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#!/usr/bin/env perl |
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# Ascetic x86_64 AT&T to MASM/NASM assembler translator by <appro>. |
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# |
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# Why AT&T to MASM and not vice versa? Several reasons. Because AT&T |
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# format is way easier to parse. Because it's simpler to "gear" from |
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# Unix ABI to Windows one [see cross-reference "card" at the end of |
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# file]. Because Linux targets were available first... |
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# |
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# In addition the script also "distills" code suitable for GNU |
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# assembler, so that it can be compiled with more rigid assemblers, |
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# such as Solaris /usr/ccs/bin/as. |
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# |
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# This translator is not designed to convert *arbitrary* assembler |
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# code from AT&T format to MASM one. It's designed to convert just |
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# enough to provide for dual-ABI OpenSSL modules development... |
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# There *are* limitations and you might have to modify your assembler |
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# code or this script to achieve the desired result... |
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# |
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# Currently recognized limitations: |
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# |
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# - can't use multiple ops per line; |
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# |
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# Dual-ABI styling rules. |
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# |
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# 1. Adhere to Unix register and stack layout [see cross-reference |
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# ABI "card" at the end for explanation]. |
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# 2. Forget about "red zone," stick to more traditional blended |
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# stack frame allocation. If volatile storage is actually required |
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# that is. If not, just leave the stack as is. |
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# 3. Functions tagged with ".type name,@function" get crafted with |
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# unified Win64 prologue and epilogue automatically. If you want |
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# to take care of ABI differences yourself, tag functions as |
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# ".type name,@abi-omnipotent" instead. |
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# 4. To optimize the Win64 prologue you can specify number of input |
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# arguments as ".type name,@function,N." Keep in mind that if N is |
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# larger than 6, then you *have to* write "abi-omnipotent" code, |
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# because >6 cases can't be addressed with unified prologue. |
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# 5. Name local labels as .L*, do *not* use dynamic labels such as 1: |
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# (sorry about latter). |
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# 6. Don't use [or hand-code with .byte] "rep ret." "ret" mnemonic is |
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# required to identify the spots, where to inject Win64 epilogue! |
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# But on the pros, it's then prefixed with rep automatically:-) |
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# 7. Stick to explicit ip-relative addressing. If you have to use |
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# GOTPCREL addressing, stick to mov symbol@GOTPCREL(%rip),%r??. |
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# Both are recognized and translated to proper Win64 addressing |
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# modes. To support legacy code a synthetic directive, .picmeup, |
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# is implemented. It puts address of the *next* instruction into |
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# target register, e.g.: |
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# |
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# .picmeup %rax |
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# lea .Label-.(%rax),%rax |
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# |
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# 8. In order to provide for structured exception handling unified |
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# Win64 prologue copies %rsp value to %rax. For further details |
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# see SEH paragraph at the end. |
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# 9. .init segment is allowed to contain calls to functions only. |
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# a. If function accepts more than 4 arguments *and* >4th argument |
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# is declared as non 64-bit value, do clear its upper part. |
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my $flavour = shift; |
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my $output = shift; |
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if ($flavour =~ /\./) { $output = $flavour; undef $flavour; } |
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open STDOUT,">$output" || die "can't open $output: $!" |
