"+$self->{base}":"", 319 $self->{opmask}; 320 } elsif ($self->{base} eq "rip") { 321 sprintf "%s[%s]",$szmap{$sz},$self->{label}; 322 } else { 323 sprintf "%s[%s%s]%s", $szmap{$sz}, 324 $self->{label}?"$self->{label}+":"", 325 $self->{base},$self->{opmask}; 326 } 327 } 328 } 329} 330{ package register; # pick up registers, which start with %. 331 sub re { 332 my ($class, $line, $opcode) = @_; 333 my $self = {}; 334 my $ret; 335 336 # optional * ----vvv--- appears in indirect jmp/call 337 if ($$line =~ /^(\*?)%(\w+)((?:{[^}]+})*)/) { 338 bless $self,$class; 339 $self->{asterisk} = $1; 340 $self->{value} = $2; 341 $self->{opmask} = $3; 342 $opcode->size($self->size()); 343 $ret = $self; 344 $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; 345 } 346 $ret; 347 } 348 sub size { 349 my $self = shift; 350 my $ret; 351 352 if ($self->{value} =~ /^r[\d]+b$/i) { $ret="b"; } 353 elsif ($self->{value} =~ /^r[\d]+w$/i) { $ret="w"; } 354 elsif ($self->{value} =~ /^r[\d]+d$/i) { $ret="l"; } 355 elsif ($self->{value} =~ /^r[\w]+$/i) { $ret="q"; } 356 elsif ($self->{value} =~ /^[a-d][hl]$/i){ $ret="b"; } 357 elsif ($self->{value} =~ /^[\w]{2}l$/i) { $ret="b"; } 358 elsif ($self->{value} =~ /^[\w]{2}$/i) { $ret="w"; } 359 elsif ($self->{value} =~ /^e[a-z]{2}$/i){ $ret="l"; } 360 361 $ret; 362 } 363 sub out { 364 my $self = shift; 365 if ($gas) { sprintf "%s%%%s%s", $self->{asterisk}, 366 $self->{value}, 367 $self->{opmask}; } 368 else { $self->{opmask} =~ s/%(k[0-7])/$1/; 369 $self->{value}.$self->{opmask}; } 370 } 371} 372{ package label; # pick up labels, which end with : 373 sub re { 374 my ($class, $line) = @_; 375 my $self = {}; 376 my $ret; 377 378 if ($$line =~ /(^[\.\w]+)\:/) { 379 bless $self,$class; 380 $self->{value} = $1; 381 $ret = $self; 382 $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; 383 384 $self->{value} =~ s/^\.L/$decor/; 385 } 386 $ret; 387 } 388 sub out { 389 my $self = shift; 390 391 if ($gas) { 392 my $func = ($globals{$self->{value}} or $self->{value}) . ":"; 393 if ($win64 && $current_function->{name} eq $self->{value} 394 && $current_function->{abi} eq "svr4") { 395 $func .= "\n"; 396 $func .= " movq %rdi,8(%rsp)\n"; 397 $func .= " movq %rsi,16(%rsp)\n"; 398 $func .= " movq %rsp,%rax\n"; 399 $func .= "${decor}SEH_begin_$current_function->{name}:\n"; 400 my $narg = $current_function->{narg}; 401 $narg=6 if (!defined($narg)); 402 $func .= " movq %rcx,%rdi\n" if ($narg>0); 403 $func .= " movq %rdx,%rsi\n" if ($narg>1); 404 $func .= " movq %r8,%rdx\n" if ($narg>2); 405 $func .= " movq %r9,%rcx\n" if ($narg>3); 406 $func .= " movq 40(%rsp),%r8\n" if ($narg>4); 407 $func .= " movq 48(%rsp),%r9\n" if ($narg>5); 408 } 409 $func; 410 } elsif ($self->{value} ne "$current_function->{name}") { 411 # Make all labels in masm global. 412 $self->{value} .= ":" if ($masm); 413 $self->{value} . ":"; 414 } elsif ($win64 && $current_function->{abi} eq "svr4") { 415 my $func = "$current_function->{name}" . 416 ($nasm ? ":" : "\tPROC $current_function->{scope}") . 417 "\n"; 418 $func .= " mov QWORD$PTR\[8+rsp\],rdi\t;WIN64 prologue\n"; 419 $func .= " mov QWORD$PTR\[16+rsp\],rsi\n"; 420 $func .= " mov rax,rsp\n"; 421 $func .= "${decor}SEH_begin_$current_function->{name}:"; 422 $func .= ":" if ($masm); 423 $func .= "\n"; 424 my $narg = $current_function->{narg}; 425 $narg=6 if (!defined($narg)); 426 $func .= " mov rdi,rcx\n" if ($narg>0); 427 $func .= " mov rsi,rdx\n" if ($narg>1); 428 $func .= " mov rdx,r8\n" if ($narg>2); 429 $func .= " mov rcx,r9\n" if ($narg>3); 430 $func .= " mov r8,QWORD$PTR\[40+rsp\]\n" if ($narg>4); 431 $func .= " mov r9,QWORD$PTR\[48+rsp\]\n" if ($narg>5); 432 $func .= "\n"; 433 } else { 434 "$current_function->{name}". 435 ($nasm ? ":" : "\tPROC $current_function->{scope}"); 436 } 437 } 438} 439{ package expr; # pick up expressions 440 sub re { 441 my ($class, $line, $opcode) = @_; 442 my $self = {}; 443 my $ret; 444 445 if ($$line =~ /(^[^,]+)/) { 446 bless $self,$class; 447 $self->{value} = $1; 448 $ret = $self; 449 $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; 450 451 $self->{value} =~ s/\@PLT// if (!$elf); 452 $self->{value} =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; 453 $self->{value} =~ s/\.L/$decor/g; 454 $self->{opcode} = $opcode; 455 } 456 $ret; 457 } 458 sub out { 459 my $self = shift; 460 if ($nasm && $self->{opcode}->mnemonic()=~m/^j(?![re]cxz)/) { 461 "NEAR ".