1 /*
2 * Copyright 2016 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 "jit_logger.h"
18
19 #include "arch/instruction_set.h"
20 #include "art_method-inl.h"
21 #include "base/time_utils.h"
22 #include "base/unix_file/fd_file.h"
23 #include "driver/compiler_driver.h"
24 #include "jit/jit.h"
25 #include "jit/jit_code_cache.h"
26 #include "oat_file-inl.h"
27
28 namespace art {
29 namespace jit {
30
31 #ifdef ART_TARGET_ANDROID
32 static const char* kLogPrefix = "/data/misc/trace";
33 #else
34 static const char* kLogPrefix = "/tmp";
35 #endif
36
37 // File format of perf-PID.map:
38 // +---------------------+
39 // |ADDR SIZE symbolname1|
40 // |ADDR SIZE symbolname2|
41 // |... |
42 // +---------------------+
OpenPerfMapLog()43 void JitLogger::OpenPerfMapLog() {
44 std::string pid_str = std::to_string(getpid());
45 std::string perf_filename = std::string(kLogPrefix) + "/perf-" + pid_str + ".map";
46 perf_file_.reset(OS::CreateEmptyFileWriteOnly(perf_filename.c_str()));
47 if (perf_file_ == nullptr) {
48 LOG(ERROR) << "Could not create perf file at " << perf_filename <<
49 " Are you on a user build? Perf only works on userdebug/eng builds";
50 }
51 }
52
WritePerfMapLog(const void * ptr,size_t code_size,ArtMethod * method)53 void JitLogger::WritePerfMapLog(const void* ptr, size_t code_size, ArtMethod* method) {
54 if (perf_file_ != nullptr) {
55 std::string method_name = method->PrettyMethod();
56
57 std::ostringstream stream;
58 stream << std::hex
59 << reinterpret_cast<uintptr_t>(ptr)
60 << " "
61 << code_size
62 << " "
63 << method_name
64 << std::endl;
65 std::string str = stream.str();
66 bool res = perf_file_->WriteFully(str.c_str(), str.size());
67 if (!res) {
68 LOG(WARNING) << "Failed to write jitted method info in log: write failure.";
69 }
70 } else {
71 LOG(WARNING) << "Failed to write jitted method info in log: log file doesn't exist.";
72 }
73 }
74
ClosePerfMapLog()75 void JitLogger::ClosePerfMapLog() {
76 if (perf_file_ != nullptr) {
77 UNUSED(perf_file_->Flush());
78 UNUSED(perf_file_->Close());
79 }
80 }
81
82 // File format of jit-PID.jump:
83 //
84 // +--------------------------------+
85 // | PerfJitHeader |
86 // +--------------------------------+
87 // | PerfJitCodeLoad { | .
88 // | struct PerfJitBase; | .
89 // | uint32_t process_id_; | .
90 // | uint32_t thread_id_; | .
91 // | uint64_t vma_; | .
92 // | uint64_t code_address_; | .
93 // | uint64_t code_size_; | .
94 // | uint64_t code_id_; | .
95 // | } | .
96 // +- -+ .
97 // | method_name'\0' | +--> one jitted method
98 // +- -+ .
99 // | jitted code binary | .
100 // | ... | .
101 // +--------------------------------+ .
102 // | PerfJitCodeDebugInfo { | .
103 // | struct PerfJitBase; | .
104 // | uint64_t address_; | .
105 // | uint64_t entry_count_; | .
106 // | struct PerfJitDebugEntry; | .
107 // | } | .
108 // +--------------------------------+
109 // | PerfJitCodeLoad |
110 // ...
111 //
112 struct PerfJitHeader {
113 uint32_t magic_; // Characters "JiTD"
114 uint32_t version_; // Header version
115 uint32_t size_; // Total size of header
116 uint32_t elf_mach_target_; // Elf mach target
117 uint32_t reserved_; // Reserved, currently not used
118 uint32_t process_id_; // Process ID of the JIT compiler
119 uint64_t time_stamp_; // Timestamp when the header is generated
120 uint64_t flags_; // Currently the flags are only used for choosing clock for timestamp,
121 // we set it to 0 to tell perf that we use CLOCK_MONOTONIC clock.
122 static const uint32_t kMagic = 0x4A695444; // "JiTD"
123 static const uint32_t kVersion = 1;
124 };
125
126 // Each record starts with such basic information: event type, total size, and timestamp.
127 struct PerfJitBase {
128 enum PerfJitEvent {
129 // A jitted code load event.
