rev 8113 : 8076475: Misuses of strncpy/strncat
Summary: Various small fixes around strncpy and strncat
Reviewed-by: dsamersoff
1 /*
2 * Copyright (c) 2008, 2015, 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 "precompiled.hpp"
26 #include "classfile/javaClasses.hpp"
27 #include "code/codeCache.hpp"
28 #include "compiler/disassembler.hpp"
29 #include "gc_interface/collectedHeap.hpp"
30 #include "memory/cardTableModRefBS.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "runtime/fprofiler.hpp"
33 #include "runtime/handles.inline.hpp"
34 #include "runtime/os.hpp"
35 #include "runtime/stubCodeGenerator.hpp"
36 #include "runtime/stubRoutines.hpp"
37 #ifdef TARGET_ARCH_x86
38 # include "depChecker_x86.hpp"
39 #endif
40 #ifdef TARGET_ARCH_sparc
41 # include "depChecker_sparc.hpp"
42 #endif
43 #ifdef TARGET_ARCH_zero
44 # include "depChecker_zero.hpp"
45 #endif
46 #ifdef TARGET_ARCH_arm
47 # include "depChecker_arm.hpp"
48 #endif
49 #ifdef TARGET_ARCH_ppc
50 # include "depChecker_ppc.hpp"
51 #endif
52 #ifdef TARGET_ARCH_aarch64
53 # include "depChecker_aarch64.hpp"
54 #endif
55 #ifdef SHARK
56 #include "shark/sharkEntry.hpp"
57 #endif
58
59 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
60
61 void* Disassembler::_library = NULL;
62 bool Disassembler::_tried_to_load_library = false;
63
64 // This routine is in the shared library:
65 Disassembler::decode_func_virtual Disassembler::_decode_instructions_virtual = NULL;
66 Disassembler::decode_func Disassembler::_decode_instructions = NULL;
67
68 static const char hsdis_library_name[] = "hsdis-"HOTSPOT_LIB_ARCH;
69 static const char decode_instructions_virtual_name[] = "decode_instructions_virtual";
70 static const char decode_instructions_name[] = "decode_instructions";
71 static bool use_new_version = true;
72 #define COMMENT_COLUMN 40 LP64_ONLY(+8) /*could be an option*/
73 #define BYTES_COMMENT ";..." /* funky byte display comment */
74
75 bool Disassembler::load_library() {
76 if (_decode_instructions_virtual != NULL || _decode_instructions != NULL) {
77 // Already succeeded.
78 return true;
79 }
80 if (_tried_to_load_library) {
81 // Do not try twice.
82 // To force retry in debugger: assign _tried_to_load_library=0
83 return false;
84 }
85 // Try to load it.
86 char ebuf[1024];
87 char buf[JVM_MAXPATHLEN];
88 os::jvm_path(buf, sizeof(buf));
89 int jvm_offset = -1;
90 int lib_offset = -1;
91 {
92 // Match "jvm[^/]*" in jvm_path.
93 const char* base = buf;
94 const char* p = strrchr(buf, *os::file_separator());
95 if (p != NULL) lib_offset = p - base + 1;
96 p = strstr(p ? p : base, "jvm");
97 if (p != NULL) jvm_offset = p - base;
98 }
99 // Find the disassembler shared library.