$self->{value}; 462 } else { 463 $self->{value}; 464 } 465 } 466} 467{ package cfi_directive; 468 # CFI directives annotate instructions that are significant for 469 # stack unwinding procedure compliant with DWARF specification, 470 # see http://dwarfstd.org/. Besides naturally expected for this 471 # script platform-specific filtering function, this module adds 472 # three auxiliary synthetic directives not recognized by [GNU] 473 # assembler: 474 # 475 # - .cfi_push to annotate push instructions in prologue, which 476 # translates to .cfi_adjust_cfa_offset (if needed) and 477 # .cfi_offset; 478 # - .cfi_pop to annotate pop instructions in epilogue, which 479 # translates to .cfi_adjust_cfa_offset (if needed) and 480 # .cfi_restore; 481 # - [and most notably] .cfi_cfa_expression which encodes 482 # DW_CFA_def_cfa_expression and passes it to .cfi_escape as 483 # byte vector; 484 # 485 # CFA expressions were introduced in DWARF specification version 486 # 3 and describe how to deduce CFA, Canonical Frame Address. This 487 # becomes handy if your stack frame is variable and you can't 488 # spare register for [previous] frame pointer. Suggested directive 489 # syntax is made-up mix of DWARF operator suffixes [subset of] 490 # and references to registers with optional bias. Following example 491 # describes offloaded *original* stack pointer at specific offset 492 # from *current* stack pointer: 493 # 494 # .cfi_cfa_expression %rsp+40,deref,+8 495 # 496 # Final +8 has everything to do with the fact that CFA is defined 497 # as reference to top of caller's stack, and on x86_64 call to 498 # subroutine pushes 8-byte return address. In other words original 499 # stack pointer upon entry to a subroutine is 8 bytes off from CFA. 500 501 # Below constants are taken from "DWARF Expressions" section of the 502 # DWARF specification, section is numbered 7.7 in versions 3 and 4. 503 my %DW_OP_simple = ( # no-arg operators, mapped directly 504 deref => 0x06, dup => 0x12, 505 drop => 0x13, over => 0x14, 506 pick => 0x15, swap => 0x16, 507 rot => 0x17, xderef => 0x18, 508 509 abs => 0x19, and => 0x1a, 510 div => 0x1b, minus => 0x1c, 511 mod => 0x1d, mul => 0x1e, 512 neg => 0x1f, not => 0x20, 513 or => 0x21, plus => 0x22, 514 shl => 0x24, shr => 0x25, 515 shra => 0x26, xor => 0x27, 516 ); 517 518 my %DW_OP_complex = ( # used in specific subroutines 519 constu => 0x10, # uleb128 520 consts => 0x11, # sleb128 521 plus_uconst => 0x23, # uleb128 522 lit0 => 0x30, # add 0-31 to opcode 523 reg0 => 0x50, # add 0-31 to opcode 524 breg0 => 0x70, # add 0-31 to opcole, sleb128 525 regx => 0x90, # uleb28 526 fbreg => 0x91, # sleb128 527 bregx => 0x92, # uleb128, sleb128 528 piece => 0x93, # uleb128 529 ); 530 531 # Following constants are defined in x86_64 ABI supplement, for 532 # example available at https://www.uclibc.org/docs/psABI-x86_64.pdf, 533 # see section 3.7 "Stack Unwind Algorithm". 534 my %DW_reg_idx = ( 535 "%rax"=>0, "%rdx"=>1, "%rcx"=>2, "%rbx"=>3, 536 "%rsi"=>4, "%rdi"=>5, "%rbp"=>6, "%rsp"=>7, 537 "%r8" =>8, "%r9" =>9, "%r10"=>10, "%r11"=>11, 538 "%r12"=>12, "%r13"=>13, "%r14"=>14, "%r15"=>15 539 ); 540 541 my ($cfa_reg, $cfa_rsp); 542 my @cfa_stack; 543 544 # [us]leb128 format is variable-length integer representation base 545 # 2^128, with most significant bit of each byte being 0 denoting 546 # *last* most significant digit. See "Variable Length Data" in the 547 # DWARF specification, numbered 7.6 at least in versions 3 and 4. 548 sub sleb128 { 549 use integer; # get right shift extend sign 550 551 my $val = shift; 552 my $sign = ($val < 0) ? -1 : 0; 553 my @ret = (); 554 555 while(1) { 556 push @ret, $val&0x7f; 557 558 # see if remaining bits are same and equal to most 559 # significant bit of the current digit, if so, it's 560 # last digit... 561 last if (($val>>6) == $sign); 562 563 @ret[-1] |= 0x80; 564 $val >>= 7; 565 } 566 567 return @ret; 568 } 569 sub uleb128 { 570 my $val = shift; 571 my @ret = (); 572 573 while(1) { 574 push @ret, $val&0x7f; 575 576 # see if it's last significant digit... 577 last if (($val >>= 7) == 0); 578 579 @ret[-1] |= 0x80; 580 } 581 582 return @ret; 583 } 584 sub const { 585 my $val = shift; 586 587 if ($val >= 0 && $val < 32) { 588 return ($DW_OP_complex{lit0}+$val); 589 } 590 return ($DW_OP_complex{consts}, sleb128($val)); 591 } 592 sub reg { 593 my $val = shift; 594 595 return if ($val !~ m/^(%r\w+)(?:([\+\-])((?:0x)?[0-9a-f]+))?/); 596 597 my $reg = $DW_reg_idx{$1}; 598 my $off = eval ("0 $2 $3"); 599 600 return (($DW_OP_complex{breg0} + $reg), sleb128($off)); 601 # Yes, we use DW_OP_bregX+0 to push register value and not 602 # DW_OP_regX, because latter would require even DW_OP_piece, 603 # which would be a waste under the circumstances. If you have 604 # to use DWP_OP_reg, use "regx:N"... 