[PATCH] landlock: Add counted_by and fix comment in landlock_ruleset

[Tingmao Wang]

For a domain, this array stores the access masks for each layer (of
which there are num_layers of them).  For an unmerged ruleset, we have
one "layer", and one element in this array.  This annotation serves as
useful documentation.

This also removes a comment saying that num_layers = 0 for unmerged
rulesets, which is incorrect (it is 1).

Signed-off-by: Tingmao Wang <m at maowtm.org>
---

I'm not sure if I should add a Fixes tag, but if I should had, it would
be ae271c1b14 ("landlock: Add ruleset and domain management").

 security/landlock/ruleset.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h
index 9d6dc632684c..7005840ac641 100644
--- a/security/landlock/ruleset.h
+++ b/security/landlock/ruleset.h
@@ -168,8 +168,7 @@ struct landlock_ruleset {
 			/**
 			 * @num_layers: Number of layers that are used in this
 			 * ruleset.  This enables to check that all the layers
-			 * allow an access request.  A value of 0 identifies a
-			 * non-merged ruleset (i.e. not a domain).
+			 * allow an access request.
 			 */
 			u32 num_layers;
 			/**
@@ -184,7 +183,8 @@ struct landlock_ruleset {
 			 * layers are set once and never changed for the
 			 * lifetime of the ruleset.
 			 */
-			struct access_masks access_masks[];
+			struct access_masks
+				access_masks[] __counted_by(num_layers);
 		};
 	};
 };

base-commit: f179e1859c711214412876c57f56f9b0cfb13264
-- 
2.53.0