1 /*
2  * Copyright (C) 2012 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 #define LOG_TAG "atrace"
18 
19 #include <errno.h>
20 #include <fcntl.h>
21 #include <getopt.h>
22 #include <inttypes.h>
23 #include <signal.h>
24 #include <stdarg.h>
25 #include <stdbool.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <sys/sendfile.h>
30 #include <time.h>
31 #include <unistd.h>
32 #include <zlib.h>
33 
34 #include <fstream>
35 #include <memory>
36 
37 #include <binder/IBinder.h>
38 #include <binder/IServiceManager.h>
39 #include <binder/Parcel.h>
40 
41 #include <android/hidl/manager/1.0/IServiceManager.h>
42 #include <hidl/ServiceManagement.h>
43 #include <cutils/properties.h>
44 
45 #include <utils/String8.h>
46 #include <utils/Timers.h>
47 #include <utils/Tokenizer.h>
48 #include <utils/Trace.h>
49 #include <android-base/file.h>
50 
51 using namespace android;
52 
53 using std::string;
54 #define NELEM(x) ((int) (sizeof(x) / sizeof((x)[0])))
55 
56 #define MAX_SYS_FILES 10
57 #define MAX_PACKAGES 16
58 
59 const char* k_traceTagsProperty = "debug.atrace.tags.enableflags";
60 
61 const char* k_traceAppsNumberProperty = "debug.atrace.app_number";
62 const char* k_traceAppsPropertyTemplate = "debug.atrace.app_%d";
63 const char* k_coreServiceCategory = "core_services";
64 const char* k_coreServicesProp = "ro.atrace.core.services";
65 
66 typedef enum { OPT, REQ } requiredness  ;
67 
68 struct TracingCategory {
69     // The name identifying the category.
70     const char* name;
71 
72     // A longer description of the category.
73     const char* longname;
74 
75     // The userland tracing tags that the category enables.
76     uint64_t tags;
77 
78     // The fname==NULL terminated list of /sys/ files that the category
79     // enables.
80     struct {
81         // Whether the file must be writable in order to enable the tracing
82         // category.
83         requiredness required;
84 
85         // The path to the enable file.
86         const char* path;
87     } sysfiles[MAX_SYS_FILES];
88 };
89 
90 /* Tracing categories */
91 static const TracingCategory k_categories[] = {
92     { "gfx",        "Graphics",         ATRACE_TAG_GRAPHICS, { } },
93     { "input",      "Input",            ATRACE_TAG_INPUT, { } },
94     { "view",       "View System",      ATRACE_TAG_VIEW, { } },
95     { "webview",    "WebView",          ATRACE_TAG_WEBVIEW, { } },
96     { "wm",         "Window Manager",   ATRACE_TAG_WINDOW_MANAGER, { } },
97     { "am",         "Activity Manager", ATRACE_TAG_ACTIVITY_MANAGER, { } },
98     { "sm",         "Sync Manager",     ATRACE_TAG_SYNC_MANAGER, { } },
99     { "audio",      "Audio",            ATRACE_TAG_AUDIO, { } },
100     { "video",      "Video",            ATRACE_TAG_VIDEO, { } },
101     { "camera",     "Camera",           ATRACE_TAG_CAMERA, { } },
102     { "hal",        "Hardware Modules", ATRACE_TAG_HAL, { } },
103     { "app",        "Application",      ATRACE_TAG_APP, { } },
104     { "res",        "Resource Loading", ATRACE_TAG_RESOURCES, { } },
105     { "dalvik",     "Dalvik VM",        ATRACE_TAG_DALVIK, { } },
106     { "rs",         "RenderScript",     ATRACE_TAG_RS, { } },
107     { "bionic",     "Bionic C Library", ATRACE_TAG_BIONIC, { } },
108     { "power",      "Power Management", ATRACE_TAG_POWER, { } },
109     { "pm",         "Package Manager",  ATRACE_TAG_PACKAGE_MANAGER, { } },
110     { "ss",         "System Server",    ATRACE_TAG_SYSTEM_SERVER, { } },
111     { "database",   "Database",         ATRACE_TAG_DATABASE, { } },
112     { "network",    "Network",          ATRACE_TAG_NETWORK, { } },
113     { "adb",        "ADB",              ATRACE_TAG_ADB, { } },
114     { k_coreServiceCategory, "Core services", 0, { } },
115     { "sched",      "CPU Scheduling",   0, {
116         { REQ,      "events/sched/sched_switch/enable" },
117         { REQ,      "events/sched/sched_wakeup/enable" },
118         { OPT,      "events/sched/sched_waking/enable" },
119         { OPT,      "events/sched/sched_blocked_reason/enable" },
120         { OPT,      "events/sched/sched_cpu_hotplug/enable" },
121     } },
122     { "irq",        "IRQ Events",   0, {
123         { REQ,      "events/irq/enable" },
124         { OPT,      "events/ipi/enable" },
125     } },
126     { "i2c",        "I2C Events",   0, {
127         { REQ,      "events/i2c/enable" },
128         { REQ,      "events/i2c/i2c_read/enable" },
129         { REQ,      "events/i2c/i2c_write/enable" },
130         { REQ,      "events/i2c/i2c_result/enable" },
131         { REQ,      "events/i2c/i2c_reply/enable" },
132         { OPT,      "events/i2c/smbus_read/enable" },
133         { OPT,      "events/i2c/smbus_write/enable" },
134         { OPT,      "events/i2c/smbus_result/enable" },
135         { OPT,      "events/i2c/smbus_reply/enable" },
136     } },
137     { "freq",       "CPU Frequency",    0, {
138         { REQ,      "events/power/cpu_frequency/enable" },
139         { OPT,      "events/power/clock_set_rate/enable" },
140         { OPT,      "events/power/cpu_frequency_limits/enable" },
141     } },
142     { "membus",     "Memory Bus Utilization", 0, {
