// SPDX-License-Identifier: GPL-2.0 #define _GNU_SOURCE#include <errno.h>#include <fcntl.h>#include <inttypes.h>#include <limits.h>#include <linux/types.h>#include <sched.h>#include <signal.h>#include <stdbool.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <syscall.h>#include <sys/mount.h>#include <sys/prctl.h>#include <sys/wait.h>#include <unistd.h> #include "pidfd.h"#include "../kselftest.h" static int safe_int(const char *numstr, int *converted){	char *err = NULL;	long sli; 	errno = 0;	sli = strtol(numstr, &err, 0);	if (errno == ERANGE && (sli == LONG_MAX || sli == LONG_MIN))		return -ERANGE; 	if (errno != 0 && sli == 0)		return -EINVAL; 	if (err == numstr || *err != '\0')		return -EINVAL; 	if (sli > INT_MAX || sli < INT_MIN)		return -ERANGE; 	*converted = (int)sli;	return 0;} static int char_left_gc(const char *buffer, size_t len){	size_t i; 	for (i = 0; i < len; i++) {		if (buffer[i] == ' ' ||		    buffer[i] == '\t')			continue; 		return i;	} 	return 0;} static int char_right_gc(const char *buffer, size_t len){	int i; 	for (i = len - 1; i >= 0; i--) {		if (buffer[i] == ' '  ||		    buffer[i] == '\t' ||		    buffer[i] == '\n' ||		    buffer[i] == '\0')			continue; 		return i + 1;	} 	return 0;} static char *trim_whitespace_in_place(char *buffer){	buffer += char_left_gc(buffer, strlen(buffer));	buffer[char_right_gc(buffer, strlen(buffer))] = '\0';	return buffer;} static pid_t get_pid_from_fdinfo_file(int pidfd, const char *key, size_t keylen){	int ret;	char path[512];	FILE *f;	size_t n = 0;	pid_t result = -1;	char *line = NULL; 	snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", pidfd); 	f = fopen(path, "re");	if (!f)		return -1; 	while (getline(&line, &n, f) != -1) {		char *numstr; 		if (strncmp(line, key, keylen))			continue; 		numstr = trim_whitespace_in_place(line + 4);		ret = safe_int(numstr, &result);		if (ret < 0)			goto out; 		break;	} out:	free(line);	fclose(f);	return result;} int main(int argc, char **argv){	int pidfd = -1, ret = 1;	pid_t pid; 	ksft_set_plan(3); 	pidfd = sys_pidfd_open(-1, 0);	if (pidfd >= 0) {		ksft_print_msg(			"%s - succeeded to open pidfd for invalid pid -1\n",			strerror(errno));		goto on_error;	}	ksft_test_result_pass("do not allow invalid pid test: passed\n"); 	pidfd = sys_pidfd_open(getpid(), 1);	if (pidfd >= 0) {		ksft_print_msg(			"%s - succeeded to open pidfd with invalid flag value specified\n",			strerror(errno));		goto on_error;	}	ksft_test_result_pass("do not allow invalid flag test: passed\n"); 	pidfd = sys_pidfd_open(getpid(), 0);	if (pidfd < 0) {		ksft_print_msg("%s - failed to open pidfd\n", strerror(errno));		goto on_error;	}	ksft_test_result_pass("open a new pidfd test: passed\n"); 	pid = get_pid_from_fdinfo_file(pidfd, "Pid:", sizeof("Pid:") - 1);	ksft_print_msg("pidfd %d refers to process with pid %d\n", pidfd, pid); 	ret = 0; on_error:	if (pidfd >= 0)		close(pidfd); 	return !ret ? ksft_exit_pass() : ksft_exit_fail();}