1 /*
2 * Copyright (C) 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "JITDebugReader.h"
18
19 #include <inttypes.h>
20 #include <stdio.h>
21 #include <sys/mman.h>
22 #include <sys/uio.h>
23 #include <sys/user.h>
24 #include <unistd.h>
25
26 #include <algorithm>
27 #include <unordered_map>
28 #include <unordered_set>
29 #include <vector>
30
31 #include <android-base/file.h>
32 #include <android-base/logging.h>
33 #include <android-base/stringprintf.h>
34 #include <android-base/strings.h>
35
36 #include "JITDebugReader_impl.h"
37 #include "dso.h"
38 #include "environment.h"
39 #include "read_apk.h"
40 #include "read_dex_file.h"
41 #include "read_elf.h"
42 #include "utils.h"
43
44 namespace simpleperf {
45
46 using namespace JITDebugReader_impl;
47 using android::base::StartsWith;
48 using android::base::StringPrintf;
49
50 // If the size of a symfile is larger than EXPECTED_MAX_SYMFILE_SIZE, we don't want to read it
51 // remotely.
52 static constexpr size_t MAX_JIT_SYMFILE_SIZE = 1 * kMegabyte;
53
54 // It takes about 30us-130us on Pixel (depending on the cpu frequency) to check if the descriptors
55 // have been updated (most time spent in process_vm_preadv). We want to know if the JIT debug info
56 // changed as soon as possible, while not wasting too much time checking for updates. So use a
57 // period of 100 ms.
58 // In system wide profiling, we may need to check JIT debug info changes for many processes, to
59 // avoid spending all time checking, wait 100 ms between any two checks.
60 static constexpr size_t kUpdateJITDebugInfoIntervalInMs = 100;
61
62 // map name used for jit zygote cache
63 static const char* kJITZygoteCacheMmapPrefix = "/memfd:jit-zygote-cache";
64
65 // Match the format of JITDescriptor in art/runtime/jit/debugger_interface.cc.
66 template <typename ADDRT>
67 struct JITDescriptor {
68 uint32_t version;
69 uint32_t action_flag;
70 ADDRT relevant_entry_addr;
71 ADDRT first_entry_addr;
72 uint8_t magic[8];
73 uint32_t flags;
74 uint32_t sizeof_descriptor;
75 uint32_t sizeof_entry;
76 uint32_t action_seqlock; // incremented before and after any modification
77 uint64_t action_timestamp; // CLOCK_MONOTONIC time of last action
78
79 bool Valid() const;
80
AndroidVersionsimpleperf::JITDescriptor81 int AndroidVersion() const { return magic[7] - '0'; }
82 };
83
84 // Match the format of JITCodeEntry in art/runtime/jit/debugger_interface.cc
85 // with JITDescriptor.magic == "Android1".
86 template <typename ADDRT>
87 struct JITCodeEntry {
88 ADDRT next_addr;
89 ADDRT prev_addr;
90 ADDRT symfile_addr;
91 uint64_t symfile_size;
92 uint64_t register_timestamp; // CLOCK_MONOTONIC time of entry registration
93
Validsimpleperf::JITCodeEntry94 bool Valid() const { return symfile_addr > 0u && symfile_size > 0u; }
95 };
96
97 // Match the format of JITCodeEntry in art/runtime/jit/debugger_interface.cc
98 // with JITDescriptor.magic == "Android1".
99 template <typename ADDRT>
100 struct __attribute__((packed)) PackedJITCodeEntry {
101 ADDRT next_addr;
102 ADDRT prev_addr;
103 ADDRT symfile_addr;
104 uint64_t symfile_size;
105 uint64_t register_timestamp;
106
Validsimpleperf::PackedJITCodeEntry107 bool Valid() const { return symfile_addr > 0u && symfile_size > 0u; }
108 };
109
110 // Match the format of JITCodeEntry in art/runtime/jit/debugger_interface.cc
111 // with JITDescriptor.magic == "Android2".
112 template <typename ADDRT>
113 struct JITCodeEntryV2 {
114 ADDRT next_addr;
115 ADDRT prev_addr;
116 ADDRT symfile_addr;
117 uint64_t symfile_size;
118 uint64_t register_timestamp; // CLOCK_MONOTONIC time of entry registration
119 uint32_t seqlock; // even value if valid
120
Validsimpleperf::JITCodeEntryV2121 bool Valid() const { return (seqlock & 1) == 0; }
122 };
123
124 // Match the format of JITCodeEntry in art/runtime/jit/debugger_interface.cc
125 // with JITDescriptor.magic == "Android2".