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if (defined($output)); |
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my $gas=1; $gas=0 if ($output =~ /\.asm$/); |
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my $elf=1; $elf=0 if (!$gas); |
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my $win64=0; |
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my $prefix=""; |
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my $decor=".L"; |
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my $masmref=8 + 50727*2**-32; # 8.00.50727 shipped with VS2005 |
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my $masm=0; |
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my $PTR=" PTR"; |
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my $nasmref=2.03; |
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my $nasm=0; |
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if ($flavour eq "mingw64") { $gas=1; $elf=0; $win64=1; |
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$prefix=`echo __USER_LABEL_PREFIX__ | $ENV{CC} -E -P -`; |
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chomp($prefix); |
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} |
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elsif ($flavour eq "macosx") { $gas=1; $elf=0; $prefix="_"; $decor="L\$"; } |
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elsif ($flavour eq "masm") { $gas=0; $elf=0; $masm=$masmref; $win64=1; $decor="\$L\$"; } |
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elsif ($flavour eq "nasm") { $gas=0; $elf=0; $nasm=$nasmref; $win64=1; $decor="\$L\$"; $PTR=""; } |
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elsif (!$gas) |
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{ if ($ENV{ASM} =~ m/nasm/ && `nasm -v` =~ m/version ([0-9]+)\.([0-9]+)/i) |
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{ $nasm = $1 + $2*0.01; $PTR=""; } |
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elsif (`ml64 2>&1` =~ m/Version ([0-9]+)\.([0-9]+)(\.([0-9]+))?/) |
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{ $masm = $1 + $2*2**-16 + $4*2**-32; } |
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die "no assembler found on %PATH" if (!($nasm || $masm)); |
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$win64=1; |
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$elf=0; |
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$decor="\$L\$"; |
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} |
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my $current_segment; |
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my $current_function; |
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my %globals; |
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{ package opcode; # pick up opcodes |
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sub re { |
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my $self = shift; # single instance in enough... |
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local *line = shift; |
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undef $ret; |
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if ($line =~ /^([a-z][a-z0-9]*)/i) { |
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$self->{op} = $1; |
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$ret = $self; |
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$line = substr($line,@+[0]); $line =~ s/^\s+//; |
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undef $self->{sz}; |
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if ($self->{op} =~ /^(movz)x?([bw]).*/) { # movz is pain... |
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$self->{op} = $1; |
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$self->{sz} = $2; |
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} elsif ($self->{op} =~ /call|jmp/) { |
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$self->{sz} = ""; |
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} elsif ($self->{op} =~ /^p/ && $' !~ /^(ush|op|insrw)/) { # SSEn |
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$self->{sz} = ""; |
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} elsif ($self->{op} =~ /^v/) { # VEX |
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$self->{sz} = ""; |
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} elsif ($self->{op} =~ /mov[dq]/ && $line =~ /%xmm/) { |
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$self->{sz} = ""; |
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} elsif ($self->{op} =~ /([a-z]{3,})([qlwb])$/) { |
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$self->{op} = $1; |
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$self->{sz} = $2; |
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} |
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} |
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$ret; |
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} |
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sub size { |
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my $self = shift; |
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my $sz = shift; |
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$self->{sz} = $sz if (defined($sz) && !defined($self->{sz})); |
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$self->{sz}; |
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} |
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sub out { |
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my $self = shift; |
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if ($gas) { |
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if ($self->{op} eq "movz") { # movz is pain... |
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sprintf "%s%s%s",$self->{op},$self->{sz},shift; |
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} elsif ($self->{op} =~ /^set/) { |
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"$self->{op}"; |
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} elsif ($self->{op} eq "ret") { |
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my $epilogue = ""; |
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if ($win64 && $current_function->{abi} eq "svr4") { |
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$epilogue = "movq 8(%rsp),%rdi\n\t" . |
