diff options
Diffstat (limited to 'src/lib/libcrypto/perlasm/x86_64-xlate.pl')
-rwxr-xr-x | src/lib/libcrypto/perlasm/x86_64-xlate.pl | 1075 |
1 files changed, 0 insertions, 1075 deletions
diff --git a/src/lib/libcrypto/perlasm/x86_64-xlate.pl b/src/lib/libcrypto/perlasm/x86_64-xlate.pl deleted file mode 100755 index 4bd53da33d..0000000000 --- a/src/lib/libcrypto/perlasm/x86_64-xlate.pl +++ /dev/null | |||
@@ -1,1075 +0,0 @@ | |||
1 | #!/usr/bin/env perl | ||
2 | |||
3 | # Ascetic x86_64 AT&T to MASM/NASM assembler translator by <appro>. | ||
4 | # | ||
5 | # Why AT&T to MASM and not vice versa? Several reasons. Because AT&T | ||
6 | # format is way easier to parse. Because it's simpler to "gear" from | ||
7 | # Unix ABI to Windows one [see cross-reference "card" at the end of | ||
8 | # file]. Because Linux targets were available first... | ||
9 | # | ||
10 | # In addition the script also "distills" code suitable for GNU | ||
11 | # assembler, so that it can be compiled with more rigid assemblers, | ||
12 | # such as Solaris /usr/ccs/bin/as. | ||
13 | # | ||
14 | # This translator is not designed to convert *arbitrary* assembler | ||
15 | # code from AT&T format to MASM one. It's designed to convert just | ||
16 | # enough to provide for dual-ABI OpenSSL modules development... | ||
17 | # There *are* limitations and you might have to modify your assembler | ||
18 | # code or this script to achieve the desired result... | ||
19 | # | ||
20 | # Currently recognized limitations: | ||
21 | # | ||
22 | # - can't use multiple ops per line; | ||
23 | # | ||
24 | # Dual-ABI styling rules. | ||
25 | # | ||
26 | # 1. Adhere to Unix register and stack layout [see cross-reference | ||
27 | # ABI "card" at the end for explanation]. | ||
28 | # 2. Forget about "red zone," stick to more traditional blended | ||
29 | # stack frame allocation. If volatile storage is actually required | ||
30 | # that is. If not, just leave the stack as is. | ||
31 | # 3. Functions tagged with ".type name,@function" get crafted with | ||
32 | # unified Win64 prologue and epilogue automatically. If you want | ||
33 | # to take care of ABI differences yourself, tag functions as | ||
34 | # ".type name,@abi-omnipotent" instead. | ||
35 | # 4. To optimize the Win64 prologue you can specify number of input | ||
36 | # arguments as ".type name,@function,N." Keep in mind that if N is | ||
37 | # larger than 6, then you *have to* write "abi-omnipotent" code, | ||
38 | # because >6 cases can't be addressed with unified prologue. | ||
39 | # 5. Name local labels as .L*, do *not* use dynamic labels such as 1: | ||
40 | # (sorry about latter). | ||
41 | # 6. Don't use [or hand-code with .byte] "rep ret." "ret" mnemonic is | ||
42 | # required to identify the spots, where to inject Win64 epilogue! | ||
43 | # But on the pros, it's then prefixed with rep automatically:-) | ||
44 | # 7. Stick to explicit ip-relative addressing. If you have to use | ||
45 | # GOTPCREL addressing, stick to mov symbol@GOTPCREL(%rip),%r??. | ||
46 | # Both are recognized and translated to proper Win64 addressing | ||
47 | # modes. To support legacy code a synthetic directive, .picmeup, | ||
48 | # is implemented. It puts address of the *next* instruction into | ||
49 | # target register, e.g.: | ||
50 | # | ||
51 | # .picmeup %rax | ||
52 | # lea .Label-.(%rax),%rax | ||
53 | # | ||
54 | # 8. In order to provide for structured exception handling unified | ||
55 | # Win64 prologue copies %rsp value to %rax. For further details | ||
56 | # see SEH paragraph at the end. | ||
57 | # 9. .init segment is allowed to contain calls to functions only. | ||
58 | # a. If function accepts more than 4 arguments *and* >4th argument | ||
59 | # is declared as non 64-bit value, do clear its upper part. | ||
60 | |||
61 | my $flavour = shift; | ||
62 | my $output = shift; | ||
63 | if ($flavour =~ /\./) { $output = $flavour; undef $flavour; } | ||
64 | |||
65 | open STDOUT,">$output" || die "can't open $output: $!" | ||
66 | if (defined($output)); | ||
67 | |||
68 | my $gas=1; $gas=0 if ($output =~ /\.asm$/); | ||
69 | my $elf=1; $elf=0 if (!$gas); | ||
70 | my $win64=0; | ||
71 | my $prefix=""; | ||
72 | my $decor=".L"; | ||
73 | |||
74 | my $masmref=8 + 50727*2**-32; # 8.00.50727 shipped with VS2005 | ||
75 | my $masm=0; | ||
76 | my $PTR=" PTR"; | ||
77 | |||
78 | my $nasmref=2.03; | ||
79 | my $nasm=0; | ||
80 | |||
81 | if ($flavour eq "mingw64") { $gas=1; $elf=0; $win64=1; | ||
82 | $prefix=`echo __USER_LABEL_PREFIX__ | $ENV{CC} -E -P -`; | ||
83 | chomp($prefix); | ||
84 | } | ||
85 | elsif ($flavour eq "macosx") { $gas=1; $elf=0; $prefix="_"; $decor="L\$"; } | ||
86 | elsif ($flavour eq "masm") { $gas=0; $elf=0; $masm=$masmref; $win64=1; $decor="\$L\$"; } | ||
87 | elsif ($flavour eq "nasm") { $gas=0; $elf=0; $nasm=$nasmref; $win64=1; $decor="\$L\$"; $PTR=""; } | ||
88 | elsif (!$gas) | ||
89 | { if ($ENV{ASM} =~ m/nasm/ && `nasm -v` =~ m/version ([0-9]+)\.([0-9]+)/i) | ||
90 | { $nasm = $1 + $2*0.01; $PTR=""; } | ||
91 | elsif (`ml64 2>&1` =~ m/Version ([0-9]+)\.([0-9]+)(\.([0-9]+))?/) | ||
92 | { $masm = $1 + $2*2**-16 + $4*2**-32; } | ||
93 | die "no assembler found on %PATH" if (!($nasm || $masm)); | ||
94 | $win64=1; | ||
95 | $elf=0; | ||
96 | $decor="\$L\$"; | ||
97 | } | ||
98 | |||
99 | my $current_segment; | ||
100 | my $current_function; | ||
101 | my %globals; | ||
102 | |||