605 } 606 sub cfa_expression { 607 my $line = shift; 608 my @ret; 609 610 foreach my $token (split(/,\s*/,$line)) { 611 if ($token =~ /^%r/) { 612 push @ret,reg($token); 613 } elsif ($token =~ /((?:0x)?[0-9a-f]+)\((%r\w+)\)/) { 614 push @ret,reg("$2+$1"); 615 } elsif ($token =~ /(\w+):(\-?(?:0x)?[0-9a-f]+)(U?)/i) { 616 my $i = 1*eval($2); 617 push @ret,$DW_OP_complex{$1}, ($3 ? uleb128($i) : sleb128($i)); 618 } elsif (my $i = 1*eval($token) or $token eq "0") { 619 if ($token =~ /^\+/) { 620 push @ret,$DW_OP_complex{plus_uconst},uleb128($i); 621 } else { 622 push @ret,const($i); 623 } 624 } else { 625 push @ret,$DW_OP_simple{$token}; 626 } 627 } 628 629 # Finally we return DW_CFA_def_cfa_expression, 15, followed by 630 # length of the expression and of course the expression itself. 631 return (15,scalar(@ret),@ret); 632 } 633 sub re { 634 my ($class, $line) = @_; 635 my $self = {}; 636 my $ret; 637 638 if ($$line =~ s/^\s*\.cfi_(\w+)\s*//) { 639 bless $self,$class; 640 $ret = $self; 641 undef $self->{value}; 642 my $dir = $1; 643 644 SWITCH: for ($dir) { 645 # What is $cfa_rsp? Effectively it's difference between %rsp 646 # value and current CFA, Canonical Frame Address, which is 647 # why it starts with -8. Recall that CFA is top of caller's 648 # stack... 649 /startproc/ && do { ($cfa_reg, $cfa_rsp) = ("%rsp", -8); last; }; 650 /endproc/ && do { ($cfa_reg, $cfa_rsp) = ("%rsp", 0); last; }; 651 /def_cfa_register/ 652 && do { $cfa_reg = $$line; last; }; 653 /def_cfa_offset/ 654 && do { $cfa_rsp = -1*eval($$line) if ($cfa_reg eq "%rsp"); 655 last; 656 }; 657 /adjust_cfa_offset/ 658 && do { $cfa_rsp -= 1*eval($$line) if ($cfa_reg eq "%rsp"); 659 last; 660 }; 661 /def_cfa/ && do { if ($$line =~ /(%r\w+)\s*,\s*(.+)/) { 662 $cfa_reg = $1; 663 $cfa_rsp = -1*eval($2) if ($cfa_reg eq "%rsp"); 664 } 665 last; 666 }; 667 /push/ && do { $dir = undef; 668 $cfa_rsp -= 8; 669 if ($cfa_reg eq "%rsp") { 670 $self->{value} = ".cfi_adjust_cfa_offset\t8\n"; 671 } 672 $self->{value} .= ".cfi_offset\t$$line,$cfa_rsp"; 673 last; 674 }; 675 /pop/ && do { $dir = undef; 676 $cfa_rsp += 8; 677 if ($cfa_reg eq "%rsp") { 678 $self->{value} = ".cfi_adjust_cfa_offset\t-8\n"; 679 } 680 $self->{value} .= ".cfi_restore\t$$line"; 681 last; 682 }; 683 /cfa_expression/ 684 && do { $dir = undef; 685 $self->{value} = ".cfi_escape\t" . 686 join(",", map(sprintf("0x%02x", $_), 687 cfa_expression($$line))); 688 last; 689 }; 690 /remember_state/ 691 && do { push @cfa_stack, [$cfa_reg, $cfa_rsp]; 692 last; 693 }; 694 /restore_state/ 695 && do { ($cfa_reg, $cfa_rsp) = @{pop @cfa_stack}; 696 last; 697 }; 698 } 699 700 $self->{value} = ".cfi_$dir\t$$line" if ($dir); 701 702 $$line = ""; 703 } 704 705 return $ret; 706 } 707 sub out { 708 my $self = shift; 709 return ($elf ? $self->{value} : undef); 710 } 711} 712{ package directive; # pick up directives, which start with . 713 sub re { 714 my ($class, $line) = @_; 715 my $self = {}; 716 my $ret; 717 my $dir; 718 719 # chain-call to cfi_directive 720 $ret = cfi_directive->re($line) and return $ret; 721 722 if ($$line =~ /^\s*(\.\w+)/) { 723 bless $self,$class; 724 $dir = $1; 725 $ret = $self; 726 undef $self->{value}; 727 $$line = substr($$line,@+[0]); $$line =~ s/^\s+//; 728 729 SWITCH: for ($dir) { 730 /\.global|\.globl|\.extern/ 731 && do { $globals{$$line} = $prefix . $$line; 732 $$line = $globals{$$line} if ($prefix); 733 last; 734 }; 735 /\.type/ && do { my ($sym,$type,$narg) = split(/\s*,\s*/,$$line); 736 if ($type eq "\@function") { 737 undef $current_function; 738 $current_function->{name} = $sym; 739 $current_function->{abi} = "svr4"; 740 $current_function->{narg} = $narg; 741 $current_function->{scope} = defined($globals{$sym})?"PUBLIC":"PRIVATE"; 742 } elsif ($type eq "\@abi-omnipotent") { 743 undef $current_function; 744 $current_function->{name} = $sym; 745 $current_function->{scope} = defined($globals{$sym})?"PUBLIC":"PRIVATE"; 746 } 747 $$line =~ s/\@abi\-omnipotent/\@function/; 748 $$line =~ s/\@function.*/\@function/; 749 last; 750 }; 751 /\.asciz/ && do { if ($$line =~ /^"(.*)"$/) { 752 $dir = ".byte"; 753 $$line = join(",",unpack("C*",$1),0); 754 } 755 last; 756 }; 757 /\.rva|\.long|\.quad|\.byte/ 758 && do { $$line =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; 759 $$line =~ s/\.L/$decor/g; 760 last; 761 }; 762 } 763 764 if ($gas) { 765 $self->{value} = $dir . "\t" . $$line; 766 767 if ($dir =~ /\.extern/) { 768 if ($flavour eq "elf") { 769 $self->{value} .= "\n.hidden $$line"; 770 } else { 771 $self->{value} = ""; 772 } 773 } elsif (!$elf && $dir =~ /\.type/) { 774 $self->{value} = ""; 775 $self->{value} = ".def\t" . ($globals{$1} or $1) . ";\t" . 