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"movq 16(%rsp),%rsi\n\t"; |
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} |
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$epilogue . ".byte 0xf3,0xc3"; |
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} elsif ($self->{op} eq "call" && !$elf && $current_segment eq ".init") { |
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".p2align\t3\n\t.quad"; |
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} else { |
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"$self->{op}$self->{sz}"; |
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} |
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} else { |
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$self->{op} =~ s/^movz/movzx/; |
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if ($self->{op} eq "ret") { |
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$self->{op} = ""; |
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if ($win64 && $current_function->{abi} eq "svr4") { |
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$self->{op} = "mov rdi,QWORD${PTR}[8+rsp]\t;WIN64 epilogue\n\t". |
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"mov rsi,QWORD${PTR}[16+rsp]\n\t"; |
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} |
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$self->{op} .= "DB\t0F3h,0C3h\t\t;repret"; |
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} elsif ($self->{op} =~ /^(pop|push)f/) { |
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$self->{op} .= $self->{sz}; |
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} elsif ($self->{op} eq "call" && $current_segment eq ".CRT\$XCU") { |
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$self->{op} = "\tDQ"; |
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} |
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$self->{op}; |
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} |
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} |
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sub mnemonic { |
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my $self=shift; |
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my $op=shift; |
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$self->{op}=$op if (defined($op)); |
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$self->{op}; |
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} |
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} |
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{ package const; # pick up constants, which start with $ |
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sub re { |
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my $self = shift; # single instance in enough... |
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local *line = shift; |
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undef $ret; |
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if ($line =~ /^\$([^,]+)/) { |
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$self->{value} = $1; |
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$ret = $self; |
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$line = substr($line,@+[0]); $line =~ s/^\s+//; |
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} |
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$ret; |
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} |
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sub out { |
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my $self = shift; |
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if ($gas) { |
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# Solaris /usr/ccs/bin/as can't handle multiplications |
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# in $self->{value} |
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$self->{value} =~ s/(?<![\w\$\.])(0x?[0-9a-f]+)/oct($1)/egi; |
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$self->{value} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg; |
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sprintf "\$%s",$self->{value}; |
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} else { |
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$self->{value} =~ s/(0b[0-1]+)/oct($1)/eig; |
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$self->{value} =~ s/0x([0-9a-f]+)/0$1h/ig if ($masm); |
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sprintf "%s",$self->{value}; |
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} |
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} |
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} |
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{ package ea; # pick up effective addresses: expr(%reg,%reg,scale) |
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sub re { |
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my $self = shift; # single instance in enough... |
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local *line = shift; |
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undef $ret; |
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# optional * ---vvv--- appears in indirect jmp/call |
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if ($line =~ /^(\*?)([^\(,]*)\(([%\w,]+)\)/) { |
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$self->{asterisk} = $1; |
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$self->{label} = $2; |
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($self->{base},$self->{index},$self->{scale})=split(/,/,$3); |
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$self->{scale} = 1 if (!defined($self->{scale})); |
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$ret = $self; |
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$line = substr($line,@+[0]); $line =~ s/^\s+//; |
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if ($win64 && $self->{label} =~ s/\@GOTPCREL//) { |
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die if (opcode->mnemonic() ne "mov"); |
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opcode->mnemonic("lea"); |
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} |
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$self->{base} =~ s/^%//; |
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$self->{index} =~ s/^%// if (defined($self->{index})); |