126 template <typename ADDRT>
127 struct __attribute__((packed)) PackedJITCodeEntryV2 {
128 ADDRT next_addr;
129 ADDRT prev_addr;
130 ADDRT symfile_addr;
131 uint64_t symfile_size;
132 uint64_t register_timestamp;
133 uint32_t seqlock;
134
Validsimpleperf::PackedJITCodeEntryV2135 bool Valid() const { return (seqlock & 1) == 0; }
136 };
137
138 // Match the format of JITCodeEntry in art/runtime/jit/debugger_interface.cc
139 // with JITDescriptor.magic == "Android2".
140 template <typename ADDRT>
141 struct __attribute__((packed)) PaddedJITCodeEntryV2 {
142 ADDRT next_addr;
143 ADDRT prev_addr;
144 ADDRT symfile_addr;
145 uint64_t symfile_size;
146 uint64_t register_timestamp;
147 uint32_t seqlock;
148 uint32_t pad;
149
Validsimpleperf::PaddedJITCodeEntryV2150 bool Valid() const { return (seqlock & 1) == 0; }
151 };
152
153 using JITDescriptor32 = JITDescriptor<uint32_t>;
154 using JITDescriptor64 = JITDescriptor<uint64_t>;
155
156 #if defined(__x86_64__)
157 // Make sure simpleperf built for i386 and x86_64 see the correct JITCodeEntry layout of i386.
158 using JITCodeEntry32 = PackedJITCodeEntry<uint32_t>;
159 using JITCodeEntry32V2 = PackedJITCodeEntryV2<uint32_t>;
160 #else
161 using JITCodeEntry32 = JITCodeEntry<uint32_t>;
162 using JITCodeEntry32V2 = JITCodeEntryV2<uint32_t>;
163 #endif
164
165 using JITCodeEntry64 = JITCodeEntry<uint64_t>;
166 #if defined(__i386__)
167 // Make sure simpleperf built for i386 and x86_64 see the correct JITCodeEntry layout of x86_64.
168 using JITCodeEntry64V2 = PaddedJITCodeEntryV2<uint64_t>;
169 #else
170 using JITCodeEntry64V2 = JITCodeEntryV2<uint64_t>;
171 #endif
172
173 template <typename ADDRT>
Valid() const174 bool JITDescriptor<ADDRT>::Valid() const {
175 const char* magic_str = reinterpret_cast<const char*>(magic);
176 if (version != 1 ||
177 !(strncmp(magic_str, "Android1", 8) == 0 || strncmp(magic_str, "Android2", 8) == 0)) {
178 return false;
179 }
180 if (sizeof(*this) != sizeof_descriptor) {
181 return false;
182 }
183 if (sizeof(ADDRT) == 4) {
184 return sizeof_entry == (AndroidVersion() == 1) ? sizeof(JITCodeEntry32)
185 : sizeof(JITCodeEntry32V2);
186 }
187 return sizeof_entry == (AndroidVersion() == 1) ? sizeof(JITCodeEntry64)
188 : sizeof(JITCodeEntry64V2);
189 }
190
191 // We want to support both 64-bit and 32-bit simpleperf when profiling either 64-bit or 32-bit
192 // apps. So using static_asserts to make sure that simpleperf on arm and aarch64 having the same
193 // view of structures, and simpleperf on i386 and x86_64 having the same view of structures.
194 static_assert(sizeof(JITDescriptor32) == 48, "");
195 static_assert(sizeof(JITDescriptor64) == 56, "");
196
197 #if defined(__i386__) or defined(__x86_64__)
198 static_assert(sizeof(JITCodeEntry32) == 28, "");
199 static_assert(sizeof(JITCodeEntry32V2) == 32, "");
200 static_assert(sizeof(JITCodeEntry64) == 40, "");
201 static_assert(sizeof(JITCodeEntry64V2) == 48, "");
202 #else
203 static_assert(sizeof(JITCodeEntry32) == 32, "");
204 static_assert(sizeof(JITCodeEntry32V2) == 40, "");
205 static_assert(sizeof(JITCodeEntry64) == 40, "");
206 static_assert(sizeof(JITCodeEntry64V2) == 48, "");
207 #endif
208
JITDebugReader(const std::string & symfile_prefix,SymFileOption symfile_option,SyncOption sync_option)209 JITDebugReader::JITDebugReader(const std::string& symfile_prefix, SymFileOption symfile_option,
210 SyncOption sync_option)
211 : symfile_prefix_(symfile_prefix), symfile_option_(symfile_option), sync_option_(sync_option) {}
212
~JITDebugReader()213 JITDebugReader::~JITDebugReader() {}
214
RegisterDebugInfoCallback(IOEventLoop * loop,const debug_info_callback_t & callback)215 bool JITDebugReader::RegisterDebugInfoCallback(IOEventLoop* loop,
216 const debug_info_callback_t& callback) {
217 debug_info_callback_ = callback;
