1 /*
2 * Copyright (c) 2008, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "asm/assembler.inline.hpp"
26 #include "asm/macroAssembler.hpp"
27 #include "ci/ciUtilities.hpp"
28 #include "classfile/javaClasses.hpp"
29 #include "code/codeCache.hpp"
30 #include "compiler/disassembler.hpp"
31 #include "gc/shared/cardTable.hpp"
32 #include "gc/shared/cardTableBarrierSet.hpp"
33 #include "gc/shared/collectedHeap.hpp"
34 #include "logging/log.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "memory/universe.hpp"
37 #include "oops/oop.inline.hpp"
38 #include "runtime/handles.inline.hpp"
39 #include "runtime/java.hpp"
40 #include "runtime/os.hpp"
41 #include "runtime/stubCodeGenerator.hpp"
42 #include "runtime/stubRoutines.hpp"
43 #include "utilities/resourceHash.hpp"
44
45 void* Disassembler::_library = nullptr;
46 bool Disassembler::_tried_to_load_library = false;
47 bool Disassembler::_library_usable = false;
48
49 // This routine is in the shared library:
50 Disassembler::decode_func_virtual Disassembler::_decode_instructions_virtual = nullptr;
51
52 static const char hsdis_library_name[] = "hsdis-" HOTSPOT_LIB_ARCH;
53 static const char decode_instructions_virtual_name[] = "decode_instructions_virtual";
54 #define COMMENT_COLUMN 52 LP64_ONLY(+8) /*could be an option*/
55 #define BYTES_COMMENT ";..." /* funky byte display comment */
56
57 class decode_env {
58 private:
59 outputStream* _output; // where the disassembly is directed to
60 CodeBlob* _codeBlob; // != nullptr only when decoding a CodeBlob
61 nmethod* _nm; // != nullptr only when decoding a nmethod
62
63 address _start; // != nullptr when decoding a range of unknown type
64 address _end; // != nullptr when decoding a range of unknown type
65
66 char _option_buf[512];
67 char _print_raw;
68 address _cur_insn; // address of instruction currently being decoded
69 int _bytes_per_line; // arch-specific formatting option
70 int _pre_decode_alignment;
71 int _post_decode_alignment;
72 bool _print_file_name;
73 bool _print_help;
74 bool _helpPrinted;
75 static bool _optionsParsed;
76 #ifndef PRODUCT
77 const AsmRemarks* _remarks; // Used with start/end range to provide code remarks.
78 ptrdiff_t _disp; // Adjustment to offset -> remark mapping.
79 #endif
80
81 enum {
82 tabspacing = 8
83 };
84
85 // Check if the event matches the expected tag
86 // The tag must be a substring of the event, and
87 // the tag must be a token in the event, i.e. separated by delimiters
88 static bool match(const char* event, const char* tag) {
89 size_t eventlen = strlen(event);
90 size_t taglen = strlen(tag);
91 if (eventlen < taglen) // size mismatch
92 return false;
93 if (strncmp(event, tag, taglen) != 0) // string mismatch
94 return false;
95 char delim = event[taglen];
96 return delim == '\0' || delim == ' ' || delim == '/' || delim == '=';
97 }
98
99 // Merge new option string with previously recorded options
100 void collect_options(const char* p) {
101 if (p == nullptr || p[0] == '\0') return;
102 size_t opt_so_far = strlen(_option_buf);
103 if (opt_so_far + 1 + strlen(p) + 1 > sizeof(_option_buf)) return;
104 char* fillp = &_option_buf[opt_so_far];
105 if (opt_so_far > 0) *fillp++ = ',';
106 strcat(fillp, p);
107 // replace white space by commas:
108 char* q = fillp;
109 while ((q = strpbrk(q, " \t\n")) != nullptr)
110 *q++ = ',';
111 }
112
113 void process_options(outputStream* ost);
114
115 void print_insn_labels();
116 void print_insn_prefix();
117 void print_address(address value);
118
119 // Properly initializes _start/_end. Overwritten too often if
120 // printing of instructions is called for each instruction.
121 void set_start(address s) { _start = s; }
122 void set_end (address e) { _end = e; }
123 void set_nm (nmethod* nm) { _nm = nm; }
124 void set_output(outputStream* st) { _output = st; }
125
126 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
127 // The disassembler library (sometimes) uses tabs to nicely align the instruction operands.
128 // Depending on the mnemonic length and the column position where the
129 // mnemonic is printed, alignment may turn out to be not so nice.
130 // To improve, we assume 8-character tab spacing and left-align the mnemonic on a tab position.
131 // Instruction comments are aligned 4 tab positions to the right of the mnemonic.
