// SPDX-License-Identifier: GPL-2.0
/*
* Based on Christian Brauner's clone3() example.
* These tests are assuming to be running in the host's
* PID namespace.
*/
#define _GNU_SOURCE
#include <errno.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <unistd.h>
#include <sched.h>
#include "../kselftest.h"
#include "clone3_selftests.h"
#define MAX_PID_NS_LEVEL 32
static int pipe_1[2];
static int pipe_2[2];
static void child_exit(int ret)
{
fflush(stdout);
fflush(stderr);
_exit(ret);
}
static int call_clone3_set_tid(pid_t *set_tid,
size_t set_tid_size,
int flags,
int expected_pid,
bool wait_for_it)
{
int status;
pid_t pid = -1;
struct __clone_args args = {
.flags = flags,
.exit_signal = SIGCHLD,
.set_tid = ptr_to_u64(set_tid),
.set_tid_size = set_tid_size,
};
pid = sys_clone3(&args, sizeof(args));
if (pid < 0) {
ksft_print_msg("%s - Failed to create new process\n",
strerror(errno));
return -errno;
}
if (pid == 0) {
int ret;
char tmp = 0;
int exit_code = EXIT_SUCCESS;
ksft_print_msg("I am the child, my PID is %d (expected %d)\n",
getpid(), set_tid[0]);
if (wait_for_it) {
ksft_print_msg("[%d] Child is ready and waiting\n",
getpid());
/* Signal the parent that the child is ready */
close(pipe_1[0]);
ret = write(pipe_1[1], &tmp, 1);
if (ret != 1) {
ksft_print_msg(
"Writing to pipe returned %d", ret);
exit_code = EXIT_FAILURE;
}
close(pipe_1[1]);
close(pipe_2[1]);
ret = read(pipe_2[0], &tmp, 1);
if (ret != 1) {
ksft_print_msg(
"Reading from pipe returned %d", ret);
exit_code = EXIT_FAILURE;
}
close(pipe_2[0]);
}
if (set_tid[0] != getpid())
child_exit(EXIT_FAILURE);
child_exit(exit_code);
}
if (expected_pid == 0 || expected_pid == pid) {
ksft_print_msg("I am the parent (%d). My child's pid is %d\n",
getpid(), pid);
} else {
ksft_print_msg(
"Expected child pid %d does not match actual pid %d\n",
expected_pid, pid);
return -1;
}
if (waitpid(pid, &status, 0) < 0) {
ksft_print_msg("Child returned %s\n", strerror(errno));
return -errno;
}
if (!WIFEXITED(status))
return -1;
return WEXITSTATUS(status);
}
static void test_clone3_set_tid(const char *desc,
pid_t *set_tid,
size_t set_tid_size,
int flags,
int expected,
int expected_pid,
bool wait_for_it)
{
int ret;
ksft_print_msg(
"[%d] Trying clone3() with CLONE_SET_TID to %d and 0x%x\n",
getpid(), set_tid[0], flags);
ret = call_clone3_set_tid(set_tid, set_tid_size, flags, expected_pid,
wait_for_it);
ksft_print_msg(
"[%d] clone3() with CLONE_SET_TID %d says: %d - expected %d\n",
getpid(), set_tid[0], ret, expected);
ksft_test_result(ret == expected, "%s with %zu TIDs and flags 0x%x\n",
desc, set_tid_size, flags);
}
int main(int argc, char *argv[])
{
FILE *f;
char buf;
char *line;
int status;
int ret = -1;
size_t len = 0;
int pid_max = 0;
uid_t uid = getuid();
char proc_path[100] = {0};
pid_t pid, ns1, ns2, ns3, ns_pid;
pid_t set_tid[MAX_PID_NS_LEVEL * 2];
ksft_print_header();
ksft_set_plan(29);
test_clone3_supported();
if (pipe(pipe_1) < 0 || pipe(pipe_2) < 0)
ksft_exit_fail_msg("pipe() failed\n");
f = fopen("/proc/sys/kernel/pid_max", "r");
if (f == NULL)
ksft_exit_fail_msg(
"%s - Could not open /proc/sys/kernel/pid_max\n",
strerror(errno));
fscanf(f, "%d", &pid_max);
fclose(f);
ksft_print_msg("/proc/sys/kernel/pid_max %d\n", pid_max);
/* Try invalid settings */
memset(&set_tid, 0, sizeof(set_tid));
test_clone3_set_tid("invalid size, 0 TID",
set_tid, MAX_PID_NS_LEVEL + 1, 0, -EINVAL, 0, 0);
test_clone3_set_tid("invalid size, 0 TID",
set_tid, MAX_PID_NS_LEVEL * 2, 0, -EINVAL, 0, 0);
test_clone3_set_tid("invalid size, 0 TID",
set_tid, MAX_PID_NS_LEVEL * 2 + 1, 0,
-EINVAL, 0, 0);
test_clone3_set_tid("invalid size, 0 TID",
set_tid, MAX_PID_NS_LEVEL * 42, 0, -EINVAL, 0, 0);
/*
* This can actually work if this test running in a MAX_PID_NS_LEVEL - 1
* nested PID namespace.