143         { REQ,      "events/memory_bus/enable" },
144     } },
145     { "idle",       "CPU Idle",         0, {
146         { REQ,      "events/power/cpu_idle/enable" },
147     } },
148     { "disk",       "Disk I/O",         0, {
149         { OPT,      "events/f2fs/f2fs_sync_file_enter/enable" },
150         { OPT,      "events/f2fs/f2fs_sync_file_exit/enable" },
151         { OPT,      "events/f2fs/f2fs_write_begin/enable" },
152         { OPT,      "events/f2fs/f2fs_write_end/enable" },
153         { OPT,      "events/ext4/ext4_da_write_begin/enable" },
154         { OPT,      "events/ext4/ext4_da_write_end/enable" },
155         { OPT,      "events/ext4/ext4_sync_file_enter/enable" },
156         { OPT,      "events/ext4/ext4_sync_file_exit/enable" },
157         { REQ,      "events/block/block_rq_issue/enable" },
158         { REQ,      "events/block/block_rq_complete/enable" },
159     } },
160     { "mmc",        "eMMC commands",    0, {
161         { REQ,      "events/mmc/enable" },
162     } },
163     { "load",       "CPU Load",         0, {
164         { REQ,      "events/cpufreq_interactive/enable" },
165     } },
166     { "sync",       "Synchronization",  0, {
167         { REQ,      "events/sync/enable" },
168     } },
169     { "workq",      "Kernel Workqueues", 0, {
170         { REQ,      "events/workqueue/enable" },
171     } },
172     { "memreclaim", "Kernel Memory Reclaim", 0, {
173         { REQ,      "events/vmscan/mm_vmscan_direct_reclaim_begin/enable" },
174         { REQ,      "events/vmscan/mm_vmscan_direct_reclaim_end/enable" },
175         { REQ,      "events/vmscan/mm_vmscan_kswapd_wake/enable" },
176         { REQ,      "events/vmscan/mm_vmscan_kswapd_sleep/enable" },
177     } },
178     { "regulators",  "Voltage and Current Regulators", 0, {
179         { REQ,      "events/regulator/enable" },
180     } },
181     { "binder_driver", "Binder Kernel driver", 0, {
182         { REQ,      "events/binder/binder_transaction/enable" },
183         { REQ,      "events/binder/binder_transaction_received/enable" },
184     } },
185     { "binder_lock", "Binder global lock trace", 0, {
186         { REQ,      "events/binder/binder_lock/enable" },
187         { REQ,      "events/binder/binder_locked/enable" },
188         { REQ,      "events/binder/binder_unlock/enable" },
189     } },
190     { "pagecache",  "Page cache", 0, {
191         { REQ,      "events/filemap/enable" },
192     } },
193 };
194 
195 /* Command line options */
196 static int g_traceDurationSeconds = 5;
197 static bool g_traceOverwrite = false;
198 static int g_traceBufferSizeKB = 2048;
199 static bool g_compress = false;
200 static bool g_nohup = false;
201 static int g_initialSleepSecs = 0;
202 static const char* g_categoriesFile = NULL;
203 static const char* g_kernelTraceFuncs = NULL;
204 static const char* g_debugAppCmdLine = "";
205 static const char* g_outputFile = nullptr;
206 
207 /* Global state */
208 static bool g_traceAborted = false;
209 static bool g_categoryEnables[NELEM(k_categories)] = {};
210 static std::string g_traceFolder;
211 
212 /* Sys file paths */
213 static const char* k_traceClockPath =
214     "trace_clock";
215 
216 static const char* k_traceBufferSizePath =
217     "buffer_size_kb";
218 
219 static const char* k_traceCmdlineSizePath =
220     "saved_cmdlines_size";
221 
222 static const char* k_tracingOverwriteEnablePath =
223     "options/overwrite";
224 
225 static const char* k_currentTracerPath =
226     "current_tracer";
227 
228 static const char* k_printTgidPath =
229     "options/print-tgid";
230 
231 static const char* k_funcgraphAbsTimePath =
232     "options/funcgraph-abstime";
233 
234 static const char* k_funcgraphCpuPath =
235     "options/funcgraph-cpu";
236 
237 static const char* k_funcgraphProcPath =
238     "options/funcgraph-proc";
239 
240 static const char* k_funcgraphFlatPath =
241     "options/funcgraph-flat";
242 
243 static const char* k_funcgraphDurationPath =
244     "options/funcgraph-duration";
245 
246 static const char* k_ftraceFilterPath =
247     "set_ftrace_filter";
248 
249 static const char* k_tracingOnPath =
250     "tracing_on";
251 
252 static const char* k_tracePath =
253     "trace";
254 
255 static const char* k_traceStreamPath =
256     "trace_pipe";
257 
258 static const char* k_traceMarkerPath =
259     "trace_marker";
260 
261 // Check whether a file exists.
fileExists(const char * filename)262 static bool fileExists(const char* filename) {
263     return access((g_traceFolder + filename).c_str(), F_OK) != -1;
264 }
265 
266 // Check whether a file is writable.
fileIsWritable(const char * filename)267 static bool fileIsWritable(const char* filename) {
268     return access((g_traceFolder + filename).c_str(), W_OK) != -1;
269 }
270 
271 // Truncate a file.
truncateFile(const char * path)272 static bool truncateFile(const char* path)
273 {
274     // This uses creat rather than truncate because some of the debug kernel
275     // device nodes (e.g. k_ftraceFilterPath) currently aren't changed by
276     // calls to truncate, but they are cleared by calls to creat.