218 read_event_ = loop->AddPeriodicEvent(SecondToTimeval(kUpdateJITDebugInfoIntervalInMs / 1000.0),
219 [this]() { return ReadAllProcesses(); });
220 return (read_event_ != nullptr && IOEventLoop::DisableEvent(read_event_));
221 }
222
MonitorProcess(pid_t pid)223 bool JITDebugReader::MonitorProcess(pid_t pid) {
224 if (processes_.find(pid) == processes_.end()) {
225 processes_[pid].pid = pid;
226 LOG(DEBUG) << "Start monitoring process " << pid;
227 if (processes_.size() == 1u) {
228 if (!IOEventLoop::EnableEvent(read_event_)) {
229 return false;
230 }
231 }
232 }
233 return true;
234 }
235
IsArtLib(const std::string & filename)236 static bool IsArtLib(const std::string& filename) {
237 return android::base::EndsWith(filename, "libart.so") ||
238 android::base::EndsWith(filename, "libartd.so");
239 }
240
UpdateRecord(const Record * record)241 bool JITDebugReader::UpdateRecord(const Record* record) {
242 if (record->type() == PERF_RECORD_MMAP) {
243 auto r = static_cast<const MmapRecord*>(record);
244 if (IsArtLib(r->filename)) {
245 pids_with_art_lib_.emplace(r->data->pid, false);
246 }
247 } else if (record->type() == PERF_RECORD_MMAP2) {
248 auto r = static_cast<const Mmap2Record*>(record);
249 if (IsArtLib(r->filename)) {
250 pids_with_art_lib_.emplace(r->data->pid, false);
251 }
252 } else if (record->type() == PERF_RECORD_FORK) {
253 auto r = static_cast<const ForkRecord*>(record);
254 if (r->data->pid != r->data->ppid &&
255 pids_with_art_lib_.find(r->data->ppid) != pids_with_art_lib_.end()) {
256 pids_with_art_lib_.emplace(r->data->pid, false);
257 }
258 } else if (record->type() == PERF_RECORD_SAMPLE) {
259 auto r = static_cast<const SampleRecord*>(record);
260 auto it = pids_with_art_lib_.find(r->tid_data.pid);
261 if (it != pids_with_art_lib_.end() && !it->second) {
262 it->second = true;
263 if (!MonitorProcess(r->tid_data.pid)) {
264 return false;
265 }
266 return ReadProcess(r->tid_data.pid);
267 }
268 }
269 return FlushDebugInfo(record->Timestamp());
270 }
271
FlushDebugInfo(uint64_t timestamp)272 bool JITDebugReader::FlushDebugInfo(uint64_t timestamp) {
273 if (sync_option_ == SyncOption::kSyncWithRecords) {
274 if (!debug_info_q_.empty() && debug_info_q_.top().timestamp < timestamp) {
275 std::vector<JITDebugInfo> debug_info;
276 while (!debug_info_q_.empty() && debug_info_q_.top().timestamp < timestamp) {
277 debug_info.emplace_back(debug_info_q_.top());
278 debug_info_q_.pop();
279 }
280 return debug_info_callback_(debug_info, false);
281 }
282 }
283 return true;
284 }
285
ReadAllProcesses()286 bool JITDebugReader::ReadAllProcesses() {
287 if (!IOEventLoop::DisableEvent(read_event_)) {
288 return false;
289 }
290 std::vector<JITDebugInfo> debug_info;
291 for (auto it = processes_.begin(); it != processes_.end();) {
292 Process& process = it->second;
293 if (!ReadProcess(process, &debug_info)) {
294 return false;
295 }
296 if (process.died) {
297 LOG(DEBUG) << "Stop monitoring process " << process.pid;
298 it = processes_.erase(it);
299 } else {
300 ++it;
301 }
302 }
303 if (!AddDebugInfo(std::move(debug_info), true)) {
304 return false;
305 }
306 if (!processes_.empty()) {
307 return IOEventLoop::EnableEvent(read_event_);
308 }
309 return true;
310 }
311
ReadProcess(pid_t pid)312 bool JITDebugReader::ReadProcess(pid_t pid) {
313 auto it = processes_.find(pid);
314 if (it != processes_.end()) {
315 std::vector<JITDebugInfo> debug_info;
316 return ReadProcess(it->second, &debug_info) && AddDebugInfo(std::move(debug_info), false);
317 }
318 return true;
319 }
320
ReadProcess(Process & process,std::vector<JITDebugInfo> * debug_info)321 bool JITDebugReader::ReadProcess(Process& process, std::vector<JITDebugInfo>* debug_info) {
322 if (process.died || (!process.initialized && !InitializeProcess(process))) {
323 return true;
324 }
325 // 1. Read descriptors.