132 void calculate_alignment() {
133 _pre_decode_alignment = ((output()->position()+tabspacing-1)/tabspacing)*tabspacing;
134 _post_decode_alignment = _pre_decode_alignment + 4*tabspacing;
135 }
136
137 void start_insn(address pc) {
138 _cur_insn = pc;
139 output()->bol();
140 print_insn_labels();
141 print_insn_prefix();
142 }
143
144 void end_insn(address pc) {
145 address pc0 = cur_insn();
146 outputStream* st = output();
147
148 if (AbstractDisassembler::show_comment()) {
149 if ((_nm != nullptr) && _nm->has_code_comment(pc0, pc)) {
150 _nm->print_code_comment_on
151 (st,
152 _post_decode_alignment ? _post_decode_alignment : COMMENT_COLUMN,
153 pc0, pc);
154 // this calls reloc_string_for which calls oop::print_value_on
155 }
156 print_hook_comments(pc0, _nm != nullptr);
157 }
158 Disassembler::annotate(pc0, output());
159 // follow each complete insn by a nice newline
160 st->bol();
161 }
162 #endif
163
164 struct SourceFileInfo {
165 struct Link : public CHeapObj<mtCode> {
166 const char* file;
167 int line;
168 Link* next;
169 Link(const char* f, int l) : file(f), line(l), next(nullptr) {}
170 };
171 Link *head, *tail;
172
173 void append(const char* file, int line) {
174 if (tail != nullptr && tail->file == file && tail->line == line) {
175 // Don't print duplicated lines at the same address. This could happen with C
176 // macros that end up having multiple "__" tokens on the same __LINE__.
177 return;
178 }
179 Link *link = new Link(file, line);
180 if (head == nullptr) {
181 head = tail = link;
182 } else {
183 tail->next = link;
184 tail = link;
185 }
186 }
187 SourceFileInfo(const char* file, int line) : head(nullptr), tail(nullptr) {
188 append(file, line);
189 }
190 };
191
192 typedef ResourceHashtable<
193 address, SourceFileInfo,
194 15889, // prime number
195 AnyObj::C_HEAP> SourceFileInfoTable;
196
197 static SourceFileInfoTable* _src_table;
198 static const char* _cached_src;
199 static GrowableArray<const char*>* _cached_src_lines;
200
201 static SourceFileInfoTable& src_table() {
202 if (_src_table == nullptr) {
203 _src_table = new (mtCode)SourceFileInfoTable();
204 }
205 return *_src_table;
206 }
207
208 public:
209 decode_env(CodeBlob* code, outputStream* output);
210 decode_env(nmethod* code, outputStream* output);
211 // Constructor for a 'decode_env' to decode an arbitrary
212 // piece of memory, hopefully containing code.
213 decode_env(address start, address end, outputStream* output
214 NOT_PRODUCT(COMMA const AsmRemarks* remarks = nullptr COMMA ptrdiff_t disp = 0));
215
216 // Add 'original_start' argument which is the original address
217 // the instructions were located at (if this is not equal to 'start').
218 address decode_instructions(address start, address end, address original_start = nullptr);
219
220 address handle_event(const char* event, address arg);
221
222 outputStream* output() { return _output; }
223 address cur_insn() { return _cur_insn; }
224 const char* options() { return _option_buf; }
225 static void hook(const char* file, int line, address pc);
226 void print_hook_comments(address pc, bool newline);
227 };
228
229 bool decode_env::_optionsParsed = false;
230
231 decode_env::SourceFileInfoTable* decode_env::_src_table = nullptr;
232 const char* decode_env::_cached_src = nullptr;
233 GrowableArray<const char*>* decode_env::_cached_src_lines = nullptr;
234
235 void decode_env::hook(const char* file, int line, address pc) {
236 // For simplication, we never free from this table. It's really not
237 // necessary as we add to the table only when PrintInterpreter is true,
238 // which means we are debugging the VM and a little bit of extra
239 // memory usage doesn't matter.
240 SourceFileInfo* found = src_table().get(pc);
241 if (found != nullptr) {
242 found->append(file, line);
243 } else {
244 SourceFileInfo sfi(file, line);
245 src_table().put(pc, sfi); // sfi is copied by value
246 }
247 }
248
249 void decode_env::print_hook_comments(address pc, bool newline) {
250 SourceFileInfo* found = src_table().get(pc);
251 outputStream* st = output();
252 if (found != nullptr) {
253 for (SourceFileInfo::Link *link = found->head; link; link = link->next) {
254 const char* file = link->file;
255 int line = link->line;
256 if (_cached_src == nullptr || strcmp(_cached_src, file) != 0) {
257 FILE* fp;
258
259 // _cached_src_lines is a single cache of the lines of a source file, and we refill this cache
260 // every time we need to print a line from a different source file. It's not the fastest,
261 // but seems bearable.
