// SPDX-License-Identifier: GPL-2.0 #define _GNU_SOURCE#include <errno.h>#include <fcntl.h>#include <sched.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/ioctl.h>#include <sys/mount.h>#include <sys/stat.h>#include <sys/types.h>#include <unistd.h>#include <linux/android/binder.h>#include <linux/android/binderfs.h> int main(int argc, char *argv[]){	int fd, ret, saved_errno;	struct binderfs_device device = { 0 }; 	ret = unshare(CLONE_NEWNS);	if (ret < 0) {		fprintf(stderr, "%s - Failed to unshare mount namespace\n",			strerror(errno));		exit(EXIT_FAILURE);	} 	ret = mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0);	if (ret < 0) {		fprintf(stderr, "%s - Failed to mount / as private\n",			strerror(errno));		exit(EXIT_FAILURE);	} 	ret = mkdir("/dev/binderfs", 0755);	if (ret < 0 && errno != EEXIST) {		fprintf(stderr, "%s - Failed to create binderfs mountpoint\n",			strerror(errno));		exit(EXIT_FAILURE);	} 	ret = mount(NULL, "/dev/binderfs", "binder", 0, 0);	if (ret < 0) {		fprintf(stderr, "%s - Failed to mount binderfs\n",			strerror(errno));		exit(EXIT_FAILURE);	} 	memcpy(device.name, "my-binder", strlen("my-binder")); 	fd = open("/dev/binderfs/binder-control", O_RDONLY | O_CLOEXEC);	if (fd < 0) {		fprintf(stderr, "%s - Failed to open binder-control device\n",			strerror(errno));		exit(EXIT_FAILURE);	} 	ret = ioctl(fd, BINDER_CTL_ADD, &device);	saved_errno = errno;	close(fd);	errno = saved_errno;	if (ret < 0) {		fprintf(stderr, "%s - Failed to allocate new binder device\n",			strerror(errno));		exit(EXIT_FAILURE);	} 	printf("Allocated new binder device with major %d, minor %d, and name %s\n",	       device.major, device.minor, device.name); 	ret = unlink("/dev/binderfs/my-binder");	if (ret < 0) {		fprintf(stderr, "%s - Failed to delete binder device\n",			strerror(errno));		exit(EXIT_FAILURE);	} 	/* Cleanup happens when the mount namespace dies. */	exit(EXIT_SUCCESS);}