1// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
2// for details. All rights reserved. Use of this source code is governed by a
3// BSD-style license that can be found in the LICENSE file.
4
5#include "vm/globals.h"
6#if defined(HOST_OS_LINUX)
7
8#include "vm/os.h"
9
10#include <errno.h> // NOLINT
11#include <fcntl.h> // NOLINT
12#include <limits.h> // NOLINT
13#include <malloc.h> // NOLINT
14#include <sys/mman.h> // NOLINT
15#include <sys/resource.h> // NOLINT
16#include <sys/stat.h> // NOLINT
17#include <sys/syscall.h> // NOLINT
18#include <sys/time.h> // NOLINT
19#include <sys/types.h> // NOLINT
20#include <time.h> // NOLINT
21#include <unistd.h> // NOLINT
22
23#include "platform/memory_sanitizer.h"
24#include "platform/utils.h"
25#include "vm/code_observers.h"
26#include "vm/dart.h"
27#include "vm/flags.h"
28#include "vm/isolate.h"
29#include "vm/lockers.h"
30#include "vm/os_thread.h"
31#include "vm/zone.h"
32
33namespace dart {
34
35#ifndef PRODUCT
36
37DEFINE_FLAG(bool,
38 generate_perf_events_symbols,
39 false,
40 "Generate events symbols for profiling with perf (disables dual "
41 "code mapping)");
42
43DEFINE_FLAG(bool,
44 generate_perf_jitdump,
45 false,
46 "Generate jitdump file to use with perf-inject (disables dual code "
47 "mapping)");
48
49DECLARE_FLAG(bool, write_protect_code);
50DECLARE_FLAG(bool, write_protect_vm_isolate);
51#if !defined(DART_PRECOMPILED_RUNTIME)
52DECLARE_FLAG(bool, code_comments);
53#endif
54
55// Linux CodeObservers.
56
57// Simple perf support: generate /tmp/perf-<pid>.map file that maps
58// memory ranges to symbol names for JIT generated code. This allows
59// perf-report to resolve addresses falling into JIT generated code.
60// However perf-annotate does not work in this mode because JIT code
61// is transient and does not exist anymore at the moment when you
62// invoke perf-report.
63class PerfCodeObserver : public CodeObserver {
64 public:
65 PerfCodeObserver() : out_file_(NULL) {
66 Dart_FileOpenCallback file_open = Dart::file_open_callback();
67 if (file_open == NULL) {
68 return;
69 }
70 intptr_t pid = getpid();
71 char* filename = OS::SCreate(NULL, "/tmp/perf-%" Pd ".map", pid);
72 out_file_ = (*file_open)(filename, true);
73 free(filename);
74 }
75
76 ~PerfCodeObserver() {
77 Dart_FileCloseCallback file_close = Dart::file_close_callback();
78 if ((file_close == NULL) || (out_file_ == NULL)) {
79 return;
80 }
81 (*file_close)(out_file_);
82 }
83
84 virtual bool IsActive() const {
85 return FLAG_generate_perf_events_symbols && (out_file_ != NULL);
86 }
87
88 virtual void Notify(const char* name,
89 uword base,
90 uword prologue_offset,
91 uword size,
92 bool optimized,
93 const CodeComments* comments) {
94 Dart_FileWriteCallback file_write = Dart::file_write_callback();
95 if ((file_write == NULL) || (out_file_ == NULL)) {
96 return;
97 }
98 const char* marker = optimized ? "*" : "";
99 char* buffer =
100 OS::SCreate(Thread::Current()->zone(), "%" Px " %" Px " %s%s\n", base,
101 size, marker, name);
102 {
103 MutexLocker ml(CodeObservers::mutex());
104 (*file_write)(buffer, strlen(buffer), out_file_);
105 }
106 }
107
108 private:
109 void* out_file_;
110
111 DISALLOW_COPY_AND_ASSIGN(PerfCodeObserver);
112};
113
114// Code observer that generates a JITDUMP[1] file that can be interpreted by
115// perf-inject to generate ELF images for JIT generated code objects, which
116// allows both perf-report and perf-annotate to recognize them.
117//
118// Usage:
119//
120// $ perf record -k mono dart --generate-perf-jitdump benchmark.dart
121// $ perf inject -j -i perf.data -o perf.data.jitted
122// $ perf report -i perf.data.jitted
123//
124// [1] see linux/tools/perf/Documentation/jitdump-specification.txt for
125// JITDUMP binary format.