262 if (_cached_src_lines != nullptr) {
263 for (int i=0; i<_cached_src_lines->length(); i++) {
264 os::free((void*)_cached_src_lines->at(i));
265 }
266 _cached_src_lines->clear();
267 } else {
268 _cached_src_lines = new (mtCode) GrowableArray<const char*>(0, mtCode);
269 }
270
271 if ((fp = os::fopen(file, "r")) == nullptr) {
272 _cached_src = nullptr;
273 return;
274 }
275 _cached_src = file;
276
277 char line[500]; // don't write lines that are too long in your source files!
278 while (fgets(line, sizeof(line), fp) != nullptr) {
279 size_t len = strlen(line);
280 if (len > 0 && line[len-1] == '\n') {
281 line[len-1] = '\0';
282 }
283 _cached_src_lines->append(os::strdup(line));
284 }
285 fclose(fp);
286 _print_file_name = true;
287 }
288
289 if (_print_file_name) {
290 // We print the file name whenever we switch to a new file, or when
291 // Disassembler::decode is called to disassemble a new block of code.
292 _print_file_name = false;
293 if (newline) {
294 st->cr();
295 }
296 st->move_to(COMMENT_COLUMN);
297 st->print(";;@FILE: %s", file);
298 newline = true;
299 }
300
301 int index = line - 1; // 1-based line number -> 0-based index.
302 if (index >= _cached_src_lines->length()) {
303 // This could happen if source file is mismatched.
304 } else {
305 const char* source_line = _cached_src_lines->at(index);
306 if (newline) {
307 st->cr();
308 }
309 st->move_to(COMMENT_COLUMN);
310 st->print(";;%5d: %s", line, source_line);
311 newline = true;
312 }
313 }
314 }
315 }
316
317 decode_env::decode_env(CodeBlob* code, outputStream* output) :
318 _output(output ? output : tty),
319 _codeBlob(code),
320 _nm(_codeBlob != nullptr && _codeBlob->is_nmethod() ? (nmethod*) code : nullptr),
321 _start(nullptr),
322 _end(nullptr),
323 _option_buf(),
324 _print_raw(0),
325 _cur_insn(nullptr),
326 _bytes_per_line(0),
327 _pre_decode_alignment(0),
328 _post_decode_alignment(0),
329 _print_file_name(false),
330 _print_help(false),
331 _helpPrinted(false)
332 NOT_PRODUCT(COMMA _remarks(nullptr))
333 NOT_PRODUCT(COMMA _disp(0))
334 {
335 memset(_option_buf, 0, sizeof(_option_buf));
336 process_options(_output);
337 }
338
339 decode_env::decode_env(nmethod* code, outputStream* output) :
340 _output(output ? output : tty),
341 _codeBlob(nullptr),
342 _nm(code),
343 _start(_nm->code_begin()),
344 _end(_nm->code_end()),
345 _option_buf(),
346 _print_raw(0),
347 _cur_insn(nullptr),
348 _bytes_per_line(0),
349 _pre_decode_alignment(0),
350 _post_decode_alignment(0),
351 _print_file_name(false),
352 _print_help(false),
353 _helpPrinted(false)
354 NOT_PRODUCT(COMMA _remarks(nullptr))
355 NOT_PRODUCT(COMMA _disp(0))
356 {
357 memset(_option_buf, 0, sizeof(_option_buf));
358 process_options(_output);
359 }
360
361 // Constructor for a 'decode_env' to decode a memory range [start, end)
362 // of unknown origin, assuming it contains code.
363 decode_env::decode_env(address start, address end, outputStream* output
364 NOT_PRODUCT(COMMA const AsmRemarks* remarks COMMA ptrdiff_t disp)) :
365 _output(output ? output : tty),
366 _codeBlob(nullptr),
367 _nm(nullptr),
368 _start(start),
369 _end(end),
370 _option_buf(),
371 _print_raw(0),
372 _cur_insn(nullptr),
373 _bytes_per_line(0),
374 _pre_decode_alignment(0),
375 _post_decode_alignment(0),
376 _print_file_name(false),
377 _print_help(false),
378 _helpPrinted(false)
379 NOT_PRODUCT(COMMA _remarks(remarks))
380 NOT_PRODUCT(COMMA _disp(disp))
381 {
382 assert(start < end, "Range must have a positive size, [" PTR_FORMAT ".." PTR_FORMAT ").", p2i(start), p2i(end));
383 memset(_option_buf, 0, sizeof(_option_buf));
384 process_options(_output);
385 }
386
387 void decode_env::process_options(outputStream* ost) {
388 // by default, output pc but not bytes:
389 _print_help = false;
390 _bytes_per_line = Disassembler::pd_instruction_alignment();
391 _print_file_name = true;
392
393 // parse the global option string
394 // We need to fill the options buffer for each newly created
395 // decode_env instance. The hsdis_* library looks for options
396 // in that buffer.