326 Descriptor jit_descriptor;
327 Descriptor dex_descriptor;
328 if (!ReadDescriptors(process, &jit_descriptor, &dex_descriptor)) {
329 return true;
330 }
331 // 2. Return if descriptors are not changed.
332 if (jit_descriptor.action_seqlock == process.last_jit_descriptor.action_seqlock &&
333 dex_descriptor.action_seqlock == process.last_dex_descriptor.action_seqlock) {
334 return true;
335 }
336
337 // 3. Read new symfiles.
338 return ReadDebugInfo(process, jit_descriptor, debug_info) &&
339 ReadDebugInfo(process, dex_descriptor, debug_info);
340 }
341
ReadDebugInfo(Process & process,Descriptor & new_descriptor,std::vector<JITDebugInfo> * debug_info)342 bool JITDebugReader::ReadDebugInfo(Process& process, Descriptor& new_descriptor,
343 std::vector<JITDebugInfo>* debug_info) {
344 DescriptorType type = new_descriptor.type;
345 Descriptor* old_descriptor =
346 (type == DescriptorType::kJIT) ? &process.last_jit_descriptor : &process.last_dex_descriptor;
347
348 bool has_update = new_descriptor.action_seqlock != old_descriptor->action_seqlock &&
349 (new_descriptor.action_seqlock & 1) == 0;
350 LOG(DEBUG) << (type == DescriptorType::kJIT ? "JIT" : "Dex") << " symfiles of pid " << process.pid
351 << ": old seqlock " << old_descriptor->action_seqlock << ", new seqlock "
352 << new_descriptor.action_seqlock;
353 if (!has_update) {
354 return true;
355 }
356 std::vector<CodeEntry> new_entries;
357 // Adding or removing one code entry will make two increments of action_seqlock. So we should
358 // not read more than (seqlock_diff / 2) new entries.
359 uint32_t read_entry_limit = (new_descriptor.action_seqlock - old_descriptor->action_seqlock) / 2;
360 if (!ReadNewCodeEntries(process, new_descriptor, old_descriptor->action_timestamp,
361 read_entry_limit, &new_entries)) {
362 return true;
363 }
364 // If the descriptor was changed while we were reading new entries, skip reading debug info this
365 // time.
366 if (IsDescriptorChanged(process, new_descriptor)) {
367 return true;
368 }
369 LOG(DEBUG) << (type == DescriptorType::kJIT ? "JIT" : "Dex") << " symfiles of pid " << process.pid
370 << ": read " << new_entries.size() << " new entries";
371
372 if (!new_entries.empty()) {
373 if (type == DescriptorType::kJIT) {
374 if (!ReadJITCodeDebugInfo(process, new_entries, debug_info)) {
375 return false;
376 }
377 } else {
378 ReadDexFileDebugInfo(process, new_entries, debug_info);
379 }
380 }
381 *old_descriptor = new_descriptor;
382 return true;
383 }
384
IsDescriptorChanged(Process & process,Descriptor & prev_descriptor)385 bool JITDebugReader::IsDescriptorChanged(Process& process, Descriptor& prev_descriptor) {
386 Descriptor tmp_jit_descriptor;
387 Descriptor tmp_dex_descriptor;
388 if (!ReadDescriptors(process, &tmp_jit_descriptor, &tmp_dex_descriptor)) {
389 return true;
390 }
391 if (prev_descriptor.type == DescriptorType::kJIT) {
392 return prev_descriptor.action_seqlock != tmp_jit_descriptor.action_seqlock;
393 }
394 return prev_descriptor.action_seqlock != tmp_dex_descriptor.action_seqlock;
395 }
396
InitializeProcess(Process & process)397 bool JITDebugReader::InitializeProcess(Process& process) {
398 // 1. Read map file to find the location of libart.so.
399 std::vector<ThreadMmap> thread_mmaps;
400 if (!GetThreadMmapsInProcess(process.pid, &thread_mmaps)) {
401 process.died = true;
402 return false;
403 }
404 std::string art_lib_path;
405 uint64_t min_vaddr_in_memory;
406 for (auto& map : thread_mmaps) {
407 if ((map.prot & PROT_EXEC) && IsArtLib(map.name)) {
408 art_lib_path = map.name;
409 min_vaddr_in_memory = map.start_addr;
410 break;
411 }
412 }
413 if (art_lib_path.empty()) {
414 return false;
415 }
416
417 // 2. Read libart.so to find the addresses of __jit_debug_descriptor and __dex_debug_descriptor.