103 | { package opcode; # pick up opcodes | ||
104 | sub re { | ||
105 | my $self = shift; # single instance in enough... | ||
106 | local *line = shift; | ||
107 | undef $ret; | ||
108 | |||
109 | if ($line =~ /^([a-z][a-z0-9]*)/i) { | ||
110 | $self->{op} = $1; | ||
111 | $ret = $self; | ||
112 | $line = substr($line,@+[0]); $line =~ s/^\s+//; | ||
113 | |||
114 | undef $self->{sz}; | ||
115 | if ($self->{op} =~ /^(movz)x?([bw]).*/) { # movz is pain... | ||
116 | $self->{op} = $1; | ||
117 | $self->{sz} = $2; | ||
118 | } elsif ($self->{op} =~ /call|jmp/) { | ||
119 | $self->{sz} = ""; | ||
120 | } elsif ($self->{op} =~ /^p/ && $' !~ /^(ush|op|insrw)/) { # SSEn | ||
121 | $self->{sz} = ""; | ||
122 | } elsif ($self->{op} =~ /^v/) { # VEX | ||
123 | $self->{sz} = ""; | ||
124 | } elsif ($self->{op} =~ /mov[dq]/ && $line =~ /%xmm/) { | ||
125 | $self->{sz} = ""; | ||
126 | } elsif ($self->{op} =~ /([a-z]{3,})([qlwb])$/) { | ||
127 | $self->{op} = $1; | ||
128 | $self->{sz} = $2; | ||
129 | } | ||
130 | } | ||
131 | $ret; | ||
132 | } | ||
133 | sub size { | ||
134 | my $self = shift; | ||
135 | my $sz = shift; | ||
136 | $self->{sz} = $sz if (defined($sz) && !defined($self->{sz})); | ||
137 | $self->{sz}; | ||
138 | } | ||
139 | sub out { | ||
140 | my $self = shift; | ||
141 | if ($gas) { | ||
142 | if ($self->{op} eq "movz") { # movz is pain... | ||
143 | sprintf "%s%s%s",$self->{op},$self->{sz},shift; | ||
144 | } elsif ($self->{op} =~ /^set/) { | ||
145 | "$self->{op}"; | ||
146 | } elsif ($self->{op} eq "ret") { | ||
147 | my $epilogue = ""; | ||
148 | if ($win64 && $current_function->{abi} eq "svr4") { | ||
149 | $epilogue = "movq 8(%rsp),%rdi\n\t" . | ||
150 | "movq 16(%rsp),%rsi\n\t"; | ||
151 | } | ||
152 | $epilogue . ".byte 0xf3,0xc3"; | ||
153 | } elsif ($self->{op} eq "call" && !$elf && $current_segment eq ".init") { | ||
154 | ".p2align\t3\n\t.quad"; | ||
155 | } else { | ||
156 | "$self->{op}$self->{sz}"; | ||
157 | } | ||
158 | } else { | ||
159 | $self->{op} =~ s/^movz/movzx/; | ||
160 | if ($self->{op} eq "ret") { | ||
161 | $self->{op} = ""; | ||
162 | if ($win64 && $current_function->{abi} eq "svr4") { | ||
163 | $self->{op} = "mov rdi,QWORD${PTR}[8+rsp]\t;WIN64 epilogue\n\t". | ||
164 | "mov rsi,QWORD${PTR}[16+rsp]\n\t"; | ||
165 | } | ||
166 | $self->{op} .= "DB\t0F3h,0C3h\t\t;repret"; | ||
167 | } elsif ($self->{op} =~ /^(pop|push)f/) { | ||
168 | $self->{op} .= $self->{sz}; | ||
169 | } elsif ($self->{op} eq "call" && $current_segment eq ".CRT\$XCU") { | ||
170 | $self->{op} = "\tDQ"; | ||
171 | } | ||
172 | $self->{op}; | ||
173 | } | ||
174 | } | ||
175 | sub mnemonic { | ||
176 | my $self=shift; | ||
177 | my $op=shift; | ||
178 | $self->{op}=$op if (defined($op)); | ||
179 | $self->{op}; | ||
180 | } | ||
181 | } | ||
182 | { package const; # pick up constants, which start with $ | ||
183 | sub re { | ||
184 | my $self = shift; # single instance in enough... | ||
185 | local *line = shift; | ||
186 | undef $ret; | ||
187 | |||
188 | if ($line =~ /^\$([^,]+)/) { | ||
189 | $self->{value} = $1; | ||
190 | $ret = $self; | ||
191 | $line = substr($line,@+[0]); $line =~ s/^\s+//; | ||
192 | } | ||
193 | $ret; | ||
194 | } | ||
195 | sub out { | ||
196 | my $self = shift; | ||
197 | |||
198 | if ($gas) { | ||
199 | # Solaris /usr/ccs/bin/as can't handle multiplications | ||
200 | # in $self->{value} | ||
201 | $self->{value} =~ s/(?<![\w\$\.])(0x?[0-9a-f]+)/oct($1)/egi; | ||
202 | $self->{value} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg; | ||
203 | sprintf "\$%s",$self->{value}; | ||
204 | } else { | ||
205 | $self->{value} =~ s/(0b[0-1]+)/oct($1)/eig; | ||
206 | $self->{value} =~ s/0x([0-9a-f]+)/0$1h/ig if ($masm); | ||
207 | sprintf "%s",$self->{value}; | ||
208 | } | ||
209 | } | ||
210 | } | ||
211 | { package ea; # pick up effective addresses: expr(%reg,%reg,scale) | ||
212 | sub re { | ||
213 | my $self = shift; # single instance in enough... | ||
214 | local *line = shift; | ||
215 | undef $ret; | ||
216 | |||
217 | # optional * ---vvv--- appears in indirect jmp/call | ||
218 | if ($line =~ /^(\*?)([^\(,]*)\(([%\w,]+)\)/) { | ||
219 | $self->{asterisk} = $1; | ||
220 | $self->{label} = $2; | ||
221 | ($self->{base},$self->{index},$self->{scale})=split(/,/,$3); | ||
222 | $self->{scale} = 1 if (!defined($self->{scale})); | ||
223 | $ret = $self; | ||
224 | $line = substr($line,@+[0]); $line =~ s/^\s+//; | ||
225 | |||
226 | if ($win64 && $self->{label} =~ s/\@GOTPCREL//) { | ||
227 | die if (opcode->mnemonic() ne "mov"); | ||
228 | opcode->mnemonic("lea"); | ||
229 | } | ||
230 | $self->{base} =~ s/^%//; | ||
231 | $self->{index} =~ s/^%// if (defined($self->{index})); | ||
232 | } | ||
233 | $ret; | ||
234 | } | ||
235 | sub size {} | ||
236 | sub out { | ||
237 | my $self = shift; | ||
238 | my $sz = shift; | ||
239 | |||
240 | $self->{label} =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; | ||
241 | $self->{label} =~ s/\.L/$decor/g; | ||
242 | |||
243 | # Silently convert all EAs to 64-bit. This is required for | ||
244 | # elder GNU assembler and results in more compact code, | ||
245 | # *but* most importantly AES module depends on this feature! | ||
246 | $self->{index} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/; | ||
247 | $self->{base} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/; | ||
248 | |||
249 | # Solaris /usr/ccs/bin/as can't handle multiplications | ||