397 collect_options(Disassembler::pd_cpu_opts());
398 collect_options(PrintAssemblyOptions);
399
400 if (strstr(options(), "print-raw")) {
401 _print_raw = (strstr(options(), "xml") ? 2 : 1);
402 }
403
404 if (_optionsParsed) return; // parse only once
405
406 if (strstr(options(), "help")) {
407 _print_help = true;
408 }
409 if (strstr(options(), "align-instr")) {
410 AbstractDisassembler::toggle_align_instr();
411 }
412 if (strstr(options(), "show-pc")) {
413 AbstractDisassembler::toggle_show_pc();
414 }
415 if (strstr(options(), "show-offset")) {
416 AbstractDisassembler::toggle_show_offset();
417 }
418 if (strstr(options(), "show-bytes")) {
419 AbstractDisassembler::toggle_show_bytes();
420 }
421 if (strstr(options(), "show-data-hex")) {
422 AbstractDisassembler::toggle_show_data_hex();
423 }
424 if (strstr(options(), "show-data-int")) {
425 AbstractDisassembler::toggle_show_data_int();
426 }
427 if (strstr(options(), "show-data-float")) {
428 AbstractDisassembler::toggle_show_data_float();
429 }
430 if (strstr(options(), "show-structs")) {
431 AbstractDisassembler::toggle_show_structs();
432 }
433 if (strstr(options(), "show-comment")) {
434 AbstractDisassembler::toggle_show_comment();
435 }
436 if (strstr(options(), "show-block-comment")) {
437 AbstractDisassembler::toggle_show_block_comment();
438 }
439 _optionsParsed = true;
440
441 if (_print_help && ! _helpPrinted) {
442 _helpPrinted = true;
443 ost->print_cr("PrintAssemblyOptions help:");
444 ost->print_cr(" print-raw test plugin by requesting raw output");
445 ost->print_cr(" print-raw-xml test plugin by requesting raw xml");
446 ost->cr();
447 ost->print_cr(" show-pc toggle printing current pc, currently %s", AbstractDisassembler::show_pc() ? "ON" : "OFF");
448 ost->print_cr(" show-offset toggle printing current offset, currently %s", AbstractDisassembler::show_offset() ? "ON" : "OFF");
449 ost->print_cr(" show-bytes toggle printing instruction bytes, currently %s", AbstractDisassembler::show_bytes() ? "ON" : "OFF");
450 ost->print_cr(" show-data-hex toggle formatting data as hex, currently %s", AbstractDisassembler::show_data_hex() ? "ON" : "OFF");
451 ost->print_cr(" show-data-int toggle formatting data as int, currently %s", AbstractDisassembler::show_data_int() ? "ON" : "OFF");
452 ost->print_cr(" show-data-float toggle formatting data as float, currently %s", AbstractDisassembler::show_data_float() ? "ON" : "OFF");
453 ost->print_cr(" show-structs toggle compiler data structures, currently %s", AbstractDisassembler::show_structs() ? "ON" : "OFF");
454 ost->print_cr(" show-comment toggle instruction comments, currently %s", AbstractDisassembler::show_comment() ? "ON" : "OFF");
455 ost->print_cr(" show-block-comment toggle block comments, currently %s", AbstractDisassembler::show_block_comment() ? "ON" : "OFF");
456 ost->print_cr(" align-instr toggle instruction alignment, currently %s", AbstractDisassembler::align_instr() ? "ON" : "OFF");
457 ost->print_cr("combined options: %s", options());
458 }
459 }
460
461 // Disassembly Event Handler.
462 // This method receives events from the disassembler library hsdis
463 // via event_to_env for each decoding step (installed by
464 // Disassembler::decode_instructions(), replacing the default
465 // callback method). This enables dumping additional info
466 // and custom line formatting.
467 // In a future extension, calling a custom decode method will be
468 // supported. We can use such a method to decode instructions the
469 // binutils decoder does not handle to our liking (suboptimal
470 // formatting, incomplete information, ...).
471 // Returns:
472 // - nullptr for all standard invocations. The function result is not
473 // examined (as of now, 20190409) by the hsdis decoder loop.
474 // - next for 'insn0' invocations.
475 // next == arg: the custom decoder didn't do anything.
476 // next > arg: the custom decoder did decode the instruction.
477 // next points to the next undecoded instruction
478 // (continuation point for decoder loop).
