blob: 43966255237383b822cd7b9ce103ab04080bacb9 [file] [log] [blame]
Alex Ray0a346432012-11-14 17:25:28 -08001/*
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#include <errno.h>
18#include <fcntl.h>
19#include <limits.h>
20#include <pthread.h>
Jamie Gennis774f9292013-02-25 18:15:40 -080021#include <stdbool.h>
Alex Ray0a346432012-11-14 17:25:28 -080022#include <stdlib.h>
23#include <string.h>
24#include <sys/types.h>
25#include <cutils/atomic.h>
26#include <cutils/compiler.h>
27#include <cutils/properties.h>
28#include <cutils/trace.h>
29
30#define LOG_TAG "cutils-trace"
Mark Salyzyn12717162014-04-29 15:49:14 -070031#include <log/log.h>
Alex Ray0a346432012-11-14 17:25:28 -080032
Chih-Hung Hsieh2d3150e2014-10-13 16:30:24 -070033/**
34 * Maximum size of a message that can be logged to the trace buffer.
35 * Note this message includes a tag, the pid, and the string given as the name.
36 * Names should be kept short to get the most use of the trace buffer.
37 */
38#define ATRACE_MESSAGE_LENGTH 1024
39
Jamie Gennisb13ea452013-04-15 18:50:22 -070040volatile int32_t atrace_is_ready = 0;
41int atrace_marker_fd = -1;
42uint64_t atrace_enabled_tags = ATRACE_TAG_NOT_READY;
43static bool atrace_is_debuggable = false;
44static volatile int32_t atrace_is_enabled = 1;
45static pthread_once_t atrace_once_control = PTHREAD_ONCE_INIT;
46static pthread_mutex_t atrace_tags_mutex = PTHREAD_MUTEX_INITIALIZER;
Jamie Gennis774f9292013-02-25 18:15:40 -080047
48// Set whether this process is debuggable, which determines whether
49// application-level tracing is allowed when the ro.debuggable system property
50// is not set to '1'.
51void atrace_set_debuggable(bool debuggable)
52{
53 atrace_is_debuggable = debuggable;
54 atrace_update_tags();
55}
56
Jamie Gennisb13ea452013-04-15 18:50:22 -070057// Set whether tracing is enabled in this process. This is used to prevent
58// the Zygote process from tracing.
59void atrace_set_tracing_enabled(bool enabled)
60{
61 android_atomic_release_store(enabled ? 1 : 0, &atrace_is_enabled);
62 atrace_update_tags();
63}
64
Jamie Gennis774f9292013-02-25 18:15:40 -080065// Check whether the given command line matches one of the comma-separated
66// values listed in the app_cmdlines property.
Jamie Gennisb13ea452013-04-15 18:50:22 -070067static bool atrace_is_cmdline_match(const char* cmdline)
68{
Jamie Gennis774f9292013-02-25 18:15:40 -080069 char value[PROPERTY_VALUE_MAX];
70 char* start = value;
71
72 property_get("debug.atrace.app_cmdlines", value, "");
73
74 while (start != NULL) {
75 char* end = strchr(start, ',');
76
77 if (end != NULL) {
78 *end = '\0';
79 end++;
80 }
81
82 if (strcmp(cmdline, start) == 0) {
83 return true;
84 }
85
86 start = end;
87 }
88
89 return false;
90}
91
92// Determine whether application-level tracing is enabled for this process.
93static bool atrace_is_app_tracing_enabled()
94{
95 bool sys_debuggable = false;
Jamie Gennis774f9292013-02-25 18:15:40 -080096 char value[PROPERTY_VALUE_MAX];
97 bool result = false;
98
99 // Check whether the system is debuggable.
100 property_get("ro.debuggable", value, "0");
101 if (value[0] == '1') {
102 sys_debuggable = true;
103 }
104
105 if (sys_debuggable || atrace_is_debuggable) {
106 // Check whether tracing is enabled for this process.