277     int traceFD = creat((g_traceFolder + path).c_str(), 0);
278     if (traceFD == -1) {
279         fprintf(stderr, "error truncating %s: %s (%d)\n", (g_traceFolder + path).c_str(),
280             strerror(errno), errno);
281         return false;
282     }
283 
284     close(traceFD);
285 
286     return true;
287 }
288 
_writeStr(const char * filename,const char * str,int flags)289 static bool _writeStr(const char* filename, const char* str, int flags)
290 {
291     std::string fullFilename = g_traceFolder + filename;
292     int fd = open(fullFilename.c_str(), flags);
293     if (fd == -1) {
294         fprintf(stderr, "error opening %s: %s (%d)\n", fullFilename.c_str(),
295                 strerror(errno), errno);
296         return false;
297     }
298 
299     bool ok = true;
300     ssize_t len = strlen(str);
301     if (write(fd, str, len) != len) {
302         fprintf(stderr, "error writing to %s: %s (%d)\n", fullFilename.c_str(),
303                 strerror(errno), errno);
304         ok = false;
305     }
306 
307     close(fd);
308 
309     return ok;
310 }
311 
312 // Write a string to a file, returning true if the write was successful.
writeStr(const char * filename,const char * str)313 static bool writeStr(const char* filename, const char* str)
314 {
315     return _writeStr(filename, str, O_WRONLY);
316 }
317 
318 // Append a string to a file, returning true if the write was successful.
appendStr(const char * filename,const char * str)319 static bool appendStr(const char* filename, const char* str)
320 {
321     return _writeStr(filename, str, O_APPEND|O_WRONLY);
322 }
323 
writeClockSyncMarker()324 static void writeClockSyncMarker()
325 {
326   char buffer[128];
327   int len = 0;
328   int fd = open((g_traceFolder + k_traceMarkerPath).c_str(), O_WRONLY);
329   if (fd == -1) {
330       fprintf(stderr, "error opening %s: %s (%d)\n", k_traceMarkerPath,
331               strerror(errno), errno);
332       return;
333   }
334   float now_in_seconds = systemTime(CLOCK_MONOTONIC) / 1000000000.0f;
335 
336   len = snprintf(buffer, 128, "trace_event_clock_sync: parent_ts=%f\n", now_in_seconds);
337   if (write(fd, buffer, len) != len) {
338       fprintf(stderr, "error writing clock sync marker %s (%d)\n", strerror(errno), errno);
339   }
340 
341   int64_t realtime_in_ms = systemTime(CLOCK_REALTIME) / 1000000;
342   len = snprintf(buffer, 128, "trace_event_clock_sync: realtime_ts=%" PRId64 "\n", realtime_in_ms);
343   if (write(fd, buffer, len) != len) {
344       fprintf(stderr, "error writing clock sync marker %s (%d)\n", strerror(errno), errno);
345   }
346 
347   close(fd);
348 }
349 
350 // Enable or disable a kernel option by writing a "1" or a "0" into a /sys
351 // file.
setKernelOptionEnable(const char * filename,bool enable)352 static bool setKernelOptionEnable(const char* filename, bool enable)
353 {
354     return writeStr(filename, enable ? "1" : "0");
355 }
356 
357 // Check whether the category is supported on the device with the current
358 // rootness.  A category is supported only if all its required /sys/ files are
359 // writable and if enabling the category will enable one or more tracing tags
360 // or /sys/ files.
isCategorySupported(const TracingCategory & category)361 static bool isCategorySupported(const TracingCategory& category)
362 {
363     if (strcmp(category.name, k_coreServiceCategory) == 0) {
364         char value[PROPERTY_VALUE_MAX];
365         property_get(k_coreServicesProp, value, "");
366         return strlen(value) != 0;
367     }
368 
369     bool ok = category.tags != 0;
370     for (int i = 0; i < MAX_SYS_FILES; i++) {
371         const char* path = category.sysfiles[i].path;
372         bool req = category.sysfiles[i].required == REQ;
373         if (path != NULL) {
374             if (req) {
375                 if (!fileIsWritable(path)) {
376                     return false;
377                 } else {
378                     ok = true;
379                 }
380             } else {
381                 ok |= fileIsWritable(path);
382             }
383         }
384     }
385     return ok;
386 }
387 
388 // Check whether the category would be supported on the device if the user
389 // were root.  This function assumes that root is able to write to any file
390 // that exists.  It performs the same logic as isCategorySupported, but it
391 // uses file existence rather than writability in the /sys/ file checks.
isCategorySupportedForRoot(const TracingCategory & category)392 static bool isCategorySupportedForRoot(const TracingCategory& category)
393 {
394     bool ok = category.tags != 0;
395     for (int i = 0; i < MAX_SYS_FILES; i++) {
396         const char* path = category.sysfiles[i].path;
397         bool req = category.sysfiles[i].required == REQ;
398         if (path != NULL) {
399             if (req) {
400                 if (!fileExists(path)) {
401                     return false;
402                 } else {
403                     ok = true;
404                 }
405             } else {
406                 ok |= fileExists(path);
407             }
408         }
409     }
410     return ok;
411 }
412 
413 // Enable or disable overwriting of the kernel trace buffers.  Disabling this
414 // will cause tracing to stop once the trace buffers have filled up.
setTraceOverwriteEnable(bool enable)415 static bool setTraceOverwriteEnable(bool enable)
416 {
417     return setKernelOptionEnable(k_tracingOverwriteEnablePath, enable);
418 }
419 
420 // Enable or disable kernel tracing.
setTracingEnabled(bool enable)421 static bool setTracingEnabled(bool enable)
422 {
423     return setKernelOptionEnable(k_tracingOnPath, enable);
424 }
425 
426 // Clear the contents of the kernel trace.
clearTrace()427 static bool clearTrace()
428 {
429     return truncateFile(k_tracePath);
430 }
431 
432 // Set the size of the kernel's trace buffer in kilobytes.
setTraceBufferSizeKB(int size)433 static bool setTraceBufferSizeKB(int size)
434 {
435     char str[32] = "1";
436     int len;
437     if (size < 1) {
438         size = 1;
439     }
440     snprintf(str, 32, "%d", size);
441     return writeStr(k_traceBufferSizePath, str);
442 }
443 
444 // Set the default size of cmdline hashtable
setCmdlineSize()445 static bool setCmdlineSize()
446 {
447     if (fileExists(k_traceCmdlineSizePath)) {
448         return writeStr(k_traceCmdlineSizePath, "8192");
449     }
450     return true;
451 }
452 
453 // Set the clock to the best available option while tracing. Use 'boot' if it's
454 // available; otherwise, use 'mono'. If neither are available use 'global'.