126class JitDumpCodeObserver : public CodeObserver {
127 public:
128 JitDumpCodeObserver() : pid_(getpid()) {
129 char* const filename = OS::SCreate(nullptr, "/tmp/jit-%" Pd ".dump", pid_);
130 const int fd = open(filename, O_CREAT | O_TRUNC | O_RDWR, 0666);
131 free(filename);
132
133 if (fd == -1) {
134 return;
135 }
136
137 // Map JITDUMP file, this mapping will be recorded by perf. This allows
138 // perf-inject to find this file later.
139 const long page_size = sysconf(_SC_PAGESIZE); // NOLINT(runtime/int)
140 if (page_size == -1) {
141 close(fd);
142 return;
143 }
144
145 mapped_ =
146 mmap(nullptr, page_size, PROT_READ | PROT_EXEC, MAP_PRIVATE, fd, 0);
147 if (mapped_ == nullptr) {
148 close(fd);
149 return;
150 }
151 mapped_size_ = page_size;
152
153 out_file_ = fdopen(fd, "w+");
154 if (out_file_ == nullptr) {
155 close(fd);
156 return;
157 }
158
159 // Buffer the output to avoid high IO overheads - we are going to be
160 // writing all JIT generated code out.
161 setvbuf(out_file_, nullptr, _IOFBF, 2 * MB);
162
163 // Disable code write protection and vm isolate write protection, because
164 // calling mprotect on the pages filled with JIT generated code objects
165 // confuses perf.
166 FLAG_write_protect_code = false;
167 FLAG_write_protect_vm_isolate = false;
168
169#if !defined(DART_PRECOMPILED_RUNTIME)
170 // Enable code comments.
171 FLAG_code_comments = true;
172#endif
173
174 // Write JITDUMP header.
175 WriteHeader();
176 }
177
178 ~JitDumpCodeObserver() {
179 if (mapped_ != nullptr) {
180 munmap(mapped_, mapped_size_);
181 mapped_ = nullptr;
182 }
183
184 if (out_file_ != nullptr) {
185 fclose(out_file_);
186 out_file_ = nullptr;
187 }
188 }
189
190 virtual bool IsActive() const {
191 return FLAG_generate_perf_jitdump && (out_file_ != nullptr);
192 }
193
194 virtual void Notify(const char* name,
195 uword base,
196 uword prologue_offset,
197 uword size,
198 bool optimized,
199 const CodeComments* comments) {
200 MutexLocker ml(CodeObservers::mutex());
201
202 const char* marker = optimized ? "*" : "";
203 char* buffer = OS::SCreate(Thread::Current()->zone(), "%s%s", marker, name);
204 const size_t name_length = strlen(buffer);
205
206 WriteDebugInfo(base, comments);
207
208 CodeLoadEvent ev;
209 ev.event = BaseEvent::kLoad;
210 ev.size = sizeof(ev) + (name_length + 1) + size;
211 ev.time_stamp = OS::GetCurrentMonotonicTicks();
212 ev.process_id = getpid();
213 ev.thread_id = syscall(SYS_gettid);
214 ev.vma = base;
215 ev.code_address = base;
216 ev.code_size = size;
217 ev.code_id = code_id_++;
218
219 WriteFully(&ev, sizeof(ev));
220 WriteFully(buffer, name_length + 1);
221 WriteFully(reinterpret_cast<void*>(base), size);
222 }
223
224 private:
225 struct Header {
226 const uint32_t magic = 0x4A695444;
227 const uint32_t version = 1;
228 const uint32_t size = sizeof(Header);
229 uint32_t elf_mach_target;
230 const uint32_t reserved = 0xDEADBEEF;
231 uint32_t process_id;
232 uint64_t time_stamp;
233 const uint64_t flags = 0;
234 };
235
236 struct BaseEvent {
237 enum Event {
238 kLoad = 0,
239 kMove = 1,
240 kDebugInfo = 2,
241 kClose = 3,
242 kUnwindingInfo = 4
243 };
244
245 uint32_t event;
246 uint32_t size;
247 uint64_t time_stamp;
248 };
249
250 struct CodeLoadEvent : BaseEvent {
251 uint32_t process_id;
252 uint32_t thread_id;
253 uint64_t vma;
254 uint64_t code_address;
255 uint64_t code_size;
256 uint64_t code_id;
257 };
258
259 struct DebugInfoEvent : BaseEvent {
260 uint64_t address;
261 uint64_t entry_count;
262 // DebugInfoEntry entries[entry_count_];
263 };
264
265 struct DebugInfoEntry {
266 uint64_t address;
267 int32_t line_number;
268 int32_t column;
269 // Followed by nul-terminated name.