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} |
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$ret; |
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} |
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sub size {} |
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sub out { |
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my $self = shift; |
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my $sz = shift; |
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$self->{label} =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; |
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$self->{label} =~ s/\.L/$decor/g; |
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# Silently convert all EAs to 64-bit. This is required for |
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# elder GNU assembler and results in more compact code, |
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# *but* most importantly AES module depends on this feature! |
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$self->{index} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/; |
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$self->{base} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/; |
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# Solaris /usr/ccs/bin/as can't handle multiplications |
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# in $self->{label}, new gas requires sign extension... |
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use integer; |
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$self->{label} =~ s/(?<![\w\$\.])(0x?[0-9a-f]+)/oct($1)/egi; |
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$self->{label} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg; |
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$self->{label} =~ s/([0-9]+)/$1<<32>>32/eg; |
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if ($gas) { |
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$self->{label} =~ s/^___imp_/__imp__/ if ($flavour eq "mingw64"); |
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if (defined($self->{index})) { |
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sprintf "%s%s(%s,%%%s,%d)",$self->{asterisk}, |
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$self->{label}, |
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$self->{base}?"%$self->{base}":"", |
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$self->{index},$self->{scale}; |
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} else { |
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sprintf "%s%s(%%%s)", $self->{asterisk},$self->{label},$self->{base}; |
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} |
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} else { |
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%szmap = ( b=>"BYTE$PTR", w=>"WORD$PTR", l=>"DWORD$PTR", |
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q=>"QWORD$PTR",o=>"OWORD$PTR",x=>"XMMWORD$PTR" ); |
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$self->{label} =~ s/\./\$/g; |
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$self->{label} =~ s/(?<![\w\$\.])0x([0-9a-f]+)/0$1h/ig; |
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$self->{label} = "($self->{label})" if ($self->{label} =~ /[\*\+\-\/]/); |
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$sz="q" if ($self->{asterisk} || opcode->mnemonic() eq "movq"); |
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$sz="l" if (opcode->mnemonic() eq "movd"); |
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if (defined($self->{index})) { |
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sprintf "%s[%s%s*%d%s]",$szmap{$sz}, |
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$self->{label}?"$self->{label}+":"", |
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$self->{index},$self->{scale}, |
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$self->{base}?"+$self->{base}":""; |
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} elsif ($self->{base} eq "rip") { |
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sprintf "%s[%s]",$szmap{$sz},$self->{label}; |
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} else { |
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sprintf "%s[%s%s]",$szmap{$sz}, |
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$self->{label}?"$self->{label}+":"", |
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$self->{base}; |
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} |
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} |
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} |
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} |
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{ package register; # pick up registers, which start with %. |
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sub re { |
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my $class = shift; # muliple instances... |
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my $self = {}; |
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local *line = shift; |
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undef $ret; |
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# optional * ---vvv--- appears in indirect jmp/call |
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if ($line =~ /^(\*?)%(\w+)/) { |
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bless $self,$class; |
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$self->{asterisk} = $1; |
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$self->{value} = $2; |
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$ret = $self; |
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$line = substr($line,@+[0]); $line =~ s/^\s+//; |
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} |
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$ret; |
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} |
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sub size { |
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my $self = shift; |
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undef $ret; |
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if ($self->{value} =~ /^r[\d]+b$/i) { $ret="b"; } |
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elsif ($self->{value} =~ /^r[\d]+w$/i) { $ret="w"; } |