479 //
480 // "Normal" sequence of events:
481 // insns - start of instruction stream decoding
482 // mach - display architecture
483 // format - display bytes-per-line
484 // for each instruction:
485 // insn - start of instruction decoding
486 // insn0 - custom decoder invocation (if any)
487 // addr - print address value
488 // /insn - end of instruction decoding
489 // /insns - premature end of instruction stream due to no progress
490 //
491 address decode_env::handle_event(const char* event, address arg) {
492
493 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
494
495 //---< Event: end decoding loop (error, no progress) >---
496 if (decode_env::match(event, "/insns")) {
497 // Nothing to be done here.
498 return nullptr;
499 }
500
501 //---< Event: start decoding loop >---
502 if (decode_env::match(event, "insns")) {
503 // Nothing to be done here.
504 return nullptr;
505 }
506
507 //---< Event: finish decoding an instruction >---
508 if (decode_env::match(event, "/insn")) {
509 output()->fill_to(_post_decode_alignment);
510 end_insn(arg);
511 return nullptr;
512 }
513
514 //---< Event: start decoding an instruction >---
515 if (decode_env::match(event, "insn")) {
516 start_insn(arg);
517 } else if (match(event, "/insn")) {
518 end_insn(arg);
519 } else if (match(event, "addr")) {
520 if (arg != nullptr) {
521 print_address(arg);
522 return arg;
523 }
524 calculate_alignment();
525 output()->fill_to(_pre_decode_alignment);
526 return nullptr;
527 }
528
529 //---< Event: call custom decoder (platform specific) >---
530 if (decode_env::match(event, "insn0")) {
531 return Disassembler::decode_instruction0(arg, output(), arg);
532 }
533
534 //---< Event: Print address >---
535 if (decode_env::match(event, "addr")) {
536 print_address(arg);
537 return arg;
538 }
539
540 //---< Event: mach (inform about machine architecture) >---
541 // This event is problematic because it messes up the output.
542 // The event is fired after the instruction address has already
543 // been printed. The decoded instruction (event "insn") is
544 // printed afterwards. That doesn't look nice.
545 if (decode_env::match(event, "mach")) {
546 guarantee(arg != nullptr, "event_to_env - arg must not be nullptr for event 'mach'");
547 static char buffer[64] = { 0, };
548 // Output suppressed because it messes up disassembly.
549 // Only print this when the mach changes.
550 if (false && (strcmp(buffer, (const char*)arg) != 0 ||
551 strlen((const char*)arg) > sizeof(buffer) - 1)) {
552 // Only print this when the mach changes
553 strncpy(buffer, (const char*)arg, sizeof(buffer) - 1);
554 buffer[sizeof(buffer) - 1] = '\0';
555 output()->print_cr("[Disassembling for mach='%s']", (const char*)arg);
556 }
557 return nullptr;
558 }
559
560 //---< Event: format bytes-per-line >---
561 if (decode_env::match(event, "format bytes-per-line")) {
562 _bytes_per_line = (int) (intptr_t) arg;
563 return nullptr;
564 }
565 #endif
566 return nullptr;
567 }
568
569 static void* event_to_env(void* env_pv, const char* event, void* arg) {
570 decode_env* env = (decode_env*) env_pv;
571 return env->handle_event(event, (address) arg);
572 }
573
574 // called by the disassembler to print out jump targets and data addresses
575 void decode_env::print_address(address adr) {
576 outputStream* st = output();
577
578 if (adr == nullptr) {
579 st->print("nullptr");
580 return;
581 }
582
583 int small_num = (int)(intptr_t)adr;
584 if ((intptr_t)adr == (intptr_t)small_num
585 && -1 <= small_num && small_num <= 9) {
586 st->print("%d", small_num);
587 return;
588 }
589
590 if (Universe::is_fully_initialized()) {
591 if (StubRoutines::contains(adr)) {
592 StubCodeDesc* desc = StubCodeDesc::desc_for(adr);
593 if (desc == nullptr) {
594 desc = StubCodeDesc::desc_for(adr + frame::pc_return_offset);
595 }
596 if (desc != nullptr) {
597 st->print("Stub::%s", desc->name());
598 if (desc->begin() != adr) {
599 st->print("%+zd " PTR_FORMAT, adr - desc->begin(), p2i(adr));
600 } else if (WizardMode) {
601 st->print(" " PTR_FORMAT, p2i(adr));
602 }
603 return;
604 }
605 st->print("Stub::<unknown> " PTR_FORMAT, p2i(adr));
606 return;
607 }
608
609 BarrierSet* bs = BarrierSet::barrier_set();
610 if (bs->is_a(BarrierSet::CardTableBarrierSet) &&
611 adr == ci_card_table_address_as<address>()) {
612 st->print("word_map_base");
613 if (WizardMode) st->print(" " INTPTR_FORMAT, p2i(adr));
614 return;
615 }
616 }
617
618 if (_nm == nullptr) {
619 // Don't do this for native methods, as the function name will be printed in
620 // nmethod::reloc_string_for().
