blob: 1e8261ee1832e87d3c82e9bdb903110a2fbcb29b [file] [log] [blame]
/*
* Copyright (C) 2016 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
#include "Log.h"
#include "Section.h"
#include <dirent.h>
#include <errno.h>
#include <mutex>
#include <set>
#include <android-base/file.h>
#include <android-base/stringprintf.h>
#include <android/util/protobuf.h>
#include <android/util/ProtoOutputStream.h>
#include <binder/IServiceManager.h>
#include <debuggerd/client.h>
#include <dumputils/dump_utils.h>
#include <log/log_event_list.h>
#include <log/log_read.h>
#include <log/logprint.h>
#include <private/android_logger.h>
#include "FdBuffer.h"
#include "Privacy.h"
#include "frameworks/base/core/proto/android/os/backtrace.proto.h"
#include "frameworks/base/core/proto/android/os/data.proto.h"
#include "frameworks/base/core/proto/android/util/log.proto.h"
#include "incidentd_util.h"
namespace android {
namespace os {
namespace incidentd {
using namespace android::base;
using namespace android::util;
// special section ids
const int FIELD_ID_INCIDENT_METADATA = 2;
// incident section parameters
const char INCIDENT_HELPER[] = "/system/bin/incident_helper";
const char* GZIP[] = {"/system/bin/gzip", NULL};
static pid_t fork_execute_incident_helper(const int id, Fpipe* p2cPipe, Fpipe* c2pPipe) {
const char* ihArgs[]{INCIDENT_HELPER, "-s", String8::format("%d", id).string(), NULL};
return fork_execute_cmd(const_cast<char**>(ihArgs), p2cPipe, c2pPipe);
}
// ================================================================================
Section::Section(int i, int64_t timeoutMs, bool userdebugAndEngOnly)
: id(i),
timeoutMs(timeoutMs),
userdebugAndEngOnly(userdebugAndEngOnly) {}
Section::~Section() {}
// ================================================================================
static inline bool isSysfs(const char* filename) { return strncmp(filename, "/sys/", 5) == 0; }
FileSection::FileSection(int id, const char* filename, const int64_t timeoutMs)
: Section(id, timeoutMs, false), mFilename(filename) {
name = "file ";
name += filename;
mIsSysfs = isSysfs(filename);
}
FileSection::~FileSection() {}
status_t FileSection::Execute(ReportWriter* writer) const {
// read from mFilename first, make sure the file is available
// add O_CLOEXEC to make sure it is closed when exec incident helper
unique_fd fd(open(mFilename, O_RDONLY | O_CLOEXEC));
if (fd.get() == -1) {
ALOGW("[%s] failed to open file", this->name.string());
// There may be some devices/architectures that won't have the file.
// Just return here without an error.
return NO_ERROR;
}
FdBuffer buffer;
Fpipe p2cPipe;
Fpipe c2pPipe;
// initiate pipes to pass data to/from incident_helper
if (!p2cPipe.init() || !c2pPipe.init()) {
ALOGW("[%s] failed to setup pipes", this->name.string());
return -errno;
}
pid_t pid = fork_execute_incident_helper(this->id, &p2cPipe, &c2pPipe);
if (pid == -1) {
ALOGW("[%s] failed to fork", this->name.string());
return -errno;
}
// parent process
status_t readStatus = buffer.readProcessedDataInStream(fd.get(), std::move(p2cPipe.writeFd()),
std::move(c2pPipe.readFd()),
this->timeoutMs, mIsSysfs);
writer->setSectionStats(buffer);
if (readStatus != NO_ERROR || buffer.timedOut()) {
ALOGW("[%s] failed to read data from incident helper: %s, timedout: %s",
this->name.string(), strerror(-readStatus), buffer.timedOut() ? "true" : "false");
kill_child(pid);
return readStatus;
}
status_t ihStatus = wait_child(pid);
if (ihStatus != NO_ERROR) {
ALOGW("[%s] abnormal child process: %s", this->name.string(), strerror(-ihStatus));
return ihStatus;
}
return writer->writeSection(buffer);
}
// ================================================================================
GZipSection::GZipSection(int id, const char* filename, ...) : Section(id) {
va_list args;
va_start(args, filename);
mFilenames = varargs(filename, args);
va_end(args);
name = "gzip";
for (int i = 0; mFilenames[i] != NULL; i++) {
name += " ";
name += mFilenames[i];
}
}
GZipSection::~GZipSection() { free(mFilenames); }
status_t GZipSection::Execute(ReportWriter* writer) const {
// Reads the files in order, use the first available one.
int index = 0;
unique_fd fd;
while (mFilenames[index] != NULL) {
fd.reset(open(mFilenames[index], O_RDONLY | O_CLOEXEC));
if (fd.get() != -1) {
break;
}
ALOGW("GZipSection failed to open file %s", mFilenames[index]);
index++; // look at the next file.
