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_NO_TEST:
56 		/*
57 		 * Uses default 'flags' and 'SIGCHLD'
58 		 * assignment.
59 		 */
60 		break;
61 	case CLONE3_ARGS_ALL_0:
62 		args.flags = 0;
63 		args.exit_signal = 0;
64 		break;
65 	case CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG:
66 		args.exit_signal = 0xbadc0ded00000000ULL;
67 		break;
68 	case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG:
69 		args.exit_signal = 0x0000000080000000ULL;
70 		break;
71 	case CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG:
72 		args.exit_signal = 0x0000000000000100ULL;
73 		break;
74 	case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG:
75 		args.exit_signal = 0x00000000000000f0ULL;
76 		break;
77 	}
78 
79 	memcpy(&args_ext.args, &args, sizeof(struct __clone_args));
80 
81 	pid = sys_clone3((struct __clone_args *)&args_ext, size);
82 	if (pid < 0) {
83 		ksft_print_msg("%s - Failed to create new process\n",
84 				strerror(errno));
85 		return -errno;
86 	}
87 
88 	if (pid == 0) {
89 		ksft_print_msg("I am the child, my PID is %d\n", getpid());
90 		_exit(EXIT_SUCCESS);
91 	}
92 
93 	ksft_print_msg("I am the parent (%d). My child's pid is %d\n",
94 			getpid(), pid);
95 
96 	if (waitpid(-1, &status, __WALL) < 0) {
97 		ksft_print_msg("Child returned %s\n", strerror(errno));
98 		return -errno;
99 	}
100 	if (WEXITSTATUS(status))
101 		return WEXITSTATUS(status);
102 
103 	return 0;
104 }
105 
106 static void test_clone3(uint64_t flags, size_t size, int expected,
107 		       enum test_mode test_mode)
108 {
109 	int ret;
110 
111 	ksft_print_msg(
112 		"[%d] Trying clone3() with flags %#" PRIx64 " (size %zu)\n",
113 		getpid(), flags, size);
114 	ret = call_clone3(flags, size, test_mode);
115 	ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n",
116 			getpid(), ret, expected);
117 	if (ret != expected)
118 		ksft_test_result_fail(
119 			"[%d] Result (%d) is different than expected (%d)\n",
120 			getpid(), ret, expected);
121 	else
122 		ksft_test_result_pass(
123 			"[%d] Result (%d) matches expectation (%d)\n",
124 			getpid(), ret, expected);
125 }
126 
127 int main(int argc, char *argv[])
128 {
129 	uid_t uid = getuid();
130 
131 	ksft_print_header();
132 	ksft_set_plan(19);
133 	test_clone3_supported();
134 
135 	/* Just a simple clone3() should return 0.*/
136 	test_clone3(0, 0, 0, CLONE3_ARGS_NO_TEST);
137 
138 	/* Do a clone3() in a new PID NS.*/
139 	if (uid == 0)
140 		test_clone3(CLONE_NEWPID, 0, 0, CLONE3_ARGS_NO_TEST);
141 	else
142 		ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
143 
144 	/* Do a clone3() with CLONE_ARGS_SIZE_VER0. */
145 	test_clone3(0, CLONE_ARGS_SIZE_VER0, 0, CLONE3_ARGS_NO_TEST);
146 
147 	/* Do a clone3() with CLONE_ARGS_SIZE_VER0 - 8 */
148 	test_clone3(0, CLONE_ARGS_SIZE_VER0 - 8, -EINVAL, CLONE3_ARGS_NO_TEST);
149 
150 	/* Do a clone3() with sizeof(struct clone_args) + 8 */
151 	test_clone3(0, sizeof(struct __clone_args) + 8, 0, CLONE3_ARGS_NO_TEST);
152 
153 	/* Do a clone3() with exit_signal having highest 32 bits non-zero */
154 	test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG);
155 
156 	/* Do a clone3() with negative 32-bit exit_signal */
157 	test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG);
158 
159 	/* Do a clone3() with exit_signal not fitting into CSIGNAL mask */
160 	test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG);
161 
162 	/* Do a clone3() with NSIG < exit_signal < CSIG */
163 	test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG);
164 
165 	test_clone3(0, sizeof(struct __clone_args) + 8, 0, CLONE3_ARGS_ALL_0);
166 
167 	test_clone3(0, sizeof(struct __clone_args) + 16, -E2BIG,
168 			CLONE3_ARGS_ALL_0);
169 
170 	test_clone3(0, sizeof(struct __clone_args) * 2, -E2BIG,
171 			CLONE3_ARGS_ALL_0);
172 
173 	/* Do a clone3() with > page size */
174 	test_clone3(0, getpagesize() + 8, -E2BIG, CLONE3_ARGS_NO_TEST);
175 
176 	/* Do a clone3() with CLONE_ARGS_SIZE_VER0 in a new PID NS. */
177 	if (uid == 0)
178 		test_clone3(CLONE_NEWPID, CLONE_ARGS_SIZE_VER0, 0,
179 				CLONE3_ARGS_NO_TEST);
180 	else
181 		ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
182 
183 	/* Do a clone3() with CLONE_ARGS_SIZE_VER0 - 8 in a new PID NS */
184 	test_clone3(CLONE_NEWPID, CLONE_ARGS_SIZE_VER0 - 8, -EINVAL,
185 			CLONE3_ARGS_NO_TEST);
186 
187 	/* Do a clone3() with sizeof(struct clone_args) + 8 in a new PID NS */
188 	if (uid == 0)
189 		test_clone3(CLONE_NEWPID, sizeof(struct __clone_args) + 8, 0,
190 				CLONE3_ARGS_NO_TEST);
191 	else
192 		ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
193 
194 	/* Do a clone3() with > page size in a new PID NS */
195 	test_clone3(CLONE_NEWPID, getpagesize() + 8, -E2BIG,
196 			CLONE3_ARGS_NO_TEST);
197 
198 	/* Do a clone3() in a new time namespace */
199 	test_clone3(CLONE_NEWTIME, 0, 0, CLONE3_ARGS_NO_TEST);
200 
201 	/* Do a clone3() with exit signal (SIGCHLD) in flags */
202 	test_clone3(SIGCHLD, 0, -EINVAL, CLONE3_ARGS_NO_TEST);
203 
204 	ksft_finished();
205 }
206