776 (defined($globals{$1})?".scl 2;":".scl 3;") . 777 "\t.type 32;\t.endef" 778 if ($win64 && $$line =~ /([^,]+),\@function/); 779 } elsif (!$elf && $dir =~ /\.size/) { 780 $self->{value} = ""; 781 if (defined($current_function)) { 782 $self->{value} .= "${decor}SEH_end_$current_function->{name}:" 783 if ($win64 && $current_function->{abi} eq "svr4"); 784 undef $current_function; 785 } 786 } elsif (!$elf && $dir =~ /\.align/) { 787 $self->{value} = ".p2align\t" . (log($$line)/log(2)); 788 } elsif ($dir eq ".section") { 789 $current_segment=$$line; 790 if (!$elf && $current_segment eq ".init") { 791 if ($flavour eq "macosx") { $self->{value} = ".mod_init_func"; } 792 elsif ($flavour eq "mingw64") { $self->{value} = ".section\t.ctors"; } 793 } 794 } elsif ($dir =~ /\.(text|data)/) { 795 $current_segment=".$1"; 796 } elsif ($dir =~ /\.global|\.globl|\.extern/) { 797 if ($flavour eq "macosx") { 798 $self->{value} .= "\n.private_extern $$line"; 799 } else { 800 $self->{value} .= "\n.hidden $$line"; 801 } 802 } elsif ($dir =~ /\.hidden/) { 803 if ($flavour eq "macosx") { $self->{value} = ".private_extern\t$prefix$$line"; } 804 elsif ($flavour eq "mingw64") { $self->{value} = ""; } 805 } elsif ($dir =~ /\.comm/) { 806 $self->{value} = "$dir\t$prefix$$line"; 807 $self->{value} =~ s|,([0-9]+),([0-9]+)$|",$1,".log($2)/log(2)|e if ($flavour eq "macosx"); 808 } 809 $$line = ""; 810 return $self; 811 } 812 813 # non-gas case or nasm/masm 814 SWITCH: for ($dir) { 815 /\.text/ && do { my $v=undef; 816 if ($nasm) { 817 $v="section .text code align=64\n"; 818 } else { 819 $v="$current_segment\tENDS\n" if ($current_segment); 820 $current_segment = ".text\$"; 821 $v.="$current_segment\tSEGMENT "; 822 $v.=$masm>=$masmref ? "ALIGN(256)" : "PAGE"; 823 $v.=" 'CODE'"; 824 } 825 $self->{value} = $v; 826 last; 827 }; 828 /\.data/ && do { my $v=undef; 829 if ($nasm) { 830 $v="section .data data align=8\n"; 831 } else { 832 $v="$current_segment\tENDS\n" if ($current_segment); 833 $current_segment = "_DATA"; 834 $v.="$current_segment\tSEGMENT"; 835 } 836 $self->{value} = $v; 837 last; 838 }; 839 /\.section/ && do { my $v=undef; 840 $$line =~ s/([^,]*).*/$1/; 841 $$line = ".CRT\$XCU" if ($$line eq ".init"); 842 if ($nasm) { 843 $v="section $$line"; 844 if ($$line=~/\.([px])data/) { 845 $v.=" rdata align="; 846 $v.=$1 eq "p"? 4 : 8; 847 } elsif ($$line=~/\.CRT\$/i) { 848 $v.=" rdata align=8"; 849 } 850 } else { 851 $v="$current_segment\tENDS\n" if ($current_segment); 852 $v.="$$line\tSEGMENT"; 853 if ($$line=~/\.([px])data/) { 854 $v.=" READONLY"; 855 $v.=" ALIGN(".($1 eq "p" ? 4 : 8).")" if ($masm>=$masmref); 856 } elsif ($$line=~/\.CRT\$/i) { 857 $v.=" READONLY "; 858 $v.=$masm>=$masmref ? "ALIGN(8)" : "DWORD"; 859 } 860 } 861 $current_segment = $$line; 862 $self->{value} = $v; 863 last; 864 }; 865 /\.extern/ && do { $self->{value} = "EXTERN\t".$$line; 866 $self->{value} .= ":NEAR" if ($masm); 867 last; 868 }; 869 /\.globl|.global/ 870 && do { $self->{value} = $masm?"PUBLIC":"global"; 871 $self->{value} .= "\t".$$line; 872 last; 873 }; 874 /\.size/ && do { if (defined($current_function)) { 875 undef $self->{value}; 876 if ($current_function->{abi} eq "svr4") { 877 $self->{value}="${decor}SEH_end_$current_function->{name}:"; 878 $self->{value}.=":\n" if($masm); 879 } 880 $self->{value}.="$current_function->{name}\tENDP" if($masm && $current_function->{name}); 881 undef $current_function; 882 } 883 last; 884 }; 885 /\.align/ && do { my $max = ($masm && $masm>=$masmref) ? 256 : 4096; 886 $self->{value} = "ALIGN\t".($$line>$max?$max:$$line); 887 last; 888 }; 889 /\.(value|long|rva|quad)/ 890 && do { my $sz = substr($1,0,1); 891 my @arr = split(/,\s*/,$$line); 892 my $last = pop(@arr); 893 my $conv = sub { my $var=shift; 894 $var=~s/^(0b[0-1]+)/oct($1)/eig; 895 $var=~s/^0x([0-9a-f]+)/0$1h/ig if ($masm); 896 if ($sz eq "D" && ($current_segment=~/.[px]data/ || $dir eq ".rva")) 897 { $var=~s/^([_a-z\$\@][_a-z0-9\$\@]*)/$nasm?"$1 wrt ..imagebase":"imagerel $1"/egi; } 898 $var; 899 }; 900 901 $sz =~ tr/bvlrq/BWDDQ/; 902 $self->{value} = "\tD$sz\t"; 903 for (@arr) { $self->{value} .= &$conv($_).","; } 904 $self->{value} .= &$conv($last); 905 last; 906 }; 907 /\.byte/ && do { my @str=split(/,\s*/,$$line); 908 map(s/(0b[0-1]+)/oct($1)/eig,@str); 909 map(s/0x([0-9a-f]+)/0$1h/ig,@str) if ($masm); 910 while ($#str>15) { 911 $self->{value}.="DB\t" 912 .join(",",@str[0..15])."\n"; 913 foreach (0..15) { shift @str; } 914 } 915 $self->{value}.="DB\t" 916 .join(",",@str) if (@str); 917 last; 918 }; 919 /\.comm/ && do { my @str=split(/,\s*/,$$line); 920 my $v=undef; 921 if ($nasm) { 922 $v.