250 | # in $self->{label}, new gas requires sign extension... | ||
251 | use integer; | ||
252 | $self->{label} =~ s/(?<![\w\$\.])(0x?[0-9a-f]+)/oct($1)/egi; | ||
253 | $self->{label} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg; | ||
254 | $self->{label} =~ s/([0-9]+)/$1<<32>>32/eg; | ||
255 | |||
256 | if ($gas) { | ||
257 | $self->{label} =~ s/^___imp_/__imp__/ if ($flavour eq "mingw64"); | ||
258 | |||
259 | if (defined($self->{index})) { | ||
260 | sprintf "%s%s(%s,%%%s,%d)",$self->{asterisk}, | ||
261 | $self->{label}, | ||
262 | $self->{base}?"%$self->{base}":"", | ||
263 | $self->{index},$self->{scale}; | ||
264 | } else { | ||
265 | sprintf "%s%s(%%%s)", $self->{asterisk},$self->{label},$self->{base}; | ||
266 | } | ||
267 | } else { | ||
268 | %szmap = ( b=>"BYTE$PTR", w=>"WORD$PTR", l=>"DWORD$PTR", | ||
269 | q=>"QWORD$PTR",o=>"OWORD$PTR",x=>"XMMWORD$PTR" ); | ||
270 | |||
271 | $self->{label} =~ s/\./\$/g; | ||
272 | $self->{label} =~ s/(?<![\w\$\.])0x([0-9a-f]+)/0$1h/ig; | ||
273 | $self->{label} = "($self->{label})" if ($self->{label} =~ /[\*\+\-\/]/); | ||
274 | $sz="q" if ($self->{asterisk} || opcode->mnemonic() eq "movq"); | ||
275 | $sz="l" if (opcode->mnemonic() eq "movd"); | ||
276 | |||
277 | if (defined($self->{index})) { | ||
278 | sprintf "%s[%s%s*%d%s]",$szmap{$sz}, | ||
279 | $self->{label}?"$self->{label}+":"", | ||
280 | $self->{index},$self->{scale}, | ||
281 | $self->{base}?"+$self->{base}":""; | ||
282 | } elsif ($self->{base} eq "rip") { | ||
283 | sprintf "%s[%s]",$szmap{$sz},$self->{label}; | ||
284 | } else { | ||
285 | sprintf "%s[%s%s]",$szmap{$sz}, | ||
286 | $self->{label}?"$self->{label}+":"", | ||
287 | $self->{base}; | ||
288 | } | ||
289 | } | ||
290 | } | ||
291 | } | ||
292 | { package register; # pick up registers, which start with %. | ||
293 | sub re { | ||
294 | my $class = shift; # muliple instances... | ||
295 | my $self = {}; | ||
296 | local *line = shift; | ||
297 | undef $ret; | ||
298 | |||
299 | # optional * ---vvv--- appears in indirect jmp/call | ||
300 | if ($line =~ /^(\*?)%(\w+)/) { | ||
301 | bless $self,$class; | ||
302 | $self->{asterisk} = $1; | ||
303 | $self->{value} = $2; | ||
304 | $ret = $self; | ||
305 | $line = substr($line,@+[0]); $line =~ s/^\s+//; | ||
306 | } | ||
307 | $ret; | ||
308 | } | ||
309 | sub size { | ||
310 | my $self = shift; | ||
311 | undef $ret; | ||
312 | |||
313 | if ($self->{value} =~ /^r[\d]+b$/i) { $ret="b"; } | ||
314 | elsif ($self->{value} =~ /^r[\d]+w$/i) { $ret="w"; } | ||
315 | elsif ($self->{value} =~ /^r[\d]+d$/i) { $ret="l"; } | ||
316 | elsif ($self->{value} =~ /^r[\w]+$/i) { $ret="q"; } | ||
317 | elsif ($self->{value} =~ /^[a-d][hl]$/i){ $ret="b"; } | ||
318 | elsif ($self->{value} =~ /^[\w]{2}l$/i) { $ret="b"; } | ||
319 | elsif ($self->{value} =~ /^[\w]{2}$/i) { $ret="w"; } | ||
320 | elsif ($self->{value} =~ /^e[a-z]{2}$/i){ $ret="l"; } | ||
321 | |||
322 | $ret; | ||
323 | } | ||
324 | sub out { | ||
325 | my $self = shift; | ||
326 | if ($gas) { sprintf "%s%%%s",$self->{asterisk},$self->{value}; } | ||
327 | else { $self->{value}; } | ||
328 | } | ||
329 | } | ||
330 | { package label; # pick up labels, which end with : | ||
331 | sub re { | ||
332 | my $self = shift; # single instance is enough... | ||
333 | local *line = shift; | ||
334 | undef $ret; | ||
335 | |||
336 | if ($line =~ /(^[\.\w]+)\:/) { | ||
337 | $self->{value} = $1; | ||
338 | $ret = $self; | ||
339 | $line = substr($line,@+[0]); $line =~ s/^\s+//; | ||
340 | |||
341 | $self->{value} =~ s/^\.L/$decor/; | ||
342 | } | ||
343 | $ret; | ||
344 | } | ||
345 | sub out { | ||
346 | my $self = shift; | ||
347 | |||
348 | if ($gas) { | ||
349 | my $func = ($globals{$self->{value}} or $self->{value}) . ":"; | ||
350 | if ($win64 && | ||
351 | $current_function->{name} eq $self->{value} && | ||
352 | $current_function->{abi} eq "svr4") { | ||
353 | $func .= "\n"; | ||
354 | $func .= " movq %rdi,8(%rsp)\n"; | ||
355 | $func .= " movq %rsi,16(%rsp)\n"; | ||
356 | $func .= " movq %rsp,%rax\n"; | ||
357 | $func .= "${decor}SEH_begin_$current_function->{name}:\n"; | ||
358 | my $narg = $current_function->{narg}; | ||
359 | $narg=6 if (!defined($narg)); | ||
360 | $func .= " movq %rcx,%rdi\n" if ($narg>0); | ||
361 | $func .= " movq %rdx,%rsi\n" if ($narg>1); | ||
362 | $func .= " movq %r8,%rdx\n" if ($narg>2); | ||
363 | $func .= " movq %r9,%rcx\n" if ($narg>3); | ||
364 | $func .= " movq 40(%rsp),%r8\n" if ($narg>4); | ||
365 | $func .= " movq 48(%rsp),%r9\n" if ($narg>5); | ||
366 | } | ||
367 | $func; | ||
368 | } elsif ($self->{value} ne "$current_function->{name}") { | ||
369 | $self->{value} .= ":" if ($masm && $ret!~m/^\$/); | ||
370 | $self->{value} . ":"; | ||
371 | } elsif ($win64 && $current_function->{abi} eq "svr4") { | ||
372 | my $func = "$current_function->{name}" . | ||
373 | ($nasm ? ":" : "\tPROC $current_function->{scope}") . | ||
374 | "\n"; | ||
375 | $func .= " mov QWORD${PTR}[8+rsp],rdi\t;WIN64 prologue\n"; | ||
376 | $func .= " mov QWORD${PTR}[16+rsp],rsi\n"; | ||
377 | $func .= " mov rax,rsp\n"; | ||
378 | $func .= "${decor}SEH_begin_$current_function->{name}:"; | ||
379 | $func .= ":" if ($masm); | ||
380 | $func .= "\n"; | ||
381 | my $narg = $current_function->{narg}; | ||
382 | $narg=6 if (!defined($narg)); | ||
383 | $func .= " mov rdi,rcx\n" if ($narg>0); | ||