107 FILE * file = fopen("/proc/self/cmdline", "r");
108 if (file) {
109 char cmdline[4096];
110 if (fgets(cmdline, sizeof(cmdline), file)) {
111 result = atrace_is_cmdline_match(cmdline);
112 } else {
113 ALOGE("Error reading cmdline: %s (%d)", strerror(errno), errno);
114 }
115 fclose(file);
116 } else {
117 ALOGE("Error opening /proc/self/cmdline: %s (%d)", strerror(errno),
118 errno);
119 }
120 }
121
122 return result;
123}
Alex Ray0a346432012-11-14 17:25:28 -0800124
125// Read the sysprop and return the value tags should be set to
126static uint64_t atrace_get_property()
127{
128 char value[PROPERTY_VALUE_MAX];
129 char *endptr;
130 uint64_t tags;
131
132 property_get("debug.atrace.tags.enableflags", value, "0");
133 errno = 0;
134 tags = strtoull(value, &endptr, 0);
135 if (value[0] == '\0' || *endptr != '\0') {
136 ALOGE("Error parsing trace property: Not a number: %s", value);
137 return 0;
138 } else if (errno == ERANGE || tags == ULLONG_MAX) {
139 ALOGE("Error parsing trace property: Number too large: %s", value);
140 return 0;
141 }
Jamie Gennis774f9292013-02-25 18:15:40 -0800142
143 // Only set the "app" tag if this process was selected for app-level debug
144 // tracing.
145 if (atrace_is_app_tracing_enabled()) {
146 tags |= ATRACE_TAG_APP;
147 } else {
148 tags &= ~ATRACE_TAG_APP;
149 }
150
Alex Ray0a346432012-11-14 17:25:28 -0800151 return (tags | ATRACE_TAG_ALWAYS) & ATRACE_TAG_VALID_MASK;
152}
153
Alex Raye7bb7bc2012-11-20 01:39:09 -0800154// Update tags if tracing is ready. Useful as a sysprop change callback.
155void atrace_update_tags()
156{
157 uint64_t tags;
158 if (CC_UNLIKELY(android_atomic_acquire_load(&atrace_is_ready))) {
Jamie Gennisb13ea452013-04-15 18:50:22 -0700159 if (android_atomic_acquire_load(&atrace_is_enabled)) {
160 tags = atrace_get_property();
161 pthread_mutex_lock(&atrace_tags_mutex);
162 atrace_enabled_tags = tags;
163 pthread_mutex_unlock(&atrace_tags_mutex);
164 } else {
165 // Tracing is disabled for this process, so we simply don't
166 // initialize the tags.
167 pthread_mutex_lock(&atrace_tags_mutex);
168 atrace_enabled_tags = ATRACE_TAG_NOT_READY;
169 pthread_mutex_unlock(&atrace_tags_mutex);
170 }
Alex Raye7bb7bc2012-11-20 01:39:09 -0800171 }
172}
173
Alex Ray0a346432012-11-14 17:25:28 -0800174static void atrace_init_once()
175{
176 atrace_marker_fd = open("/sys/kernel/debug/tracing/trace_marker", O_WRONLY);
177 if (atrace_marker_fd == -1) {
178 ALOGE("Error opening trace file: %s (%d)", strerror(errno), errno);
179 atrace_enabled_tags = 0;
180 goto done;
181 }
182
183 atrace_enabled_tags = atrace_get_property();
184
185done:
186 android_atomic_release_store(1, &atrace_is_ready);
187}
188
189void atrace_setup()
190{
191 pthread_once(&atrace_once_control, atrace_init_once);
192}
Chih-Hung Hsieh2d3150e2014-10-13 16:30:24 -0700193
194void atrace_begin_body(const char* name)
195{
196 char buf[ATRACE_MESSAGE_LENGTH];
197 size_t len;
198
199 len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "B|%d|%s", getpid(), name);
200 write(atrace_marker_fd, buf, len);
201}
202
203
204void atrace_async_begin_body(const char* name, int32_t cookie)
205{
206 char buf[ATRACE_MESSAGE_LENGTH];
207 size_t len;
208
209 len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "S|%d|%s|%" PRId32,
210 getpid(), name, cookie);
211 write(atrace_marker_fd, buf, len);
212}
213
214void atrace_async_end_body(const char* name, int32_t cookie)
215{
216 char buf[ATRACE_MESSAGE_LENGTH];
217 size_t len;
218
219 len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "F|%d|%s|%" PRId32,
220 getpid(), name, cookie);
221 write(atrace_marker_fd, buf, len);
222}
223
224void atrace_int_body(const char* name, int32_t value)
225{
226 char buf[ATRACE_MESSAGE_LENGTH];
227 size_t len;
228
229 len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "C|%d|%s|%" PRId32,
230 getpid(), name, value);
231 write(atrace_marker_fd, buf, len);
232}
233
234void atrace_int64_body(const char* name, int64_t value)
235{
236 char buf[ATRACE_MESSAGE_LENGTH];
237 size_t len;
238
239 len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "C|%d|%s|%" PRId64,
240 getpid(), name, value);
241 write(atrace_marker_fd, buf, len);
242}