="common $prefix@str[0] @str[1]"; 923 } else { 924 $v="$current_segment\tENDS\n" if ($current_segment); 925 $current_segment = "_DATA"; 926 $v.="$current_segment\tSEGMENT\n"; 927 $v.="COMM @str[0]:DWORD:".@str[1]/4; 928 } 929 $self->{value} = $v; 930 last; 931 }; 932 } 933 $$line = ""; 934 } 935 936 $ret; 937 } 938 sub out { 939 my $self = shift; 940 $self->{value}; 941 } 942} 943 944# Upon initial x86_64 introduction SSE>2 extensions were not introduced 945# yet. In order not to be bothered by tracing exact assembler versions, 946# but at the same time to provide a bare security minimum of AES-NI, we 947# hard-code some instructions. Extensions past AES-NI on the other hand 948# are traced by examining assembler version in individual perlasm 949# modules... 950 951my %regrm = ( "%eax"=>0, "%ecx"=>1, "%edx"=>2, "%ebx"=>3, 952 "%esp"=>4, "%ebp"=>5, "%esi"=>6, "%edi"=>7 ); 953 954sub rex { 955 my $opcode=shift; 956 my ($dst,$src,$rex)=@_; 957 958 $rex|=0x04 if($dst>=8); 959 $rex|=0x01 if($src>=8); 960 push @$opcode,($rex|0x40) if ($rex); 961} 962 963my $movq = sub { # elderly gas can't handle inter-register movq 964 my $arg = shift; 965 my @opcode=(0x66); 966 if ($arg =~ /%xmm([0-9]+),\s*%r(\w+)/) { 967 my ($src,$dst)=($1,$2); 968 if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } 969 rex(\@opcode,$src,$dst,0x8); 970 push @opcode,0x0f,0x7e; 971 push @opcode,0xc0|(($src&7)<<3)|($dst&7); # ModR/M 972 @opcode; 973 } elsif ($arg =~ /%r(\w+),\s*%xmm([0-9]+)/) { 974 my ($src,$dst)=($2,$1); 975 if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } 976 rex(\@opcode,$src,$dst,0x8); 977 push @opcode,0x0f,0x6e; 978 push @opcode,0xc0|(($src&7)<<3)|($dst&7); # ModR/M 979 @opcode; 980 } else { 981 (); 982 } 983}; 984 985my $pextrd = sub { 986 if (shift =~ /\$([0-9]+),\s*%xmm([0-9]+),\s*(%\w+)/) { 987 my @opcode=(0x66); 988 my $imm=$1; 989 my $src=$2; 990 my $dst=$3; 991 if ($dst =~ /%r([0-9]+)d/) { $dst = $1; } 992 elsif ($dst =~ /%e/) { $dst = $regrm{$dst}; } 993 rex(\@opcode,$src,$dst); 994 push @opcode,0x0f,0x3a,0x16; 995 push @opcode,0xc0|(($src&7)<<3)|($dst&7); # ModR/M 996 push @opcode,$imm; 997 @opcode; 998 } else { 999 (); 1000 } 1001}; 1002 1003my $pinsrd = sub { 1004 if (shift =~ /\$([0-9]+),\s*(%\w+),\s*%xmm([0-9]+)/) { 1005 my @opcode=(0x66); 1006 my $imm=$1; 1007 my $src=$2; 1008 my $dst=$3; 1009 if ($src =~ /%r([0-9]+)/) { $src = $1; } 1010 elsif ($src =~ /%e/) { $src = $regrm{$src}; } 1011 rex(\@opcode,$dst,$src); 1012 push @opcode,0x0f,0x3a,0x22; 1013 push @opcode,0xc0|(($dst&7)<<3)|($src&7); # ModR/M 1014 push @opcode,$imm; 1015 @opcode; 1016 } else { 1017 (); 1018 } 1019}; 1020 1021my $pshufb = sub { 1022 if (shift =~ /%xmm([0-9]+),\s*%xmm([0-9]+)/) { 1023 my @opcode=(0x66); 1024 rex(\@opcode,$2,$1); 1025 push @opcode,0x0f,0x38,0x00; 1026 push @opcode,0xc0|($1&7)|(($2&7)<<3); # ModR/M 1027 @opcode; 1028 } else { 1029 (); 1030 } 1031}; 1032 1033my $palignr = sub { 1034 if (shift =~ /\$([0-9]+),\s*%xmm([0-9]+),\s*%xmm([0-9]+)/) { 1035 my @opcode=(0x66); 1036 rex(\@opcode,$3,$2); 1037 push @opcode,0x0f,0x3a,0x0f; 1038 push @opcode,0xc0|($2&7)|(($3&7)<<3); # ModR/M 1039 push @opcode,$1; 1040 @opcode; 1041 } else { 1042 (); 1043 } 1044}; 1045 1046my $pclmulqdq = sub { 1047 if (shift =~ /\$([x0-9a-f]+),\s*%xmm([0-9]+),\s*%xmm([0-9]+)/) { 1048 my @opcode=(0x66); 1049 rex(\@opcode,$3,$2); 1050 push @opcode,0x0f,0x3a,0x44; 1051 push @opcode,0xc0|($2&7)|(($3&7)<<3); # ModR/M 1052 my $c=$1; 1053 push @opcode,$c=~/^0/?oct($c):$c; 1054 @opcode; 1055 } else { 1056 (); 1057 } 1058}; 1059 1060my $rdrand = sub { 1061 if (shift =~ /%[er](\w+)/) { 1062 my @opcode=(); 1063 my $dst=$1; 1064 if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } 1065 rex(\@opcode,0,$dst,8); 1066 push @opcode,0x0f,0xc7,0xf0|($dst&7); 1067 @opcode; 1068 } else { 1069 (); 1070 } 1071}; 1072 1073my $rdseed = sub { 1074 if (shift =~ /%[er](\w+)/) { 1075 my @opcode=(); 1076 my $dst=$1; 1077 if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } 1078 rex(\@opcode,0,$dst,8); 1079 push @opcode,0x0f,0xc7,0xf8|($dst&7); 1080 @opcode; 1081 } else { 1082 (); 1083 } 1084}; 1085 1086# Not all AVX-capable assemblers recognize AMD XOP extension. Since we 1087# are using only two instructions hand-code them in order to be excused 1088# from chasing assembler versions... 