clone3_clear_sighand.c

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