}
if (fd.get() == -1) {
ALOGW("[%s] can't open all the files", this->name.string());
return NO_ERROR; // e.g. LAST_KMSG will reach here in user build.
}
FdBuffer buffer;
Fpipe p2cPipe;
Fpipe c2pPipe;
// initiate pipes to pass data to/from gzip
if (!p2cPipe.init() || !c2pPipe.init()) {
ALOGW("[%s] failed to setup pipes", this->name.string());
return -errno;
}
pid_t pid = fork_execute_cmd((char* const*)GZIP, &p2cPipe, &c2pPipe);
if (pid == -1) {
ALOGW("[%s] failed to fork", this->name.string());
return -errno;
}
// parent process
// construct Fdbuffer to output GZippedfileProto, the reason to do this instead of using
// ProtoOutputStream is to avoid allocation of another buffer inside ProtoOutputStream.
sp<EncodedBuffer> internalBuffer = buffer.data();
internalBuffer->writeHeader((uint32_t)GZippedFileProto::FILENAME, WIRE_TYPE_LENGTH_DELIMITED);
size_t fileLen = strlen(mFilenames[index]);
internalBuffer->writeRawVarint32(fileLen);
for (size_t i = 0; i < fileLen; i++) {
internalBuffer->writeRawByte(mFilenames[index][i]);
}
internalBuffer->writeHeader((uint32_t)GZippedFileProto::GZIPPED_DATA,
WIRE_TYPE_LENGTH_DELIMITED);
size_t editPos = internalBuffer->wp()->pos();
internalBuffer->wp()->move(8); // reserve 8 bytes for the varint of the data size.
size_t dataBeginAt = internalBuffer->wp()->pos();
VLOG("[%s] editPos=%zu, dataBeginAt=%zu", this->name.string(), editPos, dataBeginAt);
status_t readStatus = buffer.readProcessedDataInStream(
fd.get(), std::move(p2cPipe.writeFd()), std::move(c2pPipe.readFd()), this->timeoutMs,
isSysfs(mFilenames[index]));
writer->setSectionStats(buffer);
if (readStatus != NO_ERROR || buffer.timedOut()) {
ALOGW("[%s] failed to read data from gzip: %s, timedout: %s", this->name.string(),
strerror(-readStatus), buffer.timedOut() ? "true" : "false");
kill_child(pid);
return readStatus;
}
status_t gzipStatus = wait_child(pid);
if (gzipStatus != NO_ERROR) {
ALOGW("[%s] abnormal child process: %s", this->name.string(), strerror(-gzipStatus));
return gzipStatus;
}
// Revisit the actual size from gzip result and edit the internal buffer accordingly.
size_t dataSize = buffer.size() - dataBeginAt;
internalBuffer->wp()->rewind()->move(editPos);
internalBuffer->writeRawVarint32(dataSize);
internalBuffer->copy(dataBeginAt, dataSize);
return writer->writeSection(buffer);
}
// ================================================================================
struct WorkerThreadData : public virtual RefBase {
const WorkerThreadSection* section;
Fpipe pipe;
// Lock protects these fields
mutex lock;
bool workerDone;
status_t workerError;
explicit WorkerThreadData(const WorkerThreadSection* section);
virtual ~WorkerThreadData();
};
WorkerThreadData::WorkerThreadData(const WorkerThreadSection* sec)
: section(sec), workerDone(false), workerError(NO_ERROR) {}
WorkerThreadData::~WorkerThreadData() {}
// ================================================================================
WorkerThreadSection::WorkerThreadSection(int id, const int64_t timeoutMs, bool userdebugAndEngOnly)
: Section(id, timeoutMs, userdebugAndEngOnly) {}
WorkerThreadSection::~WorkerThreadSection() {}
void sigpipe_handler(int signum) {
if (signum == SIGPIPE) {
ALOGE("Wrote to a broken pipe\n");
} else {
ALOGE("Received unexpected signal: %d\n", signum);
}
}
static void* worker_thread_func(void* cookie) {
// Don't crash the service if we write to a closed pipe (which can happen if
// dumping times out).
