1 // SPDX-License-Identifier: GPL-2.0
11 #include <sys/ioctl.h>
12 #include <sys/mount.h>
14 #include <sys/types.h>
16 #include <linux/android/binder.h>
17 #include <linux/android/binderfs.h>
18 #include "../../kselftest.h"
20 static ssize_t write_nointr(int fd, const void *buf, size_t count)
24 ret = write(fd, buf, count);
25 if (ret < 0 && errno == EINTR)
31 static void write_to_file(const char *filename, const void *buf, size_t count,
37 fd = open(filename, O_WRONLY | O_CLOEXEC);
39 ksft_exit_fail_msg("%s - Failed to open file %s\n",
40 strerror(errno), filename);
42 ret = write_nointr(fd, buf, count);
44 if (allowed_errno && (errno == allowed_errno)) {
52 if ((size_t)ret != count)
64 ksft_exit_fail_msg("%s - Failed to write to file %s\n",
65 strerror(errno), filename);
67 ksft_exit_fail_msg("Failed to write to file %s\n", filename);
70 static void change_to_userns(void)
75 /* {g,u}id_map files only allow a max of 4096 bytes written to them */
81 ret = unshare(CLONE_NEWUSER);
83 ksft_exit_fail_msg("%s - Failed to unshare user namespace\n",
86 write_to_file("/proc/self/setgroups", "deny", strlen("deny"), ENOENT);
88 ret = snprintf(idmap, sizeof(idmap), "0 %d 1", uid);
89 if (ret < 0 || (size_t)ret >= sizeof(idmap))
90 ksft_exit_fail_msg("%s - Failed to prepare uid mapping\n",
93 write_to_file("/proc/self/uid_map", idmap, strlen(idmap), 0);
95 ret = snprintf(idmap, sizeof(idmap), "0 %d 1", gid);
96 if (ret < 0 || (size_t)ret >= sizeof(idmap))
97 ksft_exit_fail_msg("%s - Failed to prepare uid mapping\n",
100 write_to_file("/proc/self/gid_map", idmap, strlen(idmap), 0);
104 ksft_exit_fail_msg("%s - Failed to setgid(0)\n",
109 ksft_exit_fail_msg("%s - Failed to setgid(0)\n",
113 static void change_to_mountns(void)
117 ret = unshare(CLONE_NEWNS);
119 ksft_exit_fail_msg("%s - Failed to unshare mount namespace\n",
122 ret = mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0);
124 ksft_exit_fail_msg("%s - Failed to mount / as private\n",
128 static void rmdir_protect_errno(const char *dir)
130 int saved_errno = errno;
135 static void __do_binderfs_test(void)
137 int fd, ret, saved_errno;
141 struct binderfs_device device = { 0 };
142 struct binder_version version = { 0 };
146 ret = mkdir("/dev/binderfs", 0755);
150 "%s - Failed to create binderfs mountpoint\n",
156 ret = mount(NULL, "/dev/binderfs", "binder", 0, 0);
159 ksft_exit_fail_msg("%s - Failed to mount binderfs\n",
162 keep ? : rmdir_protect_errno("/dev/binderfs");
164 "The Android binderfs filesystem is not available\n");
167 /* binderfs mount test passed */
170 memcpy(device.name, "my-binder", strlen("my-binder"));
172 fd = open("/dev/binderfs/binder-control", O_RDONLY | O_CLOEXEC);
175 "%s - Failed to open binder-control device\n",
178 ret = ioctl(fd, BINDER_CTL_ADD, &device);
183 keep ? : rmdir_protect_errno("/dev/binderfs");
185 "%s - Failed to allocate new binder device\n",
190 "Allocated new binder device with major %d, minor %d, and name %s\n",
191 device.major, device.minor, device.name);
193 /* binder device allocation test passed */
196 fd = open("/dev/binderfs/my-binder", O_CLOEXEC | O_RDONLY);
198 keep ? : rmdir_protect_errno("/dev/binderfs");
199 ksft_exit_fail_msg("%s - Failed to open my-binder device\n",
203 ret = ioctl(fd, BINDER_VERSION, &version);
208 keep ? : rmdir_protect_errno("/dev/binderfs");
210 "%s - Failed to open perform BINDER_VERSION request\n",
214 ksft_print_msg("Detected binder version: %d\n",
215 version.protocol_version);
217 /* binder transaction with binderfs binder device passed */
220 ret = unlink("/dev/binderfs/my-binder");
222 keep ? : rmdir_protect_errno("/dev/binderfs");
223 ksft_exit_fail_msg("%s - Failed to delete binder device\n",
227 /* binder device removal passed */
230 ret = unlink("/dev/binderfs/binder-control");
232 keep ? : rmdir_protect_errno("/dev/binderfs");
233 ksft_exit_fail_msg("Managed to delete binder-control device\n");
234 } else if (errno != EPERM) {
235 keep ? : rmdir_protect_errno("/dev/binderfs");
237 "%s - Failed to delete binder-control device but exited with unexpected error code\n",
241 /* binder-control device removal failed as expected */
242 ksft_inc_xfail_cnt();
245 ret = umount2("/dev/binderfs", MNT_DETACH);
246 keep ?: rmdir_protect_errno("/dev/binderfs");
248 ksft_exit_fail_msg("%s - Failed to unmount binderfs\n",
251 /* binderfs unmount test passed */
255 static void binderfs_test_privileged()
259 "Tests are not run as root. Skipping privileged tests\n");
261 __do_binderfs_test();
264 static void binderfs_test_unprivileged()
267 __do_binderfs_test();
270 int main(int argc, char *argv[])
272 binderfs_test_privileged();
273 binderfs_test_unprivileged();