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elsif ($self->{value} =~ /^r[\d]+d$/i) { $ret="l"; } |
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elsif ($self->{value} =~ /^r[\w]+$/i) { $ret="q"; } |
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elsif ($self->{value} =~ /^[a-d][hl]$/i){ $ret="b"; } |
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elsif ($self->{value} =~ /^[\w]{2}l$/i) { $ret="b"; } |
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elsif ($self->{value} =~ /^[\w]{2}$/i) { $ret="w"; } |
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elsif ($self->{value} =~ /^e[a-z]{2}$/i){ $ret="l"; } |
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$ret; |
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} |
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sub out { |
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my $self = shift; |
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if ($gas) { sprintf "%s%%%s",$self->{asterisk},$self->{value}; } |
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else { $self->{value}; } |
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} |
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} |
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{ package label; # pick up labels, which end with : |
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sub re { |
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my $self = shift; # single instance is enough... |
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local *line = shift; |
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undef $ret; |
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if ($line =~ /(^[\.\w]+)\:/) { |
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$self->{value} = $1; |
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$ret = $self; |
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$line = substr($line,@+[0]); $line =~ s/^\s+//; |
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$self->{value} =~ s/^\.L/$decor/; |
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} |
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$ret; |
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} |
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sub out { |
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my $self = shift; |
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if ($gas) { |
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my $func = ($globals{$self->{value}} or $self->{value}) . ":"; |
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if ($win64 && |
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$current_function->{name} eq $self->{value} && |
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$current_function->{abi} eq "svr4") { |
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$func .= "\n"; |
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$func .= " movq %rdi,8(%rsp)\n"; |
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$func .= " movq %rsi,16(%rsp)\n"; |
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$func .= " movq %rsp,%rax\n"; |
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$func .= "${decor}SEH_begin_$current_function->{name}:\n"; |
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my $narg = $current_function->{narg}; |
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$narg=6 if (!defined($narg)); |
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$func .= " movq %rcx,%rdi\n" if ($narg>0); |
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$func .= " movq %rdx,%rsi\n" if ($narg>1); |
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$func .= " movq %r8,%rdx\n" if ($narg>2); |
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$func .= " movq %r9,%rcx\n" if ($narg>3); |
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$func .= " movq 40(%rsp),%r8\n" if ($narg>4); |
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$func .= " movq 48(%rsp),%r9\n" if ($narg>5); |
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} |
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$func; |
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} elsif ($self->{value} ne "$current_function->{name}") { |
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$self->{value} .= ":" if ($masm && $ret!~m/^\$/); |
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$self->{value} . ":"; |
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} elsif ($win64 && $current_function->{abi} eq "svr4") { |
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my $func = "$current_function->{name}" . |
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($nasm ? ":" : "\tPROC $current_function->{scope}") . |
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"\n"; |
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$func .= " mov QWORD${PTR}[8+rsp],rdi\t;WIN64 prologue\n"; |
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$func .= " mov QWORD${PTR}[16+rsp],rsi\n"; |
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$func .= " mov rax,rsp\n"; |
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$func .= "${decor}SEH_begin_$current_function->{name}:"; |
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$func .= ":" if ($masm); |
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$func .= "\n"; |
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my $narg = $current_function->{narg}; |
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$narg=6 if (!defined($narg)); |
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$func .= " mov rdi,rcx\n" if ($narg>0); |
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$func .= " mov rsi,rdx\n" if ($narg>1); |
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$func .= " mov rdx,r8\n" if ($narg>2); |
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$func .= " mov rcx,r9\n" if ($narg>3); |
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$func .= " mov r8,QWORD${PTR}[40+rsp]\n" if ($narg>4); |
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|
$func .= " mov r9,QWORD${PTR}[48+rsp]\n" if ($narg>5); |
|
|
$func .= "\n"; |
|
|
} else { |
|
|
"$current_function->{name}". |
|
|
($nasm ? ":" : "\tPROC $current_function->{scope}"); |
|
|
} |
|
|
} |
|
|
} |
|
|
