new file mode 100644
@@ -0,0 +1,165 @@
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <linux/mount.h>
+#include <sys/stat.h>
+
+#ifndef SYS_open_tree_attr
+
+#ifndef __NR_open_tree_attr
+#define __NR_open_tree_attr 467
+#endif
+
+#define SYS_open_tree_attr __NR_open_tree_attr
+#endif
+
+#define TEST_DIR "test-open-tree-dir"
+#define TEST_FILE "test-open-tree-file"
+
+static int do_open_tree_attr_syscall(int dirfd, const char *path,
+ unsigned int flags)
+{
+ /* Using mount_attr in this call starts mount-specific privilege checks
+ * which end up with EPERM.
+ * The functionality when using attr == NULL is equivalent to open_tree() */
+#ifdef SYS_open_tree_attr
+ return syscall(SYS_open_tree_attr, dirfd, path, flags, NULL, 0);
+#elif defined(__NR_open_tree_attr)
+ return syscall(__NR_open_tree_attr, dirfd, path, flags, NULL, 0);
+#else
+ errno = ENOSYS;
+ return -1;
+#endif
+}
+
+static int test_no_flags(void) {
+ int treefd = -1;
+ int fd = -1;
+ int rc = 1;
+
+ treefd = do_open_tree_attr_syscall(AT_FDCWD, TEST_DIR, 0);
+ if (treefd == -1) {
+ perror("open_tree_attr");
+ goto out;
+ }
+
+ fd = openat(treefd, TEST_FILE, O_CREAT | O_RDWR, 0666);
+ if (fd < 0) {
+ perror("openat");
+ goto out;
+ }
+
+ rc = 0;
+out:
+ if (treefd != -1) {
+ close(treefd);
+ }
+ if (fd != -1) {
+ close(fd);
+ }
+ return rc;
+}
+
+static int test_relative_dirfd(void) {
+ int basefd = -1;
+ int treefd = -1;
+ int fd = -1;
+ int rc = 1;
+
+ basefd = open(".", O_PATH | O_DIRECTORY);
+ if (basefd < 0) {
+ perror("open");
+ goto out;
+ }
+
+ treefd = do_open_tree_attr_syscall(basefd, TEST_DIR, 0);
+ if (treefd < 0) {
+ perror("open_tree_attr");
+ goto out;
+ }
+
+ fd = openat(treefd, TEST_FILE, O_CREAT | O_RDWR, 0666);
+ if (fd < 0) {
+ perror("openat");
+ goto out;
+ }
+
+ rc = 0;
+ out:
+ if (basefd != -1) {
+ close(basefd);
+ }
+ if (treefd != -1) {
+ close(treefd);
+ }
+ if (fd != -1) {
+ close(fd);
+ }
+ return rc;
+}
+
+static int test_at_empty_path(void) {
+ int treefd = -1;
+ int dirfd = -1;
+ int fd = -1;
+ int rc = 1;
+
+ dirfd = open(TEST_DIR, O_PATH | O_DIRECTORY);
+ if (dirfd < 0) {
+ perror("open");
+ goto out;
+ }
+
+ treefd = do_open_tree_attr_syscall(dirfd, "", AT_EMPTY_PATH);
+ if (treefd == -1) {
+ perror("open_tree_attr");
+ goto out;
+ }
+
+ fd = openat(treefd, TEST_FILE, O_CREAT | O_RDWR, 0666);
+ if (fd < 0) {
+ perror("openat");
+ goto out;
+ }
+
+ rc = 0;
+out:
+ if (dirfd != -1) {
+ close(dirfd);
+ }
+ if (treefd != -1) {
+ close(treefd);
+ }
+ if (fd != -1) {
+ close(fd);
+ }
+ return rc;
+}
+
+static void cleanup(void) {
+ if (unlink(TEST_DIR "/" TEST_FILE) == -1 && errno != ENOENT) {
+ perror("unlink");
+ }
+ if (rmdir(TEST_DIR) == -1 && errno != ENOENT) {
+ perror("rmdir");
+ }
+}
+
+int main(void) {
+ cleanup();
+
+ if (mkdir(TEST_DIR, 0777) == -1) {
+ perror("mkdir");
+ return 1;
+ }
+
+ int rc = test_no_flags() || test_at_empty_path() || test_relative_dirfd();
+
+ cleanup();
+
+ return rc;
+}
new file mode 100755
@@ -0,0 +1,5 @@
+#!/bin/sh
+
+./test/test-open_tree_attr-syscall
+
+PSEUDO_IGNORE_PATHS=/ ./test/test-open_tree_attr-syscall