signal(SIGPIPE, sigpipe_handler);
WorkerThreadData* data = (WorkerThreadData*)cookie;
status_t err = data->section->BlockingCall(data->pipe.writeFd().get());
{
unique_lock<mutex> lock(data->lock);
data->workerDone = true;
data->workerError = err;
}
data->pipe.writeFd().reset();
data->decStrong(data->section);
// data might be gone now. don't use it after this point in this thread.
return NULL;
}
status_t WorkerThreadSection::Execute(ReportWriter* writer) const {
status_t err = NO_ERROR;
pthread_t thread;
pthread_attr_t attr;
bool workerDone = false;
FdBuffer buffer;
// Data shared between this thread and the worker thread.
sp<WorkerThreadData> data = new WorkerThreadData(this);
// Create the pipe
if (!data->pipe.init()) {
return -errno;
}
// Create the thread
err = pthread_attr_init(&attr);
if (err != 0) {
return -err;
}
// TODO: Do we need to tweak thread priority?
err = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
if (err != 0) {
pthread_attr_destroy(&attr);
return -err;
}
// The worker thread needs a reference and we can't let the count go to zero
// if that thread is slow to start.
data->incStrong(this);
err = pthread_create(&thread, &attr, worker_thread_func, (void*)data.get());
pthread_attr_destroy(&attr);
if (err != 0) {
data->decStrong(this);
return -err;
}
// Loop reading until either the timeout or the worker side is done (i.e. eof).
err = buffer.read(data->pipe.readFd().get(), this->timeoutMs);
if (err != NO_ERROR) {
ALOGE("[%s] reader failed with error '%s'", this->name.string(), strerror(-err));
}
// Done with the read fd. The worker thread closes the write one so
// we never race and get here first.
data->pipe.readFd().reset();
// If the worker side is finished, then return its error (which may overwrite
// our possible error -- but it's more interesting anyway). If not, then we timed out.
{
unique_lock<mutex> lock(data->lock);
if (data->workerError != NO_ERROR) {
err = data->workerError;
ALOGE("[%s] worker failed with error '%s'", this->name.string(), strerror(-err));
}
workerDone = data->workerDone;
}
writer->setSectionStats(buffer);
if (err != NO_ERROR) {
char errMsg[128];
snprintf(errMsg, 128, "[%s] failed with error '%s'",
this->name.string(), strerror(-err));
writer->error(this, err, "WorkerThreadSection failed.");
return NO_ERROR;
}
if (buffer.truncated()) {
ALOGW("[%s] too large, truncating", this->name.string());
// Do not write a truncated section. It won't pass through the PrivacyFilter.
return NO_ERROR;
}
if (!workerDone || buffer.timedOut()) {
ALOGW("[%s] timed out", this->name.string());
return NO_ERROR;
}
// Write the data that was collected
return writer->writeSection(buffer);
}
// ================================================================================
CommandSection::CommandSection(int id, const int64_t timeoutMs, const char* command, ...)
: Section(id, timeoutMs) {
va_list args;
va_start(args, command);
mCommand = varargs(command, args);
va_end(args);
name = "cmd";
for (int i = 0; mCommand[i] != NULL; i++) {
name += " ";
name += mCommand[i];
}
}
CommandSection::CommandSection(int id, const char* command, ...) : Section(id) {
va_list args;
va_start(args, command);
mCommand = varargs(command, args);
va_end(args);
name = "cmd";
for (int i = 0; mCommand[i] != NULL; i++) {
name += " ";
name += mCommand[i];
}
}
CommandSection::~CommandSection() { free(mCommand); }
status_t CommandSection::Execute(ReportWriter* writer) const {
FdBuffer buffer;
Fpipe cmdPipe;
Fpipe ihPipe;
if (!cmdPipe.init() || !ihPipe.init()) {
ALOGW("[%s] failed to setup pipes", this->name.string());
return -errno;
}
pid_t cmdPid = fork_execute_cmd((char* const*)mCommand, NULL, &cmdPipe);
if (cmdPid == -1) {
ALOGW("[%s] failed to fork", this->name.string());
return -errno;
}
pid_t ihPid = fork_execute_incident_helper(this->id, &cmdPipe, &ihPipe);
if (ihPid == -1) {
ALOGW("[%s] failed to fork", this->name.string());
return -errno;
}
cmdPipe.writeFd().reset();
status_t readStatus = buffer.read(ihPipe.readFd().get(), this->timeoutMs);
writer->setSectionStats(buffer);
if (readStatus != NO_ERROR || buffer.timedOut()) {
ALOGW("[%s] failed to read data from incident helper: %s, timedout: %s",
this->name.string(), strerror(-readStatus), buffer.timedOut() ? "true" : "false");
kill_child(cmdPid);
kill_child(ihPid);
return readStatus;
}
// Waiting for command here has one trade-off: the failed status of command won't be detected
// until buffer timeout, but it has advatage on starting the data stream earlier.
