// 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/ioctl.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){	struct pidfd_info info = {		.mask = PIDFD_INFO_CGROUPID,	};	int pidfd = -1, ret = 1;	pid_t pid; 	ksft_set_plan(4); 	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); 	if (ioctl(pidfd, PIDFD_GET_INFO, &info) < 0) {		ksft_print_msg("%s - failed to get info from pidfd\n", strerror(errno));		goto on_error;	}	if (info.pid != pid) {		ksft_print_msg("pid from fdinfo file %d does not match pid from ioctl %d\n",			       pid, info.pid);		goto on_error;	}	if (info.ppid != getppid()) {		ksft_print_msg("ppid %d does not match ppid from ioctl %d\n",			       pid, info.pid);		goto on_error;	}	if (info.ruid != getuid()) {		ksft_print_msg("uid %d does not match uid from ioctl %d\n",			       getuid(), info.ruid);		goto on_error;	}	if (info.rgid != getgid()) {		ksft_print_msg("gid %d does not match gid from ioctl %d\n",			       getgid(), info.rgid);		goto on_error;	}	if (info.euid != geteuid()) {		ksft_print_msg("euid %d does not match euid from ioctl %d\n",			       geteuid(), info.euid);		goto on_error;	}	if (info.egid != getegid()) {		ksft_print_msg("egid %d does not match egid from ioctl %d\n",			       getegid(), info.egid);		goto on_error;	}	if (info.suid != geteuid()) {		ksft_print_msg("suid %d does not match suid from ioctl %d\n",			       geteuid(), info.suid);		goto on_error;	}	if (info.sgid != getegid()) {		ksft_print_msg("sgid %d does not match sgid from ioctl %d\n",			       getegid(), info.sgid);		goto on_error;	}	if ((info.mask & PIDFD_INFO_CGROUPID) && info.cgroupid == 0) {		ksft_print_msg("cgroupid should not be 0 when PIDFD_INFO_CGROUPID is set\n");		goto on_error;	}	ksft_test_result_pass("get info from pidfd test: passed\n"); 	ret = 0; on_error:	if (pidfd >= 0)		close(pidfd); 	if (ret)		ksft_exit_fail();	ksft_exit_pass();}