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/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define DEBUG false // STOPSHIP if true
#include "Log.h"
#include "frameworks/base/cmds/statsd/src/statsd_config.pb.h" // Alert
#include <android-base/unique_fd.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <string>
namespace {
const char kDropboxTag[] = "perfetto";
}
namespace android {
namespace os {
namespace statsd {
bool CollectPerfettoTraceAndUploadToDropbox(const PerfettoDetails& config) {
VLOG("Starting trace collection through perfetto");
if (!config.has_trace_config()) {
ALOGE("The perfetto trace config is empty, aborting");
return false;
}
android::base::unique_fd readPipe;
android::base::unique_fd writePipe;
if (!android::base::Pipe(&readPipe, &writePipe)) {
ALOGE("pipe() failed while calling the Perfetto client: %s", strerror(errno));
return false;
}
pid_t pid = fork();
if (pid < 0) {
ALOGE("fork() failed while calling the Perfetto client: %s", strerror(errno));
return false;
}
if (pid == 0) {
// Child process.
// No malloc calls or library calls after this point. Remember that even
// ALOGx (aka android_printLog()) can use dynamic memory for vsprintf().
writePipe.reset(); // Close the write end (owned by the main process).
// Replace stdin with |readPipe| so the main process can write into it.
if (dup2(readPipe.get(), STDIN_FILENO) < 0) _exit(1);
readPipe.reset();
// Replace stdout/stderr with /dev/null and close any other file
// descriptor. This is to avoid SELinux complaining about perfetto
// trying to access files accidentally left open by statsd (i.e. files
// that have been opened without the O_CLOEXEC flag).
int devNullFd = open("/dev/null", O_RDWR | O_CLOEXEC);
if (dup2(devNullFd, STDOUT_FILENO) < 0) _exit(2);
if (dup2(devNullFd, STDERR_FILENO) < 0) _exit(3);
close(devNullFd);
for (int i = 0; i < 1024; i++) {
if (i != STDIN_FILENO && i != STDOUT_FILENO && i != STDERR_FILENO) close(i);
}
execl("/system/bin/perfetto", "perfetto", "--background", "--config", "-", "--dropbox",
kDropboxTag, nullptr);
// execl() doesn't return in case of success, if we get here something
// failed.
_exit(4);
}
// Main process.
readPipe.reset(); // Close the read end (owned by the child process).
// Using fopen() because fwrite() has the right logic to chunking write()
// over a pipe (see __sfvwrite()).
FILE* writePipeStream = fdopen(writePipe.get(), "wb");
if (!writePipeStream) {
ALOGE("fdopen() failed while calling the Perfetto client: %s", strerror(errno));
return false;
}
std::string cfgProto = config.trace_config().SerializeAsString();
size_t bytesWritten = fwrite(cfgProto.data(), 1, cfgProto.size(), writePipeStream);
fclose(writePipeStream);
if (bytesWritten != cfgProto.size() || cfgProto.size() == 0) {
ALOGE("fwrite() failed (ret: %zd) while calling the Perfetto client: %s", bytesWritten,
strerror(errno));
return false;
}
// This does NOT wait for the full duration of the trace. It just waits until
// the process has read the config from stdin and detached.
int childStatus = 0;
waitpid(pid, &childStatus, 0);
if (!WIFEXITED(childStatus) || WEXITSTATUS(childStatus) != 0) {
ALOGE("Child process failed (0x%x) while calling the Perfetto client", childStatus);
return false;
}
VLOG("CollectPerfettoTraceAndUploadToDropbox() succeeded");
return true;
}
} // namespace statsd
} // namespace os
} // namespace android
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