100 // Search for several paths derived from libjvm, in this order:
101 // 1. <home>/jre/lib/<arch>/<vm>/libhsdis-<arch>.so (for compatibility)
102 // 2. <home>/jre/lib/<arch>/<vm>/hsdis-<arch>.so
103 // 3. <home>/jre/lib/<arch>/hsdis-<arch>.so
104 // 4. hsdis-<arch>.so (using LD_LIBRARY_PATH)
105 if (jvm_offset >= 0) {
106 // 1. <home>/jre/lib/<arch>/<vm>/libhsdis-<arch>.so
107 strcpy(&buf[jvm_offset], hsdis_library_name);
108 strcat(&buf[jvm_offset], os::dll_file_extension());
109 _library = os::dll_load(buf, ebuf, sizeof ebuf);
110 if (_library == NULL) {
111 // 2. <home>/jre/lib/<arch>/<vm>/hsdis-<arch>.so
112 strcpy(&buf[lib_offset], hsdis_library_name);
113 strcat(&buf[lib_offset], os::dll_file_extension());
114 _library = os::dll_load(buf, ebuf, sizeof ebuf);
115 }
116 if (_library == NULL) {
117 // 3. <home>/jre/lib/<arch>/hsdis-<arch>.so
118 buf[lib_offset - 1] = '\0';
119 const char* p = strrchr(buf, *os::file_separator());
120 if (p != NULL) {
121 lib_offset = p - buf + 1;
122 strcpy(&buf[lib_offset], hsdis_library_name);
123 strcat(&buf[lib_offset], os::dll_file_extension());
124 _library = os::dll_load(buf, ebuf, sizeof ebuf);
125 }
126 }
127 }
128 if (_library == NULL) {
129 // 4. hsdis-<arch>.so (using LD_LIBRARY_PATH)
130 strcpy(&buf[0], hsdis_library_name);
131 strcat(&buf[0], os::dll_file_extension());
132 _library = os::dll_load(buf, ebuf, sizeof ebuf);
133 }
134 if (_library != NULL) {
135 _decode_instructions_virtual = CAST_TO_FN_PTR(Disassembler::decode_func_virtual,
136 os::dll_lookup(_library, decode_instructions_virtual_name));
137 }
138 if (_decode_instructions_virtual == NULL) {
139 // could not spot in new version, try old version
140 _decode_instructions = CAST_TO_FN_PTR(Disassembler::decode_func,
141 os::dll_lookup(_library, decode_instructions_name));
142 use_new_version = false;
143 } else {
144 use_new_version = true;
145 }
146 _tried_to_load_library = true;
147 if (_decode_instructions_virtual == NULL && _decode_instructions == NULL) {
148 tty->print_cr("Could not load %s; %s; %s", buf,
149 ((_library != NULL)
150 ? "entry point is missing"
151 : (WizardMode || PrintMiscellaneous)
152 ? (const char*)ebuf
153 : "library not loadable"),
154 "PrintAssembly is disabled");
155 return false;
156 }
157
158 // Success.
159 tty->print_cr("Loaded disassembler from %s", buf);
160 return true;
161 }
162
163
164 class decode_env {
165 private:
166 nmethod* _nm;
167 CodeBlob* _code;
168 CodeStrings _strings;
169 outputStream* _output;
170 address _start, _end;
171
172 char _option_buf[512];
173 char _print_raw;
174 bool _print_pc;
175 bool _print_bytes;
176 address _cur_insn;
177 int _total_ticks;
178 int _bytes_per_line; // arch-specific formatting option
179
180 static bool match(const char* event, const char* tag) {
181 size_t taglen = strlen(tag);
182 if (strncmp(event, tag, taglen) != 0)
183 return false;
184 char delim = event[taglen];
185 return delim == '\0' || delim == ' ' || delim == '/' || delim == '=';
186 }
187
188 void collect_options(const char* p) {
189 if (p == NULL || p[0] == '\0') return;
190 size_t opt_so_far = strlen(_option_buf);
191 if (opt_so_far + 1 + strlen(p) + 1 > sizeof(_option_buf)) return;
192 char* fillp = &_option_buf[opt_so_far];
193 if (opt_so_far > 0) *fillp++ = ',';
194 strcat(fillp, p);
195 // replace white space by commas:
196 char* q = fillp;
197 while ((q = strpbrk(q, " \t\n")) != NULL)
198 *q++ = ',';
199 // Note that multiple PrintAssemblyOptions flags accumulate with \n,
200 // which we want to be changed to a comma...