418 const DescriptorsLocation* location = GetDescriptorsLocation(art_lib_path);
419 if (location == nullptr) {
420 return false;
421 }
422 process.is_64bit = location->is_64bit;
423 process.jit_descriptor_addr = location->jit_descriptor_addr + min_vaddr_in_memory;
424 process.dex_descriptor_addr = location->dex_descriptor_addr + min_vaddr_in_memory;
425
426 for (auto& map : thread_mmaps) {
427 if (StartsWith(map.name, kJITZygoteCacheMmapPrefix)) {
428 process.jit_zygote_cache_ranges_.emplace_back(map.start_addr, map.start_addr + map.len);
429 }
430 }
431
432 process.initialized = true;
433 return true;
434 }
435
GetDescriptorsLocation(const std::string & art_lib_path)436 const JITDebugReader::DescriptorsLocation* JITDebugReader::GetDescriptorsLocation(
437 const std::string& art_lib_path) {
438 auto it = descriptors_location_cache_.find(art_lib_path);
439 if (it != descriptors_location_cache_.end()) {
440 return it->second.jit_descriptor_addr == 0u ? nullptr : &it->second;
441 }
442 DescriptorsLocation& location = descriptors_location_cache_[art_lib_path];
443
444 // Read libart.so to find the addresses of __jit_debug_descriptor and __dex_debug_descriptor.
445 ElfStatus status;
446 auto elf = ElfFile::Open(art_lib_path, &status);
447 if (!elf) {
448 LOG(ERROR) << "failed to read min_exec_vaddr from " << art_lib_path << ": " << status;
449 return nullptr;
450 }
451
452 const size_t kPageSize = getpagesize();
453 const size_t kPageMask = ~(kPageSize - 1);
454 uint64_t file_offset;
455 uint64_t min_vaddr_in_file = elf->ReadMinExecutableVaddr(&file_offset);
456 // min_vaddr_in_file is the min vaddr of executable segments. It may not be page aligned.
457 // And dynamic linker will create map mapping to (segment.p_vaddr & kPageMask).
458 uint64_t aligned_segment_vaddr = min_vaddr_in_file & kPageMask;
459 const char* jit_str = "__jit_debug_descriptor";
460 const char* dex_str = "__dex_debug_descriptor";
461 uint64_t jit_addr = 0u;
462 uint64_t dex_addr = 0u;
463
464 auto callback = [&](const ElfFileSymbol& symbol) {
465 if (symbol.name == jit_str) {
466 jit_addr = symbol.vaddr - aligned_segment_vaddr;
467 } else if (symbol.name == dex_str) {
468 dex_addr = symbol.vaddr - aligned_segment_vaddr;
469 }
470 };
471 elf->ParseDynamicSymbols(callback);
472 if (jit_addr == 0u || dex_addr == 0u) {
473 return nullptr;
474 }
475 location.is_64bit = elf->Is64Bit();
476 location.jit_descriptor_addr = jit_addr;
477 location.dex_descriptor_addr = dex_addr;
478 return &location;
479 }
480
ReadRemoteMem(Process & process,uint64_t remote_addr,uint64_t size,void * data)481 bool JITDebugReader::ReadRemoteMem(Process& process, uint64_t remote_addr, uint64_t size,
482 void* data) {
483 iovec local_iov;
484 local_iov.iov_base = data;
485 local_iov.iov_len = size;
486 iovec remote_iov;
487 remote_iov.iov_base = reinterpret_cast<void*>(static_cast<uintptr_t>(remote_addr));
488 remote_iov.iov_len = size;
489 ssize_t result = process_vm_readv(process.pid, &local_iov, 1, &remote_iov, 1, 0);
490 if (static_cast<size_t>(result) != size) {
491 PLOG(DEBUG) << "ReadRemoteMem("
492 << " pid " << process.pid << ", addr " << std::hex << remote_addr << ", size "
493 << size << ") failed";
494 process.died = true;
495 return false;
496 }
497 return true;
498 }
499
ReadDescriptors(Process & process,Descriptor * jit_descriptor,Descriptor * dex_descriptor)500 bool JITDebugReader::ReadDescriptors(Process& process, Descriptor* jit_descriptor,
501 Descriptor* dex_descriptor) {
502 if (process.is_64bit) {
503 return ReadDescriptorsImpl<JITDescriptor64>(process, jit_descriptor, dex_descriptor);
504 }
505 return ReadDescriptorsImpl<JITDescriptor32>(process, jit_descriptor, dex_descriptor);
506 }
507
508 template <typename DescriptorT>
ReadDescriptorsImpl(Process & process,Descriptor * jit_descriptor,Descriptor * dex_descriptor)509 bool JITDebugReader::ReadDescriptorsImpl(Process& process, Descriptor* jit_descriptor,
510 Descriptor* dex_descriptor) {