455 // Any write to the trace_clock sysfs file will reset the buffer, so only
456 // update it if the requested value is not the current value.
setClock()457 static bool setClock()
458 {
459     std::ifstream clockFile((g_traceFolder + k_traceClockPath).c_str(), O_RDONLY);
460     std::string clockStr((std::istreambuf_iterator<char>(clockFile)),
461         std::istreambuf_iterator<char>());
462 
463     std::string newClock;
464     if (clockStr.find("boot") != std::string::npos) {
465         newClock = "boot";
466     } else if (clockStr.find("mono") != std::string::npos) {
467         newClock = "mono";
468     } else {
469         newClock = "global";
470     }
471 
472     size_t begin = clockStr.find("[") + 1;
473     size_t end = clockStr.find("]");
474     if (newClock.compare(0, std::string::npos, clockStr, begin, end-begin) == 0) {
475         return true;
476     }
477     return writeStr(k_traceClockPath, newClock.c_str());
478 }
479 
setPrintTgidEnableIfPresent(bool enable)480 static bool setPrintTgidEnableIfPresent(bool enable)
481 {
482     if (fileExists(k_printTgidPath)) {
483         return setKernelOptionEnable(k_printTgidPath, enable);
484     }
485     return true;
486 }
487 
488 // Poke all the binder-enabled processes in the system to get them to re-read
489 // their system properties.
pokeBinderServices()490 static bool pokeBinderServices()
491 {
492     sp<IServiceManager> sm = defaultServiceManager();
493     Vector<String16> services = sm->listServices();
494     for (size_t i = 0; i < services.size(); i++) {
495         sp<IBinder> obj = sm->checkService(services[i]);
496         if (obj != NULL) {
497             Parcel data;
498             if (obj->transact(IBinder::SYSPROPS_TRANSACTION, data,
499                     NULL, 0) != OK) {
500                 if (false) {
501                     // XXX: For some reason this fails on tablets trying to
502                     // poke the "phone" service.  It's not clear whether some
503                     // are expected to fail.
504                     String8 svc(services[i]);
505                     fprintf(stderr, "error poking binder service %s\n",
506                         svc.string());
507                     return false;
508                 }
509             }
510         }
511     }
512     return true;
513 }
514 
515 // Poke all the HAL processes in the system to get them to re-read
516 // their system properties.
pokeHalServices()517 static void pokeHalServices()
518 {
519     using ::android::hidl::base::V1_0::IBase;
520     using ::android::hidl::manager::V1_0::IServiceManager;
521     using ::android::hardware::hidl_string;
522     using ::android::hardware::Return;
523 
524     sp<IServiceManager> sm = ::android::hardware::defaultServiceManager();
525 
526     if (sm == nullptr) {
527         fprintf(stderr, "failed to get IServiceManager to poke hal services\n");
528         return;
529     }
530 
531     auto listRet = sm->list([&](const auto &interfaces) {
532         for (size_t i = 0; i < interfaces.size(); i++) {
533             string fqInstanceName = interfaces[i];
534             string::size_type n = fqInstanceName.find("/");
535             if (n == std::string::npos || interfaces[i].size() == n+1)
536                 continue;
537             hidl_string fqInterfaceName = fqInstanceName.substr(0, n);
538             hidl_string instanceName = fqInstanceName.substr(n+1, std::string::npos);
539             Return<sp<IBase>> interfaceRet = sm->get(fqInterfaceName, instanceName);
540             if (!interfaceRet.isOk()) {
541                 // ignore
542                 continue;
543             }
544 
545             sp<IBase> interface = interfaceRet;
546             if (interface == nullptr) {
547                 // ignore
548                 continue;
549             }
550 
551             auto notifyRet = interface->notifySyspropsChanged();
552             if (!notifyRet.isOk()) {
553                 // ignore
554             }
555         }
556     });
557     if (!listRet.isOk()) {
558         // TODO(b/34242478) fix this when we determine the correct ACL
559         //fprintf(stderr, "failed to list services: %s\n", listRet.description().c_str());
560     }
561 }
562 
563 // Set the trace tags that userland tracing uses, and poke the running
564 // processes to pick up the new value.
setTagsProperty(uint64_t tags)565 static bool setTagsProperty(uint64_t tags)
566 {
567     char buf[PROPERTY_VALUE_MAX];
568     snprintf(buf, sizeof(buf), "%#" PRIx64, tags);
569     if (property_set(k_traceTagsProperty, buf) < 0) {
570         fprintf(stderr, "error setting trace tags system property\n");
571         return false;
572     }
573     return true;
574 }
575 
clearAppProperties()576 static void clearAppProperties()
577 {
578     char buf[PROPERTY_KEY_MAX];
579     for (int i = 0; i < MAX_PACKAGES; i++) {
580         snprintf(buf, sizeof(buf), k_traceAppsPropertyTemplate, i);
581         if (property_set(buf, "") < 0) {
582             fprintf(stderr, "failed to clear system property: %s\n", buf);
583         }
584     }
585     if (property_set(k_traceAppsNumberProperty, "") < 0) {
586         fprintf(stderr, "failed to clear system property: %s",
587               k_traceAppsNumberProperty);
588     }
589 }
590 
591 // Set the system property that indicates which apps should perform
592 // application-level tracing.