621 // Allocate the buffer on the stack instead of as RESOURCE array.
622 // In case we do DecodeErrorFile, Thread will not be initialized,
623 // causing a "assert(current != __null) failed" failure.
624 const int buflen = 1024;
625 char buf[buflen];
626 int offset;
627 if (os::dll_address_to_function_name(adr, buf, buflen, &offset)) {
628 st->print(PTR_FORMAT " = %s", p2i(adr), buf);
629 if (offset != 0) {
630 st->print("+%d", offset);
631 }
632 return;
633 }
634 }
635
636 // Fall through to a simple (hexadecimal) numeral.
637 st->print(PTR_FORMAT, p2i(adr));
638 }
639
640 void decode_env::print_insn_labels() {
641 if (AbstractDisassembler::show_block_comment()) {
642 address p = cur_insn();
643 outputStream* st = output();
644
645 //---< Block comments for nmethod >---
646 // Outputs a bol() before and a cr() after, but only if a comment is printed.
647 // Prints nmethod_section_label as well.
648 if (_nm != nullptr) {
649 _nm->print_block_comment(st, p);
650 }
651 else if (_codeBlob != nullptr) {
652 _codeBlob->print_block_comment(st, p);
653 }
654 #ifndef PRODUCT
655 else if (_remarks != nullptr) {
656 _remarks->print((p - _start) + _disp, st);
657 }
658 #endif
659 }
660 }
661
662 void decode_env::print_insn_prefix() {
663 address p = cur_insn();
664 outputStream* st = output();
665 AbstractDisassembler::print_location(p, _start, _end, st, false, false);
666 AbstractDisassembler::print_instruction(p, Assembler::instr_len(p), Assembler::instr_maxlen(), st, true, false);
667 }
668
669 ATTRIBUTE_PRINTF(2, 3)
670 static int printf_to_env(void* env_pv, const char* format, ...) {
671 decode_env* env = (decode_env*) env_pv;
672 outputStream* st = env->output();
673 size_t flen = strlen(format);
674 const char* raw = nullptr;
675 if (flen == 0) return 0;
676 if (flen == 1 && format[0] == '\n') { st->bol(); return 1; }
677 if (flen < 2 ||
678 strchr(format, '%') == nullptr) {
679 raw = format;
680 } else if (format[0] == '%' && format[1] == '%' &&
681 strchr(format+2, '%') == nullptr) {
682 // happens a lot on machines with names like %foo
683 flen--;
684 raw = format+1;
685 }
686 if (raw != nullptr) {
687 st->print_raw(raw, flen);
688 return (int) flen;
689 }
690 va_list ap;
691 va_start(ap, format);
692 julong cnt0 = st->count();
693 st->vprint(format, ap);
694 julong cnt1 = st->count();
695 va_end(ap);
696 return (int)(cnt1 - cnt0);
697 }
698
699 // The 'original_start' argument holds the original address where
700 // the instructions were located in the originating system. If zero (nullptr)
701 // is passed in, there is no original address.
702 address decode_env::decode_instructions(address start, address end, address original_start /* = 0*/) {
703 // CodeComment in Stubs.
704 // Properly initialize _start/_end. Overwritten too often if
705 // printing of instructions is called for each instruction.
706 assert((_start == nullptr) || (start == nullptr) || (_start == start), "don't overwrite CTOR values");
707 assert((_end == nullptr) || (end == nullptr) || (_end == end ), "don't overwrite CTOR values");
708 if (start != nullptr) set_start(start);
709 if (end != nullptr) set_end(end);
710 if (original_start == nullptr) {
711 original_start = start;
712 }
713
714 //---< Check (and correct) alignment >---
715 // Don't check alignment of end, it is not aligned.
716 if (((uint64_t)start & ((uint64_t)Disassembler::pd_instruction_alignment() - 1)) != 0) {
717 output()->print_cr("Decode range start:" PTR_FORMAT ": ... (unaligned)", p2i(start));
718 start = (address)((uint64_t)start & ~((uint64_t)Disassembler::pd_instruction_alignment() - 1));
719 }
720
721 // Trying to decode instructions doesn't make sense if we
722 // couldn't load the disassembler library.
723 if (Disassembler::is_abstract()) {
724 return nullptr;
725 }
726
727 // decode a series of instructions and return the end of the last instruction
728
729 if (_print_raw) {
730 // Print whatever the library wants to print, w/o fancy callbacks.
731 // This is mainly for debugging the library itself.