511 DescriptorT raw_jit_descriptor;
512 DescriptorT raw_dex_descriptor;
513 iovec local_iovs[2];
514 local_iovs[0].iov_base = &raw_jit_descriptor;
515 local_iovs[0].iov_len = sizeof(DescriptorT);
516 local_iovs[1].iov_base = &raw_dex_descriptor;
517 local_iovs[1].iov_len = sizeof(DescriptorT);
518 iovec remote_iovs[2];
519 remote_iovs[0].iov_base =
520 reinterpret_cast<void*>(static_cast<uintptr_t>(process.jit_descriptor_addr));
521 remote_iovs[0].iov_len = sizeof(DescriptorT);
522 remote_iovs[1].iov_base =
523 reinterpret_cast<void*>(static_cast<uintptr_t>(process.dex_descriptor_addr));
524 remote_iovs[1].iov_len = sizeof(DescriptorT);
525 ssize_t result = process_vm_readv(process.pid, local_iovs, 2, remote_iovs, 2, 0);
526 if (static_cast<size_t>(result) != sizeof(DescriptorT) * 2) {
527 PLOG(DEBUG) << "ReadDescriptor(pid " << process.pid << ", jit_addr " << std::hex
528 << process.jit_descriptor_addr << ", dex_addr " << process.dex_descriptor_addr
529 << ") failed";
530 process.died = true;
531 return false;
532 }
533
534 if (!ParseDescriptor(raw_jit_descriptor, jit_descriptor) ||
535 !ParseDescriptor(raw_dex_descriptor, dex_descriptor)) {
536 return false;
537 }
538 jit_descriptor->type = DescriptorType::kJIT;
539 dex_descriptor->type = DescriptorType::kDEX;
540 return true;
541 }
542
543 template <typename DescriptorT>
ParseDescriptor(const DescriptorT & raw_descriptor,Descriptor * descriptor)544 bool JITDebugReader::ParseDescriptor(const DescriptorT& raw_descriptor, Descriptor* descriptor) {
545 if (!raw_descriptor.Valid()) {
546 return false;
547 }
548 descriptor->action_seqlock = raw_descriptor.action_seqlock;
549 descriptor->action_timestamp = raw_descriptor.action_timestamp;
550 descriptor->first_entry_addr = raw_descriptor.first_entry_addr;
551 descriptor->version = raw_descriptor.AndroidVersion();
552 return true;
553 }
554
555 // Read new code entries with timestamp > last_action_timestamp.
556 // Since we don't stop the app process while reading code entries, it is possible we are reading
557 // broken data. So return false once we detect that the data is broken.
ReadNewCodeEntries(Process & process,const Descriptor & descriptor,uint64_t last_action_timestamp,uint32_t read_entry_limit,std::vector<CodeEntry> * new_code_entries)558 bool JITDebugReader::ReadNewCodeEntries(Process& process, const Descriptor& descriptor,
559 uint64_t last_action_timestamp, uint32_t read_entry_limit,
560 std::vector<CodeEntry>* new_code_entries) {
561 if (descriptor.version == 1) {
562 if (process.is_64bit) {
563 return ReadNewCodeEntriesImpl<JITCodeEntry64>(process, descriptor, last_action_timestamp,
564 read_entry_limit, new_code_entries);
565 }
566 return ReadNewCodeEntriesImpl<JITCodeEntry32>(process, descriptor, last_action_timestamp,
567 read_entry_limit, new_code_entries);
568 }
569 if (descriptor.version == 2) {
570 if (process.is_64bit) {
571 return ReadNewCodeEntriesImpl<JITCodeEntry64V2>(process, descriptor, last_action_timestamp,
572 read_entry_limit, new_code_entries);
573 }
574 return ReadNewCodeEntriesImpl<JITCodeEntry32V2>(process, descriptor, last_action_timestamp,
575 read_entry_limit, new_code_entries);
576 }
577 return false;
578 }
579
580 template <typename CodeEntryT>
ReadNewCodeEntriesImpl(Process & process,const Descriptor & descriptor,uint64_t last_action_timestamp,uint32_t read_entry_limit,std::vector<CodeEntry> * new_code_entries)581 bool JITDebugReader::ReadNewCodeEntriesImpl(Process& process, const Descriptor& descriptor,
582 uint64_t last_action_timestamp,
583 uint32_t read_entry_limit,
584 std::vector<CodeEntry>* new_code_entries) {
585 uint64_t current_entry_addr = descriptor.first_entry_addr;
586 uint64_t prev_entry_addr = 0u;
587 std::unordered_set<uint64_t> entry_addr_set;
588 for (size_t i = 0u; i < read_entry_limit && current_entry_addr != 0u; ++i) {
589 if (entry_addr_set.find(current_entry_addr) != entry_addr_set.end()) {
590 // We enter a loop, which means a broken linked list.