{ package expr; # pick up expressioins |
|
|
sub re { |
|
|
my $self = shift; # single instance is enough... |
|
|
local *line = shift; |
|
|
undef $ret; |
|
|
|
|
|
if ($line =~ /(^[^,]+)/) { |
|
|
$self->{value} = $1; |
|
|
$ret = $self; |
|
|
$line = substr($line,@+[0]); $line =~ s/^\s+//; |
|
|
|
|
|
$self->{value} =~ s/\@PLT// if (!$elf); |
|
|
$self->{value} =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; |
|
|
$self->{value} =~ s/\.L/$decor/g; |
|
|
} |
|
|
$ret; |
|
|
} |
|
|
sub out { |
|
|
my $self = shift; |
|
|
if ($nasm && opcode->mnemonic()=~m/^j/) { |
|
|
"NEAR ".$self->{value}; |
|
|
} else { |
|
|
$self->{value}; |
|
|
} |
|
|
} |
|
|
} |
|
|
{ package directive; # pick up directives, which start with . |
|
|
sub re { |
|
|
my $self = shift; # single instance is enough... |
|
|
local *line = shift; |
|
|
undef $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+)/) { |
|
|
$dir = $1; |
|
|
$ret = $self; |
|
|
undef $self->{value}; |
|
|
$line = substr($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 ($prefix); |
|
|
last; |
|
|
}; |
|
|
/\.type/ && do { ($sym,$type,$narg) = split(',',$line); |
|
|
if ($type eq "\@function") { |
|
|
undef $current_function; |
|
|
$current_function->{name} = $sym; |
|
|
$current_function->{abi} = "svr4"; |
|
|
$current_function->{narg} = $narg; |
|
|
$current_function->{scope} = defined($globals{$sym})?"PUBLIC":"PRIVATE"; |
|
|
} elsif ($type eq "\@abi-omnipotent") { |
|
|
undef $current_function; |
|
|
$current_function->{name} = $sym; |
|
|
$current_function->{scope} = defined($globals{$sym})?"PUBLIC":"PRIVATE"; |
|
|
} |
|
|
$line =~ s/\@abi\-omnipotent/\@function/; |
|
|
$line =~ s/\@function.*/\@function/; |
|
|
last; |
|
|
}; |
|
|
/\.asciz/ && do { if ($line =~ /^"(.*)"$/) { |
|
|
$dir = ".byte"; |
|
|
$line = join(",",unpack("C*",$1),0); |
|
|
} |
|
|
last; |
|
|
}; |
|
|
/\.rva|\.long|\.quad/ |
|
|
&& do { $line =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; |
|
|
$line =~ s/\.L/$decor/g; |
|
|
last; |
|
|
}; |
|
|
} |
|
|
|
|
|
if ($gas) { |
|
|
$self->{value} = $dir . "\t" . $line; |
|
|
|
|
|
if ($dir =~ /\.extern/) { |
|
|
$self->{value} = ""; # swallow extern |
|
|
} elsif (!$elf && $dir =~ /\.type/) { |
|
|
$self->{value} = ""; |
|
|
$self->{value} = ".def\t" . ($globals{$1} or $1) . ";\t" . |
|
|
(defined($globals{$1})?".scl 2;":".scl 3;") . |
|
|
"\t.type 32;\t.endef" |
|
|
if ($win64 && $line =~ /([^,]+),\@function/); |
|
|
} elsif (!$elf && $dir =~ /\.size/) { |
|
|
$self->{value} = ""; |
|
|
if (defined($current_function)) { |
|
|
$self->{value} .= "${decor}SEH_end_$current_function->{name}:" |
|
|
if ($win64 && $current_function->{abi} eq "svr4"); |
|
|
undef $current_function; |
|
|
} |
|
|
} elsif (!$elf && $dir =~ /\.align/) { |
|
|
$self->{value} = ".p2align\t" . (log($line)/log(2)); |
|
|
} elsif ($dir eq ".section") { |
|
|
$current_segment=$line; |
|
|
if (!$elf && $current_segment eq ".init") { |
|
|
if ($flavour eq "macosx") { $self->{value} = ".mod_init_func"; } |
|
|
elsif ($flavour eq "mingw64") { $self->{value} = ".section\t.ctors"; } |
|
|
} |
|
|
} elsif ($dir =~ /\.(text|data)/) { |
|
|
$current_segment=".$1"; |
|
|
} elsif ($dir =~ /\.hidden/) { |
|
|
if ($flavour eq "macosx") { $self->{value} = ".private_extern\t$prefix$line"; } |
|
|
elsif ($flavour eq "mingw64") { $self->{value} = ""; } |
|
|
} elsif ($dir =~ /\.comm/) { |
|
|
$self->{value} = "$dir\t$prefix$line"; |
|
|
$self->{value} =~ s|,([0-9]+),([0-9]+)$|",$1,".log($2)/log(2)|e if ($flavour eq "macosx"); |
|
|
} |
|
|
$line = ""; |
|
|
return $self; |
|
|
} |
|
|
|
|
|
# non-gas case or nasm/masm |
|
|
SWITCH: for ($dir) { |
|
|
/\.text/ && do { my $v=undef; |
|
|
if ($nasm) { |
|
|
$v="section .text code align=64\n"; |
|
|
} else { |
|
|
$v="$current_segment\tENDS\n" if ($current_segment); |
|
|
$current_segment = ".text\$"; |
|
|
$v.="$current_segment\tSEGMENT "; |
|
|
$v.=$masm>=$masmref ? "ALIGN(64)" : "PAGE"; |
|
|
$v.=" 'CODE'"; |
|
|
} |
|
|
$self->{value} = $v; |
|
|
last; |
|
|
}; |
|
|
/\.data/ && do { my $v=undef; |
|
|
if ($nasm) { |
|
|
$v="section .data data align=8\n"; |
|
|
} else { |
|
|
$v="$current_segment\tENDS\n" if ($current_segment); |
|
|
$current_segment = "_DATA"; |
|
|
$v.="$current_segment\tSEGMENT"; |
|
|
} |
|
|
$self->{value} = $v; |
|
|
last; |
|
|
}; |
|
|
/\.section/ && do { my $v=undef; |
|
|
$line =~ s/([^,]*).*/$1/; |
|
|
$line = ".CRT\$XCU" if ($line eq ".init"); |
|
|
if ($nasm) { |
|
|
$v="section $line"; |
|
|
if ($line=~/\.([px])data/) { |
|
|
$v.=" rdata align="; |
|
|
$v.=$1 eq "p"? 4 : 8; |
|
|
} elsif ($line=~/\.CRT\$/i) { |
|
|
$v.=" rdata align=8"; |
|
|
} |
|
|
} else { |
|
|
$v="$current_segment\tENDS\n" if ($current_segment); |
|
|
$v.="$line\tSEGMENT"; |
|
|
if ($line=~/\.([px])data/) { |
|
|
$v.=" READONLY"; |
|
|
$v.=" ALIGN(".($1 eq "p" ? 4 : 8).")" if ($masm>=$masmref); |
|
|
} elsif ($line=~/\.CRT\$/i) { |
|
|
$v.=" READONLY "; |
|
|
$v.=$masm>=$masmref ? "ALIGN(8)" : "DWORD"; |
|
|
} |
|
|
} |
|
|
$current_segment = $line; |
|
|
$self->{value} = $v; |
|
|
last; |
|
|
}; |
|
|
/\.extern/ && do { $self->{value} = "EXTERN\t".$line; |
|
|
$self->{value} .= ":NEAR" if ($masm); |
|
|
last; |
|
|
}; |
|
|
/\.globl|.global/ |
|
|
&& do { $self->{value} = $masm?"PUBLIC":"global"; |
|
|
$self->{value} .= "\t".$line; |
|
|
last; |
|
|
}; |
|
|
/\.size/ && do { if (defined($current_function)) { |
|
|
undef $self->{value}; |
|
|
if ($current_function->{abi} eq "svr4") { |
|
|
$self->{value}="${decor}SEH_end_$current_function->{name}:"; |
|
|
$self->{value}.=":\n" if($masm); |
|
|
} |
|
|
$self->{value}.="$current_function->{name}\tENDP" if($masm && $current_function->{name}); |
|
|
undef $current_function; |
|
|
} |
|
|
last; |
|
|
}; |
|
|
/\.align/ && do { $self->{value} = "ALIGN\t".$line; last; }; |
|
|
/\.(value|long|rva|quad)/ |
|
|
&& do { my $sz = substr($1,0,1); |
|
|
my @arr = split(/,\s*/,$line); |
|
|
my $last = pop(@arr); |
|
|
my $conv = sub { my $var=shift; |
|
|
$var=~s/^(0b[0-1]+)/oct($1)/eig; |
|
|
$var=~s/^0x([0-9a-f]+)/0$1h/ig if ($masm); |
|
|
if ($sz eq "D" && ($current_segment=~/.[px]data/ || $dir eq ".rva")) |
|
|
{ $var=~s/([_a-z\$\@][_a-z0-9\$\@]*)/$nasm?"$1 wrt ..imagebase":"imagerel $1"/egi; } |
|
|
$var; |
|
|
}; |
|
|
|
|
|
$sz =~ tr/bvlrq/BWDDQ/; |
|
|
$self->{value} = "\tD$sz\t"; |
|
|
for (@arr) { $self->{value} .= &$conv($_).","; } |
