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// Copyright 2018 The gVisor Authors.
//
// 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 <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/auxv.h>
#include <sys/prctl.h>
#include <sys/time.h>
#include <iostream>
#include <ostream>
#include <string>
// Pretty-print a sigset_t.
std::ostream& operator<<(std::ostream& out, const sigset_t& s) {
out << "{ ";
for (int i = 0; i < NSIG; i++) {
if (sigismember(&s, i)) {
out << i << " ";
}
}
out << "}";
return out;
}
// Verify that the signo handler is handler.
int CheckSigHandler(uint32_t signo, uintptr_t handler) {
struct sigaction sa;
int ret = sigaction(signo, nullptr, &sa);
if (ret < 0) {
perror("sigaction");
return 1;
}
if (reinterpret_cast<void (*)(int)>(handler) != sa.sa_handler) {
std::cerr << "signo " << signo << " handler got: " << sa.sa_handler
<< " expected: " << std::hex << handler;
return 1;
}
return 0;
}
// Verify that the signo is blocked.
int CheckSigBlocked(uint32_t signo) {
sigset_t s;
int ret = sigprocmask(SIG_SETMASK, nullptr, &s);
if (ret < 0) {
perror("sigprocmask");
return 1;
}
if (!sigismember(&s, signo)) {
std::cerr << "signal " << signo << " not blocked in signal mask: " << s
<< std::endl;
return 1;
}
return 0;
}
// Verify that the itimer is enabled.
int CheckItimerEnabled(uint32_t timer) {
struct itimerval itv;
int ret = getitimer(timer, &itv);
if (ret < 0) {
perror("getitimer");
return 1;
}
if (!itv.it_value.tv_sec && !itv.it_value.tv_usec &&
!itv.it_interval.tv_sec && !itv.it_interval.tv_usec) {
std::cerr << "timer " << timer
<< " not enabled. value sec: " << itv.it_value.tv_sec
<< " usec: " << itv.it_value.tv_usec
<< " interval sec: " << itv.it_interval.tv_sec
<< " usec: " << itv.it_interval.tv_usec << std::endl;
return 1;
}
return 0;
}
int PrintExecFn() {
unsigned long execfn = getauxval(AT_EXECFN);
if (!execfn) {
std::cerr << "AT_EXECFN missing" << std::endl;
return 1;
}
std::cerr << reinterpret_cast<const char*>(execfn) << std::endl;
return 0;
}
int PrintExecName() {
const size_t name_length = 20;
char name[name_length] = {0};
if (prctl(PR_GET_NAME, name) < 0) {
std::cerr << "prctl(PR_GET_NAME) failed" << std::endl;
return 1;
}
std::cerr << name << std::endl;
return 0;
}
void usage(const std::string& prog) {
std::cerr << "usage:\n"
<< "\t" << prog << " CheckSigHandler <signo> <handler addr (hex)>\n"
<< "\t" << prog << " CheckSigBlocked <signo>\n"
<< "\t" << prog << " CheckTimerDisabled <timer>\n"
<< "\t" << prog << " PrintExecFn\n"
<< "\t" << prog << " PrintExecName" << std::endl;
}
int main(int argc, char** argv) {
if (argc < 2) {
usage(argv[0]);
return 1;
}
std::string func(argv[1]);
if (func == "CheckSigHandler") {
if (argc != 4) {
usage(argv[0]);
return 1;
}
char* end;
uint32_t signo = strtoul(argv[2], &end, 10);
if (end == argv[2]) {
std::cerr << "invalid signo: " << argv[2] << std::endl;
return 1;
}
uintptr_t handler = strtoull(argv[3], &end, 16);
if (end == argv[3]) {
std::cerr << "invalid handler: " << std::hex << argv[3] << std::endl;
return 1;
}
return CheckSigHandler(signo, handler);
}
if (func == "CheckSigBlocked") {
if (argc != 3) {
usage(argv[0]);
return 1;
}
char* end;
uint32_t signo = strtoul(argv[2], &end, 10);
if (end == argv[2]) {
std::cerr << "invalid signo: " << argv[2] << std::endl;
return 1;
}
return CheckSigBlocked(signo);
}
if (func == "CheckItimerEnabled") {
if (argc != 3) {
usage(argv[0]);
return 1;
}
char* end;
uint32_t timer = strtoul(argv[2], &end, 10);
if (end == argv[2]) {
std::cerr << "invalid signo: " << argv[2] << std::endl;
return 1;
}
return CheckItimerEnabled(timer);
}
if (func == "PrintExecFn") {
// N.B. This will be called as an interpreter script, with the script passed
// as the third argument. We don't care about that script.
return PrintExecFn();
}
if (func == "PrintExecName") {
// N.B. This may be called as an interpreter script like PrintExecFn.
return PrintExecName();
}
std::cerr << "Invalid function: " << func << std::endl;
return 1;
}
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