591 return false;
592 }
593 CodeEntryT entry;
594 if (!ReadRemoteMem(process, current_entry_addr, sizeof(entry), &entry)) {
595 return false;
596 }
597 if (entry.prev_addr != prev_entry_addr || !entry.Valid()) {
598 // A broken linked list
599 return false;
600 }
601 if (entry.register_timestamp <= last_action_timestamp) {
602 // The linked list has entries with timestamp in decreasing order. So stop searching
603 // once we hit an entry with timestamp <= last_action_timestmap.
604 break;
605 }
606 if (entry.symfile_size > 0) {
607 CodeEntry code_entry;
608 code_entry.addr = current_entry_addr;
609 code_entry.symfile_addr = entry.symfile_addr;
610 code_entry.symfile_size = entry.symfile_size;
611 code_entry.timestamp = entry.register_timestamp;
612 new_code_entries->push_back(code_entry);
613 }
614 entry_addr_set.insert(current_entry_addr);
615 prev_entry_addr = current_entry_addr;
616 current_entry_addr = entry.next_addr;
617 }
618 return true;
619 }
620
ReadJITCodeDebugInfo(Process & process,const std::vector<CodeEntry> & jit_entries,std::vector<JITDebugInfo> * debug_info)621 bool JITDebugReader::ReadJITCodeDebugInfo(Process& process,
622 const std::vector<CodeEntry>& jit_entries,
623 std::vector<JITDebugInfo>* debug_info) {
624 std::vector<char> data;
625
626 for (auto& jit_entry : jit_entries) {
627 if (jit_entry.symfile_size > MAX_JIT_SYMFILE_SIZE) {
628 continue;
629 }
630 if (data.size() < jit_entry.symfile_size) {
631 data.resize(jit_entry.symfile_size);
632 }
633 if (!ReadRemoteMem(process, jit_entry.symfile_addr, jit_entry.symfile_size, data.data())) {
634 continue;
635 }
636 if (!IsValidElfFileMagic(data.data(), jit_entry.symfile_size)) {
637 continue;
638 }
639 TempSymFile* symfile = GetTempSymFile(process, jit_entry);
640 if (symfile == nullptr) {
641 return false;
642 }
643 uint64_t file_offset = symfile->GetOffset();
644 if (!symfile->WriteEntry(data.data(), jit_entry.symfile_size)) {
645 return false;
646 }
647
648 auto callback = [&](const ElfFileSymbol& symbol) {
649 if (symbol.len == 0) { // Some arm labels can have zero length.
650 return;
651 }
652 // Pass out the location of the symfile for unwinding and symbolization.
653 std::string location_in_file =
654 StringPrintf(":%" PRIu64 "-%" PRIu64, file_offset, file_offset + jit_entry.symfile_size);
655 debug_info->emplace_back(process.pid, jit_entry.timestamp, symbol.vaddr, symbol.len,
656 symfile->GetPath() + location_in_file, file_offset);
657
658 LOG(VERBOSE) << "JITSymbol " << symbol.name << " at [" << std::hex << symbol.vaddr << " - "
659 << (symbol.vaddr + symbol.len) << " with size " << symbol.len << " in "
660 << symfile->GetPath() << location_in_file;
661 };
662 ElfStatus status;
663 auto elf = ElfFile::Open(data.data(), jit_entry.symfile_size, &status);
664 if (elf) {
665 elf->ParseSymbols(callback);
666 }
667 }
668
669 if (app_symfile_) {
670 app_symfile_->Flush();
671 }
672 if (zygote_symfile_) {
673 zygote_symfile_->Flush();
674 }
675 return true;
676 }
677
GetTempSymFile(Process & process,const CodeEntry & jit_entry)678 TempSymFile* JITDebugReader::GetTempSymFile(Process& process, const CodeEntry& jit_entry) {
679 bool is_zygote = false;
680 for (const auto& range : process.jit_zygote_cache_ranges_) {
681 if (jit_entry.symfile_addr >= range.first && jit_entry.symfile_addr < range.second) {
682 is_zygote = true;
683 break;
684 }
685 }
686 if (is_zygote) {
687 if (!zygote_symfile_) {
688 std::string path = symfile_prefix_ + "_" + kJITZygoteCacheFile;
689 zygote_symfile_ =
690 TempSymFile::Create(std::move(path), symfile_option_ == SymFileOption::kDropSymFiles);
691 }
692 return zygote_symfile_.get();
693 }
694 if (!app_symfile_) {
695 std::string path = symfile_prefix_ + "_" + kJITAppCacheFile;
696 app_symfile_ =
697 TempSymFile::Create(std::move(path), symfile_option_ == SymFileOption::kDropSymFiles);
698 }
699 return app_symfile_.get();
700 }
701
ReadDexFileDebugInfo(Process & process,const std::vector<CodeEntry> & dex_entries,std::vector<JITDebugInfo> * debug_info)702 void JITDebugReader::ReadDexFileDebugInfo(Process& process,
703 const std::vector<CodeEntry>& dex_entries,
704 std::vector<JITDebugInfo>* debug_info) {
705 std::vector<ThreadMmap> thread_mmaps;
706 if (!GetThreadMmapsInProcess(process.pid, &thread_mmaps)) {
707 process.died = true;
708 return;
709 }
710 auto comp = [](const ThreadMmap& map, uint64_t addr) { return map.start_addr <= addr; };
711 for (auto& dex_entry : dex_entries) {
712 auto it =
713 std::lower_bound(thread_mmaps.begin(), thread_mmaps.end(), dex_entry.symfile_addr, comp);
714 if (it == thread_mmaps.begin()) {
715 continue;
716 }
717 --it;
718 if (it->start_addr + it->len < dex_entry.symfile_addr + dex_entry.symfile_size) {
719 continue;
720 }
721 std::string file_path;
722 std::string zip_path;
723 std::string entry_path;
724 std::shared_ptr<ThreadMmap> dex_file_map;
725 std::vector<Symbol> symbols;
726 // Offset of dex file in .vdex file or .apk file.
