diff options
Diffstat (limited to 'tools/testing/selftests/clone3/clone3_set_tid.c')
| -rw-r--r-- | tools/testing/selftests/clone3/clone3_set_tid.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/tools/testing/selftests/clone3/clone3_set_tid.c b/tools/testing/selftests/clone3/clone3_set_tid.c new file mode 100644 index 000000000000..25beb22f35b5 --- /dev/null +++ b/tools/testing/selftests/clone3/clone3_set_tid.c @@ -0,0 +1,397 @@ +// 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" + +#ifndef MAX_PID_NS_LEVEL +#define MAX_PID_NS_LEVEL 32 +#endif + +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(struct clone_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(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); + if (ret != expected) + ksft_test_result_fail( + "[%d] Result (%d) is different than expected (%d)\n", + getpid(), ret, expected); + else + ksft_test_result_pass( + "[%d] Result (%d) matches expectation (%d)\n", + getpid(), ret, expected); +} +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(); + test_clone3_supported(); + ksft_set_plan(29); + + 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(set_tid, MAX_PID_NS_LEVEL + 1, 0, -EINVAL, 0, 0); + + test_clone3_set_tid(set_tid, MAX_PID_NS_LEVEL * 2, 0, -EINVAL, 0, 0); + + test_clone3_set_tid(set_tid, MAX_PID_NS_LEVEL * 2 + 1, 0, + -EINVAL, 0, 0); + + test_clone3_set_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(set_tid, MAX_PID_NS_LEVEL - 1, 0, -EINVAL, 0, 0); + + memset(&set_tid, 0xff, sizeof(set_tid)); + test_clone3_set_tid(set_tid, MAX_PID_NS_LEVEL + 1, 0, -EINVAL, 0, 0); + + test_clone3_set_tid(set_tid, MAX_PID_NS_LEVEL * 2, 0, -EINVAL, 0, 0); + + test_clone3_set_tid(set_tid, MAX_PID_NS_LEVEL * 2 + 1, 0, + -EINVAL, 0, 0); + + test_clone3_set_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(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(set_tid, 1, 0, -EINVAL, 0, 0); + + set_tid[0] = -1; + test_clone3_set_tid(set_tid, 1, 0, -EINVAL, 0, 0); + + /* Claim that the set_tid array actually contains 2 elements. */ + test_clone3_set_tid(set_tid, 2, 0, -EINVAL, 0, 0); + + /* Try it in a new PID namespace */ + if (uid == 0) + test_clone3_set_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(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(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, 1, 0, -EINVAL, 0, 0); + + if (uid == 0) + test_clone3_set_tid(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(set_tid, 1, 0, 0, 0, 0); + + /* This should fail as there is no PID 1 in that namespace */ + test_clone3_set_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(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(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(set_tid, 2, 0, -EINVAL, 0, 0); + + set_tid[0] = 43; + set_tid[1] = pid; + test_clone3_set_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(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(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(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(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); + + if (ns3 == pid && ns2 == 42 && ns1 == 1) + ksft_test_result_pass( + "PIDs in all namespaces as expected (%d,%d,%d)\n", + ns3, ns2, ns1); + else + ksft_test_result_fail( + "PIDs in all namespaces not as expected (%d,%d,%d)\n", + ns3, ns2, ns1); +out: + ret = 0; + + return !ret ? ksft_exit_pass() : ksft_exit_fail(); +} |