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 enum test_mode {
  24         CLONE3_ARGS_NO_TEST,
  25         CLONE3_ARGS_ALL_0,
  26         CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG,
  27         CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG,
  28         CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG,
  29         CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
  30 };
  31
  32 static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
  33 {
  34         struct __clone_args args = {
  35                 .flags = flags,
  36                 .exit_signal = SIGCHLD,
  37         };
  38
  39         struct clone_args_extended {
  40                 struct __clone_args args;
  41                 __aligned_u64 excess_space[2];
  42         } args_ext;
  43
  44         pid_t pid = -1;
  45         int status;
  46
  47         memset(&args_ext, 0, sizeof(args_ext));
  48         if (size > sizeof(struct __clone_args))
  49                 args_ext.excess_space[1] = 1;
  50
  51         if (size == 0)
  52                 size = sizeof(struct __clone_args);
  53
  54         switch (test_mode) {
  55         case CLONE3_ARGS_ALL_0:
  56                 args.flags = 0;
  57                 args.exit_signal = 0;
  58                 break;
  59         case CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG:
  60                 args.exit_signal = 0xbadc0ded00000000ULL;
  61                 break;
  62         case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG:
  63                 args.exit_signal = 0x0000000080000000ULL;
  64                 break;
  65         case CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG:
  66                 args.exit_signal = 0x0000000000000100ULL;
  67                 break;
  68         case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG:
  69                 args.exit_signal = 0x00000000000000f0ULL;
  70                 break;
  71         }
  72
  73         memcpy(&args_ext.args, &args, sizeof(struct __clone_args));
  74
  75         pid = sys_clone3((struct __clone_args *)&args_ext, size);
  76         if (pid < 0) {
  77                 ksft_print_msg("%s - Failed to create new process\n",
  78                                 strerror(errno));
  79                 return -errno;
  80         }
  81
  82         if (pid == 0) {
  83                 ksft_print_msg("I am the child, my PID is %d\n", getpid());
  84                 _exit(EXIT_SUCCESS);
  85         }
  86
  87         ksft_print_msg("I am the parent (%d). My child's pid is %d\n",
  88                         getpid(), pid);
  89
  90         if (waitpid(-1, &status, __WALL) < 0) {
  91                 ksft_print_msg("Child returned %s\n", strerror(errno));
  92                 return -errno;
  93         }
  94         if (WEXITSTATUS(status))
  95                 return WEXITSTATUS(status);
  96
  97         return 0;
  98 }
  99
 100 static void test_clone3(uint64_t flags, size_t size, int expected,
 101                        enum test_mode test_mode)
 102 {
 103         int ret;
 104
 105         ksft_print_msg(
 106                 "[%d] Trying clone3() with flags %#" PRIx64 " (size %zu)\n",
 107                 getpid(), flags, size);
 108         ret = call_clone3(flags, size, test_mode);
 109         ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n",
 110                         getpid(), ret, expected);
 111         if (ret != expected)
 112                 ksft_test_result_fail(
 113                         "[%d] Result (%d) is different than expected (%d)\n",
 114                         getpid(), ret, expected);
 115         else
 116                 ksft_test_result_pass(
 117                         "[%d] Result (%d) matches expectation (%d)\n",
 118                         getpid(), ret, expected);
 119 }
 120
 121 int main(int argc, char *argv[])
 122 {
 123         pid_t pid;
 124
 125         uid_t uid = getuid();
 126
 127         ksft_print_header();
 128         ksft_set_plan(17);
 129         test_clone3_supported();
 130
 131         /* Just a simple clone3() should return 0.*/
 132         test_clone3(0, 0, 0, CLONE3_ARGS_NO_TEST);
 133
 134         /* Do a clone3() in a new PID NS.*/
 135         if (uid == 0)
 136                 test_clone3(CLONE_NEWPID, 0, 0, CLONE3_ARGS_NO_TEST);
 137         else
 138                 ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
 139
 140         /* Do a clone3() with CLONE_ARGS_SIZE_VER0. */
 141         test_clone3(0, CLONE_ARGS_SIZE_VER0, 0, CLONE3_ARGS_NO_TEST);
 142
 143         /* Do a clone3() with CLONE_ARGS_SIZE_VER0 - 8 */
 144         test_clone3(0, CLONE_ARGS_SIZE_VER0 - 8, -EINVAL, CLONE3_ARGS_NO_TEST);
 145
 146         /* Do a clone3() with sizeof(struct clone_args) + 8 */
 147         test_clone3(0, sizeof(struct __clone_args) + 8, 0, CLONE3_ARGS_NO_TEST);
 148
 149         /* Do a clone3() with exit_signal having highest 32 bits non-zero */
 150         test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG);
 151
 152         /* Do a clone3() with negative 32-bit exit_signal */
 153         test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG);
 154
 155         /* Do a clone3() with exit_signal not fitting into CSIGNAL mask */
 156         test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG);
 157
 158         /* Do a clone3() with NSIG < exit_signal < CSIG */
 159         test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG);
 160
 161         test_clone3(0, sizeof(struct __clone_args) + 8, 0, CLONE3_ARGS_ALL_0);
 162
 163         test_clone3(0, sizeof(struct __clone_args) + 16, -E2BIG,
 164                         CLONE3_ARGS_ALL_0);
 165
 166         test_clone3(0, sizeof(struct __clone_args) * 2, -E2BIG,
 167                         CLONE3_ARGS_ALL_0);
 168
 169         /* Do a clone3() with > page size */
 170         test_clone3(0, getpagesize() + 8, -E2BIG, CLONE3_ARGS_NO_TEST);
 171
 172         /* Do a clone3() with CLONE_ARGS_SIZE_VER0 in a new PID NS. */
 173         if (uid == 0)
 174                 test_clone3(CLONE_NEWPID, CLONE_ARGS_SIZE_VER0, 0,
 175                                 CLONE3_ARGS_NO_TEST);
 176         else
 177                 ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
 178
 179         /* Do a clone3() with CLONE_ARGS_SIZE_VER0 - 8 in a new PID NS */
 180         test_clone3(CLONE_NEWPID, CLONE_ARGS_SIZE_VER0 - 8, -EINVAL,
 181                         CLONE3_ARGS_NO_TEST);
 182
 183         /* Do a clone3() with sizeof(struct clone_args) + 8 in a new PID NS */
 184         if (uid == 0)
 185                 test_clone3(CLONE_NEWPID, sizeof(struct __clone_args) + 8, 0,
 186                                 CLONE3_ARGS_NO_TEST);
 187         else
 188                 ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
 189
 190         /* Do a clone3() with > page size in a new PID NS */
 191         test_clone3(CLONE_NEWPID, getpagesize() + 8, -E2BIG,
 192                         CLONE3_ARGS_NO_TEST);
 193
 194         return !ksft_get_fail_cnt() ? ksft_exit_pass() : ksft_exit_fail();
 195 }