384 | $func .= " mov rsi,rdx\n" if ($narg>1); | ||
385 | $func .= " mov rdx,r8\n" if ($narg>2); | ||
386 | $func .= " mov rcx,r9\n" if ($narg>3); | ||
387 | $func .= " mov r8,QWORD${PTR}[40+rsp]\n" if ($narg>4); | ||
388 | $func .= " mov r9,QWORD${PTR}[48+rsp]\n" if ($narg>5); | ||
389 | $func .= "\n"; | ||
390 | } else { | ||
391 | "$current_function->{name}". | ||
392 | ($nasm ? ":" : "\tPROC $current_function->{scope}"); | ||
393 | } | ||
394 | } | ||
395 | } | ||
396 | { package expr; # pick up expressioins | ||
397 | sub re { | ||
398 | my $self = shift; # single instance is enough... | ||
399 | local *line = shift; | ||
400 | undef $ret; | ||
401 | |||
402 | if ($line =~ /(^[^,]+)/) { | ||
403 | $self->{value} = $1; | ||
404 | $ret = $self; | ||
405 | $line = substr($line,@+[0]); $line =~ s/^\s+//; | ||
406 | |||
407 | $self->{value} =~ s/\@PLT// if (!$elf); | ||
408 | $self->{value} =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; | ||
409 | $self->{value} =~ s/\.L/$decor/g; | ||
410 | } | ||
411 | $ret; | ||
412 | } | ||
413 | sub out { | ||
414 | my $self = shift; | ||
415 | if ($nasm && opcode->mnemonic()=~m/^j/) { | ||
416 | "NEAR ".$self->{value}; | ||
417 | } else { | ||
418 | $self->{value}; | ||
419 | } | ||
420 | } | ||
421 | } | ||
422 | { package directive; # pick up directives, which start with . | ||
423 | sub re { | ||
424 | my $self = shift; # single instance is enough... | ||
425 | local *line = shift; | ||
426 | undef $ret; | ||
427 | my $dir; | ||
428 | my %opcode = # lea 2f-1f(%rip),%dst; 1: nop; 2: | ||
429 | ( "%rax"=>0x01058d48, "%rcx"=>0x010d8d48, | ||
430 | "%rdx"=>0x01158d48, "%rbx"=>0x011d8d48, | ||
431 | "%rsp"=>0x01258d48, "%rbp"=>0x012d8d48, | ||
432 | "%rsi"=>0x01358d48, "%rdi"=>0x013d8d48, | ||
433 | "%r8" =>0x01058d4c, "%r9" =>0x010d8d4c, | ||
434 | "%r10"=>0x01158d4c, "%r11"=>0x011d8d4c, | ||
435 | "%r12"=>0x01258d4c, "%r13"=>0x012d8d4c, | ||
436 | "%r14"=>0x01358d4c, "%r15"=>0x013d8d4c ); | ||
437 | |||
438 | if ($line =~ /^\s*(\.\w+)/) { | ||
439 | $dir = $1; | ||
440 | $ret = $self; | ||
441 | undef $self->{value}; | ||
442 | $line = substr($line,@+[0]); $line =~ s/^\s+//; | ||
443 | |||
444 | SWITCH: for ($dir) { | ||
445 | /\.picmeup/ && do { if ($line =~ /(%r[\w]+)/i) { | ||
446 | $dir="\t.long"; | ||
447 | $line=sprintf "0x%x,0x90000000",$opcode{$1}; | ||
448 | } | ||
449 | last; | ||
450 | }; | ||
451 | /\.global|\.globl|\.extern/ | ||
452 | && do { $globals{$line} = $prefix . $line; | ||
453 | $line = $globals{$line} if ($prefix); | ||
454 | last; | ||
455 | }; | ||
456 | /\.type/ && do { ($sym,$type,$narg) = split(',',$line); | ||
457 | if ($type eq "\@function") { | ||
458 | undef $current_function; | ||
459 | $current_function->{name} = $sym; | ||
460 | $current_function->{abi} = "svr4"; | ||
461 | $current_function->{narg} = $narg; | ||
462 | $current_function->{scope} = defined($globals{$sym})?"PUBLIC":"PRIVATE"; | ||
463 | } elsif ($type eq "\@abi-omnipotent") { | ||
464 | undef $current_function; | ||
465 | $current_function->{name} = $sym; | ||
466 | $current_function->{scope} = defined($globals{$sym})?"PUBLIC":"PRIVATE"; | ||
467 | } | ||
468 | $line =~ s/\@abi\-omnipotent/\@function/; | ||
469 | $line =~ s/\@function.*/\@function/; | ||
470 | last; | ||
471 | }; | ||
472 | /\.asciz/ && do { if ($line =~ /^"(.*)"$/) { | ||
473 | $dir = ".byte"; | ||
474 | $line = join(",",unpack("C*",$1),0); | ||
475 | } | ||
476 | last; | ||
477 | }; | ||
478 | /\.rva|\.long|\.quad/ | ||
479 | && do { $line =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei; | ||
480 | $line =~ s/\.L/$decor/g; | ||
481 | last; | ||
482 | }; | ||
483 | } | ||
484 | |||
485 | if ($gas) { | ||
486 | $self->{value} = $dir . "\t" . $line; | ||
487 | |||
488 | if ($dir =~ /\.extern/) { | ||
489 | $self->{value} = ""; # swallow extern | ||
490 | } elsif (!$elf && $dir =~ /\.type/) { | ||
491 | $self->{value} = ""; | ||
492 | $self->{value} = ".def\t" . ($globals{$1} or $1) . ";\t" . | ||
493 | (defined($globals{$1})?".scl 2;":".scl 3;") . | ||
494 | "\t.type 32;\t.endef" | ||
495 | if ($win64 && $line =~ /([^,]+),\@function/); | ||
496 | } elsif (!$elf && $dir =~ /\.size/) { | ||
497 | $self->{value} = ""; | ||
498 | if (defined($current_function)) { | ||
499 | $self->{value} .= "${decor}SEH_end_$current_function->{name}:" | ||
500 | if ($win64 && $current_function->{abi} eq "svr4"); | ||
501 | undef $current_function; | ||
502 | } | ||
503 | } elsif (!$elf && $dir =~ /\.align/) { | ||
504 | $self->{value} = ".p2align\t" . (log($line)/log(2)); | ||
505 | } elsif ($dir eq ".section") { | ||
506 | $current_segment=$line; | ||
507 | if (!$elf && $current_segment eq ".init") { | ||
508 | if ($flavour eq "macosx") { $self->{value} = ".mod_init_func"; } | ||
509 | elsif ($flavour eq "mingw64") { $self->{value} = ".section\t.ctors"; } | ||
510 | } | ||
511 | } elsif ($dir =~ /\.(text|data)/) { | ||
512 | $current_segment=".$1"; | ||
513 | } elsif ($dir =~ /\.hidden/) { | ||
514 | if ($flavour eq "macosx") { $self->{value} = ".private_extern\t$prefix$line"; } | ||
515 | elsif ($flavour eq "mingw64") { $self->{value} = ""; } | ||
516 | } elsif ($dir =~ /\.comm/) { | ||
517 | $self->{value} = "$dir\t$prefix$line"; | ||
518 | $self->{value} =~ s|,([0-9]+),([0-9]+)$|",$1,".log($2)/log(2)|e if ($flavour eq "macosx"); | ||
519 | } | ||
520 | $line = ""; | ||
521 | return $self; | ||
522 | } | ||
523 | |||
