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 #define DEBUG false // STOPSHIP if true 18 #include "config/ConfigKey.h" 19 #include "Log.h" 20 21 #include "frameworks/base/cmds/statsd/src/statsd_config.pb.h" // Alert 22 23 #include <android-base/unique_fd.h> 24 #include <errno.h> 25 #include <fcntl.h> 26 #include <inttypes.h> 27 #include <sys/types.h> 28 #include <sys/wait.h> 29 #include <unistd.h> 30 31 #include <string> 32 33 namespace { 34 const char kDropboxTag[] = "perfetto"; 35 } 36 37 namespace android { 38 namespace os { 39 namespace statsd { 40 41 bool CollectPerfettoTraceAndUploadToDropbox(const PerfettoDetails& config, 42 int64_t subscription_id, 43 int64_t alert_id, 44 const ConfigKey& configKey) { 45 VLOG("Starting trace collection through perfetto"); 46 47 if (!config.has_trace_config()) { 48 ALOGE("The perfetto trace config is empty, aborting"); 49 return false; 50 } 51 52 char subscriptionId[25]; 53 char alertId[25]; 54 char configId[25]; 55 char configUid[25]; 56 snprintf(subscriptionId, sizeof(subscriptionId), "%" PRId64, subscription_id); 57 snprintf(alertId, sizeof(alertId), "%" PRId64, alert_id); 58 snprintf(configId, sizeof(configId), "%" PRId64, configKey.GetId()); 59 snprintf(configUid, sizeof(configUid), "%d", configKey.GetUid()); 60 61 android::base::unique_fd readPipe; 62 android::base::unique_fd writePipe; 63 if (!android::base::Pipe(&readPipe, &writePipe)) { 64 ALOGE("pipe() failed while calling the Perfetto client: %s", strerror(errno)); 65 return false; 66 } 67 68 pid_t pid = fork(); 69 if (pid < 0) { 70 ALOGE("fork() failed while calling the Perfetto client: %s", strerror(errno)); 71 return false; 72 } 73 74 if (pid == 0) { 75 // Child process. 76 77 // No malloc calls or library calls after this point. Remember that even 78 // ALOGx (aka android_printLog()) can use dynamic memory for vsprintf(). 79 80 writePipe.reset(); // Close the write end (owned by the main process). 81 82 // Replace stdin with |readPipe| so the main process can write into it. 83 if (dup2(readPipe.get(), STDIN_FILENO) < 0) _exit(1); 84 readPipe.reset(); 85 86 // Replace stdout/stderr with /dev/null and close any other file 87 // descriptor. This is to avoid SELinux complaining about perfetto 88 // trying to access files accidentally left open by statsd (i.e. files 89 // that have been opened without the O_CLOEXEC flag). 90 int devNullFd = open("/dev/null", O_RDWR | O_CLOEXEC); 91 if (dup2(devNullFd, STDOUT_FILENO) < 0) _exit(2); 92 if (dup2(devNullFd, STDERR_FILENO) < 0) _exit(3); 93 close(devNullFd); 94 for (int i = 0; i < 1024; i++) { 95 if (i != STDIN_FILENO && i != STDOUT_FILENO && i != STDERR_FILENO) close(i); 96 } 97 98 execl("/system/bin/perfetto", "perfetto", "--background", "--config", "-", "--dropbox", 99 kDropboxTag, "--alert-id", alertId, "--config-id", configId, "--config-uid", 100 configUid, "--subscription-id", subscriptionId, nullptr); 101 102 // execl() doesn't return in case of success, if we get here something 103 // failed. 104 _exit(4); 105 } 106 107 // Main process. 108 109 readPipe.reset(); // Close the read end (owned by the child process). 110 111 // Using fdopen() because fwrite() has the right logic to chunking write() 112 // over a pipe (see __sfvwrite()). 113 FILE* writePipeStream = android::base::Fdopen(std::move(writePipe), "wb"); 114 if (!writePipeStream) { 115 ALOGE("fdopen() failed while calling the Perfetto client: %s", strerror(errno)); 116 return false; 117 } 118 119 const std::string& cfgProto = config.trace_config(); 120 size_t bytesWritten = fwrite(cfgProto.data(), 1, cfgProto.size(), writePipeStream); 121 fclose(writePipeStream); 122 if (bytesWritten != cfgProto.size() || cfgProto.size() == 0) { 123 ALOGE("fwrite() failed (ret: %zd) while calling the Perfetto client: %s", bytesWritten, 124 strerror(errno)); 125 return false; 126 } 127 128 // This does NOT wait for the full duration of the trace. It just waits until 129 // the process has read the config from stdin and detached. 130 int childStatus = 0; 131 waitpid(pid, &childStatus, 0); 132 if (!WIFEXITED(childStatus) || WEXITSTATUS(childStatus) != 0) { 133 ALOGE("Child process failed (0x%x) while calling the Perfetto client", childStatus); 134 return false; 135 } 136 137 VLOG("CollectPerfettoTraceAndUploadToDropbox() succeeded"); 138 return true; 139 } 140 141 } // namespace statsd 142 } // namespace os 143 } // namespace android 144
