131 lines
3.4 KiB
C++
131 lines
3.4 KiB
C++
/*
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* Copyright (C) 2022 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <errno.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <sys/ptrace.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <time.h>
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#include <unistd.h>
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#include "PidUtils.h"
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namespace unwindstack {
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static bool Exited(pid_t pid) {
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int status;
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pid_t wait_pid = waitpid(pid, &status, WNOHANG);
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if (wait_pid != pid) {
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return false;
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}
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if (WIFEXITED(status)) {
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fprintf(stderr, "%d died: Process exited with code %d\n", pid, WEXITSTATUS(status));
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} else if (WIFSIGNALED(status)) {
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fprintf(stderr, "%d died: Process exited due to signal %d\n", pid, WTERMSIG(status));
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} else {
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fprintf(stderr, "%d died: Process finished for unknown reason\n", pid);
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}
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return true;
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}
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bool Quiesce(pid_t pid) {
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siginfo_t si;
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// Wait for up to 10 seconds.
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for (time_t start_time = time(nullptr); time(nullptr) - start_time < 10;) {
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if (ptrace(PTRACE_GETSIGINFO, pid, 0, &si) == 0) {
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return true;
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}
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if (errno != ESRCH) {
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if (errno == EINVAL) {
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// The process is in group-stop state, so try and kick the
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// process out of that state.
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if (ptrace(PTRACE_LISTEN, pid, 0, 0) == -1) {
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// Cannot recover from this, so just pretend it worked and see
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// if we can unwind.
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return true;
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}
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} else {
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perror("ptrace getsiginfo failed");
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return false;
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}
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}
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usleep(5000);
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}
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fprintf(stderr, "Did not quiesce in 10 seconds\n");
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return false;
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}
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bool Attach(pid_t pid) {
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// Wait up to 45 seconds to attach.
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for (time_t start_time = time(nullptr); time(nullptr) - start_time < 45;) {
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if (ptrace(PTRACE_ATTACH, pid, 0, 0) == 0) {
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break;
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}
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if (errno != ESRCH) {
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perror("Failed to attach");
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return false;
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}
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usleep(5000);
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}
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if (Quiesce(pid)) {
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return true;
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}
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if (ptrace(PTRACE_DETACH, pid, 0, 0) == -1) {
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perror("Failed to detach");
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}
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return false;
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}
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bool Detach(pid_t pid) {
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if (ptrace(PTRACE_DETACH, pid, 0, 0) == -1) {
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perror("ptrace detach failed");
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return false;
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}
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return true;
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}
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bool RunWhenQuiesced(pid_t pid, bool leave_attached, std::function<PidRunEnum()> fn) {
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// Wait up to 120 seconds to run the fn.
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PidRunEnum status = PID_RUN_KEEP_GOING;
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for (time_t start_time = time(nullptr);
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time(nullptr) - start_time < 120 && status == PID_RUN_KEEP_GOING;) {
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if (Attach(pid)) {
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status = fn();
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if (status == PID_RUN_PASS && leave_attached) {
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return true;
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}
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if (!Detach(pid)) {
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return false;
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}
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} else if (Exited(pid)) {
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return false;
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}
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usleep(5000);
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}
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if (status == PID_RUN_KEEP_GOING) {
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fprintf(stderr, "Timed out waiting for pid %d to be ready\n", pid);
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}
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return status == PID_RUN_PASS;
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}
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} // namespace unwindstack
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