status_t cmdStatus = wait_child(cmdPid);
status_t ihStatus = wait_child(ihPid);
if (cmdStatus != NO_ERROR || ihStatus != NO_ERROR) {
ALOGW("[%s] abnormal child processes, return status: command: %s, incident helper: %s",
this->name.string(), strerror(-cmdStatus), strerror(-ihStatus));
// Not a fatal error.
return NO_ERROR;
}
return writer->writeSection(buffer);
}
// ================================================================================
DumpsysSection::DumpsysSection(int id, bool userdebugAndEngOnly, const char* service, ...)
: WorkerThreadSection(id, REMOTE_CALL_TIMEOUT_MS, userdebugAndEngOnly), mService(service) {
name = "dumpsys ";
name += service;
va_list args;
va_start(args, service);
while (true) {
const char* arg = va_arg(args, const char*);
if (arg == NULL) {
break;
}
mArgs.add(String16(arg));
name += " ";
name += arg;
}
va_end(args);
}
DumpsysSection::~DumpsysSection() {}
status_t DumpsysSection::BlockingCall(int pipeWriteFd) const {
// checkService won't wait for the service to show up like getService will.
sp<IBinder> service = defaultServiceManager()->checkService(mService);
if (service == NULL) {
ALOGW("DumpsysSection: Can't lookup service: %s", String8(mService).string());
return NAME_NOT_FOUND;
}
service->dump(pipeWriteFd, mArgs);
return NO_ERROR;
}
// ================================================================================
// initialization only once in Section.cpp.
map<log_id_t, log_time> LogSection::gLastLogsRetrieved;
LogSection::LogSection(int id, log_id_t logID) : WorkerThreadSection(id), mLogID(logID) {
name = "logcat ";
name += android_log_id_to_name(logID);
switch (logID) {
case LOG_ID_EVENTS:
case LOG_ID_STATS:
case LOG_ID_SECURITY:
mBinary = true;
break;
default:
mBinary = false;
}
}
LogSection::~LogSection() {}
static size_t trimTail(char const* buf, size_t len) {
while (len > 0) {
char c = buf[len - 1];
if (c == '\0' || c == ' ' || c == '\n' || c == '\r' || c == ':') {
len--;
} else {
break;
}
}
return len;
}
static inline int32_t get4LE(uint8_t const* src) {
return src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
}
status_t LogSection::BlockingCall(int pipeWriteFd) const {
// Open log buffer and getting logs since last retrieved time if any.
unique_ptr<logger_list, void (*)(logger_list*)> loggers(
gLastLogsRetrieved.find(mLogID) == gLastLogsRetrieved.end()
? android_logger_list_alloc(ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK, 0, 0)
: android_logger_list_alloc_time(ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK,
gLastLogsRetrieved[mLogID], 0),
android_logger_list_free);
if (android_logger_open(loggers.get(), mLogID) == NULL) {
ALOGE("[%s] Can't get logger.", this->name.string());
return -1;
}
log_msg msg;
log_time lastTimestamp(0);
ProtoOutputStream proto;
while (true) { // keeps reading until logd buffer is fully read.
status_t err = android_logger_list_read(loggers.get(), &msg);
// err = 0 - no content, unexpected connection drop or EOF.