732 FILE* out = stdout;
733 FILE* xmlout = (_print_raw > 1 ? out : nullptr);
734 return
735 (address)
736 (*Disassembler::_decode_instructions_virtual)((uintptr_t)start, (uintptr_t)end,
737 start, end - start,
738 nullptr, (void*) xmlout,
739 nullptr, (void*) out,
740 options(), 0/*nice new line*/);
741 }
742
743 return
744 (address)
745 (*Disassembler::_decode_instructions_virtual)((uintptr_t)start, (uintptr_t)end,
746 start, end - start,
747 &event_to_env, (void*) this,
748 &printf_to_env, (void*) this,
749 options(), 0/*nice new line*/);
750 }
751
752 // ----------------------------------------------------------------------------
753 // Disassembler
754 // Used as a static wrapper for decode_env.
755 // Each method will create a decode_env before decoding.
756 // You can call the decode_env methods directly if you already have one.
757
758 void* Disassembler::dll_load(char* buf, int buflen, int offset, char* ebuf, int ebuflen, outputStream* st) {
759 int sz = buflen - offset;
760 int written = jio_snprintf(&buf[offset], sz, "%s%s", hsdis_library_name, JNI_LIB_SUFFIX);
761 if (written < sz) { // written successfully, not truncated.
762 if (Verbose) st->print_cr("Trying to load: %s", buf);
763 return os::dll_load(buf, ebuf, ebuflen);
764 } else if (Verbose) {
765 st->print_cr("Try to load hsdis library failed: the length of path is beyond the OS limit");
766 }
767 return nullptr;
768 }
769
770 bool Disassembler::load_library(outputStream* st) {
771 // Do not try to load multiple times. Failed once -> fails always.
772 // To force retry in debugger: assign _tried_to_load_library=0
773 if (_tried_to_load_library) {
774 return _library_usable;
775 }
776
777 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
778 // Print to given stream, if any.
779 // Print to tty if Verbose is on and no stream given.
780 st = ((st == nullptr) && Verbose) ? tty : st;
781
782 // Compute fully qualified library name.
783 char ebuf[1024];
784 char buf[JVM_MAXPATHLEN];
785 os::jvm_path(buf, sizeof(buf));
786 int jvm_offset = -1;
787 int lib_offset = -1;
788
789 if (is_vm_statically_linked()) {
790 char* p = strrchr(buf, '/');
791 *p = '\0';
792 strcat(p, "/lib/");
793 lib_offset = jvm_offset = (int)strlen(buf);
794 } else {
795 // Match "libjvm" instead of "jvm" on *nix platforms. Creates better matches.
796 // Match "[lib]jvm[^/]*" in jvm_path.
797 const char* base = buf;
798 const char* p = strrchr(buf, *os::file_separator());
799 if (p != nullptr) lib_offset = p - base + 1; // this points to the first char after separator
800 #ifdef _WIN32
801 p = strstr(p ? p : base, "jvm");
802 if (p != nullptr) jvm_offset = p - base; // this points to 'j' in jvm.
803 #else
804 p = strstr(p ? p : base, "libjvm");
805 if (p != nullptr) jvm_offset = p - base + 3; // this points to 'j' in libjvm.
806 #endif
807 }
808
809 // Find the disassembler shared library.
810 // Search for several paths derived from libjvm, in this order:
811 // 1. <home>/lib/<vm>/libhsdis-<arch>.so (for compatibility)
812 // 2. <home>/lib/<vm>/hsdis-<arch>.so
813 // 3. <home>/lib/hsdis-<arch>.so
814 // 4. hsdis-<arch>.so (using LD_LIBRARY_PATH)
815 if (jvm_offset >= 0) {
816 // 1. <home>/lib/<vm>/libhsdis-<arch>.so
817 _library = dll_load(buf, sizeof buf, jvm_offset, ebuf, sizeof ebuf, st);
818 if (_library == nullptr && lib_offset >= 0) {
819 // 2. <home>/lib/<vm>/hsdis-<arch>.so
820 _library = dll_load(buf, sizeof buf, lib_offset, ebuf, sizeof ebuf, st);
821 }
822 if (_library == nullptr && lib_offset > 0) {
823 // 3. <home>/lib/hsdis-<arch>.so
824 buf[lib_offset - 1] = '\0';
825 const char* p = strrchr(buf, *os::file_separator());
826 if (p != nullptr) {
827 lib_offset = p - buf + 1;
828 _library = dll_load(buf, sizeof buf, lib_offset, ebuf, sizeof ebuf, st);
829 }
830 }
831 }
832 if (_library == nullptr) {
833 _library = dll_load(buf, sizeof buf, 0, ebuf, sizeof ebuf, st);
834 }
835
836 // load the decoder function to use.
