[PATCH] landlock: Clarify documentation for struct landlock_ruleset_attr

[Günther Noack]

The explanation for @handled_access_fs and @handled_access_net has
significant overlap and is better explained together.  I tried to clarify
the wording and break up longer sentences as well.  I am putting emphasis
on the word "handled" to make it clearer that "handled" is a term with
special meaning in the context of Landlock.

I'd like to transfer this wording into the man pages as well.

Signed-off-by: Günther Noack <gnoack at google.com>
Cc: Alejandro Colomar <alx at kernel.org>
Cc: Mickaël Salaün <mic at digikod.net>
Cc: Konstantin Meskhidze <konstantin.meskhidze at huawei.com>
Cc: linux-security-module at vger.kernel.org
---
 include/uapi/linux/landlock.h | 42 ++++++++++++++++++-----------------
 1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/include/uapi/linux/landlock.h b/include/uapi/linux/landlock.h
index 68625e728f43..6f1b05c6995b 100644
--- a/include/uapi/linux/landlock.h
+++ b/include/uapi/linux/landlock.h
@@ -12,30 +12,32 @@
 #include <linux/types.h>
 
 /**
- * struct landlock_ruleset_attr - Ruleset definition
+ * struct landlock_ruleset_attr - Ruleset definition.
  *
- * Argument of sys_landlock_create_ruleset().  This structure can grow in
- * future versions.
+ * @handled_access_fs: Bitmask of handled filesystem actions (cf. `Filesystem flags`_)
+ * @handled_access_net: Bitmask of handled network actions (cf. `Network flags`_)
+ *
+ * Argument of sys_landlock_create_ruleset().
+ *
+ * This struct defines a set of *handled access rights*, a set of actions on
+ * different object types, which should be denied by default when the ruleset is
+ * enacted.  Vice versa, access rights that are not specifically listed here are
+ * going to be allowed when the ruleset is enacted.
+ *
+ * One exception is the %LANDLOCK_ACCESS_FS_REFER access right, which is always
+ * implicitly *handled*, even when its bit is not set in @handled_access_fs.
+ * However, in order to add new rules with this access right, the bit must still
+ * be set explicitly.
+ *
+ * The explicit listing of *handled access rights* is required for backwards
+ * compatibility reasons.  In most use cases, processes that use Landlock will
+ * *handle* a wide range or all access rights that they know about at build
+ * time.
+ *
+ * This structure can grow in future Landlock versions.
  */
 struct landlock_ruleset_attr {
-	/**
-	 * @handled_access_fs: Bitmask of actions (cf. `Filesystem flags`_)
-	 * that is handled by this ruleset and should then be forbidden if no
-	 * rule explicitly allow them: it is a deny-by-default list that should
-	 * contain as much Landlock access rights as possible. Indeed, all
-	 * Landlock filesystem access rights that are not part of
-	 * handled_access_fs are allowed.  This is needed for backward
-	 * compatibility reasons.  One exception is the
-	 * %LANDLOCK_ACCESS_FS_REFER access right, which is always implicitly
-	 * handled, but must still be explicitly handled to add new rules with
-	 * this access right.
-	 */
 	__u64 handled_access_fs;
-	/**
-	 * @handled_access_net: Bitmask of actions (cf. `Network flags`_)
-	 * that is handled by this ruleset and should then be forbidden if no
-	 * rule explicitly allow them.
-	 */
 	__u64 handled_access_net;
 };
 
-- 
2.45.2.803.g4e1b14247a-goog