524 | # non-gas case or nasm/masm | ||
525 | SWITCH: for ($dir) { | ||
526 | /\.text/ && do { my $v=undef; | ||
527 | if ($nasm) { | ||
528 | $v="section .text code align=64\n"; | ||
529 | } else { | ||
530 | $v="$current_segment\tENDS\n" if ($current_segment); | ||
531 | $current_segment = ".text\$"; | ||
532 | $v.="$current_segment\tSEGMENT "; | ||
533 | $v.=$masm>=$masmref ? "ALIGN(64)" : "PAGE"; | ||
534 | $v.=" 'CODE'"; | ||
535 | } | ||
536 | $self->{value} = $v; | ||
537 | last; | ||
538 | }; | ||
539 | /\.data/ && do { my $v=undef; | ||
540 | if ($nasm) { | ||
541 | $v="section .data data align=8\n"; | ||
542 | } else { | ||
543 | $v="$current_segment\tENDS\n" if ($current_segment); | ||
544 | $current_segment = "_DATA"; | ||
545 | $v.="$current_segment\tSEGMENT"; | ||
546 | } | ||
547 | $self->{value} = $v; | ||
548 | last; | ||
549 | }; | ||
550 | /\.section/ && do { my $v=undef; | ||
551 | $line =~ s/([^,]*).*/$1/; | ||
552 | $line = ".CRT\$XCU" if ($line eq ".init"); | ||
553 | if ($nasm) { | ||
554 | $v="section $line"; | ||
555 | if ($line=~/\.([px])data/) { | ||
556 | $v.=" rdata align="; | ||
557 | $v.=$1 eq "p"? 4 : 8; | ||
558 | } elsif ($line=~/\.CRT\$/i) { | ||
559 | $v.=" rdata align=8"; | ||
560 | } | ||
561 | } else { | ||
562 | $v="$current_segment\tENDS\n" if ($current_segment); | ||
563 | $v.="$line\tSEGMENT"; | ||
564 | if ($line=~/\.([px])data/) { | ||
565 | $v.=" READONLY"; | ||
566 | $v.=" ALIGN(".($1 eq "p" ? 4 : 8).")" if ($masm>=$masmref); | ||
567 | } elsif ($line=~/\.CRT\$/i) { | ||
568 | $v.=" READONLY "; | ||
569 | $v.=$masm>=$masmref ? "ALIGN(8)" : "DWORD"; | ||
570 | } | ||
571 | } | ||
572 | $current_segment = $line; | ||
573 | $self->{value} = $v; | ||
574 | last; | ||
575 | }; | ||
576 | /\.extern/ && do { $self->{value} = "EXTERN\t".$line; | ||
577 | $self->{value} .= ":NEAR" if ($masm); | ||
578 | last; | ||
579 | }; | ||
580 | /\.globl|.global/ | ||
581 | && do { $self->{value} = $masm?"PUBLIC":"global"; | ||
582 | $self->{value} .= "\t".$line; | ||
583 | last; | ||
584 | }; | ||
585 | /\.size/ && do { if (defined($current_function)) { | ||
586 | undef $self->{value}; | ||
587 | if ($current_function->{abi} eq "svr4") { | ||
588 | $self->{value}="${decor}SEH_end_$current_function->{name}:"; | ||
589 | $self->{value}.=":\n" if($masm); | ||
590 | } | ||
591 | $self->{value}.="$current_function->{name}\tENDP" if($masm && $current_function->{name}); | ||
592 | undef $current_function; | ||
593 | } | ||
594 | last; | ||
595 | }; | ||
596 | /\.align/ && do { $self->{value} = "ALIGN\t".$line; last; }; | ||
597 | /\.(value|long|rva|quad)/ | ||
598 | && do { my $sz = substr($1,0,1); | ||
599 | my @arr = split(/,\s*/,$line); | ||
600 | my $last = pop(@arr); | ||
601 | my $conv = sub { my $var=shift; | ||
602 | $var=~s/^(0b[0-1]+)/oct($1)/eig; | ||
603 | $var=~s/^0x([0-9a-f]+)/0$1h/ig if ($masm); | ||
604 | if ($sz eq "D" && ($current_segment=~/.[px]data/ || $dir eq ".rva")) | ||
605 | { $var=~s/([_a-z\$\@][_a-z0-9\$\@]*)/$nasm?"$1 wrt ..imagebase":"imagerel $1"/egi; } | ||
606 | $var; | ||
607 | }; | ||
608 | |||
609 | $sz =~ tr/bvlrq/BWDDQ/; | ||
610 | $self->{value} = "\tD$sz\t"; | ||
611 | for (@arr) { $self->{value} .= &$conv($_).","; } | ||
612 | $self->{value} .= &$conv($last); | ||
613 | last; | ||
614 | }; | ||
615 | /\.byte/ && do { my @str=split(/,\s*/,$line); | ||
616 | map(s/(0b[0-1]+)/oct($1)/eig,@str); | ||
617 | map(s/0x([0-9a-f]+)/0$1h/ig,@str) if ($masm); | ||
618 | while ($#str>15) { | ||
619 | $self->{value}.="DB\t" | ||
620 | .join(",",@str[0..15])."\n"; | ||
621 | foreach (0..15) { shift @str; } | ||
622 | } | ||
623 | $self->{value}.="DB\t" | ||
624 | .join(",",@str) if (@str); | ||
625 | last; | ||
626 | }; | ||
627 | /\.comm/ && do { my @str=split(/,\s*/,$line); | ||
628 | my $v=undef; | ||
629 | if ($nasm) { | ||
630 | $v.="common $prefix@str[0] @str[1]"; | ||
631 | } else { | ||
632 | $v="$current_segment\tENDS\n" if ($current_segment); | ||
633 | $current_segment = "_DATA"; | ||
634 | $v.="$current_segment\tSEGMENT\n"; | ||
635 | $v.="COMM @str[0]:DWORD:".@str[1]/4; | ||
636 | } | ||
637 | $self->{value} = $v; | ||
638 | last; | ||
639 | }; | ||
640 | } | ||
641 | $line = ""; | ||
642 | } | ||
643 | |||
644 | $ret; | ||
645 | } | ||
646 | sub out { | ||
647 | my $self = shift; | ||
648 | $self->{value}; | ||
649 | } | ||
650 | } | ||
651 | |||
652 | sub rex { | ||
653 | local *opcode=shift; | ||
654 | my ($dst,$src,$rex)=@_; | ||
655 | |||
656 | $rex|=0x04 if($dst>=8); | ||
657 | $rex|=0x01 if($src>=8); | ||
658 | push @opcode,($rex|0x40) if ($rex); | ||
659 | } | ||
660 | |||
661 | # older gas and ml64 don't handle SSE>2 instructions | ||
662 | my %regrm = ( "%eax"=>0, "%ecx"=>1, "%edx"=>2, "%ebx"=>3, | ||
663 | "%esp"=>4, "%ebp"=>5, "%esi"=>6, "%edi"=>7 ); | ||
664 | |||
665 | if ($flavour ne "openbsd") { | ||
666 | |||
667 | $movq = sub { # elderly gas can't handle inter-register movq | ||
668 | my $arg = shift; | ||
669 | my @opcode=(0x66); | ||
670 | if ($arg =~ /%xmm([0-9]+),\s*%r(\w+)/) { | ||
671 | my ($src,$dst)=($1,$2); | ||
672 | if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } | ||
673 | rex(\@opcode,$src,$dst,0x8); | ||
674 | push @opcode,0x0f,0x7e; | ||
675 | push @opcode,0xc0|(($src&7)<<3)|($dst&7); # ModR/M | ||
676 | @opcode; | ||
677 | } elsif ($arg =~ /%r(\w+),\s*%xmm([0-9]+)/) { | ||
678 | my ($src,$dst)=($2,$1); | ||