setAppCmdlineProperty(char * cmdline)593 static bool setAppCmdlineProperty(char* cmdline)
594 {
595     char buf[PROPERTY_KEY_MAX];
596     int i = 0;
597     char* start = cmdline;
598     while (start != NULL) {
599         if (i == MAX_PACKAGES) {
600             fprintf(stderr, "error: only 16 packages could be traced at once\n");
601             clearAppProperties();
602             return false;
603         }
604         char* end = strchr(start, ',');
605         if (end != NULL) {
606             *end = '\0';
607             end++;
608         }
609         snprintf(buf, sizeof(buf), k_traceAppsPropertyTemplate, i);
610         if (property_set(buf, start) < 0) {
611             fprintf(stderr, "error setting trace app %d property to %s\n", i, buf);
612             clearAppProperties();
613             return false;
614         }
615         start = end;
616         i++;
617     }
618 
619     snprintf(buf, sizeof(buf), "%d", i);
620     if (property_set(k_traceAppsNumberProperty, buf) < 0) {
621         fprintf(stderr, "error setting trace app number property to %s\n", buf);
622         clearAppProperties();
623         return false;
624     }
625     return true;
626 }
627 
628 // Disable all /sys/ enable files.
disableKernelTraceEvents()629 static bool disableKernelTraceEvents() {
630     bool ok = true;
631     for (int i = 0; i < NELEM(k_categories); i++) {
632         const TracingCategory &c = k_categories[i];
633         for (int j = 0; j < MAX_SYS_FILES; j++) {
634             const char* path = c.sysfiles[j].path;
635             if (path != NULL && fileIsWritable(path)) {
636                 ok &= setKernelOptionEnable(path, false);
637             }
638         }
639     }
640     return ok;
641 }
642 
643 // Verify that the comma separated list of functions are being traced by the
644 // kernel.
verifyKernelTraceFuncs(const char * funcs)645 static bool verifyKernelTraceFuncs(const char* funcs)
646 {
647     std::string buf;
648     if (!android::base::ReadFileToString(g_traceFolder + k_ftraceFilterPath, &buf)) {
649          fprintf(stderr, "error opening %s: %s (%d)\n", k_ftraceFilterPath,
650             strerror(errno), errno);
651          return false;
652     }
653 
654     String8 funcList = String8::format("\n%s",buf.c_str());
655 
656     // Make sure that every function listed in funcs is in the list we just
657     // read from the kernel, except for wildcard inputs.
658     bool ok = true;
659     char* myFuncs = strdup(funcs);
660     char* func = strtok(myFuncs, ",");
661     while (func) {
662         if (!strchr(func, '*')) {
663             String8 fancyFunc = String8::format("\n%s\n", func);
664             bool found = funcList.find(fancyFunc.string(), 0) >= 0;
665             if (!found || func[0] == '\0') {
666                 fprintf(stderr, "error: \"%s\" is not a valid kernel function "
667                         "to trace.\n", func);
668                 ok = false;
669             }
670         }
671         func = strtok(NULL, ",");
672     }
673     free(myFuncs);
674     return ok;
675 }
676 
677 // Set the comma separated list of functions that the kernel is to trace.
setKernelTraceFuncs(const char * funcs)678 static bool setKernelTraceFuncs(const char* funcs)
679 {
680     bool ok = true;
681 
682     if (funcs == NULL || funcs[0] == '\0') {
683         // Disable kernel function tracing.
684         if (fileIsWritable(k_currentTracerPath)) {
685             ok &= writeStr(k_currentTracerPath, "nop");
686         }
687         if (fileIsWritable(k_ftraceFilterPath)) {
688             ok &= truncateFile(k_ftraceFilterPath);
689         }
690     } else {
691         // Enable kernel function tracing.
692         ok &= writeStr(k_currentTracerPath, "function_graph");
693         ok &= setKernelOptionEnable(k_funcgraphAbsTimePath, true);
694         ok &= setKernelOptionEnable(k_funcgraphCpuPath, true);
695         ok &= setKernelOptionEnable(k_funcgraphProcPath, true);
696         ok &= setKernelOptionEnable(k_funcgraphFlatPath, true);
697 
698         // Set the requested filter functions.
699         ok &= truncateFile(k_ftraceFilterPath);
700         char* myFuncs = strdup(funcs);
701         char* func = strtok(myFuncs, ",");
702         while (func) {
703             ok &= appendStr(k_ftraceFilterPath, func);
704             func = strtok(NULL, ",");
705         }
706         free(myFuncs);
707 
708         // Verify that the set functions are being traced.
709         if (ok) {
710             ok &= verifyKernelTraceFuncs(funcs);
711         }
712     }
713 
714     return ok;
715 }
716 
setCategoryEnable(const char * name,bool enable)717 static bool setCategoryEnable(const char* name, bool enable)
718 {
719     for (int i = 0; i < NELEM(k_categories); i++) {
720         const TracingCategory& c = k_categories[i];
721         if (strcmp(name, c.name) == 0) {
722             if (isCategorySupported(c)) {
723                 g_categoryEnables[i] = enable;
724                 return true;
725             } else {
726                 if (isCategorySupportedForRoot(c)) {
727                     fprintf(stderr, "error: category \"%s\" requires root "
728                             "privileges.\n", name);
729                 } else {
730                     fprintf(stderr, "error: category \"%s\" is not supported "
731                             "on this device.\n", name);
732                 }
733                 return false;
734             }
735         }
736     }
737     fprintf(stderr, "error: unknown tracing category \"%s\"\n", name);
738     return false;
739 }
740 
setCategoriesEnableFromFile(const char * categories_file)741 static bool setCategoriesEnableFromFile(const char* categories_file)
742 {
743     if (!categories_file) {
744         return true;
745     }
746     Tokenizer* tokenizer = NULL;
747     if (Tokenizer::open(String8(categories_file), &tokenizer) != NO_ERROR) {
748         return false;
749     }
750     bool ok = true;
751     while (!tokenizer->isEol()) {
752         String8 token = tokenizer->nextToken(" ");
753         if (token.isEmpty()) {
754             tokenizer->skipDelimiters(" ");
755             continue;
756         }
757         ok &= setCategoryEnable(token.string(), true);
758     }
759     delete tokenizer;
760     return ok;
761 }
762 
763 // Set all the kernel tracing settings to the desired state for this trace
764 // capture.
setUpTrace()765 static bool setUpTrace()
766 {
767     bool ok = true;
768 
769     // Set up the tracing options.