|
|
$self->{value} .= &$conv($last); |
|
|
last; |
|
|
}; |
|
|
/\.byte/ && do { my @str=split(/,\s*/,$line); |
|
|
map(s/(0b[0-1]+)/oct($1)/eig,@str); |
|
|
map(s/0x([0-9a-f]+)/0$1h/ig,@str) if ($masm); |
|
|
while ($#str>15) { |
|
|
$self->{value}.="DB\t" |
|
|
.join(",",@str[0..15])."\n"; |
|
|
foreach (0..15) { shift @str; } |
|
|
} |
|
|
$self->{value}.="DB\t" |
|
|
.join(",",@str) if (@str); |
|
|
last; |
|
|
}; |
|
|
/\.comm/ && do { my @str=split(/,\s*/,$line); |
|
|
my $v=undef; |
|
|
if ($nasm) { |
|
|
$v.="common $prefix@str[0] @str[1]"; |
|
|
} else { |
|
|
$v="$current_segment\tENDS\n" if ($current_segment); |
|
|
$current_segment = "_DATA"; |
|
|
$v.="$current_segment\tSEGMENT\n"; |
|
|
$v.="COMM @str[0]:DWORD:".@str[1]/4; |
|
|
} |
|
|
$self->{value} = $v; |
|
|
last; |
|
|
}; |
|
|
} |
|
|
$line = ""; |
|
|
} |
|
|
|
|
|
$ret; |
|
|
} |
|
|
sub out { |
|
|
my $self = shift; |
|
|
$self->{value}; |
|
|
} |
|
|
} |
|
|
|
|
|
sub rex { |
|
|
local *opcode=shift; |
|
|
my ($dst,$src,$rex)=@_; |
|
|
|
|
|
$rex|=0x04 if($dst>=8); |
|
|
$rex|=0x01 if($src>=8); |
|
|
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 $arg = shift; |
|
|
my @opcode=(0x66); |
|
|
if ($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); |
|
|
$imm=$1; |
|
|
$src=$2; |
|
|
$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); |
|
|
$imm=$1; |
|
|
$src=$2; |
|
|
$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,$1,8); |
|
|
push @opcode,0x0f,0xc7,0xf0|($dst&7); |
|
|
@opcode; |
|
|
} else { |
|
|
(); |
|
|
} |
|
|
}; |
|
|
|
|
|
if ($nasm) { |
|
|
print <<___; |
|
|
default rel |
|
|
%define XMMWORD |
|
|
___ |
|
|
} elsif ($masm) { |
|
|
print <<___; |
|
|
OPTION DOTNAME |
|
|
___ |
|
|
} |
|
|
while($line=<>) { |
|
|
|
|
|
chomp($line); |
|
|
|
|
|
$line =~ s|[#!].*$||; # get rid of asm-style comments... |
|
|
$line =~ s|/\*.*\*/||; # ... and C-style comments... |
|
|
$line =~ s|^\s+||; # ... and skip white spaces in beginning |
|
|
|
|
|
undef $label; |
|
|
undef $opcode; |
|
|
undef @args; |
|
|
|
|
|
if ($label=label->re(\$line)) { print $label->out(); } |
|
|
|
|
|
if (directive->re(\$line)) { |
|
|
printf "%s",directive->out(); |
|
|
} elsif ($opcode=opcode->re(\$line)) { |
|
|
my $asm = eval("\$".$opcode->mnemonic()); |
|
|
undef @bytes; |
|
|
|
|
|
if ((ref($asm) eq 'CODE') && scalar(@bytes=&$asm($line))) { |
|
|
print $gas?".byte\t":"DB\t",join(',',@bytes),"\n"; |
|
|
next; |
|
|
} |
|
|
|
|
|
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; } |
|
|
|
|
|
push @args,$arg; |
|
|
|
|
|
last ARGUMENT if ($line !~ /^,/); |
|
|
|
|
|
$line =~ s/^,\s*//; |
|
|
} # ARGUMENT: |
|
|
|
|
|
if ($#args>=0) { |
|
|
my $insn; |
|
|
my $sz=opcode->size(); |
|
|
|
|
|
if ($gas) { |
|
|
$insn = $opcode->out($#args>=1?$args[$#args]->size():$sz); |
|
|
@args = map($_->out($sz),@args); |
|
|
printf "\t%s\t%s",$insn,join(",",@args); |
|
|
} else { |
|
|
$insn = $opcode->out(); |
|
|
foreach (@args) { |
|
|
my $arg = $_->out(); |
|
|
# $insn.=$sz compensates for movq, pinsrw, ... |
|
|
if ($arg =~ /^xmm[0-9]+$/) { $insn.=$sz; $sz="x" if(!$sz); last; } |
|
|
if ($arg =~ /^mm[0-9]+$/) { $insn.=$sz; $sz="q" if(!$sz); last; } |
|
|
} |
|
|
@args = reverse(@args); |
|
|
undef $sz if ($nasm && $opcode->mnemonic() eq "lea"); |
|
|
printf "\t%s\t%s",$insn,join(",",map($_->out($sz),@args)); |
|
|
} |
|
|
} else { |
|
|
printf "\t%s",$opcode->out(); |
|
|
} |
|
|
} |
|
|
|
|
|
print $line,"\n"; |
|
|
} |
|
|
|
|
|
print "\n$current_segment\tENDS\n" if ($current_segment && $masm); |
|
|
print "END\n" if ($masm); |
|
|
|
|
|
close STDOUT; |
|
|
|
|
|
################################################# |
|
|
# Cross-reference x86_64 ABI "card" |
|
|
# |
|
|
# Unix Win64 |
|
|
# %rax * * |
|
|
# %rbx - - |
|
|
# %rcx #4 #1 |
|
|
# %rdx #3 #2 |
|
|
# %rsi #2 - |
|
|
# %rdi #1 - |
|
|
# %rbp - - |
|
|
# %rsp - - |
|
|
# %r8 #5 #3 |
|
|
# %r9 #6 #4 |
|
|
# %r10 * * |
|
|
# %r11 * * |
|
|
# %r12 - - |
|
|
# %r13 - - |
|
|
# %r14 - - |
|
|
# %r15 - - |
|
|
# |
|
|
# (*) volatile register |
|
|
# (-) preserved by callee |
|
|
# (#) Nth argument, volatile |
|
|
# |
|
|
# In Unix terms top of stack is argument transfer area for arguments |
|
|
# which could not be accomodated in registers. Or in other words 7th |
|
|
# [integer] argument resides at 8(%rsp) upon function entry point. |
|
|
# 128 bytes above %rsp constitute a "red zone" which is not touched |
|
|
# by signal handlers and can be used as temporal storage without |
|
|
# allocating a frame. |
|
|
# |
|
|
# In Win64 terms N*8 bytes on top of stack is argument transfer area, |
|
|
# which belongs to/can be overwritten by callee. N is the number of |
|
|
# arguments passed to callee, *but* not less than 4! This means that |
|
|
# upon function entry point 5th argument resides at 40(%rsp), as well |
|
|
# as that 32 bytes from 8(%rsp) can always be used as temporal |
|
|
# storage [without allocating a frame]. One can actually argue that |
|
|
# one can assume a "red zone" above stack pointer under Win64 as well. |
|
|
# Point is that at apparently no occasion Windows kernel would alter |
|
|
# the area above user stack pointer in true asynchronous manner... |
|
|
# |
|
|
# All the above means that if assembler programmer adheres to Unix |
|
|
# register and stack layout, but disregards the "red zone" existense, |
|
|
# it's possible to use following prologue and epilogue to "gear" from |
|
|
# Unix to Win64 ABI in leaf functions with not more than 6 arguments. |
|
|
# |
|
|
# omnipotent_function: |
|
|
# ifdef WIN64 |
|
|
# movq %rdi,8(%rsp) |
|
|
# movq %rsi,16(%rsp) |
|
|
# movq %rcx,%rdi ; if 1st argument is actually present |
|
|
# movq %rdx,%rsi ; if 2nd argument is actually ... |
|
|
# movq %r8,%rdx ; if 3rd argument is ... |
|
|
# movq %r9,%rcx ; if 4th argument ... |
|
|
# movq 40(%rsp),%r8 ; if 5th ... |
|
|
# movq 48(%rsp),%r9 ; if 6th ... |
|
|
# endif |
|
|
# ... |
|
|
# ifdef WIN64 |
|
|
# movq 8(%rsp),%rdi |
|
|
# movq 16(%rsp),%rsi |
|
|
# endif |
|
|
# ret |
|
|
# |
|
|
################################################# |
|
|
# Win64 SEH, Structured Exception Handling. |
|
|
# |
|
|
# Unlike on Unix systems(*) lack of Win64 stack unwinding information |
|
|
# has undesired side-effect at run-time: if an exception is raised in |
|
|
# assembler subroutine such as those in question (basically we're |
|