837 if (_library != nullptr) {
838 _decode_instructions_virtual = CAST_TO_FN_PTR(Disassembler::decode_func_virtual,
839 os::dll_lookup(_library, decode_instructions_virtual_name));
840 } else {
841 log_warning(os)("Loading hsdis library failed");
842 }
843 _tried_to_load_library = true;
844 _library_usable = _decode_instructions_virtual != nullptr;
845
846 // Create a dummy environment to initialize PrintAssemblyOptions.
847 // The PrintAssemblyOptions must be known for abstract disassemblies as well.
848 decode_env dummy((unsigned char*)(&buf[0]), (unsigned char*)(&buf[1]), st);
849
850 // Report problems during dll_load or dll_lookup, if any.
851 if (st != nullptr) {
852 // Success.
853 if (_library_usable) {
854 st->print_cr("Loaded disassembler from %s", buf);
855 } else {
856 st->print_cr("Could not load %s; %s; %s",
857 buf,
858 ((_library != nullptr)
859 ? "entry point is missing"
860 : ((WizardMode || PrintMiscellaneous)
861 ? (const char*)ebuf
862 : "library not loadable")),
863 "PrintAssembly defaults to abstract disassembly.");
864 }
865 }
866 #endif
867 return _library_usable;
868 }
869
870
871 // Directly disassemble code blob.
872 void Disassembler::decode(CodeBlob* cb, outputStream* st) {
873 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
874 if (cb->is_nmethod()) {
875 // If we have an nmethod at hand,
876 // call the specialized decoder directly.
877 ((nmethod*)cb)->decode2(st);
878 return;
879 }
880
881 decode_env env(cb, st);
882 env.output()->print_cr("--------------------------------------------------------------------------------");
883 env.output()->print("Decoding CodeBlob");
884 if (cb->name() != nullptr) {
885 env.output()->print(", name: %s,", cb->name());
886 }
887 env.output()->print_cr(" at [" PTR_FORMAT ", " PTR_FORMAT "] " JLONG_FORMAT " bytes", p2i(cb->code_begin()), p2i(cb->code_end()), ((jlong)(cb->code_end() - cb->code_begin())));
888
889 if (is_abstract()) {
890 AbstractDisassembler::decode_abstract(cb->code_begin(), cb->code_end(), env.output(), Assembler::instr_maxlen());
891 } else {
892 env.decode_instructions(cb->code_begin(), cb->code_end());
893 }
894 env.output()->print_cr("--------------------------------------------------------------------------------");
895 #endif
896 }
897
898 // Decode a nmethod.
899 // This includes printing the constant pool and all code segments.
900 // The nmethod data structures (oop maps, relocations and the like) are not printed.
901 void Disassembler::decode(nmethod* nm, outputStream* st) {
902 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
903 ttyLocker ttyl;
904
905 decode_env env(nm, st);
906 env.output()->print_cr("--------------------------------------------------------------------------------");
907 nm->print_constant_pool(env.output());
908 env.output()->print_cr("--------------------------------------------------------------------------------");
909 env.output()->cr();
910 if (is_abstract()) {
911 AbstractDisassembler::decode_abstract(nm->code_begin(), nm->code_end(), env.output(), Assembler::instr_maxlen());
912 } else {
913 env.decode_instructions(nm->code_begin(), nm->code_end());
914 }
915 env.output()->print_cr("--------------------------------------------------------------------------------");
916 #endif
917 }
918
919 // Decode a range, given as [start address, end address)
920 void Disassembler::decode(address start, address end, outputStream* st
921 NOT_PRODUCT(COMMA const AsmRemarks* remarks COMMA ptrdiff_t disp)) {
922 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
923 //---< Test memory before decoding >---
924 if (!os::is_readable_range(start, end)) {
925 //---< Allow output suppression, but prevent writing to a nullptr stream. Could happen with +PrintStubCode. >---
926 if (st != nullptr) {
927 st->print("Memory range [" PTR_FORMAT ".." PTR_FORMAT "] not readable", p2i(start), p2i(end));
928 }
929 return;
930 }
931
932 if (is_abstract()) {
933 AbstractDisassembler::decode_abstract(start, end, st, Assembler::instr_maxlen());
934 } else {
935 // This seems to be just a chunk of memory.
936 decode_env env(start, end, st NOT_PRODUCT(COMMA remarks COMMA disp));
937 env.output()->print_cr("--------------------------------------------------------------------------------");
938 env.decode_instructions(start, end);
939 env.output()->print_cr("--------------------------------------------------------------------------------");
940 }
941 #endif
942 }
943
944 // To prevent excessive code expansion in the interpreter generator, we
945 // do not inline this function into Disassembler::hook().
946 void Disassembler::_hook(const char* file, int line, MacroAssembler* masm) {
947 decode_env::hook(file, line, masm->code_section()->end());
948 }