679 | if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; } | ||
680 | rex(\@opcode,$src,$dst,0x8); | ||
681 | push @opcode,0x0f,0x6e; | ||
682 | push @opcode,0xc0|(($src&7)<<3)|($dst&7); # ModR/M | ||
683 | @opcode; | ||
684 | } else { | ||
685 | (); | ||
686 | } | ||
687 | }; | ||
688 | |||
689 | } | ||
690 | |||
691 | my $pextrd = sub { | ||
692 | if (shift =~ /\$([0-9]+),\s*%xmm([0-9]+),\s*(%\w+)/) { | ||
693 | my @opcode=(0x66); | ||
694 | $imm=$1; | ||
695 | $src=$2; | ||
696 | $dst=$3; | ||
697 | if ($dst =~ /%r([0-9]+)d/) { $dst = $1; } | ||
698 | elsif ($dst =~ /%e/) { $dst = $regrm{$dst}; } | ||
699 | rex(\@opcode,$src,$dst); | ||
700 | push @opcode,0x0f,0x3a,0x16; | ||
701 | push @opcode,0xc0|(($src&7)<<3)|($dst&7); # ModR/M | ||
702 | push @opcode,$imm; | ||
703 | @opcode; | ||
704 | } else { | ||
705 | (); | ||
706 | } | ||
707 | }; | ||
708 | |||
709 | my $pinsrd = sub { | ||
710 | if (shift =~ /\$([0-9]+),\s*(%\w+),\s*%xmm([0-9]+)/) { | ||
711 | my @opcode=(0x66); | ||
712 | $imm=$1; | ||
713 | $src=$2; | ||
714 | $dst=$3; | ||
715 | if ($src =~ /%r([0-9]+)/) { $src = $1; } | ||
716 | elsif ($src =~ /%e/) { $src = $regrm{$src}; } | ||
717 | rex(\@opcode,$dst,$src); | ||
718 | push @opcode,0x0f,0x3a,0x22; | ||
719 | push @opcode,0xc0|(($dst&7)<<3)|($src&7); # ModR/M | ||
720 | push @opcode,$imm; | ||
721 | @opcode; | ||
722 | } else { | ||
723 | (); | ||
724 | } | ||
725 | }; | ||
726 | |||
727 | if ($flavour ne "openbsd") { | ||
728 | |||
729 | $pshufb = sub { | ||
730 | if (shift =~ /%xmm([0-9]+),\s*%xmm([0-9]+)/) { | ||
731 | my @opcode=(0x66); | ||
732 | rex(\@opcode,$2,$1); | ||
733 | push @opcode,0x0f,0x38,0x00; | ||
734 | push @opcode,0xc0|($1&7)|(($2&7)<<3); # ModR/M | ||
735 | @opcode; | ||
736 | } else { | ||
737 | (); | ||
738 | } | ||
739 | }; | ||
740 | |||
741 | $palignr = sub { | ||
742 | if (shift =~ /\$([0-9]+),\s*%xmm([0-9]+),\s*%xmm([0-9]+)/) { | ||
743 | my @opcode=(0x66); | ||
744 | rex(\@opcode,$3,$2); | ||
745 | push @opcode,0x0f,0x3a,0x0f; | ||
746 | push @opcode,0xc0|($2&7)|(($3&7)<<3); # ModR/M | ||
747 | push @opcode,$1; | ||
748 | @opcode; | ||
749 | } else { | ||
750 | (); | ||
751 | } | ||
752 | }; | ||
753 | |||
754 | $pclmulqdq = sub { | ||
755 | if (shift =~ /\$([x0-9a-f]+),\s*%xmm([0-9]+),\s*%xmm([0-9]+)/) { | ||
756 | my @opcode=(0x66); | ||
757 | rex(\@opcode,$3,$2); | ||
758 | push @opcode,0x0f,0x3a,0x44; | ||
759 | push @opcode,0xc0|($2&7)|(($3&7)<<3); # ModR/M | ||
760 | my $c=$1; | ||
761 | push @opcode,$c=~/^0/?oct($c):$c; | ||
762 | @opcode; | ||
763 | } else { | ||
764 | (); | ||
765 | } | ||
766 | }; | ||
767 | |||
768 | } | ||
769 | |||
770 | if ($nasm) { | ||
771 | print <<___; | ||
772 | default rel | ||
773 | %define XMMWORD | ||
774 | ___ | ||
775 | } elsif ($masm) { | ||
776 | print <<___; | ||
777 | OPTION DOTNAME | ||
778 | ___ | ||
779 | } | ||
780 | while($line=<>) { | ||
781 | |||
782 | chomp($line); | ||
783 | |||
784 | $line =~ s|[#!].*$||; # get rid of asm-style comments... | ||
785 | $line =~ s|/\*.*\*/||; # ... and C-style comments... | ||
786 | $line =~ s|^\s+||; # ... and skip white spaces in beginning | ||
787 | |||
788 | undef $label; | ||
789 | undef $opcode; | ||
790 | undef @args; | ||
791 | |||
792 | if ($label=label->re(\$line)) { print $label->out(); } | ||
793 | |||
794 | if (directive->re(\$line)) { | ||
795 | printf "%s",directive->out(); | ||
796 | } elsif ($opcode=opcode->re(\$line)) { | ||
797 | my $asm = eval("\$".$opcode->mnemonic()); | ||
798 | undef @bytes; | ||
799 | |||
800 | if ((ref($asm) eq 'CODE') && scalar(@bytes=&$asm($line))) { | ||
801 | print $gas?".byte\t":"DB\t",join(',',@bytes),"\n"; | ||
802 | next; | ||
803 | } | ||
804 | |||
805 | ARGUMENT: while (1) { | ||
806 | my $arg; | ||
807 | |||
808 | if ($arg=register->re(\$line)) { opcode->size($arg->size()); } | ||
809 | elsif ($arg=const->re(\$line)) { } | ||
810 | elsif ($arg=ea->re(\$line)) { } | ||
811 | elsif ($arg=expr->re(\$line)) { } | ||
812 | else { last ARGUMENT; } | ||
813 | |||
814 | push @args,$arg; | ||
815 | |||
816 | last ARGUMENT if ($line !~ /^,/); | ||
817 | |||
818 | $line =~ s/^,\s*//; | ||
819 | } # ARGUMENT: | ||
820 | |||
821 | if ($#args>=0) { | ||
822 | my $insn; | ||
823 | my $sz=opcode->size(); | ||
824 | |||
825 | if ($gas) { | ||
826 | $insn = $opcode->out($#args>=1?$args[$#args]->size():$sz); | ||
827 | @args = map($_->out($sz),@args); | ||
828 | printf "\t%s\t%s",$insn,join(",",@args); | ||
829 | } else { | ||
830 | $insn = $opcode->out(); | ||
831 | foreach (@args) { | ||
832 | my $arg = $_->out(); | ||
833 | # $insn.=$sz compensates for movq, pinsrw, ... | ||
834 | if ($arg =~ /^xmm[0-9]+$/) { $insn.=$sz; $sz="x" if(!$sz); last; } | ||
835 | if ($arg =~ /^mm[0-9]+$/) { $insn.=$sz; $sz="q" if(!$sz); last; } | ||
836 | } | ||
837 | @args = reverse(@args); | ||
838 | undef $sz if ($nasm && $opcode->mnemonic() eq "lea"); | ||
839 | printf "\t%s\t%s",$insn,join(",",map($_->out($sz),@args)); | ||
840 | } | ||
841 | } else { | ||
842 | printf "\t%s",$opcode->out(); | ||
843 | } | ||
844 | } | ||
845 | |||
846 | print $line,"\n"; | ||
847 | } | ||
848 | |||
849 | print "\n$current_segment\tENDS\n" if ($current_segment && $masm); | ||
850 | print "END\n" if ($masm); | ||
851 | |||
852 | close STDOUT; | ||
853 | |||
854 | ################################################# | ||
855 | # Cross-reference x86_64 ABI "card" | ||
