// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2018 Dmitry V. Levin <[email protected]>
* All rights reserved.
*
* Check whether PTRACE_GET_SYSCALL_INFO semantics implemented in the kernel
* matches userspace expectations.
*/
#include "../kselftest_harness.h"
#include <err.h>
#include <signal.h>
#include <asm/unistd.h>
#include "linux/ptrace.h"
static int
kill_tracee(pid_t pid)
{
if (!pid)
return 0;
int saved_errno = errno;
int rc = kill(pid, SIGKILL);
errno = saved_errno;
return rc;
}
static long
sys_ptrace(int request, pid_t pid, unsigned long addr, unsigned long data)
{
return syscall(__NR_ptrace, request, pid, addr, data);
}
#define LOG_KILL_TRACEE(fmt, ...) \
do { \
kill_tracee(pid); \
TH_LOG("wait #%d: " fmt, \
ptrace_stop, ##__VA_ARGS__); \
} while (0)
TEST(get_syscall_info)
{
static const unsigned long args[][7] = {
/* a sequence of architecture-agnostic syscalls */
{
__NR_chdir,
(unsigned long) "",
0xbad1fed1,
0xbad2fed2,
0xbad3fed3,
0xbad4fed4,
0xbad5fed5
},
{
__NR_gettid,
0xcaf0bea0,
0xcaf1bea1,
0xcaf2bea2,
0xcaf3bea3,
0xcaf4bea4,
0xcaf5bea5
},
{
__NR_exit_group,
0,
0xfac1c0d1,
0xfac2c0d2,
0xfac3c0d3,
0xfac4c0d4,
0xfac5c0d5
}
};
const unsigned long *exp_args;
pid_t pid = fork();
ASSERT_LE(0, pid) {
TH_LOG("fork: %m");
}
if (pid == 0) {
/* get the pid before PTRACE_TRACEME */
pid = getpid();
ASSERT_EQ(0, sys_ptrace(PTRACE_TRACEME, 0, 0, 0)) {
TH_LOG("PTRACE_TRACEME: %m");
}
ASSERT_EQ(0, kill(pid, SIGSTOP)) {
/* cannot happen */
TH_LOG("kill SIGSTOP: %m");
}
for (unsigned int i = 0; i < ARRAY_SIZE(args); ++i) {
syscall(args[i][0],
args[i][1], args[i][2], args[i][3],
args[i][4], args[i][5], args[i][6]);
}
/* unreachable */
_exit(1);
}
const struct {
unsigned int is_error;
int rval;
} *exp_param, exit_param[] = {
{ 1, -ENOENT }, /* chdir */
{ 0, pid } /* gettid */
};
unsigned int ptrace_stop;
for (ptrace_stop = 0; ; ++ptrace_stop) {
struct ptrace_syscall_info info = {
.op = 0xff /* invalid PTRACE_SYSCALL_INFO_* op */
};
const size_t size = sizeof(info);
const int expected_none_size =
(void *) &info.entry - (void *) &info;
const int expected_entry_size =
(void *) &info.entry.args[6] - (void *) &info;
const int expected_exit_size =
(void *) (&info.exit.is_error + 1) -
(void *) &info;
int status;
long rc;
ASSERT_EQ(pid, wait(&status)) {
/* cannot happen */
LOG_KILL_TRACEE("wait: %m");
}
if (WIFEXITED(status)) {
pid = 0; /* the tracee is no more */
ASSERT_EQ(0, WEXITSTATUS(status));
break;
}
ASSERT_FALSE(WIFSIGNALED(status)) {
pid = 0; /* the tracee is no more */
LOG_KILL_TRACEE("unexpected signal %u",
WTERMSIG(status));
}
ASSERT_TRUE(WIFSTOPPED(status)) {
/* cannot happen */
LOG_KILL_TRACEE("unexpected wait status %#x", status);
}
switch (WSTOPSIG(status)) {
case SIGSTOP:
ASSERT_EQ(0, ptrace_stop) {
LOG_KILL_TRACEE("unexpected signal stop");
}
ASSERT_EQ(0, sys_ptrace(PTRACE_SETOPTIONS, pid, 0,
PTRACE_O_TRACESYSGOOD)) {
LOG_KILL_TRACEE("PTRACE_SETOPTIONS: %m");
}
ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO,
pid, size,
(unsigned long) &info))) {
LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m");
}
ASSERT_EQ(expected_none_size, rc) {
LOG_KILL_TRACEE("signal stop mismatch");
}
ASSERT_EQ(PTRACE_SYSCALL_INFO_NONE, info.op) {
LOG_KILL_TRACEE("signal stop mismatch");
}
ASSERT_TRUE(info.arch) {
LOG_KILL_TRACEE("signal stop mismatch");
}
ASSERT_TRUE(info.instruction_pointer) {
LOG_KILL_TRACEE("signal stop mismatch");
}
ASSERT_TRUE(info.stack_pointer) {
LOG_KILL_TRACEE("signal stop mismatch");
}
break;
case SIGTRAP | 0x80:
ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO,
pid, size,
(unsigned long) &info))) {
LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m");
}
switch (ptrace_stop) {
case 1: /* entering chdir */
case 3: /* entering gettid */
case 5: /* entering exit_group */
exp_args = args[ptrace_stop / 2];
ASSERT_EQ(expected_entry_size, rc) {
LOG_KILL_TRACEE("entry stop mismatch");
}
ASSERT_EQ(PTRACE_SYSCALL_INFO_ENTRY, info.op) {
LOG_KILL_TRACEE("entry stop mismatch");
}
ASSERT_TRUE(info.arch) {
LOG_KILL_TRACEE("entry stop mismatch");
}
ASSERT_TRUE(info.instruction_pointer) {
LOG_KILL_TRACEE("entry stop mismatch");
}
ASSERT_TRUE(info.stack_pointer) {
LOG_KILL_TRACEE("entry stop mismatch");
}
ASSERT_EQ(exp_args[0], info.entry.nr) {
LOG_KILL_TRACEE("entry stop mismatch");
}
ASSERT_EQ(exp_args[1], info.entry.args[0]) {
LOG_KILL_TRACEE("entry stop mismatch");
}
ASSERT_EQ(exp_args[2], info.entry.args[1]) {
LOG_KILL_TRACEE("entry stop mismatch");
}
ASSERT_EQ(exp_args[3], info.entry.args[2]) {
LOG_KILL_TRACEE("entry stop mismatch");
}
ASSERT_EQ(exp_args[4], info.entry.args[3]) {
LOG_KILL_TRACEE("entry stop mismatch");
}
ASSERT_EQ(exp_args[5], info.entry.args[4]) {
LOG_KILL_TRACEE("entry stop mismatch");
}
ASSERT_EQ(exp_args[6], info.entry.args[5]) {
LOG_KILL_TRACEE("entry stop mismatch");
}
break;
case 2: /* exiting chdir */
case 4: /* exiting gettid */
exp_param = &exit_param[ptrace_stop / 2 - 1];
ASSERT_EQ(expected_exit_size, rc) {
LOG_KILL_TRACEE("exit stop mismatch");
}
ASSERT_EQ(PTRACE_SYSCALL_INFO_EXIT, info.op) {
LOG_KILL_TRACEE("exit stop mismatch");
}
ASSERT_TRUE(info.arch) {
LOG_KILL_TRACEE("exit stop mismatch");
}
ASSERT_TRUE(info.instruction_pointer) {
LOG_KILL_TRACEE("exit stop mismatch");
}
ASSERT_TRUE(info.stack_pointer) {
LOG_KILL_TRACEE("exit stop mismatch");
}
ASSERT_EQ(exp_param->is_error,
info.exit.is_error) {
LOG_KILL_TRACEE("exit stop mismatch");
}
ASSERT_EQ(exp_param->rval, info.exit.rval) {
LOG_KILL_TRACEE("exit stop mismatch");
}
break;
default:
LOG_KILL_TRACEE("unexpected syscall stop");
abort();
}
break;
default:
LOG_KILL_TRACEE("unexpected stop signal %#x",
WSTOPSIG(status));
abort();
}
ASSERT_EQ(0, sys_ptrace(PTRACE_SYSCALL, pid, 0, 0)) {
LOG_KILL_TRACEE("PTRACE_SYSCALL: %m");
}
}
ASSERT_EQ(ARRAY_SIZE(args) * 2, ptrace_stop);
}
TEST_HARNESS_MAIN
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