|
# referring to segmentation violations caused by malformed input |
|
|
# parameters), the application is briskly terminated without invoking |
|
|
# any exception handlers, most notably without generating memory dump |
|
|
# or any user notification whatsoever. This poses a problem. It's |
|
|
# possible to address it by registering custom language-specific |
|
|
# handler that would restore processor context to the state at |
|
|
# subroutine entry point and return "exception is not handled, keep |
|
|
# unwinding" code. Writing such handler can be a challenge... But it's |
|
|
# doable, though requires certain coding convention. Consider following |
|
|
# snippet: |
|
|
# |
|
|
# .type function,@function |
|
|
# function: |
|
|
# movq %rsp,%rax # copy rsp to volatile register |
|
|
# pushq %r15 # save non-volatile registers |
|
|
# pushq %rbx |
|
|
# pushq %rbp |
|
|
# movq %rsp,%r11 |
|
|
# subq %rdi,%r11 # prepare [variable] stack frame |
|
|
# andq $-64,%r11 |
|
|
# movq %rax,0(%r11) # check for exceptions |
|
|
# movq %r11,%rsp # allocate [variable] stack frame |
|
|
# movq %rax,0(%rsp) # save original rsp value |
|
|
# magic_point: |
|
|
# ... |
|
|
# movq 0(%rsp),%rcx # pull original rsp value |
|
|
# movq -24(%rcx),%rbp # restore non-volatile registers |
|
|
# movq -16(%rcx),%rbx |
|
|
# movq -8(%rcx),%r15 |
|
|
# movq %rcx,%rsp # restore original rsp |
|
|
# ret |
|
|
# .size function,.-function |
|
|
# |
|
|
# The key is that up to magic_point copy of original rsp value remains |
|
|
# in chosen volatile register and no non-volatile register, except for |
|
|
# rsp, is modified. While past magic_point rsp remains constant till |
|
|
# the very end of the function. In this case custom language-specific |
|
|
# exception handler would look like this: |
|
|
# |
|
|
# EXCEPTION_DISPOSITION handler (EXCEPTION_RECORD *rec,ULONG64 frame, |
|
|
# CONTEXT *context,DISPATCHER_CONTEXT *disp) |
|
|
# { ULONG64 *rsp = (ULONG64 *)context->Rax; |
|
|
# if (context->Rip >= magic_point) |
|
|
# { rsp = ((ULONG64 **)context->Rsp)[0]; |
|
|
# context->Rbp = rsp[-3]; |
|
|
# context->Rbx = rsp[-2]; |
|
|
# context->R15 = rsp[-1]; |
|
|
# } |
|
|
# context->Rsp = (ULONG64)rsp; |
|
|
# context->Rdi = rsp[1]; |
|
|
# context->Rsi = rsp[2]; |
|
|
# |
|
|
# memcpy (disp->ContextRecord,context,sizeof(CONTEXT)); |
|
|
# RtlVirtualUnwind(UNW_FLAG_NHANDLER,disp->ImageBase, |
|
|
# dips->ControlPc,disp->FunctionEntry,disp->ContextRecord, |
|
|
# &disp->HandlerData,&disp->EstablisherFrame,NULL); |
|
|
# return ExceptionContinueSearch; |
|
|
# } |
|
|
# |
|
|
# It's appropriate to implement this handler in assembler, directly in |
|
|
# function's module. In order to do that one has to know members' |
|
|
# offsets in CONTEXT and DISPATCHER_CONTEXT structures and some constant |
|
|
# values. Here they are: |
|
|
# |
|
|
# CONTEXT.Rax 120 |
|
|
# CONTEXT.Rcx 128 |
|
|
# CONTEXT.Rdx 136 |
|
|
# CONTEXT.Rbx 144 |
|
|
# CONTEXT.Rsp 152 |
|
|
# CONTEXT.Rbp 160 |
|
|
# CONTEXT.Rsi 168 |
|
|
# CONTEXT.Rdi 176 |
|
|
# CONTEXT.R8 184 |
|
|
# CONTEXT.R9 192 |
|
|
# CONTEXT.R10 200 |
|
|
# CONTEXT.R11 208 |
|
|
# CONTEXT.R12 216 |
|
|
# CONTEXT.R13 224 |
|
|
# CONTEXT.R14 232 |
|
|
# CONTEXT.R15 240 |
|
|
# CONTEXT.Rip 248 |
|
|
# CONTEXT.Xmm6 512 |
|
|
# sizeof(CONTEXT) 1232 |
|
|
# DISPATCHER_CONTEXT.ControlPc 0 |
|
|
# DISPATCHER_CONTEXT.ImageBase 8 |
|
|
# DISPATCHER_CONTEXT.FunctionEntry 16 |
|
|
# DISPATCHER_CONTEXT.EstablisherFrame 24 |
|
|
# DISPATCHER_CONTEXT.TargetIp 32 |
|
|
# DISPATCHER_CONTEXT.ContextRecord 40 |
|
|
# DISPATCHER_CONTEXT.LanguageHandler 48 |
|
|
# DISPATCHER_CONTEXT.HandlerData 56 |
|
|
# UNW_FLAG_NHANDLER 0 |
|
|
# ExceptionContinueSearch 1 |
|
|
# |
|
|
# In order to tie the handler to the function one has to compose |
|
|
# couple of structures: one for .xdata segment and one for .pdata. |
|
|
# |
|
|
# UNWIND_INFO structure for .xdata segment would be |
|
|
# |
|
|
# function_unwind_info: |
|
|
# .byte 9,0,0,0 |
|
|
# .rva handler |
|
|
# |
|
|
# This structure designates exception handler for a function with |
|
|
# zero-length prologue, no stack frame or frame register. |
|
|
# |
|
|
# To facilitate composing of .pdata structures, auto-generated "gear" |
|
|
# prologue copies rsp value to rax and denotes next instruction with |
|
|
# .LSEH_begin_{function_name} label. This essentially defines the SEH |
|
|
# styling rule mentioned in the beginning. Position of this label is |
|
|
# chosen in such manner that possible exceptions raised in the "gear" |
|
|
# prologue would be accounted to caller and unwound from latter's frame. |
|
|
# End of function is marked with respective .LSEH_end_{function_name} |
|
|
# label. To summarize, .pdata segment would contain |
|
|
# |
|
|
# .rva .LSEH_begin_function |
|
|
# .rva .LSEH_end_function |
|
|
# .rva function_unwind_info |
|
|
# |
|
|
# Reference to functon_unwind_info from .xdata segment is the anchor. |
|
|
# In case you wonder why references are 32-bit .rvas and not 64-bit |
|
|
# .quads. References put into these two segments are required to be |
|
|
# *relative* to the base address of the current binary module, a.k.a. |
|
|
# image base. No Win64 module, be it .exe or .dll, can be larger than |
|
|
# 2GB and thus such relative references can be and are accommodated in |
|
|
# 32 bits. |
|
|
# |
|
|
# Having reviewed the example function code, one can argue that "movq |
|
|
# %rsp,%rax" above is redundant. It is not! Keep in mind that on Unix |
|
|
# rax would contain an undefined value. If this "offends" you, use |
|
|
# another register and refrain from modifying rax till magic_point is |
|
|
# reached, i.e. as if it was a non-volatile register. If more registers |
|
|
# are required prior [variable] frame setup is completed, note that |
|
|
# nobody says that you can have only one "magic point." You can |
|
|
# "liberate" non-volatile registers by denoting last stack off-load |
|
|
# instruction and reflecting it in finer grade unwind logic in handler. |
|
|
# After all, isn't it why it's called *language-specific* handler... |
|
|
# |
|
|
# 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... |
|
|
# |
|
|
# (*) 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 |
|
|
# will always be invoked, core dumped and appropriate exit code |
|
|
# returned to parent (for user notification).
|
|
|
|