270 };
271
272 // ELF machine architectures
273 // From linux/include/uapi/linux/elf-em.h
274 static const uint32_t EM_386 = 3;
275 static const uint32_t EM_X86_64 = 62;
276 static const uint32_t EM_ARM = 40;
277 static const uint32_t EM_AARCH64 = 183;
278
279 static uint32_t GetElfMachineArchitecture() {
280#if TARGET_ARCH_IA32
281 return EM_386;
282#elif TARGET_ARCH_X64
283 return EM_X86_64;
284#elif TARGET_ARCH_ARM
285 return EM_ARM;
286#elif TARGET_ARCH_ARM64
287 return EM_AARCH64;
288#else
289 UNREACHABLE();
290 return 0;
291#endif
292 }
293
294#if ARCH_IS_64_BIT
295 static const int kElfHeaderSize = 0x40;
296#else
297 static const int kElfHeaderSize = 0x34;
298#endif
299
300 void WriteDebugInfo(uword base, const CodeComments* comments) {
301 if (comments == nullptr || comments->Length() == 0) {
302 return;
303 }
304
305 // Open the comments file for the given code object.
306 // Note: for some reason we can't emit all comments into a single file
307 // the mapping between PCs and lines goes out of sync (might be
308 // perf-annotate bug).
309 char* comments_file_name =
310 OS::SCreate(nullptr, "/tmp/jit-%" Pd "-%" Pd ".cmts", pid_, code_id_);
311 const intptr_t filename_length = strlen(comments_file_name);
312 FILE* comments_file = fopen(comments_file_name, "w");
313 setvbuf(comments_file, nullptr, _IOFBF, 2 * MB);
314
315 // Count the number of DebugInfoEntry we are going to emit: one
316 // per PC.
317 intptr_t entry_count = 0;
318 for (uint64_t i = 0, len = comments->Length(); i < len;) {
319 const intptr_t pc_offset = comments->PCOffsetAt(i);
320 while (i < len && comments->PCOffsetAt(i) == pc_offset) {
321 i++;
322 }
323 entry_count++;
324 }
325
326 DebugInfoEvent info;
327 info.event = BaseEvent::kDebugInfo;
328 info.time_stamp = OS::GetCurrentMonotonicTicks();
329 info.address = base;
330 info.entry_count = entry_count;
331 info.size = sizeof(info) +
332 entry_count * (sizeof(DebugInfoEntry) + filename_length + 1);
333 const int32_t padding = Utils::RoundUp(info.size, 8) - info.size;
334 info.size += padding;
335
336 // Write out DebugInfoEvent record followed by entry_count DebugInfoEntry
337 // records.
338 WriteFully(&info, sizeof(info));
339 intptr_t line_number = 0; // Line number within comments_file.
340 for (intptr_t i = 0, len = comments->Length(); i < len;) {
341 const intptr_t pc_offset = comments->PCOffsetAt(i);
342 while (i < len && comments->PCOffsetAt(i) == pc_offset) {
343 line_number += WriteLn(comments_file, comments->CommentAt(i));
344 i++;
345 }
346 DebugInfoEntry entry;
347 entry.address = base + pc_offset + kElfHeaderSize;
348 entry.line_number = line_number;
349 entry.column = 0;
350 WriteFully(&entry, sizeof(entry));
351 WriteFully(comments_file_name, filename_length + 1);
352 }
353
354 // Write out the padding.
355 const char padding_bytes[8] = {0};
356 WriteFully(padding_bytes, padding);
357
358 fclose(comments_file);
359 free(comments_file_name);
360 }
361
362 void WriteHeader() {
363 Header header;
364 header.elf_mach_target = GetElfMachineArchitecture();
365 header.process_id = getpid();
366 header.time_stamp = OS::GetCurrentTimeMicros();
367 WriteFully(&header, sizeof(header));
368 }
369
370 // Returns number of new-lines written.