*/
test_clone3_set_tid("invalid size, 0 TID",
set_tid, MAX_PID_NS_LEVEL - 1, 0, -EINVAL, 0, 0);
memset(&set_tid, 0xff, sizeof(set_tid));
test_clone3_set_tid("invalid size, TID all 1s",
set_tid, MAX_PID_NS_LEVEL + 1, 0, -EINVAL, 0, 0);
test_clone3_set_tid("invalid size, TID all 1s",
set_tid, MAX_PID_NS_LEVEL * 2, 0, -EINVAL, 0, 0);
test_clone3_set_tid("invalid size, TID all 1s",
set_tid, MAX_PID_NS_LEVEL * 2 + 1, 0,
-EINVAL, 0, 0);
test_clone3_set_tid("invalid size, TID all 1s",
set_tid, MAX_PID_NS_LEVEL * 42, 0, -EINVAL, 0, 0);
/*
* This can actually work if this test running in a MAX_PID_NS_LEVEL - 1
* nested PID namespace.
*/
test_clone3_set_tid("invalid size, TID all 1s",
set_tid, MAX_PID_NS_LEVEL - 1, 0, -EINVAL, 0, 0);
memset(&set_tid, 0, sizeof(set_tid));
/* Try with an invalid PID */
set_tid[0] = 0;
test_clone3_set_tid("valid size, 0 TID",
set_tid, 1, 0, -EINVAL, 0, 0);
set_tid[0] = -1;
test_clone3_set_tid("valid size, -1 TID",
set_tid, 1, 0, -EINVAL, 0, 0);
/* Claim that the set_tid array actually contains 2 elements. */
test_clone3_set_tid("2 TIDs, -1 and 0",
set_tid, 2, 0, -EINVAL, 0, 0);
/* Try it in a new PID namespace */
if (uid == 0)
test_clone3_set_tid("valid size, -1 TID",
set_tid, 1, CLONE_NEWPID, -EINVAL, 0, 0);
else
ksft_test_result_skip("Clone3() with set_tid requires root\n");
/* Try with a valid PID (1) this should return -EEXIST. */
set_tid[0] = 1;
if (uid == 0)
test_clone3_set_tid("duplicate PID 1",
set_tid, 1, 0, -EEXIST, 0, 0);
else
ksft_test_result_skip("Clone3() with set_tid requires root\n");
/* Try it in a new PID namespace */
if (uid == 0)
test_clone3_set_tid("duplicate PID 1",
set_tid, 1, CLONE_NEWPID, 0, 0, 0);
else
ksft_test_result_skip("Clone3() with set_tid requires root\n");
/* pid_max should fail everywhere */
set_tid[0] = pid_max;
test_clone3_set_tid("set TID to maximum",
set_tid, 1, 0, -EINVAL, 0, 0);
if (uid == 0)
test_clone3_set_tid("set TID to maximum",
set_tid, 1, CLONE_NEWPID, -EINVAL, 0, 0);
else
ksft_test_result_skip("Clone3() with set_tid requires root\n");
if (uid != 0) {
/*
* All remaining tests require root. Tell the framework
* that all those tests are skipped as non-root.
*/
ksft_cnt.ksft_xskip += ksft_plan - ksft_test_num();
goto out;
}
/* Find the current active PID */
pid = fork();
if (pid == 0) {
ksft_print_msg("Child has PID %d\n", getpid());
child_exit(EXIT_SUCCESS);
}
if (waitpid(pid, &status, 0) < 0)
ksft_exit_fail_msg("Waiting for child %d failed", pid);
/* After the child has finished, its PID should be free. */
set_tid[0] = pid;
test_clone3_set_tid("reallocate child TID",
set_tid, 1, 0, 0, 0, 0);
/* This should fail as there is no PID 1 in that namespace */
test_clone3_set_tid("duplicate child TID",
set_tid, 1, CLONE_NEWPID, -EINVAL, 0, 0);
/*
* Creating a process with PID 1 in the newly created most nested
* PID namespace and PID 'pid' in the parent PID namespace. This
* needs to work.