201 }
202
203 void print_insn_labels();
204 void print_insn_bytes(address pc0, address pc);
205 void print_address(address value);
206
207 public:
208 decode_env(CodeBlob* code, outputStream* output, CodeStrings c = CodeStrings());
209
210 address decode_instructions(address start, address end);
211
212 void start_insn(address pc) {
213 _cur_insn = pc;
214 output()->bol();
215 print_insn_labels();
216 }
217
218 void end_insn(address pc) {
219 address pc0 = cur_insn();
220 outputStream* st = output();
221 if (_print_bytes && pc > pc0)
222 print_insn_bytes(pc0, pc);
223 if (_nm != NULL) {
224 _nm->print_code_comment_on(st, COMMENT_COLUMN, pc0, pc);
225 // this calls reloc_string_for which calls oop::print_value_on
226 }
227
228 // Output pc bucket ticks if we have any
229 if (total_ticks() != 0) {
230 address bucket_pc = FlatProfiler::bucket_start_for(pc);
231 if (bucket_pc != NULL && bucket_pc > pc0 && bucket_pc <= pc) {
232 int bucket_count = FlatProfiler::bucket_count_for(pc0);
233 if (bucket_count != 0) {
234 st->bol();
235 st->print_cr("%3.1f%% [%d]", bucket_count*100.0/total_ticks(), bucket_count);
236 }
237 }
238 }
239 // follow each complete insn by a nice newline
240 st->cr();
241 }
242
243 address handle_event(const char* event, address arg);
244
245 outputStream* output() { return _output; }
246 address cur_insn() { return _cur_insn; }
247 int total_ticks() { return _total_ticks; }
248 void set_total_ticks(int n) { _total_ticks = n; }
249 const char* options() { return _option_buf; }
250 };
251
252 decode_env::decode_env(CodeBlob* code, outputStream* output, CodeStrings c) {
253 memset(this, 0, sizeof(*this)); // Beware, this zeroes bits of fields.
254 _output = output ? output : tty;
255 _code = code;
256 if (code != NULL && code->is_nmethod())
257 _nm = (nmethod*) code;
258 _strings.copy(c);
259
260 // by default, output pc but not bytes:
261 _print_pc = true;
262 _print_bytes = false;
263 _bytes_per_line = Disassembler::pd_instruction_alignment();
264
265 // parse the global option string:
266 collect_options(Disassembler::pd_cpu_opts());
267 collect_options(PrintAssemblyOptions);
268
269 if (strstr(options(), "hsdis-")) {
270 if (strstr(options(), "hsdis-print-raw"))
271 _print_raw = (strstr(options(), "xml") ? 2 : 1);
272 if (strstr(options(), "hsdis-print-pc"))
273 _print_pc = !_print_pc;
274 if (strstr(options(), "hsdis-print-bytes"))
275 _print_bytes = !_print_bytes;
276 }
277 if (strstr(options(), "help")) {
278 tty->print_cr("PrintAssemblyOptions help:");
279 tty->print_cr(" hsdis-print-raw test plugin by requesting raw output");
280 tty->print_cr(" hsdis-print-raw-xml test plugin by requesting raw xml");
281 tty->print_cr(" hsdis-print-pc turn off PC printing (on by default)");
282 tty->print_cr(" hsdis-print-bytes turn on instruction byte output");
283 tty->print_cr("combined options: %s", options());
284 }
285 }
286
287 address decode_env::handle_event(const char* event, address arg) {
288 if (match(event, "insn")) {
289 start_insn(arg);
290 } else if (match(event, "/insn")) {
291 end_insn(arg);
292 } else if (match(event, "addr")) {
293 if (arg != NULL) {
294 print_address(arg);
295 return arg;
296 }
297 } else if (match(event, "mach")) {
298 static char buffer[32] = { 0, };
299 if (strcmp(buffer, (const char*)arg) != 0 ||
300 strlen((const char*)arg) > sizeof(buffer) - 1) {
301 // Only print this when the mach changes
302 strncpy(buffer, (const char*)arg, sizeof(buffer) - 1);
303 buffer[sizeof(buffer) - 1] = '\0';
304 output()->print_cr("[Disassembling for mach='%s']", arg);
305 }
306 } else if (match(event, "format bytes-per-line")) {
307 _bytes_per_line = (int) (intptr_t) arg;
308 } else {
309 // ignore unrecognized markup
310 }
311 return NULL;
312 }
313
314 // called by the disassembler to print out jump targets and data addresses
315 void decode_env::print_address(address adr) {
316 outputStream* st = _output;
317
318 if (adr == NULL) {
319 st->print("NULL");
320 return;
321 }
322
323 int small_num = (int)(intptr_t)adr;
324 if ((intptr_t)adr == (intptr_t)small_num
325 && -1 <= small_num && small_num <= 9) {
326 st->print("%d", small_num);
327 return;
328 }
329
330 if (Universe::is_fully_initialized()) {
331 if (StubRoutines::contains(adr)) {
332 StubCodeDesc* desc = StubCodeDesc::desc_for(adr);
333 if (desc == NULL)
334 desc = StubCodeDesc::desc_for(adr + frame::pc_return_offset);
335 if (desc != NULL) {
336 st->print("Stub::%s", desc->name());
337 if (desc->begin() != adr)
338 st->print("%+d 0x%p",adr - desc->begin(), adr);
339 else if (WizardMode) st->print(" " PTR_FORMAT, adr);
340 return;
341 }
342 st->print("Stub::<unknown> " PTR_FORMAT, adr);
343 return;
344 }
345
346 BarrierSet* bs = Universe::heap()->barrier_set();
347 if (bs->is_a(BarrierSet::CardTableModRef) &&
348 adr == (address)(barrier_set_cast<CardTableModRefBS>(bs)->byte_map_base)) {
349 st->print("word_map_base");
350 if (WizardMode) st->print(" " INTPTR_FORMAT, (intptr_t)adr);
351 return;
352 }
353 }
354
355 // Fall through to a simple (hexadecimal) numeral.