371 intptr_t WriteLn(FILE* f, const char* comment) {
372 fputs(comment, f);
373 fputc('\n', f);
374
375 intptr_t line_count = 1;
376 while ((comment = strstr(comment, "\n")) != nullptr) {
377 line_count++;
378 }
379 return line_count;
380 }
381
382 void WriteFully(const void* buffer, size_t size) {
383 const char* ptr = static_cast<const char*>(buffer);
384 while (size > 0) {
385 const size_t written = fwrite(ptr, 1, size, out_file_);
386 if (written == 0) {
387 UNREACHABLE();
388 break;
389 }
390 size -= written;
391 ptr += written;
392 }
393 }
394
395 const intptr_t pid_;
396
397 FILE* out_file_ = nullptr;
398 void* mapped_ = nullptr;
399 long mapped_size_ = 0; // NOLINT(runtime/int)
400
401 intptr_t code_id_ = 0;
402
403 DISALLOW_COPY_AND_ASSIGN(JitDumpCodeObserver);
404};
405
406#endif // !PRODUCT
407
408const char* OS::Name() {
409 return "linux";
410}
411
412intptr_t OS::ProcessId() {
413 return static_cast<intptr_t>(getpid());
414}
415
416static bool LocalTime(int64_t seconds_since_epoch, tm* tm_result) {
417 time_t seconds = static_cast<time_t>(seconds_since_epoch);
418 if (seconds != seconds_since_epoch) return false;
419 struct tm* error_code = localtime_r(&seconds, tm_result);
420 return error_code != NULL;
421}
422
423const char* OS::GetTimeZoneName(int64_t seconds_since_epoch) {
424 tm decomposed;
425 bool succeeded = LocalTime(seconds_since_epoch, &decomposed);
426 // If unsuccessful, return an empty string like V8 does.
427 return (succeeded && (decomposed.tm_zone != NULL)) ? decomposed.tm_zone : "";
428}
429
430int OS::GetTimeZoneOffsetInSeconds(int64_t seconds_since_epoch) {
431 tm decomposed;
432 bool succeeded = LocalTime(seconds_since_epoch, &decomposed);
433 // Even if the offset was 24 hours it would still easily fit into 32 bits.
434 // If unsuccessful, return zero like V8 does.
435 return succeeded ? static_cast<int>(decomposed.tm_gmtoff) : 0;
436}
437
438int OS::GetLocalTimeZoneAdjustmentInSeconds() {
439 // TODO(floitsch): avoid excessive calls to tzset?
440 tzset();
441 // Even if the offset was 24 hours it would still easily fit into 32 bits.
442 // Note that Unix and Dart disagree on the sign.
443 return static_cast<int>(-timezone);
444}
445
446int64_t OS::GetCurrentTimeMillis() {
447 return GetCurrentTimeMicros() / 1000;
448}
449
450int64_t OS::GetCurrentTimeMicros() {
451 // gettimeofday has microsecond resolution.
452 struct timeval tv;
453 if (gettimeofday(&tv, NULL) < 0) {
454 UNREACHABLE();
455 return 0;
456 }
457 return (static_cast<int64_t>(tv.tv_sec) * 1000000) + tv.tv_usec;
458}
459
460int64_t OS::GetCurrentMonotonicTicks() {
461 struct timespec ts;
462 if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) {
463 UNREACHABLE();
464 return 0;
465 }
466 // Convert to nanoseconds.
467 int64_t result = ts.tv_sec;
468 result *= kNanosecondsPerSecond;
469 result += ts.tv_nsec;
470 return result;
471}
472
473int64_t OS::GetCurrentMonotonicFrequency() {
474 return kNanosecondsPerSecond;
475}
476
477int64_t OS::GetCurrentMonotonicMicros() {
478 int64_t ticks = GetCurrentMonotonicTicks();
479 ASSERT(GetCurrentMonotonicFrequency() == kNanosecondsPerSecond);
480 return ticks / kNanosecondsPerMicrosecond;
481}
482
483int64_t OS::GetCurrentThreadCPUMicros() {
484 struct timespec ts;
485 if (clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts) != 0) {
486 UNREACHABLE();
487 return -1;
488 }
489 int64_t result = ts.tv_sec;
490 result *= kMicrosecondsPerSecond;
491 result += (ts.tv_nsec / kNanosecondsPerMicrosecond);
492 return result;
493}
494
495int64_t OS::GetCurrentThreadCPUMicrosForTimeline() {
496 return OS::GetCurrentThreadCPUMicros();
497}
498
499// TODO(5411554): May need to hoist these architecture dependent code
500// into a architecture specific file e.g: os_ia32_linux.cc
501intptr_t OS::ActivationFrameAlignment() {
502#if defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64) || \
503 defined(TARGET_ARCH_ARM64)
504 const int kMinimumAlignment = 16;
505#elif defined(TARGET_ARCH_ARM)
506 const int kMinimumAlignment = 8;
507#else
508#error Unsupported architecture.
509#endif
510 intptr_t alignment = kMinimumAlignment;
511 // TODO(5411554): Allow overriding default stack alignment for
512 // testing purposes.
