blob: 26726cf89747f8acce536b34e07fcdd710241dda [file] [log] [blame]
/*
* Copyright 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.
*/
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits>
#include <string_view>
#include <thread>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/parseint.h>
#include <android-base/unique_fd.h>
#include <debuggerd/client.h>
#include <procinfo/process.h>
#include "util.h"
using android::base::unique_fd;
static void usage(int exit_code) {
fprintf(stderr, "usage: debuggerd [-bj] PID\n");
fprintf(stderr, "\n");
fprintf(stderr, "-b, --backtrace just a backtrace rather than a full tombstone\n");
fprintf(stderr, "-j collect java traces\n");
_exit(exit_code);
}
int main(int argc, char* argv[]) {
if (argc <= 1) usage(0);
if (argc > 3) usage(1);
DebuggerdDumpType dump_type = kDebuggerdTombstone;
if (argc == 3) {
std::string_view flag = argv[1];
if (flag == "-b" || flag == "--backtrace") {
dump_type = kDebuggerdNativeBacktrace;
} else if (flag == "-j") {
dump_type = kDebuggerdJavaBacktrace;
} else {
usage(1);
}
}
pid_t pid;
if (!android::base::ParseInt(argv[argc - 1], &pid, 1, std::numeric_limits<pid_t>::max())) {
usage(1);
}
if (getuid() != 0) {
errx(1, "root is required");
}
// Check to see if the process exists and that we can actually send a signal to it.
android::procinfo::ProcessInfo proc_info;
if (!android::procinfo::GetProcessInfo(pid, &proc_info)) {
err(1, "failed to fetch info for process %d", pid);
}
if (proc_info.state == android::procinfo::kProcessStateZombie) {
errx(1, "process %d is a zombie", pid);
}
// Send a signal to the main thread pid, not a side thread. The signal
// handler always sets the crashing tid to the main thread pid when sent this
// signal. This is to avoid a problem where the signal is sent to a process,
// but happens on a side thread and the intercept mismatches since it
// is looking for the main thread pid, not the tid of this random thread.
// See b/194346289 for extra details.
if (kill(proc_info.pid, 0) != 0) {
if (pid == proc_info.pid) {
err(1, "cannot send signal to process %d", pid);
} else {
err(1, "cannot send signal to main thread %d (requested thread %d)", proc_info.pid, pid);
}
}
unique_fd output_fd(fcntl(STDOUT_FILENO, F_DUPFD_CLOEXEC, 0));
if (output_fd.get() == -1) {
err(1, "failed to fcntl dup stdout");
}
if (!debuggerd_trigger_dump(proc_info.pid, dump_type, 0, std::move(output_fd))) {
if (pid == proc_info.pid) {
errx(1, "failed to dump process %d", pid);
} else {
errx(1, "failed to dump main thread %d (requested thread %d)", proc_info.pid, pid);
}
}
return 0;
}