356 st->print(PTR_FORMAT, adr);
357 }
358
359 void decode_env::print_insn_labels() {
360 address p = cur_insn();
361 outputStream* st = output();
362 CodeBlob* cb = _code;
363 if (cb != NULL) {
364 cb->print_block_comment(st, p);
365 }
366 _strings.print_block_comment(st, (intptr_t)(p - _start));
367 if (_print_pc) {
368 st->print(" " PTR_FORMAT ": ", p);
369 }
370 }
371
372 void decode_env::print_insn_bytes(address pc, address pc_limit) {
373 outputStream* st = output();
374 size_t incr = 1;
375 size_t perline = _bytes_per_line;
376 if ((size_t) Disassembler::pd_instruction_alignment() >= sizeof(int)
377 && !((uintptr_t)pc % sizeof(int))
378 && !((uintptr_t)pc_limit % sizeof(int))) {
379 incr = sizeof(int);
380 if (perline % incr) perline += incr - (perline % incr);
381 }
382 while (pc < pc_limit) {
383 // tab to the desired column:
384 st->move_to(COMMENT_COLUMN);
385 address pc0 = pc;
386 address pc1 = pc + perline;
387 if (pc1 > pc_limit) pc1 = pc_limit;
388 for (; pc < pc1; pc += incr) {
389 if (pc == pc0)
390 st->print(BYTES_COMMENT);
391 else if ((uint)(pc - pc0) % sizeof(int) == 0)
392 st->print(" "); // put out a space on word boundaries
393 if (incr == sizeof(int))
394 st->print("%08lx", *(int*)pc);
395 else st->print("%02x", (*pc)&0xFF);
396 }
397 st->cr();
398 }
399 }
400
401
402 static void* event_to_env(void* env_pv, const char* event, void* arg) {
403 decode_env* env = (decode_env*) env_pv;
404 return env->handle_event(event, (address) arg);
405 }
406
407 ATTRIBUTE_PRINTF(2, 3)
408 static int printf_to_env(void* env_pv, const char* format, ...) {
409 decode_env* env = (decode_env*) env_pv;
410 outputStream* st = env->output();
411 size_t flen = strlen(format);
412 const char* raw = NULL;
413 if (flen == 0) return 0;
414 if (flen == 1 && format[0] == '\n') { st->bol(); return 1; }
415 if (flen < 2 ||
416 strchr(format, '%') == NULL) {
417 raw = format;
418 } else if (format[0] == '%' && format[1] == '%' &&
419 strchr(format+2, '%') == NULL) {
420 // happens a lot on machines with names like %foo
421 flen--;
422 raw = format+1;
423 }
424 if (raw != NULL) {
425 st->print_raw(raw, (int) flen);
426 return (int) flen;
427 }
428 va_list ap;
429 va_start(ap, format);
430 julong cnt0 = st->count();
431 st->vprint(format, ap);
432 julong cnt1 = st->count();
433 va_end(ap);
434 return (int)(cnt1 - cnt0);
435 }
436
437 address decode_env::decode_instructions(address start, address end) {
438 _start = start; _end = end;
439
440 assert(((((intptr_t)start | (intptr_t)end) % Disassembler::pd_instruction_alignment()) == 0), "misaligned insn addr");
441
442 const int show_bytes = false; // for disassembler debugging
443
444 //_version = Disassembler::pd_cpu_version();
445
446 if (!Disassembler::can_decode()) {
447 return NULL;
448 }
449
450 // decode a series of instructions and return the end of the last instruction
451
452 if (_print_raw) {
453 // Print whatever the library wants to print, w/o fancy callbacks.