770     ok &= setCategoriesEnableFromFile(g_categoriesFile);
771     ok &= setTraceOverwriteEnable(g_traceOverwrite);
772     ok &= setTraceBufferSizeKB(g_traceBufferSizeKB);
773     // TODO: Re-enable after stabilization
774     //ok &= setCmdlineSize();
775     ok &= setClock();
776     ok &= setPrintTgidEnableIfPresent(true);
777     ok &= setKernelTraceFuncs(g_kernelTraceFuncs);
778 
779     // Set up the tags property.
780     uint64_t tags = 0;
781     for (int i = 0; i < NELEM(k_categories); i++) {
782         if (g_categoryEnables[i]) {
783             const TracingCategory &c = k_categories[i];
784             tags |= c.tags;
785         }
786     }
787     ok &= setTagsProperty(tags);
788 
789     bool coreServicesTagEnabled = false;
790     for (int i = 0; i < NELEM(k_categories); i++) {
791         if (strcmp(k_categories[i].name, k_coreServiceCategory) == 0) {
792             coreServicesTagEnabled = g_categoryEnables[i];
793         }
794     }
795 
796     std::string packageList(g_debugAppCmdLine);
797     if (coreServicesTagEnabled) {
798         char value[PROPERTY_VALUE_MAX];
799         property_get(k_coreServicesProp, value, "");
800         if (!packageList.empty()) {
801             packageList += ",";
802         }
803         packageList += value;
804     }
805     ok &= setAppCmdlineProperty(&packageList[0]);
806     ok &= pokeBinderServices();
807     pokeHalServices();
808 
809     // Disable all the sysfs enables.  This is done as a separate loop from
810     // the enables to allow the same enable to exist in multiple categories.
811     ok &= disableKernelTraceEvents();
812 
813     // Enable all the sysfs enables that are in an enabled category.
814     for (int i = 0; i < NELEM(k_categories); i++) {
815         if (g_categoryEnables[i]) {
816             const TracingCategory &c = k_categories[i];
817             for (int j = 0; j < MAX_SYS_FILES; j++) {
818                 const char* path = c.sysfiles[j].path;
819                 bool required = c.sysfiles[j].required == REQ;
820                 if (path != NULL) {
821                     if (fileIsWritable(path)) {
822                         ok &= setKernelOptionEnable(path, true);
823                     } else if (required) {
824                         fprintf(stderr, "error writing file %s\n", path);
825                         ok = false;
826                     }
827                 }
828             }
829         }
830     }
831 
832     return ok;
833 }
834 
835 // Reset all the kernel tracing settings to their default state.
cleanUpTrace()836 static void cleanUpTrace()
837 {
838     // Disable all tracing that we're able to.
839     disableKernelTraceEvents();
840 
841     // Reset the system properties.
842     setTagsProperty(0);
843     clearAppProperties();
844     pokeBinderServices();
845 
846     // Set the options back to their defaults.
847     setTraceOverwriteEnable(true);
848     setTraceBufferSizeKB(1);
849     setPrintTgidEnableIfPresent(false);
850     setKernelTraceFuncs(NULL);
851 }
852 
853 
854 // Enable tracing in the kernel.
startTrace()855 static bool startTrace()
856 {
857     return setTracingEnabled(true);
858 }
859 
860 // Disable tracing in the kernel.
stopTrace()861 static void stopTrace()
862 {
863     setTracingEnabled(false);
864 }
865 
866 // Read data from the tracing pipe and forward to stdout
streamTrace()867 static void streamTrace()
868 {
869     char trace_data[4096];
870     int traceFD = open((g_traceFolder + k_traceStreamPath).c_str(), O_RDWR);
871     if (traceFD == -1) {
872         fprintf(stderr, "error opening %s: %s (%d)\n", k_traceStreamPath,
873                 strerror(errno), errno);
874         return;
875     }
876     while (!g_traceAborted) {
877         ssize_t bytes_read = read(traceFD, trace_data, 4096);
878         if (bytes_read > 0) {
879             write(STDOUT_FILENO, trace_data, bytes_read);
880             fflush(stdout);
881         } else {
882             if (!g_traceAborted) {
883                 fprintf(stderr, "read returned %zd bytes err %d (%s)\n",
884                         bytes_read, errno, strerror(errno));
885             }
886             break;
887         }
888     }
889 }
890 
891 // Read the current kernel trace and write it to stdout.
dumpTrace(int outFd)892 static void dumpTrace(int outFd)
893 {
894     ALOGI("Dumping trace");
895     int traceFD = open((g_traceFolder + k_tracePath).c_str(), O_RDWR);
896     if (traceFD == -1) {
897         fprintf(stderr, "error opening %s: %s (%d)\n", k_tracePath,
898                 strerror(errno), errno);
899         return;
900     }
901 
902     if (g_compress) {
903         z_stream zs;
904         memset(&zs, 0, sizeof(zs));
905 
906         int result = deflateInit(&zs, Z_DEFAULT_COMPRESSION);
907         if (result != Z_OK) {
908             fprintf(stderr, "error initializing zlib: %d\n", result);
909             close(traceFD);
910             return;
911         }
912 
913         constexpr size_t bufSize = 64*1024;
914         std::unique_ptr<uint8_t> in(new uint8_t[bufSize]);
915         std::unique_ptr<uint8_t> out(new uint8_t[bufSize]);
916         if (!in || !out) {
917             fprintf(stderr, "couldn't allocate buffers\n");
918             close(traceFD);
919             return;
920         }
921 
922         int flush = Z_NO_FLUSH;
923 
924         zs.next_out = reinterpret_cast<Bytef*>(out.get());
925         zs.avail_out = bufSize;
926 
927         do {
928 
929             if (zs.avail_in == 0) {
930                 // More input is needed.
