include/uapi: add linux/openat2.h (#42220)

We include the header through src/include/override/fcntl.h, hence we should
have the latest copy of the header.

(E.g. compilation fails with musl-libc-1.2.5-6.fc44.x86_64 and older kernel
headers.)

diff --git a/src/include/uapi/linux/openat2.h b/src/include/uapi/linux/openat2.h
new file mode 100644 (file)
index 0000000..4759c47
--- /dev/null
+++ b/src/include/uapi/linux/openat2.h
@@ -0,0 +1,43 @@
+/* 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 */