130 // In ART JIT, it is used to log a new method is jit compiled and committed to jit-code-cache.
131 // Note that such kLoad event supports code cache GC in ART JIT.
132 // For every kLoad event recorded in jit-PID.dump and every perf sample recorded in perf.data,
133 // each event/sample has time stamp. In case code cache GC happens in ART JIT, and a new
134 // jitted method is committed to the same address of a previously deleted method,
135 // the time stamp information can help profiler to tell whether this sample belongs to the
136 // era of the first jitted method, or does it belong to the period of the second jitted method.
137 // JitCodeCache doesn't have to record any event on 'code delete'.
138 kLoad = 0,
139
140 // A jitted code move event, i,e. a jitted code moved from one address to another address.
141 // It helps profiler to map samples to the right symbol even when the code is moved.
142 // In ART JIT, this event can help log such behavior:
143 // A jitted method is recorded in previous kLoad event, but due to some reason,
144 // it is moved to another address in jit-code-cache.
145 kMove = 1,
146
147 // Logs debug line/column information.
148 kDebugInfo = 2,
149
150 // Logs JIT VM end of life event.
151 kClose = 3
152 };
153 uint32_t event_; // Must be one of the events defined in PerfJitEvent.
154 uint32_t size_; // Total size of this event record.
155 // For example, for kLoad event, size of the event record is:
156 // sizeof(PerfJitCodeLoad) + method_name.size() + compiled code size.
157 uint64_t time_stamp_; // Timestamp for the event.
158 };
159
160 // Logs a jitted code load event (kLoad).
161 // In ART JIT, it is used to log a new method is jit compiled and commited to jit-code-cache.
162 struct PerfJitCodeLoad : PerfJitBase {
163 uint32_t process_id_; // Process ID who performs the jit code load.
164 // In ART JIT, it is the pid of the JIT compiler.
165 uint32_t thread_id_; // Thread ID who performs the jit code load.
166 // In ART JIT, it is the tid of the JIT compiler.
167 uint64_t vma_; // Address of the code section. In ART JIT, because code_address_
168 // uses absolute address, this field is 0.
169 uint64_t code_address_; // Address where is jitted code is loaded.
170 uint64_t code_size_; // Size of the jitted code.
171 uint64_t code_id_; // Unique ID for each jitted code.
172 };
173
174 // This structure is for source line/column mapping.
175 // Currently this feature is not implemented in ART JIT yet.
176 struct PerfJitDebugEntry {
177 uint64_t address_; // Code address which maps to the line/column in source.
178 uint32_t line_number_; // Source line number starting at 1.
179 uint32_t column_; // Column discriminator, default 0.
180 const char name_[0]; // Followed by null-terminated name or \0xff\0 if same as previous.
181 };
182
183 // Logs debug line information (kDebugInfo).
184 // This structure is for source line/column mapping.
185 // Currently this feature is not implemented in ART JIT yet.
186 struct PerfJitCodeDebugInfo : PerfJitBase {
187 uint64_t address_; // Starting code address which the debug info describes.
188 uint64_t entry_count_; // How many instances of PerfJitDebugEntry.
189 PerfJitDebugEntry entries_[0]; // Followed by entry_count_ instances of PerfJitDebugEntry.
190 };
191
GetElfMach()192 static uint32_t GetElfMach() {
193 #if defined(__arm__)
194 static const uint32_t kElfMachARM = 0x28;
195 return kElfMachARM;
196 #elif defined(__aarch64__)
197 static const uint32_t kElfMachARM64 = 0xB7;
198 return kElfMachARM64;
199 #elif defined(__i386__)
200 static const uint32_t kElfMachIA32 = 0x3;
201 return kElfMachIA32;
202 #elif defined(__x86_64__)
203 static const uint32_t kElfMachX64 = 0x3E;
204 return kElfMachX64;
205 #else
206 UNIMPLEMENTED(WARNING) << "Unsupported architecture in JitLogger";
207 return 0;
208 #endif
209 }
210
OpenMarkerFile()211 void JitLogger::OpenMarkerFile() {
212 int fd = jit_dump_file_->Fd();
213 // The 'perf inject' tool requires that the jit-PID.dump file
214 // must have a mmap(PROT_READ|PROT_EXEC) record in perf.data.