1089 1090sub rxb { 1091 my $opcode=shift; 1092 my ($dst,$src1,$src2,$rxb)=@_; 1093 1094 $rxb|=0x7<<5; 1095 $rxb&=~(0x04<<5) if($dst>=8); 1096 $rxb&=~(0x01<<5) if($src1>=8); 1097 $rxb&=~(0x02<<5) if($src2>=8); 1098 push @$opcode,$rxb; 1099} 1100 1101my $vprotd = sub { 1102 if (shift =~ /\$([x0-9a-f]+),\s*%xmm([0-9]+),\s*%xmm([0-9]+)/) { 1103 my @opcode=(0x8f); 1104 rxb(\@opcode,$3,$2,-1,0x08); 1105 push @opcode,0x78,0xc2; 1106 push @opcode,0xc0|($2&7)|(($3&7)<<3); # ModR/M 1107 my $c=$1; 1108 push @opcode,$c=~/^0/?oct($c):$c; 1109 @opcode; 1110 } else { 1111 (); 1112 } 1113}; 1114 1115my $vprotq = sub { 1116 if (shift =~ /\$([x0-9a-f]+),\s*%xmm([0-9]+),\s*%xmm([0-9]+)/) { 1117 my @opcode=(0x8f); 1118 rxb(\@opcode,$3,$2,-1,0x08); 1119 push @opcode,0x78,0xc3; 1120 push @opcode,0xc0|($2&7)|(($3&7)<<3); # ModR/M 1121 my $c=$1; 1122 push @opcode,$c=~/^0/?oct($c):$c; 1123 @opcode; 1124 } else { 1125 (); 1126 } 1127}; 1128 1129# Intel Control-flow Enforcement Technology extension. All functions and 1130# indirect branch targets will have to start with this instruction... 1131 1132my $endbranch = sub { 1133 (0xf3,0x0f,0x1e,0xfa); 1134}; 1135 1136######################################################################## 1137 1138{ 1139 my $comment = "#"; 1140 $comment = ";" if ($masm || $nasm); 1141 print <<___; 1142$comment This file is generated from a similarly-named Perl script in the BoringSSL 1143$comment source tree. Do not edit by hand. 1144 1145___ 1146} 1147 1148if ($nasm) { 1149 print <<___; 1150default rel 1151%define XMMWORD 1152%define YMMWORD 1153%define ZMMWORD 1154 1155%ifdef BORINGSSL_PREFIX 1156%include "boringssl_prefix_symbols_nasm.inc" 1157%endif 1158___ 1159} elsif ($masm) { 1160 print <<___; 1161OPTION DOTNAME 1162___ 1163} 1164 1165if ($gas) { 1166 print <<___; 1167#if defined(__has_feature) 1168#if __has_feature(memory_sanitizer) && !defined(OPENSSL_NO_ASM) 1169#define OPENSSL_NO_ASM 1170#endif 1171#endif 1172 1173#if defined(__x86_64__) && !defined(OPENSSL_NO_ASM) 1174#if defined(BORINGSSL_PREFIX) 1175#include <boringssl_prefix_symbols_asm.h> 1176#endif 1177___ 1178} 1179 1180while(defined(my $line=<>)) { 1181 1182 $line =~ s|\R$||; # Better chomp 1183 1184 if ($nasm) { 1185 $line =~ s|^#ifdef |%ifdef |; 1186 $line =~ s|^#ifndef |%ifndef |; 1187 $line =~ s|^#endif|%endif|; 1188 $line =~ s|[#!].*$||; # get rid of asm-style comments... 1189 } else { 1190 # Get rid of asm-style comments but not preprocessor directives. The 1191 # former are identified by having a letter after the '#' and starting in 1192 # the first column. 1193 $line =~ s|!.*$||; 1194 $line =~ s|(?<=.)#.*$||; 1195 $line =~ s|^#([^a-z].*)?$||; 1196 } 1197 1198 $line =~ s|/\*.*\*/||; # ... and C-style comments... 1199 $line =~ s|^\s+||; # ... and skip white spaces in beginning 1200 $line =~ s|\s+$||; # ... and at the end 1201 1202 if (my $label=label->re(\$line)) { print $label->out(); } 1203 1204 if (my $directive=directive->re(\$line)) { 1205 printf "%s",$directive->out(); 1206 } elsif (my $opcode=opcode->re(\$line)) { 1207 my $asm = eval("\$".$opcode->mnemonic()); 1208 1209 if ((ref($asm) eq 'CODE') && scalar(my @bytes=&$asm($line))) { 1210 print $gas?".byte\t":"DB\t",join(',',@bytes),"\n"; 1211 next; 1212 } 1213 1214 my @args; 1215 ARGUMENT: while (1) { 1216 my $arg; 1217 1218 ($arg=register->re(\$line, $opcode))|| 1219 ($arg=const->re(\$line)) || 1220 ($arg=ea->re(\$line, $opcode)) || 1221 ($arg=expr->re(\$line, $opcode)) || 1222 last ARGUMENT; 1223 1224 push @args,$arg; 1225 1226 last ARGUMENT if ($line !~ /^,/); 1227 1228 $line =~ s/^,\s*//; 1229 } # ARGUMENT: 1230 1231 if ($#args>=0) { 1232 my $insn; 1233 my $sz=$opcode->size(); 1234 1235 if ($gas) { 1236 $insn = $opcode->out($#args>=1?$args[$#args]->size():$sz); 1237 @args = map($_->out($sz),@args); 1238 printf "\t%s\t%s",$insn,join(",",@args); 1239 } else { 1240 $insn = $opcode->out(); 1241 foreach (@args) { 1242 my $arg = $_->out(); 1243 # $insn.=$sz compensates for movq, pinsrw, ... 1244 if ($arg =~ /^xmm[0-9]+$/) { $insn.=$sz; $sz="x" if(!$sz); last; } 1245 if ($arg =~ /^ymm[0-9]+$/) { $insn.=$sz; $sz="y" if(!$sz); last; } 1246 if ($arg =~ /^zmm[0-9]+$/) { $insn.=$sz; $sz="z" if(!$sz); last; } 1247 if ($arg =~ /^mm[0-9]+$/) { $insn.=$sz; $sz="q" if(!$sz); last; } 1248 } 1249 @args = reverse(@args); 1250 undef $sz if ($nasm && $opcode->mnemonic() eq "lea"); 1251 printf "\t%s\t%s",$insn,join(",",map($_->out($sz),@args)); 1252 } 1253 } else { 1254 printf "\t%s",$opcode->out(); 1255 } 1256 } 1257 1258 print $line,"\n"; 1259} 1260 1261print "\n$current_segment\tENDS\n" if ($current_segment && $masm); 1262print "END\n" if ($masm); 1263print "#endif\n" if ($gas); 1264 1265 1266close STDOUT; 1267 1268 ################################################# 1269# Cross-reference x86_64 ABI "card" 1270# 1271# Unix Win64 1272# %rax * * 1273# %rbx - - 1274# %rcx #4 #1 1275# %rdx #3 #2 1276# %rsi #2 - 1277# %rdi #1 - 1278# %rbp - - 1279# %rsp - - 1280# %r8 #5 #3 1281# %r9 #6 #4 1282# %r10 * * 1283# %r11 * * 1284# %r12 - - 1285# %r13 - - 1286# %r14 - - 1287# %r15 - - 1288# 1289# (*) volatile register 1290# (-) preserved by callee 1291# (#) Nth argument, volatile 1292# 1293# In Unix terms top of stack is argument transfer area for arguments 1294# which could not be accommodated in registers. Or in other words 7th 1295# [integer] argument resides at 8(%rsp) upon function entry point. 