*/
set_tid[0] = 1;
set_tid[1] = pid;
test_clone3_set_tid("create PID 1 in new NS",
set_tid, 2, CLONE_NEWPID, 0, pid, 0);
ksft_print_msg("unshare PID namespace\n");
if (unshare(CLONE_NEWPID) == -1)
ksft_exit_fail_msg("unshare(CLONE_NEWPID) failed: %s\n",
strerror(errno));
set_tid[0] = pid;
/* This should fail as there is no PID 1 in that namespace */
test_clone3_set_tid("duplicate PID 1",
set_tid, 1, 0, -EINVAL, 0, 0);
/* Let's create a PID 1 */
ns_pid = fork();
if (ns_pid == 0) {
/*
* This and the next test cases check that all pid-s are
* released on error paths.
*/
set_tid[0] = 43;
set_tid[1] = -1;
test_clone3_set_tid("check leak on invalid TID -1",
set_tid, 2, 0, -EINVAL, 0, 0);
set_tid[0] = 43;
set_tid[1] = pid;
test_clone3_set_tid("check leak on invalid specific TID",
set_tid, 2, 0, 0, 43, 0);
ksft_print_msg("Child in PID namespace has PID %d\n", getpid());
set_tid[0] = 2;
test_clone3_set_tid("create PID 2 in child NS",
set_tid, 1, 0, 0, 2, 0);
set_tid[0] = 1;
set_tid[1] = -1;
set_tid[2] = pid;
/* This should fail as there is invalid PID at level '1'. */
test_clone3_set_tid("fail due to invalid TID at level 1",
set_tid, 3, CLONE_NEWPID, -EINVAL, 0, 0);
set_tid[0] = 1;
set_tid[1] = 42;
set_tid[2] = pid;
/*
* This should fail as there are not enough active PID
* namespaces. Again assuming this is running in the host's
* PID namespace. Not yet nested.
*/
test_clone3_set_tid("fail due to too few active PID NSs",
set_tid, 4, CLONE_NEWPID, -EINVAL, 0, 0);
/*
* This should work and from the parent we should see
* something like 'NSpid: pid 42 1'.
*/
test_clone3_set_tid("verify that we have 3 PID NSs",
set_tid, 3, CLONE_NEWPID, 0, 42, true);
child_exit(ksft_cnt.ksft_fail);
}
close(pipe_1[1]);
close(pipe_2[0]);
while (read(pipe_1[0], &buf, 1) > 0) {
ksft_print_msg("[%d] Child is ready and waiting\n", getpid());
break;
}
snprintf(proc_path, sizeof(proc_path), "/proc/%d/status", pid);
f = fopen(proc_path, "r");
if (f == NULL)
ksft_exit_fail_msg(
"%s - Could not open %s\n",
strerror(errno), proc_path);
while (getline(&line, &len, f) != -1) {
if (strstr(line, "NSpid")) {
int i;
/* Verify that all generated PIDs are as expected. */
i = sscanf(line, "NSpid:\t%d\t%d\t%d",
&ns3, &ns2, &ns1);
if (i != 3) {
ksft_print_msg(
"Unexpected 'NSPid:' entry: %s",
line);
ns1 = ns2 = ns3 = 0;
}
break;
}
}
fclose(f);
free(line);
close(pipe_2[0]);
/* Tell the clone3()'d child to finish. */
write(pipe_2[1], &buf, 1);
close(pipe_2[1]);
if (waitpid(ns_pid, &status, 0) < 0) {
ksft_print_msg("Child returned %s\n", strerror(errno));
ret = -errno;
goto out;
}
if (!WIFEXITED(status))
ksft_test_result_fail("Child error\n");
ksft_cnt.ksft_pass += 6 - (ksft_cnt.ksft_fail - WEXITSTATUS(status));
ksft_cnt.ksft_fail = WEXITSTATUS(status);
ksft_print_msg("Expecting PIDs %d, 42, 1\n", pid);
ksft_print_msg("Have PIDs in namespaces: %d, %d, %d\n", ns3, ns2, ns1);
ksft_test_result(ns3 == pid && ns2 == 42 && ns1 == 1,
"PIDs in all namespaces as expected\n");
out:
ret = 0;
if (ret)
ksft_exit_fail();
ksft_exit_pass();
}
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