454 // This is mainly for debugging the library itself.
455 FILE* out = stdout;
456 FILE* xmlout = (_print_raw > 1 ? out : NULL);
457 return use_new_version ?
458 (address)
459 (*Disassembler::_decode_instructions_virtual)((uintptr_t)start, (uintptr_t)end,
460 start, end - start,
461 NULL, (void*) xmlout,
462 NULL, (void*) out,
463 options(), 0/*nice new line*/)
464 :
465 (address)
466 (*Disassembler::_decode_instructions)(start, end,
467 NULL, (void*) xmlout,
468 NULL, (void*) out,
469 options());
470 }
471
472 return use_new_version ?
473 (address)
474 (*Disassembler::_decode_instructions_virtual)((uintptr_t)start, (uintptr_t)end,
475 start, end - start,
476 &event_to_env, (void*) this,
477 &printf_to_env, (void*) this,
478 options(), 0/*nice new line*/)
479 :
480 (address)
481 (*Disassembler::_decode_instructions)(start, end,
482 &event_to_env, (void*) this,
483 &printf_to_env, (void*) this,
484 options());
485 }
486
487
488 void Disassembler::decode(CodeBlob* cb, outputStream* st) {
489 if (!load_library()) return;
490 decode_env env(cb, st);
491 env.output()->print_cr("Decoding CodeBlob " PTR_FORMAT, cb);
492 env.decode_instructions(cb->code_begin(), cb->code_end());
493 }
494
495 void Disassembler::decode(address start, address end, outputStream* st, CodeStrings c) {
496 if (!load_library()) return;
497 decode_env env(CodeCache::find_blob_unsafe(start), st, c);
498 env.decode_instructions(start, end);
499 }
500
501 void Disassembler::decode(nmethod* nm, outputStream* st) {
502 if (!load_library()) return;
503 decode_env env(nm, st);
504 env.output()->print_cr("Decoding compiled method " PTR_FORMAT ":", nm);
505 env.output()->print_cr("Code:");
506
507 #ifdef SHARK
508 SharkEntry* entry = (SharkEntry *) nm->code_begin();
509 unsigned char* p = entry->code_start();
510 unsigned char* end = entry->code_limit();
511 #else
512 unsigned char* p = nm->code_begin();
513 unsigned char* end = nm->code_end();
514 #endif // SHARK
515
516 // If there has been profiling, print the buckets.
517 if (FlatProfiler::bucket_start_for(p) != NULL) {
518 unsigned char* p1 = p;
519 int total_bucket_count = 0;
520 while (p1 < end) {
521 unsigned char* p0 = p1;
522 p1 += pd_instruction_alignment();
523 address bucket_pc = FlatProfiler::bucket_start_for(p1);
524 if (bucket_pc != NULL && bucket_pc > p0 && bucket_pc <= p1)
525 total_bucket_count += FlatProfiler::bucket_count_for(p0);
526 }
527 env.set_total_ticks(total_bucket_count);
528 }
529
530 // Print constant table.
531 if (nm->consts_size() > 0) {
532 nm->print_nmethod_labels(env.output(), nm->consts_begin());
533 int offset = 0;
534 for (address p = nm->consts_begin(); p < nm->consts_end(); p += 4, offset += 4) {
535 if ((offset % 8) == 0) {
536 env.output()->print_cr(" " PTR_FORMAT " (offset: %4d): " PTR32_FORMAT " " PTR64_FORMAT, p, offset, *((int32_t*) p), *((int64_t*) p));
537 } else {
538 env.output()->print_cr(" " PTR_FORMAT " (offset: %4d): " PTR32_FORMAT, p, offset, *((int32_t*) p));
539 }
540 }
541 }
542
543 env.decode_instructions(p, end);
544 }
--- EOF ---