727 uint64_t dex_file_offset = dex_entry.symfile_addr - it->start_addr + it->pgoff;
728 if (ParseExtractedInMemoryPath(it->name, &zip_path, &entry_path)) {
729 file_path = GetUrlInApk(zip_path, entry_path);
730 dex_file_map = std::make_shared<ThreadMmap>(*it);
731 } else if (IsRegularFile(it->name)) {
732 file_path = it->name;
733 } else {
734 // Read a dex file only existing in memory.
735 file_path = StringPrintf("%s_pid_%d_addr_0x%" PRIx64 "-0x%" PRIx64 "", kDexFileInMemoryPrefix,
736 process.pid, dex_entry.symfile_addr,
737 dex_entry.symfile_addr + dex_entry.symfile_size);
738 dex_file_map.reset(new ThreadMmap(dex_entry.symfile_addr, dex_entry.symfile_size, 0,
739 file_path.c_str(), PROT_READ));
740 symbols = ReadDexFileSymbolsInMemory(process, dex_entry.symfile_addr, dex_entry.symfile_size);
741 dex_file_offset = 0;
742 }
743
744 debug_info->emplace_back(process.pid, dex_entry.timestamp, dex_file_offset, file_path,
745 dex_file_map, std::move(symbols));
746 LOG(VERBOSE) << "DexFile " << file_path << "+" << std::hex << dex_file_offset << " in map ["
747 << it->start_addr << " - " << (it->start_addr + it->len) << "] with size "
748 << dex_entry.symfile_size;
749 }
750 }
751
ReadDexFileSymbolsInMemory(Process & process,uint64_t addr,uint64_t size)752 std::vector<Symbol> JITDebugReader::ReadDexFileSymbolsInMemory(Process& process, uint64_t addr,
753 uint64_t size) {
754 std::vector<Symbol> symbols;
755 std::vector<uint8_t> data(size, 0);
756 if (!ReadRemoteMem(process, addr, size, data.data())) {
757 LOG(DEBUG) << "failed to read dex file in memory for process " << process.pid << ", addr "
758 << std::hex << addr << "-" << (addr + size);
759 return symbols;
760 }
761
762 auto process_symbol = [&](DexFileSymbol* symbol) {
763 symbols.emplace_back(symbol->name, symbol->addr, symbol->size);
764 };
765 if (!ReadSymbolsFromDexFileInMemory(data.data(), data.size(), "dex_file_in_memory", {0},
766 process_symbol)) {
767 LOG(DEBUG) << "failed to parse dex file in memory for process " << process.pid << ", addr "
768 << std::hex << addr << "-" << (addr + size);
769 return symbols;
770 }
771 std::sort(symbols.begin(), symbols.end(), Symbol::CompareValueByAddr);
772 return symbols;
773 }
774
AddDebugInfo(std::vector<JITDebugInfo> debug_info,bool sync_kernel_records)775 bool JITDebugReader::AddDebugInfo(std::vector<JITDebugInfo> debug_info, bool sync_kernel_records) {
776 if (!debug_info.empty()) {
777 if (sync_option_ == SyncOption::kSyncWithRecords) {
778 for (auto& info : debug_info) {
779 debug_info_q_.push(std::move(info));
780 }
781 } else {
782 return debug_info_callback_(std::move(debug_info), sync_kernel_records);
783 }
784 }
785 return true;
786 }
787
788 } // namespace simpleperf
789