1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #define _GNU_SOURCE
4 #include <errno.h>
5 #include <sched.h>
6 #include <signal.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <string.h>
10 #include <unistd.h>
11 #include <linux/sched.h>
12 #include <linux/types.h>
13 #include <sys/syscall.h>
14 #include <sys/wait.h>
15 
16 #include "../kselftest.h"
17 #include "clone3_selftests.h"
18 
19 #ifndef CLONE_CLEAR_SIGHAND
20 #define CLONE_CLEAR_SIGHAND 0x100000000ULL
21 #endif
22 
23 static void nop_handler(int signo)
24 {
25 }
26 
27 static int wait_for_pid(pid_t pid)
28 {
29 	int status, ret;
30 
31 again:
32 	ret = waitpid(pid, &status, 0);
33 	if (ret == -1) {
34 		if (errno == EINTR)
35 			goto again;
36 
37 		return -1;
38 	}
39 
40 	if (!WIFEXITED(status))
41 		return -1;
42 
43 	return WEXITSTATUS(status);
44 }
45 
46 static void test_clone3_clear_sighand(void)
47 {
48 	int ret;
49 	pid_t pid;
50 	struct clone_args args = {};
51 	struct sigaction act;
52 
53 	/*
54 	 * Check that CLONE_CLEAR_SIGHAND and CLONE_SIGHAND are mutually
55 	 * exclusive.
56 	 */
57 	args.flags |= CLONE_CLEAR_SIGHAND | CLONE_SIGHAND;
58 	args.exit_signal = SIGCHLD;
59 	pid = sys_clone3(&args, sizeof(args));
60 	if (pid > 0)
61 		ksft_exit_fail_msg(
62 			"clone3(CLONE_CLEAR_SIGHAND | CLONE_SIGHAND) succeeded\n");
63 
64 	act.sa_handler = nop_handler;
65 	ret = sigemptyset(&act.sa_mask);
66 	if (ret < 0)
67 		ksft_exit_fail_msg("%s - sigemptyset() failed\n",
68 				   strerror(errno));
69 
70 	act.sa_flags = 0;
71 
72 	/* Register signal handler for SIGUSR1 */
73 	ret = sigaction(SIGUSR1, &act, NULL);
74 	if (ret < 0)
75 		ksft_exit_fail_msg(
76 			"%s - sigaction(SIGUSR1, &act, NULL) failed\n",
77 			strerror(errno));
78 
79 	/* Register signal handler for SIGUSR2 */
80 	ret = sigaction(SIGUSR2, &act, NULL);
81 	if (ret < 0)
82 		ksft_exit_fail_msg(
83 			"%s - sigaction(SIGUSR2, &act, NULL) failed\n",
84 			strerror(errno));
85 
86 	/* Check that CLONE_CLEAR_SIGHAND works. */
87 	args.flags = CLONE_CLEAR_SIGHAND;
88 	pid = sys_clone3(&args, sizeof(args));
89 	if (pid < 0)
90 		ksft_exit_fail_msg("%s - clone3(CLONE_CLEAR_SIGHAND) failed\n",
91 				   strerror(errno));
92 
93 	if (pid == 0) {
94 		ret = sigaction(SIGUSR1, NULL, &act);
95 		if (ret < 0)
96 			exit(EXIT_FAILURE);
97 
98 		if (act.sa_handler != SIG_DFL)
99 			exit(EXIT_FAILURE);
100 
101 		ret = sigaction(SIGUSR2, NULL, &act);
102 		if (ret < 0)
103 			exit(EXIT_FAILURE);
104 
105 		if (act.sa_handler != SIG_DFL)
106 			exit(EXIT_FAILURE);
107 
108 		exit(EXIT_SUCCESS);
109 	}
110 
111 	ret = wait_for_pid(pid);
112 	if (ret)
113 		ksft_exit_fail_msg(
114 			"Failed to clear signal handler for child process\n");
115 
116 	ksft_test_result_pass("Cleared signal handlers for child process\n");
117 }
118 
119 int main(int argc, char **argv)
120 {
121 	ksft_print_header();
122 	test_clone3_supported();
123 
124 	ksft_set_plan(1);
125 
126 	test_clone3_clear_sighand();
127 
128 	return ksft_exit_pass();
129 }
130