Add tests for the new O_EMPTYPATH flag of openat(2)/openat2(2).
Also, the current openat2 tests include a helper header file that
defines the necessary structs and constants to use openat2(2), such as
struct open_how. This may result in conflicting definitions when the
system header openat2.h is present as well.
So add openat2.h generated by 'make headers' to the uapi header
files in ./tools/include and remove the helper file definitions of
the current openat2 selftests.
Signed-off-by: Jori Koolstra <jkoolstra@xs4all.nl>
Link: https://patch.msgid.link/20260424114611.1678641-3-jkoolstra@xs4all.nl
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _LINUX_OPENAT2_H
+#define _LINUX_OPENAT2_H
+
+#include <linux/types.h>
+
+/*
+ * Arguments for how openat2(2) should open the target path. If only @flags and
+ * @mode are non-zero, then openat2(2) operates very similarly to openat(2).
+ *
+ * However, unlike openat(2), unknown or invalid bits in @flags result in
+ * -EINVAL rather than being silently ignored. @mode must be zero unless one of
+ * {O_CREAT, O_TMPFILE} are set.
+ *
+ * @flags: O_* flags.
+ * @mode: O_CREAT/O_TMPFILE file mode.
+ * @resolve: RESOLVE_* flags.
+ */
+struct open_how {
+ __u64 flags;
+ __u64 mode;
+ __u64 resolve;
+};
+
+/* how->resolve flags for openat2(2). */
+#define RESOLVE_NO_XDEV 0x01 /* Block mount-point crossings
+ (includes bind-mounts). */
+#define RESOLVE_NO_MAGICLINKS 0x02 /* Block traversal through procfs-style
+ "magic-links". */
+#define RESOLVE_NO_SYMLINKS 0x04 /* Block traversal through all symlinks
+ (implies OEXT_NO_MAGICLINKS) */
+#define RESOLVE_BENEATH 0x08 /* Block "lexical" trickery like
+ "..", symlinks, and absolute
+ paths which escape the dirfd. */
+#define RESOLVE_IN_ROOT 0x10 /* Make all jumps to "/" and ".."
+ be scoped inside the dirfd
+ (similar to chroot(2)). */
+#define RESOLVE_CACHED 0x20 /* Only complete if resolution can be
+ completed through cached lookup. May
+ return -EAGAIN if that's not
+ possible. */
+
+#endif /* _LINUX_OPENAT2_H */
# SPDX-License-Identifier: GPL-2.0-or-later
CFLAGS += $(KHDR_INCLUDES)
-CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined
-TEST_GEN_PROGS := openat2_test resolve_test rename_attack_test
+CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined $(TOOLS_INCLUDES)
+TEST_GEN_PROGS := openat2_test resolve_test rename_attack_test emptypath_test
# gcc requires -static-libasan in order to ensure that Address Sanitizer's
# library is the first one loaded. However, clang already statically links the
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#define __SANE_USERSPACE_TYPES__
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "kselftest.h"
+
+#ifndef O_EMPTYPATH
+#define O_EMPTYPATH (1 << 26)
+#endif
+
+int main(void)
+{
+ int opath_fd, reopen_fd;
+ const char *path = "/tmp/emptypath_test";
+
+ ksft_print_header();
+ ksft_set_plan(2);
+
+ opath_fd = open(path, O_CREAT | O_WRONLY, S_IRWXU);
+ if (opath_fd < 0)
+ ksft_exit_fail_msg("create %s: %m\n", path);
+ close(opath_fd);
+
+ opath_fd = open(path, O_PATH);
+ if (opath_fd < 0)
+ ksft_exit_fail_msg("open %s O_PATH: %m\n", path);
+
+ reopen_fd = openat(opath_fd, "", O_RDONLY);
+ if (reopen_fd < 0 && errno == ENOENT)
+ ksft_test_result_pass("empty path without O_EMPTYPATH returns ENOENT\n");
+ else if (reopen_fd >= 0) {
+ ksft_test_result_fail("empty path without O_EMPTYPATH unexpectedly succeeded\n");
+ close(reopen_fd);
+ } else {
+ ksft_test_result_fail("empty path without O_EMPTYPATH: expected ENOENT, got %m\n");
+ }
+
+ reopen_fd = openat(opath_fd, "", O_RDONLY | O_EMPTYPATH);
+
+ if (reopen_fd < 0 && errno == EINVAL)
+ ksft_exit_skip("O_EMPTYPATH not supported\n");
+
+ if (reopen_fd >= 0) {
+ ksft_test_result_pass("O_EMPTYPATH reopens O_PATH fd\n");
+ close(reopen_fd);
+ } else {
+ ksft_test_result_fail("O_EMPTYPATH failed: %m\n");
+ }
+
+ unlink(path);
+ ksft_finished();
+}
#include <limits.h>
#include <linux/types.h>
#include <linux/unistd.h>
+#include <linux/openat2.h>
#include "kselftest_harness.h"
#define BUILD_BUG_ON(e) ((void)(sizeof(struct { int:(-!!(e)); })))
-/*
- * Arguments for how openat2(2) should open the target path. If @resolve is
- * zero, then openat2(2) operates very similarly to openat(2).
- *
- * However, unlike openat(2), unknown bits in @flags result in -EINVAL rather
- * than being silently ignored. @mode must be zero unless one of {O_CREAT,
- * O_TMPFILE} are set.
- *
- * @flags: O_* flags.
- * @mode: O_CREAT/O_TMPFILE file mode.
- * @resolve: RESOLVE_* flags.
- */
-struct open_how {
- __u64 flags;
- __u64 mode;
- __u64 resolve;
-};
-
#define OPEN_HOW_SIZE_VER0 24 /* sizeof first published struct */
#define OPEN_HOW_SIZE_LATEST OPEN_HOW_SIZE_VER0
-#ifndef RESOLVE_IN_ROOT
-/* how->resolve flags for openat2(2). */
-#define RESOLVE_NO_XDEV 0x01 /* Block mount-point crossings
- (includes bind-mounts). */
-#define RESOLVE_NO_MAGICLINKS 0x02 /* Block traversal through procfs-style
- "magic-links". */
-#define RESOLVE_NO_SYMLINKS 0x04 /* Block traversal through all symlinks
- (implies OEXT_NO_MAGICLINKS) */
-#define RESOLVE_BENEATH 0x08 /* Block "lexical" trickery like
- "..", symlinks, and absolute
- paths which escape the dirfd. */
-#define RESOLVE_IN_ROOT 0x10 /* Make all jumps to "/" and ".."
- be scoped inside the dirfd
- (similar to chroot(2)). */
-#endif /* RESOLVE_IN_ROOT */
-
__maybe_unused
static bool needs_openat2(const struct open_how *how)
{
projects / thirdparty / linux.git / commitdiff