// err = +ive number - size of retrieved data from logger
// err = -ive number, OS supplied error _except_ for -EAGAIN
// err = -EAGAIN, graceful indication for ANDRODI_LOG_NONBLOCK that this is the end of data.
if (err <= 0) {
if (err != -EAGAIN) {
ALOGW("[%s] fails to read a log_msg.\n", this->name.string());
}
// dump previous logs and don't consider this error a failure.
break;
}
if (mBinary) {
// remove the first uint32 which is tag's index in event log tags
android_log_context context = create_android_log_parser(msg.msg() + sizeof(uint32_t),
msg.len() - sizeof(uint32_t));
;
android_log_list_element elem;
lastTimestamp.tv_sec = msg.entry_v1.sec;
lastTimestamp.tv_nsec = msg.entry_v1.nsec;
// format a BinaryLogEntry
uint64_t token = proto.start(LogProto::BINARY_LOGS);
proto.write(BinaryLogEntry::SEC, msg.entry_v1.sec);
proto.write(BinaryLogEntry::NANOSEC, msg.entry_v1.nsec);
proto.write(BinaryLogEntry::UID, (int)msg.entry_v4.uid);
proto.write(BinaryLogEntry::PID, msg.entry_v1.pid);
proto.write(BinaryLogEntry::TID, msg.entry_v1.tid);
proto.write(BinaryLogEntry::TAG_INDEX,
get4LE(reinterpret_cast<uint8_t const*>(msg.msg())));
do {
elem = android_log_read_next(context);
uint64_t elemToken = proto.start(BinaryLogEntry::ELEMS);
switch (elem.type) {
case EVENT_TYPE_INT:
proto.write(BinaryLogEntry::Elem::TYPE,
BinaryLogEntry::Elem::EVENT_TYPE_INT);
proto.write(BinaryLogEntry::Elem::VAL_INT32, (int)elem.data.int32);
break;
case EVENT_TYPE_LONG:
proto.write(BinaryLogEntry::Elem::TYPE,
BinaryLogEntry::Elem::EVENT_TYPE_LONG);
proto.write(BinaryLogEntry::Elem::VAL_INT64, (long long)elem.data.int64);
break;
case EVENT_TYPE_STRING:
proto.write(BinaryLogEntry::Elem::TYPE,
BinaryLogEntry::Elem::EVENT_TYPE_STRING);
proto.write(BinaryLogEntry::Elem::VAL_STRING, elem.data.string, elem.len);
break;
case EVENT_TYPE_FLOAT:
proto.write(BinaryLogEntry::Elem::TYPE,
BinaryLogEntry::Elem::EVENT_TYPE_FLOAT);
proto.write(BinaryLogEntry::Elem::VAL_FLOAT, elem.data.float32);
break;
case EVENT_TYPE_LIST:
proto.write(BinaryLogEntry::Elem::TYPE,
BinaryLogEntry::Elem::EVENT_TYPE_LIST);
break;
case EVENT_TYPE_LIST_STOP:
proto.write(BinaryLogEntry::Elem::TYPE,
BinaryLogEntry::Elem::EVENT_TYPE_LIST_STOP);
break;
case EVENT_TYPE_UNKNOWN:
proto.write(BinaryLogEntry::Elem::TYPE,
BinaryLogEntry::Elem::EVENT_TYPE_UNKNOWN);
break;
}
proto.end(elemToken);
} while ((elem.type != EVENT_TYPE_UNKNOWN) && !elem.complete);
proto.end(token);
if (context) {
android_log_destroy(&context);
}
} else {
AndroidLogEntry entry;
err = android_log_processLogBuffer(&msg.entry_v1, &entry);
if (err != NO_ERROR) {
ALOGW("[%s] fails to process to an entry.\n", this->name.string());
break;
}
lastTimestamp.tv_sec = entry.tv_sec;
lastTimestamp.tv_nsec = entry.tv_nsec;
// format a TextLogEntry
uint64_t token = proto.start(LogProto::TEXT_LOGS);
proto.write(TextLogEntry::SEC, (long long)entry.tv_sec);
proto.write(TextLogEntry::NANOSEC, (long long)entry.tv_nsec);
proto.write(TextLogEntry::PRIORITY, (int)entry.priority);
proto.write(TextLogEntry::UID, entry.uid);
proto.write(TextLogEntry::PID, entry.pid);
proto.write(TextLogEntry::TID, entry.tid);
proto.write(TextLogEntry::TAG, entry.tag, trimTail(entry.tag, entry.tagLen));
proto.write(TextLogEntry::LOG, entry.message,
trimTail(entry.message, entry.messageLen));
proto.end(token);
}
}
gLastLogsRetrieved[mLogID] = lastTimestamp;
if (!proto.flush(pipeWriteFd) && errno == EPIPE) {
ALOGE("[%s] wrote to a broken pipe\n", this->name.string());
return EPIPE;
}
return NO_ERROR;
}
// ================================================================================