856 | # | ||
857 | # Unix Win64 | ||
858 | # %rax * * | ||
859 | # %rbx - - | ||
860 | # %rcx #4 #1 | ||
861 | # %rdx #3 #2 | ||
862 | # %rsi #2 - | ||
863 | # %rdi #1 - | ||
864 | # %rbp - - | ||
865 | # %rsp - - | ||
866 | # %r8 #5 #3 | ||
867 | # %r9 #6 #4 | ||
868 | # %r10 * * | ||
869 | # %r11 * * | ||
870 | # %r12 - - | ||
871 | # %r13 - - | ||
872 | # %r14 - - | ||
873 | # %r15 - - | ||
874 | # | ||
875 | # (*) volatile register | ||
876 | # (-) preserved by callee | ||
877 | # (#) Nth argument, volatile | ||
878 | # | ||
879 | # In Unix terms top of stack is argument transfer area for arguments | ||
880 | # which could not be accomodated in registers. Or in other words 7th | ||
881 | # [integer] argument resides at 8(%rsp) upon function entry point. | ||
882 | # 128 bytes above %rsp constitute a "red zone" which is not touched | ||
883 | # by signal handlers and can be used as temporal storage without | ||
884 | # allocating a frame. | ||
885 | # | ||
886 | # In Win64 terms N*8 bytes on top of stack is argument transfer area, | ||
887 | # which belongs to/can be overwritten by callee. N is the number of | ||
888 | # arguments passed to callee, *but* not less than 4! This means that | ||
889 | # upon function entry point 5th argument resides at 40(%rsp), as well | ||
890 | # as that 32 bytes from 8(%rsp) can always be used as temporal | ||
891 | # storage [without allocating a frame]. One can actually argue that | ||
892 | # one can assume a "red zone" above stack pointer under Win64 as well. | ||
893 | # Point is that at apparently no occasion Windows kernel would alter | ||
894 | # the area above user stack pointer in true asynchronous manner... | ||
895 | # | ||
896 | # All the above means that if assembler programmer adheres to Unix | ||
897 | # register and stack layout, but disregards the "red zone" existense, | ||
898 | # it's possible to use following prologue and epilogue to "gear" from | ||
899 | # Unix to Win64 ABI in leaf functions with not more than 6 arguments. | ||
900 | # | ||
901 | # omnipotent_function: | ||
902 | # ifdef WIN64 | ||
903 | # movq %rdi,8(%rsp) | ||
904 | # movq %rsi,16(%rsp) | ||
905 | # movq %rcx,%rdi ; if 1st argument is actually present | ||
906 | # movq %rdx,%rsi ; if 2nd argument is actually ... | ||
907 | # movq %r8,%rdx ; if 3rd argument is ... | ||
908 | # movq %r9,%rcx ; if 4th argument ... | ||
909 | # movq 40(%rsp),%r8 ; if 5th ... | ||
910 | # movq 48(%rsp),%r9 ; if 6th ... | ||
911 | # endif | ||
912 | # ... | ||
913 | # ifdef WIN64 | ||
914 | # movq 8(%rsp),%rdi | ||
915 | # movq 16(%rsp),%rsi | ||
916 | # endif | ||
917 | # ret | ||
918 | # | ||
919 | ################################################# | ||
920 | # Win64 SEH, Structured Exception Handling. | ||
921 | # | ||
922 | # Unlike on Unix systems(*) lack of Win64 stack unwinding information | ||
923 | # has undesired side-effect at run-time: if an exception is raised in | ||
924 | # assembler subroutine such as those in question (basically we're | ||
925 | # referring to segmentation violations caused by malformed input | ||
926 | # parameters), the application is briskly terminated without invoking | ||
927 | # any exception handlers, most notably without generating memory dump | ||
928 | # or any user notification whatsoever. This poses a problem. It's | ||
929 | # possible to address it by registering custom language-specific | ||
930 | # handler that would restore processor context to the state at | ||
931 | # subroutine entry point and return "exception is not handled, keep | ||
932 | # unwinding" code. Writing such handler can be a challenge... But it's | ||
933 | # doable, though requires certain coding convention. Consider following | ||
934 | # snippet: | ||
935 | # | ||
936 | # .type function,@function | ||
937 | # function: | ||
938 | # movq %rsp,%rax # copy rsp to volatile register | ||
939 | # pushq %r15 # save non-volatile registers | ||
940 | # pushq %rbx | ||
941 | # pushq %rbp | ||
942 | # movq %rsp,%r11 | ||
943 | # subq %rdi,%r11 # prepare [variable] stack frame | ||
944 | # andq $-64,%r11 | ||
945 | # movq %rax,0(%r11) # check for exceptions | ||
946 | # movq %r11,%rsp # allocate [variable] stack frame | ||
947 | # movq %rax,0(%rsp) # save original rsp value | ||
948 | # magic_point: | ||
949 | # ... | ||
950 | # movq 0(%rsp),%rcx # pull original rsp value | ||
951 | # movq -24(%rcx),%rbp # restore non-volatile registers | ||
952 | # movq -16(%rcx),%rbx | ||
953 | # movq -8(%rcx),%r15 | ||
954 | # movq %rcx,%rsp # restore original rsp | ||
955 | # ret | ||
956 | # .size function,.-function | ||
957 | # | ||
958 | # The key is that up to magic_point copy of original rsp value remains | ||
959 | # in chosen volatile register and no non-volatile register, except for | ||
960 | # rsp, is modified. While past magic_point rsp remains constant till | ||
961 | # the very end of the function. In this case custom language-specific | ||
962 | # exception handler would look like this: | ||
963 | # | ||
964 | # EXCEPTION_DISPOSITION handler (EXCEPTION_RECORD *rec,ULONG64 frame, | ||
965 | # CONTEXT *context,DISPATCHER_CONTEXT *disp) | ||
966 | # { ULONG64 *rsp = (ULONG64 *)context->Rax; | ||
967 | # if (context->Rip >= magic_point) | ||
968 | # { rsp = ((ULONG64 **)context->Rsp)[0]; | ||
969 | # context->Rbp = rsp[-3]; | ||
970 | # context->Rbx = rsp[-2]; | ||
971 | # context->R15 = rsp[-1]; | ||
