tools/testing/selftests/clone3/clone3.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /* Based on Christian Brauner's clone3() example */
   4
   5 #define _GNU_SOURCE
   6 #include <errno.h>
   7 #include <inttypes.h>
   8 #include <linux/types.h>
   9 #include <linux/sched.h>
  10 #include <stdint.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <sys/syscall.h>
  14 #include <sys/types.h>
  15 #include <sys/un.h>
  16 #include <sys/wait.h>
  17 #include <unistd.h>
  18 #include <sched.h>
  19
  20 #include "../kselftest.h"
  21 #include "clone3_selftests.h"
  22
  23 /*
  24  * Different sizes of struct clone_args
  25  */
  26 #ifndef CLONE3_ARGS_SIZE_V0
  27 #define CLONE3_ARGS_SIZE_V0 64
  28 #endif
  29
  30 enum test_mode {
  31         CLONE3_ARGS_NO_TEST,
  32         CLONE3_ARGS_ALL_0,
  33         CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG,
  34         CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG,
  35         CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG,
  36         CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
  37 };
  38
  39 static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
  40 {
  41         struct clone_args args = {
  42                 .flags = flags,
  43                 .exit_signal = SIGCHLD,
  44         };
  45
  46         struct clone_args_extended {
  47                 struct clone_args args;
  48                 __aligned_u64 excess_space[2];
  49         } args_ext;
  50
  51         pid_t pid = -1;
  52         int status;
  53
  54         memset(&args_ext, 0, sizeof(args_ext));
  55         if (size > sizeof(struct clone_args))
  56                 args_ext.excess_space[1] = 1;
  57
  58         if (size == 0)
  59                 size = sizeof(struct clone_args);
  60
  61         switch (test_mode) {
  62         case CLONE3_ARGS_ALL_0:
  63                 args.flags = 0;
  64                 args.exit_signal = 0;
  65                 break;
  66         case CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG:
  67                 args.exit_signal = 0xbadc0ded00000000ULL;
  68                 break;
  69         case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG:
  70                 args.exit_signal = 0x0000000080000000ULL;
  71                 break;
  72         case CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG:
  73                 args.exit_signal = 0x0000000000000100ULL;
  74                 break;
  75         case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG:
  76                 args.exit_signal = 0x00000000000000f0ULL;
  77                 break;
  78         }
  79
  80         memcpy(&args_ext.args, &args, sizeof(struct clone_args));
  81
  82         pid = sys_clone3((struct clone_args *)&args_ext, size);
  83         if (pid < 0) {
  84                 ksft_print_msg("%s - Failed to create new process\n",
  85                                 strerror(errno));
  86                 return -errno;
  87         }
  88
  89         if (pid == 0) {
  90                 ksft_print_msg("I am the child, my PID is %d\n", getpid());
  91                 _exit(EXIT_SUCCESS);
  92         }
  93
  94         ksft_print_msg("I am the parent (%d). My child's pid is %d\n",
  95                         getpid(), pid);
  96
  97         if (waitpid(-1, &status, __WALL) < 0) {
  98                 ksft_print_msg("Child returned %s\n", strerror(errno));
  99                 return -errno;
 100         }
 101         if (WEXITSTATUS(status))
 102                 return WEXITSTATUS(status);
 103
 104         return 0;
 105 }
 106
 107 static void test_clone3(uint64_t flags, size_t size, int expected,
 108                        enum test_mode test_mode)
 109 {
 110         int ret;
 111
 112         ksft_print_msg(
 113                 "[%d] Trying clone3() with flags %#" PRIx64 " (size %zu)\n",
