diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h
index e55a3314bcb0721d13cacc0259b040a6c3b92d1a..38a6d66d9e8871b27b464c009344bde6a1e9de0e 100644
--- a/include/uapi/linux/fcntl.h
+++ b/include/uapi/linux/fcntl.h
@@ -90,37 +90,69 @@
 #define DN_ATTRIB	0x00000020	/* File changed attibutes */
 #define DN_MULTISHOT	0x80000000	/* Don't remove notifier */
 
+#define AT_FDCWD		-100    /* Special value for dirfd used to
+					   indicate openat should use the
+					   current working directory. */
+
+
+/* Generic flags for the *at(2) family of syscalls. */
+
+/* Reserved for per-syscall flags	0xff. */
+#define AT_SYMLINK_NOFOLLOW		0x100   /* Do not follow symbolic
+						   links. */
+/* Reserved for per-syscall flags	0x200 */
+#define AT_SYMLINK_FOLLOW		0x400   /* Follow symbolic links. */
+#define AT_NO_AUTOMOUNT			0x800	/* Suppress terminal automount
+						   traversal. */
+#define AT_EMPTY_PATH			0x1000	/* Allow empty relative
+						   pathname to operate on dirfd
+						   directly. */
 /*
- * The constants AT_REMOVEDIR and AT_EACCESS have the same value.  AT_EACCESS is
- * meaningful only to faccessat, while AT_REMOVEDIR is meaningful only to
- * unlinkat.  The two functions do completely different things and therefore,
- * the flags can be allowed to overlap.  For example, passing AT_REMOVEDIR to
- * faccessat would be undefined behavior and thus treating it equivalent to
- * AT_EACCESS is valid undefined behavior.
+ * These flags are currently statx(2)-specific, but they could be made generic
+ * in the future and so they should not be used for other per-syscall flags.
  */
-#define AT_FDCWD		-100    /* Special value used to indicate
-                                           openat should use the current
-                                           working directory. */
-#define AT_SYMLINK_NOFOLLOW	0x100   /* Do not follow symbolic links.  */
+#define AT_STATX_SYNC_TYPE		0x6000	/* Type of synchronisation required from statx() */
+#define AT_STATX_SYNC_AS_STAT		0x0000	/* - Do whatever stat() does */
+#define AT_STATX_FORCE_SYNC		0x2000	/* - Force the attributes to be sync'd with the server */
+#define AT_STATX_DONT_SYNC		0x4000	/* - Don't sync attributes with the server */
+
+#define AT_RECURSIVE			0x8000	/* Apply to the entire subtree */
+
+/*
+ * Per-syscall flags for the *at(2) family of syscalls.
+ *
+ * These are flags that are so syscall-specific that a user passing these flags
+ * to the wrong syscall is so "clearly wrong" that we can safely call such
+ * usage "undefined behaviour".
+ *
+ * For example, the constants AT_REMOVEDIR and AT_EACCESS have the same value.
+ * AT_EACCESS is meaningful only to faccessat, while AT_REMOVEDIR is meaningful
+ * only to unlinkat. The two functions do completely different things and
+ * therefore, the flags can be allowed to overlap. For example, passing
+ * AT_REMOVEDIR to faccessat would be undefined behavior and thus treating it
+ * equivalent to AT_EACCESS is valid undefined behavior.
+ *
+ * Note for implementers: When picking a new per-syscall AT_* flag, try to
+ * reuse already existing flags first. This leaves us with as many unused bits
+ * as possible, so we can use them for generic bits in the future if necessary.
+ */
+
+/* Flags for renameat2(2) (must match legacy RENAME_* flags). */
+#define AT_RENAME_NOREPLACE	0x0001
+#define AT_RENAME_EXCHANGE	0x0002
+#define AT_RENAME_WHITEOUT	0x0004
+
+/* Flag for faccessat(2). */
 #define AT_EACCESS		0x200	/* Test access permitted for
                                            effective IDs, not real IDs.  */
+/* Flag for unlinkat(2). */
 #define AT_REMOVEDIR		0x200   /* Remove directory instead of
                                            unlinking file.  */
-#define AT_SYMLINK_FOLLOW	0x400   /* Follow symbolic links.  */
-#define AT_NO_AUTOMOUNT		0x800	/* Suppress terminal automount traversal */
-#define AT_EMPTY_PATH		0x1000	/* Allow empty relative pathname */
-
-#define AT_STATX_SYNC_TYPE	0x6000	/* Type of synchronisation required from statx() */
-#define AT_STATX_SYNC_AS_STAT	0x0000	/* - Do whatever stat() does */
-#define AT_STATX_FORCE_SYNC	0x2000	/* - Force the attributes to be sync'd with the server */
-#define AT_STATX_DONT_SYNC	0x4000	/* - Don't sync attributes with the server */
-
-#define AT_RECURSIVE		0x8000	/* Apply to the entire subtree */
+/* Flags for name_to_handle_at(2). */
+#define AT_HANDLE_FID		0x200	/* File handle is needed to compare
+					   object identity and may not be
+					   usable with open_by_handle_at(2). */
 
-/* Flags for name_to_handle_at(2). We reuse AT_ flag space to save bits... */
-#define AT_HANDLE_FID		AT_REMOVEDIR	/* file handle is needed to
-					compare object identity and may not
-					be usable to open_by_handle_at(2) */
 #if defined(__KERNEL__)
 #define AT_GETATTR_NOSEC	0x80000000
 #endif