972 | # } | ||
973 | # context->Rsp = (ULONG64)rsp; | ||
974 | # context->Rdi = rsp[1]; | ||
975 | # context->Rsi = rsp[2]; | ||
976 | # | ||
977 | # memcpy (disp->ContextRecord,context,sizeof(CONTEXT)); | ||
978 | # RtlVirtualUnwind(UNW_FLAG_NHANDLER,disp->ImageBase, | ||
979 | # dips->ControlPc,disp->FunctionEntry,disp->ContextRecord, | ||
980 | # &disp->HandlerData,&disp->EstablisherFrame,NULL); | ||
981 | # return ExceptionContinueSearch; | ||
982 | # } | ||
983 | # | ||
984 | # It's appropriate to implement this handler in assembler, directly in | ||
985 | # function's module. In order to do that one has to know members' | ||
986 | # offsets in CONTEXT and DISPATCHER_CONTEXT structures and some constant | ||
987 | # values. Here they are: | ||
988 | # | ||
989 | # CONTEXT.Rax 120 | ||
990 | # CONTEXT.Rcx 128 | ||
991 | # CONTEXT.Rdx 136 | ||
992 | # CONTEXT.Rbx 144 | ||
993 | # CONTEXT.Rsp 152 | ||
994 | # CONTEXT.Rbp 160 | ||
995 | # CONTEXT.Rsi 168 | ||
996 | # CONTEXT.Rdi 176 | ||
997 | # CONTEXT.R8 184 | ||
998 | # CONTEXT.R9 192 | ||
999 | # CONTEXT.R10 200 | ||
1000 | # CONTEXT.R11 208 | ||
1001 | # CONTEXT.R12 216 | ||
1002 | # CONTEXT.R13 224 | ||
1003 | # CONTEXT.R14 232 | ||
1004 | # CONTEXT.R15 240 | ||
1005 | # CONTEXT.Rip 248 | ||
1006 | # CONTEXT.Xmm6 512 | ||
1007 | # sizeof(CONTEXT) 1232 | ||
1008 | # DISPATCHER_CONTEXT.ControlPc 0 | ||
1009 | # DISPATCHER_CONTEXT.ImageBase 8 | ||
1010 | # DISPATCHER_CONTEXT.FunctionEntry 16 | ||
1011 | # DISPATCHER_CONTEXT.EstablisherFrame 24 | ||
1012 | # DISPATCHER_CONTEXT.TargetIp 32 | ||
1013 | # DISPATCHER_CONTEXT.ContextRecord 40 | ||
1014 | # DISPATCHER_CONTEXT.LanguageHandler 48 | ||
1015 | # DISPATCHER_CONTEXT.HandlerData 56 | ||
1016 | # UNW_FLAG_NHANDLER 0 | ||
1017 | # ExceptionContinueSearch 1 | ||
1018 | # | ||
1019 | # In order to tie the handler to the function one has to compose | ||
1020 | # couple of structures: one for .xdata segment and one for .pdata. | ||
1021 | # | ||
1022 | # UNWIND_INFO structure for .xdata segment would be | ||
1023 | # | ||
1024 | # function_unwind_info: | ||
1025 | # .byte 9,0,0,0 | ||
1026 | # .rva handler | ||
1027 | # | ||
1028 | # This structure designates exception handler for a function with | ||
1029 | # zero-length prologue, no stack frame or frame register. | ||
1030 | # | ||
1031 | # To facilitate composing of .pdata structures, auto-generated "gear" | ||
1032 | # prologue copies rsp value to rax and denotes next instruction with | ||
1033 | # .LSEH_begin_{function_name} label. This essentially defines the SEH | ||
1034 | # styling rule mentioned in the beginning. Position of this label is | ||
1035 | # chosen in such manner that possible exceptions raised in the "gear" | ||
1036 | # prologue would be accounted to caller and unwound from latter's frame. | ||
1037 | # End of function is marked with respective .LSEH_end_{function_name} | ||
1038 | # label. To summarize, .pdata segment would contain | ||
1039 | # | ||
1040 | # .rva .LSEH_begin_function | ||
1041 | # .rva .LSEH_end_function | ||
1042 | # .rva function_unwind_info | ||
1043 | # | ||
1044 | # Reference to functon_unwind_info from .xdata segment is the anchor. | ||
1045 | # In case you wonder why references are 32-bit .rvas and not 64-bit | ||
1046 | # .quads. References put into these two segments are required to be | ||
1047 | # *relative* to the base address of the current binary module, a.k.a. | ||
1048 | # image base. No Win64 module, be it .exe or .dll, can be larger than | ||
1049 | # 2GB and thus such relative references can be and are accommodated in | ||
1050 | # 32 bits. | ||
1051 | # | ||
1052 | # Having reviewed the example function code, one can argue that "movq | ||
1053 | # %rsp,%rax" above is redundant. It is not! Keep in mind that on Unix | ||
1054 | # rax would contain an undefined value. If this "offends" you, use | ||
1055 | # another register and refrain from modifying rax till magic_point is | ||
1056 | # reached, i.e. as if it was a non-volatile register. If more registers | ||
1057 | # are required prior [variable] frame setup is completed, note that | ||
1058 | # nobody says that you can have only one "magic point." You can | ||
1059 | # "liberate" non-volatile registers by denoting last stack off-load | ||
1060 | # instruction and reflecting it in finer grade unwind logic in handler. | ||
1061 | # After all, isn't it why it's called *language-specific* handler... | ||
1062 | # | ||
1063 | # Attentive reader can notice that exceptions would be mishandled in | ||
1064 | # auto-generated "gear" epilogue. Well, exception effectively can't | ||
1065 | # occur there, because if memory area used by it was subject to | ||
1066 | # segmentation violation, then it would be raised upon call to the | ||
1067 | # function (and as already mentioned be accounted to caller, which is | ||
1068 | # not a problem). If you're still not comfortable, then define tail | ||
1069 | # "magic point" just prior ret instruction and have handler treat it... | ||
1070 | # | ||
1071 | # (*) Note that we're talking about run-time, not debug-time. Lack of | ||
1072 | # unwind information makes debugging hard on both Windows and | ||
1073 | # Unix. "Unlike" referes to the fact that on Unix signal handler | ||
1074 | # will always be invoked, core dumped and appropriate exit code | ||
1075 | # returned to parent (for user notification). | ||