513 // Flags::DebugIsInt("stackalign", &alignment);
514 ASSERT(Utils::IsPowerOfTwo(alignment));
515 ASSERT(alignment >= kMinimumAlignment);
516 return alignment;
517}
518
519int OS::NumberOfAvailableProcessors() {
520 return sysconf(_SC_NPROCESSORS_ONLN);
521}
522
523void OS::Sleep(int64_t millis) {
524 int64_t micros = millis * kMicrosecondsPerMillisecond;
525 SleepMicros(micros);
526}
527
528void OS::SleepMicros(int64_t micros) {
529 struct timespec req; // requested.
530 struct timespec rem; // remainder.
531 int64_t seconds = micros / kMicrosecondsPerSecond;
532 micros = micros - seconds * kMicrosecondsPerSecond;
533 int64_t nanos = micros * kNanosecondsPerMicrosecond;
534 req.tv_sec = seconds;
535 req.tv_nsec = nanos;
536 while (true) {
537 int r = nanosleep(&req, &rem);
538 if (r == 0) {
539 break;
540 }
541 // We should only ever see an interrupt error.
542 ASSERT(errno == EINTR);
543 // Copy remainder into requested and repeat.
544 req = rem;
545 }
546}
547
548// TODO(regis): Function called only from the simulator.
549void OS::DebugBreak() {
550 __builtin_trap();
551}
552
553DART_NOINLINE uintptr_t OS::GetProgramCounter() {
554 return reinterpret_cast<uintptr_t>(
555 __builtin_extract_return_addr(__builtin_return_address(0)));
556}
557
558void OS::Print(const char* format, ...) {
559 va_list args;
560 va_start(args, format);
561 VFPrint(stdout, format, args);
562 va_end(args);
563}
564
565void OS::VFPrint(FILE* stream, const char* format, va_list args) {
566 vfprintf(stream, format, args);
567 fflush(stream);
568}
569
570char* OS::SCreate(Zone* zone, const char* format, ...) {
571 va_list args;
572 va_start(args, format);
573 char* buffer = VSCreate(zone, format, args);
574 va_end(args);
575 return buffer;
576}
577
578char* OS::VSCreate(Zone* zone, const char* format, va_list args) {
579 // Measure.
580 va_list measure_args;
581 va_copy(measure_args, args);
582 intptr_t len = Utils::VSNPrint(NULL, 0, format, measure_args);
583 va_end(measure_args);
584
585 char* buffer;
586 if (zone != nullptr) {
587 buffer = zone->Alloc<char>(len + 1);
588 } else {
589 buffer = reinterpret_cast<char*>(malloc(len + 1));
590 }
591 ASSERT(buffer != NULL);
592
593 // Print.
594 va_list print_args;
595 va_copy(print_args, args);
596 Utils::VSNPrint(buffer, len + 1, format, print_args);
597 va_end(print_args);
598 return buffer;
599}
600
601bool OS::StringToInt64(const char* str, int64_t* value) {
602 ASSERT(str != NULL && strlen(str) > 0 && value != NULL);
603 int32_t base = 10;
604 char* endptr;
605 int i = 0;
606 if (str[0] == '-') {
607 i = 1;
608 } else if (str[0] == '+') {
609 i = 1;
610 }
611 if ((str[i] == '0') && (str[i + 1] == 'x' || str[i + 1] == 'X') &&
612 (str[i + 2] != '\0')) {
613 base = 16;
614 }
615 errno = 0;
616 if (base == 16) {
617 // Unsigned 64-bit hexadecimal integer literals are allowed but
618 // immediately interpreted as signed 64-bit integers.
619 *value = static_cast<int64_t>(strtoull(str, &endptr, base));
620 } else {
621 *value = strtoll(str, &endptr, base);
622 }
623 return ((errno == 0) && (endptr != str) && (*endptr == 0));
624}
625
626void OS::RegisterCodeObservers() {
627#ifndef PRODUCT
628 if (FLAG_generate_perf_events_symbols) {
629 CodeObservers::Register(new PerfCodeObserver);
630 }
631
632 if (FLAG_generate_perf_jitdump) {
633 CodeObservers::Register(new JitDumpCodeObserver);
634 }
635#endif // !PRODUCT
636}
637
638void OS::PrintErr(const char* format, ...) {
639 va_list args;
640 va_start(args, format);
641 VFPrint(stderr, format, args);
642 va_end(args);
643}
644
645void OS::Init() {}
646
647void OS::Cleanup() {}
648
649void OS::PrepareToAbort() {}
650
651void OS::Abort() {
652 PrepareToAbort();
653 abort();
654}
655
656void OS::Exit(int code) {
657 exit(code);
658}
659
660} // namespace dart
661
662#endif // defined(HOST_OS_LINUX)
663