1296# 128 bytes above %rsp constitute a "red zone" which is not touched 1297# by signal handlers and can be used as temporal storage without 1298# allocating a frame. 1299# 1300# In Win64 terms N*8 bytes on top of stack is argument transfer area, 1301# which belongs to/can be overwritten by callee. N is the number of 1302# arguments passed to callee, *but* not less than 4! This means that 1303# upon function entry point 5th argument resides at 40(%rsp), as well 1304# as that 32 bytes from 8(%rsp) can always be used as temporal 1305# storage [without allocating a frame]. One can actually argue that 1306# one can assume a "red zone" above stack pointer under Win64 as well. 1307# Point is that at apparently no occasion Windows kernel would alter 1308# the area above user stack pointer in true asynchronous manner... 1309# 1310# All the above means that if assembler programmer adheres to Unix 1311# register and stack layout, but disregards the "red zone" existence, 1312# it's possible to use following prologue and epilogue to "gear" from 1313# Unix to Win64 ABI in leaf functions with not more than 6 arguments. 1314# 1315# omnipotent_function: 1316# ifdef WIN64 1317# movq %rdi,8(%rsp) 1318# movq %rsi,16(%rsp) 1319# movq %rcx,%rdi ; if 1st argument is actually present 1320# movq %rdx,%rsi ; if 2nd argument is actually ... 1321# movq %r8,%rdx ; if 3rd argument is ... 1322# movq %r9,%rcx ; if 4th argument ... 1323# movq 40(%rsp),%r8 ; if 5th ... 1324# movq 48(%rsp),%r9 ; if 6th ... 1325# endif 1326# ... 1327# ifdef WIN64 1328# movq 8(%rsp),%rdi 1329# movq 16(%rsp),%rsi 1330# endif 1331# ret 1332# 1333 ################################################# 1334# Win64 SEH, Structured Exception Handling. 1335# 1336# Unlike on Unix systems(*) lack of Win64 stack unwinding information 1337# has undesired side-effect at run-time: if an exception is raised in 1338# assembler subroutine such as those in question (basically we're 1339# referring to segmentation violations caused by malformed input 1340# parameters), the application is briskly terminated without invoking 1341# any exception handlers, most notably without generating memory dump 1342# or any user notification whatsoever. This poses a problem. It's 1343# possible to address it by registering custom language-specific 1344# handler that would restore processor context to the state at 1345# subroutine entry point and return "exception is not handled, keep 1346# unwinding" code. Writing such handler can be a challenge... But it's 1347# doable, though requires certain coding convention. Consider following 1348# snippet: 1349# 1350# .type function,@function 1351# function: 1352# movq %rsp,%rax # copy rsp to volatile register 1353# pushq %r15 # save non-volatile registers 1354# pushq %rbx 1355# pushq %rbp 1356# movq %rsp,%r11 1357# subq %rdi,%r11 # prepare [variable] stack frame 1358# andq $-64,%r11 1359# movq %rax,0(%r11) # check for exceptions 1360# movq %r11,%rsp # allocate [variable] stack frame 1361# movq %rax,0(%rsp) # save original rsp value 1362# magic_point: 1363# ... 1364# movq 0(%rsp),%rcx # pull original rsp value 1365# movq -24(%rcx),%rbp # restore non-volatile registers 1366# movq -16(%rcx),%rbx 1367# movq -8(%rcx),%r15 1368# movq %rcx,%rsp # restore original rsp 1369# magic_epilogue: 1370# ret 1371# .size function,.-function 1372# 1373# The key is that up to magic_point copy of original rsp value remains 1374# in chosen volatile register and no non-volatile register, except for 1375# rsp, is modified. While past magic_point rsp remains constant till 1376# the very end of the function. In this case custom language-specific 1377# exception handler would look like this: 1378# 1379# EXCEPTION_DISPOSITION handler (EXCEPTION_RECORD *rec,ULONG64 frame, 1380# CONTEXT *context,DISPATCHER_CONTEXT *disp) 1381# { ULONG64 *rsp = (ULONG64 *)context->Rax; 1382# ULONG64 rip = context->Rip; 1383# 1384# if (rip >= magic_point) 1385# { rsp = (ULONG64 *)context->Rsp; 1386# if (rip < magic_epilogue) 1387# { rsp = (ULONG64 *)rsp[0]; 1388# context->Rbp = rsp[-3]; 1389# context->Rbx = rsp[-2]; 1390# context->R15 = rsp[-1]; 1391# } 1392# } 1393# context->Rsp = (ULONG64)rsp; 1394# context->Rdi = rsp[1]; 1395# context->Rsi = rsp[2]; 1396# 1397# memcpy (disp->ContextRecord,context,sizeof(CONTEXT)); 1398# RtlVirtualUnwind(UNW_FLAG_NHANDLER,disp->ImageBase, 1399# dips->ControlPc,disp->FunctionEntry,disp->ContextRecord, 1400# &disp->HandlerData,&disp->EstablisherFrame,NULL); 1401# return ExceptionContinueSearch; 1402# } 1403# 1404# It's appropriate to implement this handler in assembler, directly in 1405# function's module. In order to do that one has to know members' 1406# offsets in CONTEXT and DISPATCHER_CONTEXT structures and some constant 1407# values. Here they are: 1408# 1409# CONTEXT.Rax 120 1410# CONTEXT.Rcx 128 1411# CONTEXT.Rdx 136 1412# CONTEXT.Rbx 144 1413# CONTEXT.Rsp 152 1414# CONTEXT.Rbp 160 1415# CONTEXT.Rsi 168 1416# CONTEXT.Rdi 176 1417# CONTEXT.R8 184 1418# CONTEXT.R9 192 1419# CONTEXT.R10 200 1420# CONTEXT.R11 208 1421# CONTEXT.R12 216 1422# CONTEXT.R13 224 1423# CONTEXT.R14 232 1424# CONTEXT.R15 240 1425# CONTEXT.Rip 248 1426# CONTEXT.Xmm6 512 1427# sizeof(CONTEXT) 1232 1428# DISPATCHER_CONTEXT.ControlPc 0 1429# DISPATCHER_CONTEXT.ImageBase 8 1430# DISPATCHER_CONTEXT.FunctionEntry 16 1431# DISPATCHER_CONTEXT.EstablisherFrame 24 1432# DISPATCHER_CONTEXT.TargetIp 32 1433# DISPATCHER_CONTEXT.ContextRecord 40 1434# DISPATCHER_CONTEXT.LanguageHandler 48 1435# DISPATCHER_CONTEXT.HandlerData 56 1436# UNW_FLAG_NHANDLER 0 1437# ExceptionContinueSearch 1 1438# 1439# In order to tie the handler to the function one has to compose 1440# couple of structures: one for .xdata segment and one for .pdata. 1441# 1442# UNWIND_INFO structure for .xdata segment would be 1443# 1444# function_unwind_info: 1445# .byte 9,0,0,0 1446# .rva handler 1447# 1448# This structure designates exception handler for a function with 1449# zero-length prologue, no stack frame or frame register. 1450# 1451# To facilitate composing of .pdata structures, auto-generated "gear" 1452# prologue copies rsp value to rax and denotes next instruction with 1453# .LSEH_begin_{function_name} label. This essentially defines the SEH 1454# styling rule mentioned in the beginning. Position of this label is 1455# chosen in such manner that possible exceptions raised in the "gear" 1456# prologue would be accounted to caller and unwound from latter's frame. 1457# End of function is marked with respective .LSEH_end_{function_name} 1458# label. To summarize, .pdata segment would contain 1459# 1460# .rva .LSEH_begin_function 1461# .rva .LSEH_end_function 1462# .rva function_unwind_info 1463# 1464# Reference to function_unwind_info from .xdata segment is the anchor. 1465# In case you wonder why references are 32-bit .rvas and not 64-bit 1466# .quads. References put into these two segments are required to be 1467# *relative* to the base address of the current binary module, a.k.a. 1468# image base. No Win64 module, be it .exe or .dll, can be larger than 1469# 2GB and thus such relative references can be and are accommodated in 1470# 32 bits. 1471# 1472# Having reviewed the example function code, one can argue that "movq 1473# %rsp,%rax" above is redundant. It is not! Keep in mind that on Unix 1474# rax would contain an undefined value. If this "offends" you, use 1475# another register and refrain from modifying rax till magic_point is 1476# reached, i.e. as if it was a non-volatile register. If more registers 1477# are required prior [variable] frame setup is completed, note that 1478# nobody says that you can have only one "magic point." You can 1479# "liberate" non-volatile registers by denoting last stack off-load 1480# instruction and reflecting it in finer grade unwind logic in handler. 1481# After all, isn't it why it's called *language-specific* handler... 1482# 1483# SE handlers are also involved in unwinding stack when executable is 1484# profiled or debugged. Profiling implies additional limitations that 1485# are too subtle to discuss here. For now it's sufficient to say that 1486# in order to simplify handlers one should either a) offload original 1487# %rsp to stack (like discussed above); or b) if you have a register to 1488# spare for frame pointer, choose volatile one. 1489# 1490# (*) Note that we're talking about run-time, not debug-time. Lack of 1491# unwind information makes debugging hard on both Windows and 1492# Unix. "Unlike" refers to the fact that on Unix signal handler 1493# will always be invoked, core dumped and appropriate exit code 1494# returned to parent (for user notification). 1495