 114                 getpid(), flags, size);
 115         ret = call_clone3(flags, size, test_mode);
 116         ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n",
 117                         getpid(), ret, expected);
 118         if (ret != expected)
 119                 ksft_test_result_fail(
 120                         "[%d] Result (%d) is different than expected (%d)\n",
 121                         getpid(), ret, expected);
 122         else
 123                 ksft_test_result_pass(
 124                         "[%d] Result (%d) matches expectation (%d)\n",
 125                         getpid(), ret, expected);
 126 }
 127
 128 int main(int argc, char *argv[])
 129 {
 130         pid_t pid;
 131
 132         uid_t uid = getuid();
 133
 134         test_clone3_supported();
 135         ksft_print_header();
 136         ksft_set_plan(17);
 137
 138         /* Just a simple clone3() should return 0.*/
 139         test_clone3(0, 0, 0, CLONE3_ARGS_NO_TEST);
 140
 141         /* Do a clone3() in a new PID NS.*/
 142         if (uid == 0)
 143                 test_clone3(CLONE_NEWPID, 0, 0, CLONE3_ARGS_NO_TEST);
 144         else
 145                 ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
 146
 147         /* Do a clone3() with CLONE3_ARGS_SIZE_V0. */
 148         test_clone3(0, CLONE3_ARGS_SIZE_V0, 0, CLONE3_ARGS_NO_TEST);
 149
 150         /* Do a clone3() with CLONE3_ARGS_SIZE_V0 - 8 */
 151         test_clone3(0, CLONE3_ARGS_SIZE_V0 - 8, -EINVAL, CLONE3_ARGS_NO_TEST);
 152
 153         /* Do a clone3() with sizeof(struct clone_args) + 8 */
 154         test_clone3(0, sizeof(struct clone_args) + 8, 0, CLONE3_ARGS_NO_TEST);
 155
 156         /* Do a clone3() with exit_signal having highest 32 bits non-zero */
 157         test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG);
 158
 159         /* Do a clone3() with negative 32-bit exit_signal */
 160         test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG);
 161
 162         /* Do a clone3() with exit_signal not fitting into CSIGNAL mask */
 163         test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG);
 164
 165         /* Do a clone3() with NSIG < exit_signal < CSIG */
 166         test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG);
 167
 168         test_clone3(0, sizeof(struct clone_args) + 8, 0, CLONE3_ARGS_ALL_0);
 169
 170         test_clone3(0, sizeof(struct clone_args) + 16, -E2BIG,
 171                         CLONE3_ARGS_ALL_0);
 172
 173         test_clone3(0, sizeof(struct clone_args) * 2, -E2BIG,
 174                         CLONE3_ARGS_ALL_0);
 175
 176         /* Do a clone3() with > page size */
 177         test_clone3(0, getpagesize() + 8, -E2BIG, CLONE3_ARGS_NO_TEST);
 178
 179         /* Do a clone3() with CLONE3_ARGS_SIZE_V0 in a new PID NS. */
 180         if (uid == 0)
 181                 test_clone3(CLONE_NEWPID, CLONE3_ARGS_SIZE_V0, 0,
 182                                 CLONE3_ARGS_NO_TEST);
 183         else
 184                 ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
 185
 186         /* Do a clone3() with CLONE3_ARGS_SIZE_V0 - 8 in a new PID NS */
 187         test_clone3(CLONE_NEWPID, CLONE3_ARGS_SIZE_V0 - 8, -EINVAL,
 188                         CLONE3_ARGS_NO_TEST);
 189
 190         /* Do a clone3() with sizeof(struct clone_args) + 8 in a new PID NS */
 191         if (uid == 0)
 192                 test_clone3(CLONE_NEWPID, sizeof(struct clone_args) + 8, 0,
 193                                 CLONE3_ARGS_NO_TEST);
 194         else
 195                 ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
 196
 197         /* Do a clone3() with > page size in a new PID NS */
 198         test_clone3(CLONE_NEWPID, getpagesize() + 8, -E2BIG,
 199                         CLONE3_ARGS_NO_TEST);
 200
 201         return !ksft_get_fail_cnt() ? ksft_exit_pass() : ksft_exit_fail();
 202 }