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 }
203