931                 result = read(traceFD, in.get(), bufSize);
932                 if (result < 0) {
933                     fprintf(stderr, "error reading trace: %s (%d)\n",
934                             strerror(errno), errno);
935                     result = Z_STREAM_END;
936                     break;
937                 } else if (result == 0) {
938                     flush = Z_FINISH;
939                 } else {
940                     zs.next_in = reinterpret_cast<Bytef*>(in.get());
941                     zs.avail_in = result;
942                 }
943             }
944 
945             if (zs.avail_out == 0) {
946                 // Need to write the output.
947                 result = write(outFd, out.get(), bufSize);
948                 if ((size_t)result < bufSize) {
949                     fprintf(stderr, "error writing deflated trace: %s (%d)\n",
950                             strerror(errno), errno);
951                     result = Z_STREAM_END; // skip deflate error message
952                     zs.avail_out = bufSize; // skip the final write
953                     break;
954                 }
955                 zs.next_out = reinterpret_cast<Bytef*>(out.get());
956                 zs.avail_out = bufSize;
957             }
958 
959         } while ((result = deflate(&zs, flush)) == Z_OK);
960 
961         if (result != Z_STREAM_END) {
962             fprintf(stderr, "error deflating trace: %s\n", zs.msg);
963         }
964 
965         if (zs.avail_out < bufSize) {
966             size_t bytes = bufSize - zs.avail_out;
967             result = write(outFd, out.get(), bytes);
968             if ((size_t)result < bytes) {
969                 fprintf(stderr, "error writing deflated trace: %s (%d)\n",
970                         strerror(errno), errno);
971             }
972         }
973 
974         result = deflateEnd(&zs);
975         if (result != Z_OK) {
976             fprintf(stderr, "error cleaning up zlib: %d\n", result);
977         }
978     } else {
979         ssize_t sent = 0;
980         while ((sent = sendfile(outFd, traceFD, NULL, 64*1024*1024)) > 0);
981         if (sent == -1) {
982             fprintf(stderr, "error dumping trace: %s (%d)\n", strerror(errno),
983                     errno);
984         }
985     }
986 
987     close(traceFD);
988 }
989 
handleSignal(int)990 static void handleSignal(int /*signo*/)
991 {
992     if (!g_nohup) {
993         g_traceAborted = true;
994     }
995 }
996 
registerSigHandler()997 static void registerSigHandler()
998 {
999     struct sigaction sa;
1000     sigemptyset(&sa.sa_mask);
1001     sa.sa_flags = 0;
1002     sa.sa_handler = handleSignal;
1003     sigaction(SIGHUP, &sa, NULL);
1004     sigaction(SIGINT, &sa, NULL);
1005     sigaction(SIGQUIT, &sa, NULL);
1006     sigaction(SIGTERM, &sa, NULL);
1007 }
1008 
listSupportedCategories()1009 static void listSupportedCategories()
1010 {
1011     for (int i = 0; i < NELEM(k_categories); i++) {
1012         const TracingCategory& c = k_categories[i];
1013         if (isCategorySupported(c)) {
1014             printf("  %10s - %s\n", c.name, c.longname);
1015         }
1016     }
1017 }
1018 
1019 // Print the command usage help to stderr.
showHelp(const char * cmd)1020 static void showHelp(const char *cmd)
1021 {
1022     fprintf(stderr, "usage: %s [options] [categories...]\n", cmd);
1023     fprintf(stderr, "options include:\n"
1024                     "  -a appname      enable app-level tracing for a comma "
1025                         "separated list of cmdlines\n"
1026                     "  -b N            use a trace buffer size of N KB\n"
1027                     "  -c              trace into a circular buffer\n"
1028                     "  -f filename     use the categories written in a file as space-separated\n"
1029                     "                    values in a line\n"
1030                     "  -k fname,...    trace the listed kernel functions\n"
1031                     "  -n              ignore signals\n"
1032                     "  -s N            sleep for N seconds before tracing [default 0]\n"
1033                     "  -t N            trace for N seconds [default 5]\n"
1034                     "  -z              compress the trace dump\n"
1035                     "  --async_start   start circular trace and return immediately\n"
1036                     "  --async_dump    dump the current contents of circular trace buffer\n"
1037                     "  --async_stop    stop tracing and dump the current contents of circular\n"
1038                     "                    trace buffer\n"
1039                     "  --stream        stream trace to stdout as it enters the trace buffer\n"
1040                     "                    Note: this can take significant CPU time, and is best\n"
1041                     "                    used for measuring things that are not affected by\n"
1042                     "                    CPU performance, like pagecache usage.\n"
1043                     "  --list_categories\n"
1044                     "                  list the available tracing categories\n"
1045                     " -o filename      write the trace to the specified file instead\n"
1046                     "                    of stdout.\n"
1047             );
1048 }
1049 
findTraceFiles()1050 bool findTraceFiles()
1051 {
1052     static const std::string debugfs_path = "/sys/kernel/debug/tracing/";
1053     static const std::string tracefs_path = "/sys/kernel/tracing/";
1054     static const std::string trace_file = "trace_marker";
1055 
1056     bool tracefs = access((tracefs_path + trace_file).c_str(), F_OK) != -1;
1057     bool debugfs = access((debugfs_path + trace_file).c_str(), F_OK) != -1;
1058 
1059     if (!tracefs && !debugfs) {
1060         fprintf(stderr, "Error: Did not find trace folder\n");
1061         return false;
1062     }
1063 
1064     if (tracefs) {
1065         g_traceFolder = tracefs_path;
1066     } else {
1067         g_traceFolder = debugfs_path;
1068     }
1069 
1070     return true;
1071 }
1072 
main(int argc,char ** argv)1073 int main(int argc, char **argv)
1074 {
1075     bool async = false;
1076     bool traceStart = true;
1077     bool traceStop = true;
1078     bool traceDump = true;