TombstoneSection::TombstoneSection(int id, const char* type, const int64_t timeoutMs)
: WorkerThreadSection(id, timeoutMs), mType(type) {
name = "tombstone ";
name += type;
}
TombstoneSection::~TombstoneSection() {}
status_t TombstoneSection::BlockingCall(int pipeWriteFd) const {
std::unique_ptr<DIR, decltype(&closedir)> proc(opendir("/proc"), closedir);
if (proc.get() == nullptr) {
ALOGE("opendir /proc failed: %s\n", strerror(errno));
return -errno;
}
const std::set<int> hal_pids = get_interesting_hal_pids();
ProtoOutputStream proto;
struct dirent* d;
status_t err = NO_ERROR;
while ((d = readdir(proc.get()))) {
int pid = atoi(d->d_name);
if (pid <= 0) {
continue;
}
const std::string link_name = android::base::StringPrintf("/proc/%d/exe", pid);
std::string exe;
if (!android::base::Readlink(link_name, &exe)) {
ALOGE("Section %s: Can't read '%s': %s\n", name.string(),
link_name.c_str(), strerror(errno));
continue;
}
bool is_java_process;
if (exe == "/system/bin/app_process32" || exe == "/system/bin/app_process64") {
if (mType != "java") continue;
// Don't bother dumping backtraces for the zygote.
if (IsZygote(pid)) {
VLOG("Skipping Zygote");
continue;
}
is_java_process = true;
} else if (should_dump_native_traces(exe.c_str())) {
if (mType != "native") continue;
is_java_process = false;
} else if (hal_pids.find(pid) != hal_pids.end()) {
if (mType != "hal") continue;
is_java_process = false;
} else {
// Probably a native process we don't care about, continue.
VLOG("Skipping %d", pid);
continue;
}
Fpipe dumpPipe;
if (!dumpPipe.init()) {
ALOGW("[%s] failed to setup dump pipe", this->name.string());
err = -errno;
break;
}
const uint64_t start = Nanotime();
pid_t child = fork();
if (child < 0) {
ALOGE("Failed to fork child process");
break;
} else if (child == 0) {
// This is the child process.
dumpPipe.readFd().reset();
const int ret = dump_backtrace_to_file_timeout(
pid, is_java_process ? kDebuggerdJavaBacktrace : kDebuggerdNativeBacktrace,
is_java_process ? 5 : 20, dumpPipe.writeFd().get());
if (ret == -1) {
if (errno == 0) {
ALOGW("Dumping failed for pid '%d', likely due to a timeout\n", pid);
} else {
ALOGE("Dumping failed for pid '%d': %s\n", pid, strerror(errno));
}
}
dumpPipe.writeFd().reset();
_exit(EXIT_SUCCESS);
}
dumpPipe.writeFd().reset();
// Parent process.
// Read from the pipe concurrently to avoid blocking the child.
FdBuffer buffer;
err = buffer.readFully(dumpPipe.readFd().get());
// Wait on the child to avoid it becoming a zombie process.
status_t cStatus = wait_child(child);
if (err != NO_ERROR) {
ALOGW("[%s] failed to read stack dump: %d", this->name.string(), err);
dumpPipe.readFd().reset();
break;
}
if (cStatus != NO_ERROR) {
ALOGE("[%s] child had an issue: %s\n", this->name.string(), strerror(-cStatus));
}
auto dump = std::make_unique<char[]>(buffer.size());
sp<ProtoReader> reader = buffer.data()->read();
int i = 0;
while (reader->hasNext()) {
dump[i] = reader->next();
i++;
}
uint64_t token = proto.start(android::os::BackTraceProto::TRACES);
proto.write(android::os::BackTraceProto::Stack::PID, pid);
proto.write(android::os::BackTraceProto::Stack::DUMP, dump.get(), i);
proto.write(android::os::BackTraceProto::Stack::DUMP_DURATION_NS,
static_cast<long long>(Nanotime() - start));
proto.end(token);
dumpPipe.readFd().reset();
}
if (!proto.flush(pipeWriteFd) && errno == EPIPE) {
ALOGE("[%s] wrote to a broken pipe\n", this->name.string());
if (err != NO_ERROR) {
return EPIPE;
}
}
return err;
}
} // namespace incidentd
} // namespace os
} // namespace android