215 marker_address_ = mmap(nullptr, kPageSize, PROT_READ | PROT_EXEC, MAP_PRIVATE, fd, 0);
216 if (marker_address_ == MAP_FAILED) {
217 LOG(WARNING) << "Failed to create record in perf.data. JITed code profiling will not work.";
218 return;
219 }
220 }
221
CloseMarkerFile()222 void JitLogger::CloseMarkerFile() {
223 if (marker_address_ != nullptr) {
224 munmap(marker_address_, kPageSize);
225 }
226 }
227
WriteJitDumpDebugInfo()228 void JitLogger::WriteJitDumpDebugInfo() {
229 // In the future, we can add java source file line/column mapping here.
230 }
231
WriteJitDumpHeader()232 void JitLogger::WriteJitDumpHeader() {
233 PerfJitHeader header;
234
235 std::memset(&header, 0, sizeof(header));
236 header.magic_ = PerfJitHeader::kMagic;
237 header.version_ = PerfJitHeader::kVersion;
238 header.size_ = sizeof(header);
239 header.elf_mach_target_ = GetElfMach();
240 header.process_id_ = static_cast<uint32_t>(getpid());
241 header.time_stamp_ = art::NanoTime(); // CLOCK_MONOTONIC clock is required.
242 header.flags_ = 0;
243
244 bool res = jit_dump_file_->WriteFully(reinterpret_cast<const char*>(&header), sizeof(header));
245 if (!res) {
246 LOG(WARNING) << "Failed to write profiling log. The 'perf inject' tool will not work.";
247 }
248 }
249
OpenJitDumpLog()250 void JitLogger::OpenJitDumpLog() {
251 std::string pid_str = std::to_string(getpid());
252 std::string jitdump_filename = std::string(kLogPrefix) + "/jit-" + pid_str + ".dump";
253
254 jit_dump_file_.reset(OS::CreateEmptyFile(jitdump_filename.c_str()));
255 if (jit_dump_file_ == nullptr) {
256 LOG(ERROR) << "Could not create jit dump file at " << jitdump_filename <<
257 " Are you on a user build? Perf only works on userdebug/eng builds";
258 return;
259 }
260
261 OpenMarkerFile();
262
263 // Continue to write jit-PID.dump file even above OpenMarkerFile() fails.
264 // Even if that means 'perf inject' tool cannot work, developers can still use other tools
265 // to map the samples in perf.data to the information (symbol,address,code) recorded
266 // in the jit-PID.dump file, and still proceed the jitted code analysis.
267 WriteJitDumpHeader();
268 }
269
WriteJitDumpLog(const void * ptr,size_t code_size,ArtMethod * method)270 void JitLogger::WriteJitDumpLog(const void* ptr, size_t code_size, ArtMethod* method) {
271 if (jit_dump_file_ != nullptr) {
272 std::string method_name = method->PrettyMethod();
273
274 PerfJitCodeLoad jit_code;
275 std::memset(&jit_code, 0, sizeof(jit_code));
276 jit_code.event_ = PerfJitCodeLoad::kLoad;
277 jit_code.size_ = sizeof(jit_code) + method_name.size() + 1 + code_size;
278 jit_code.time_stamp_ = art::NanoTime(); // CLOCK_MONOTONIC clock is required.
279 jit_code.process_id_ = static_cast<uint32_t>(getpid());
280 jit_code.thread_id_ = static_cast<uint32_t>(art::GetTid());
281 jit_code.vma_ = 0x0;
282 jit_code.code_address_ = reinterpret_cast<uint64_t>(ptr);
283 jit_code.code_size_ = code_size;
284 jit_code.code_id_ = code_index_++;
285
286 // Write one complete jitted method info, including:
287 // - PerfJitCodeLoad structure
288 // - Method name
289 // - Complete generated code of this method
290 //
291 // Use UNUSED() here to avoid compiler warnings.
292 UNUSED(jit_dump_file_->WriteFully(reinterpret_cast<const char*>(&jit_code), sizeof(jit_code)));
293 UNUSED(jit_dump_file_->WriteFully(method_name.c_str(), method_name.size() + 1));
294 UNUSED(jit_dump_file_->WriteFully(ptr, code_size));
295
296 WriteJitDumpDebugInfo();
297 }
298 }
299
CloseJitDumpLog()300 void JitLogger::CloseJitDumpLog() {
301 if (jit_dump_file_ != nullptr) {
302 CloseMarkerFile();
303 UNUSED(jit_dump_file_->Flush());
304 UNUSED(jit_dump_file_->Close());
305 }
306 }
307
308 } // namespace jit
309 } // namespace art
310