1079     bool traceStream = false;
1080 
1081     if (argc == 2 && 0 == strcmp(argv[1], "--help")) {
1082         showHelp(argv[0]);
1083         exit(0);
1084     }
1085 
1086     if (!findTraceFiles()) {
1087         fprintf(stderr, "No trace folder found\n");
1088         exit(-1);
1089     }
1090 
1091     for (;;) {
1092         int ret;
1093         int option_index = 0;
1094         static struct option long_options[] = {
1095             {"async_start",     no_argument, 0,  0 },
1096             {"async_stop",      no_argument, 0,  0 },
1097             {"async_dump",      no_argument, 0,  0 },
1098             {"list_categories", no_argument, 0,  0 },
1099             {"stream",          no_argument, 0,  0 },
1100             {           0,                0, 0,  0 }
1101         };
1102 
1103         ret = getopt_long(argc, argv, "a:b:cf:k:ns:t:zo:",
1104                           long_options, &option_index);
1105 
1106         if (ret < 0) {
1107             for (int i = optind; i < argc; i++) {
1108                 if (!setCategoryEnable(argv[i], true)) {
1109                     fprintf(stderr, "error enabling tracing category \"%s\"\n", argv[i]);
1110                     exit(1);
1111                 }
1112             }
1113             break;
1114         }
1115 
1116         switch(ret) {
1117             case 'a':
1118                 g_debugAppCmdLine = optarg;
1119             break;
1120 
1121             case 'b':
1122                 g_traceBufferSizeKB = atoi(optarg);
1123             break;
1124 
1125             case 'c':
1126                 g_traceOverwrite = true;
1127             break;
1128 
1129             case 'f':
1130                 g_categoriesFile = optarg;
1131             break;
1132 
1133             case 'k':
1134                 g_kernelTraceFuncs = optarg;
1135             break;
1136 
1137             case 'n':
1138                 g_nohup = true;
1139             break;
1140 
1141             case 's':
1142                 g_initialSleepSecs = atoi(optarg);
1143             break;
1144 
1145             case 't':
1146                 g_traceDurationSeconds = atoi(optarg);
1147             break;
1148 
1149             case 'z':
1150                 g_compress = true;
1151             break;
1152 
1153             case 'o':
1154                 g_outputFile = optarg;
1155             break;
1156 
1157             case 0:
1158                 if (!strcmp(long_options[option_index].name, "async_start")) {
1159                     async = true;
1160                     traceStop = false;
1161                     traceDump = false;
1162                     g_traceOverwrite = true;
1163                 } else if (!strcmp(long_options[option_index].name, "async_stop")) {
1164                     async = true;
1165                     traceStart = false;
1166                 } else if (!strcmp(long_options[option_index].name, "async_dump")) {
1167                     async = true;
1168                     traceStart = false;
1169                     traceStop = false;
1170                 } else if (!strcmp(long_options[option_index].name, "stream")) {
1171                     traceStream = true;
1172                     traceDump = false;
1173                 } else if (!strcmp(long_options[option_index].name, "list_categories")) {
1174                     listSupportedCategories();
1175                     exit(0);
1176                 }
1177             break;
1178 
1179             default:
1180                 fprintf(stderr, "\n");
1181                 showHelp(argv[0]);
1182                 exit(-1);
1183             break;
1184         }
1185     }
1186 
1187     registerSigHandler();
1188 
1189     if (g_initialSleepSecs > 0) {
1190         sleep(g_initialSleepSecs);
1191     }
1192 
1193     bool ok = true;
1194     ok &= setUpTrace();
1195     ok &= startTrace();
1196 
1197     if (ok && traceStart) {
1198         if (!traceStream) {
1199             printf("capturing trace...");
1200             fflush(stdout);
1201         }
1202 
1203         // We clear the trace after starting it because tracing gets enabled for
1204         // each CPU individually in the kernel. Having the beginning of the trace
1205         // contain entries from only one CPU can cause "begin" entries without a
1206         // matching "end" entry to show up if a task gets migrated from one CPU to
1207         // another.
1208         ok = clearTrace();
1209 
1210         writeClockSyncMarker();
1211         if (ok && !async && !traceStream) {
1212             // Sleep to allow the trace to be captured.
1213             struct timespec timeLeft;
1214             timeLeft.tv_sec = g_traceDurationSeconds;
1215             timeLeft.tv_nsec = 0;
1216             do {
1217                 if (g_traceAborted) {
1218                     break;
1219                 }
1220             } while (nanosleep(&timeLeft, &timeLeft) == -1 && errno == EINTR);
1221         }
1222 
1223         if (traceStream) {
1224             streamTrace();
1225         }
1226     }
1227 
1228     // Stop the trace and restore the default settings.
1229     if (traceStop)
1230         stopTrace();
1231 
1232     if (ok && traceDump) {
1233         if (!g_traceAborted) {
1234             printf(" done\n");
1235             fflush(stdout);
1236             int outFd = STDOUT_FILENO;
1237             if (g_outputFile) {
1238                 outFd = open(g_outputFile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1239             }
1240             if (outFd == -1) {
1241                 printf("Failed to open '%s', err=%d", g_outputFile, errno);
1242             } else {
1243                 dprintf(outFd, "TRACE:\n");
1244                 dumpTrace(outFd);
1245                 if (g_outputFile) {
1246                     close(outFd);
1247                 }
1248             }
1249         } else {
1250             printf("\ntrace aborted.\n");
1251             fflush(stdout);
1252         }
1253         clearTrace();
1254     } else if (!ok) {
1255         fprintf(stderr, "unable to start tracing\n");
1256     }
1257 
1258     // Reset the trace buffer size to 1.
1259     if (traceStop)
1260         cleanUpTrace();
1261 
1262     return g_traceAborted ? 1 : 0;
1263 }
1264