[PATCH -next v2 6/6] landlock: update chmod and chown support in document

From: Xiu Jianfeng
Date: Sat Aug 27 2022 - 07:16:26 EST


update LANDLOCK_ACCESS_FS_{CHMOD, CHGRP} support and add abi change
in the document.

Signed-off-by: Xiu Jianfeng <xiujianfeng@xxxxxxxxxx>
---
Documentation/userspace-api/landlock.rst | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst
index 2509c2fbf98f..0e97a7998fa1 100644
--- a/Documentation/userspace-api/landlock.rst
+++ b/Documentation/userspace-api/landlock.rst
@@ -61,7 +61,9 @@ the need to be explicit about the denied-by-default access rights.
LANDLOCK_ACCESS_FS_MAKE_BLOCK |
LANDLOCK_ACCESS_FS_MAKE_SYM |
LANDLOCK_ACCESS_FS_REFER |
- LANDLOCK_ACCESS_FS_TRUNCATE,
+ LANDLOCK_ACCESS_FS_TRUNCATE |
+ LANDLOCK_ACCESS_FS_CHMOD |
+ LANDLOCK_ACCESS_FS_CHGRP
};

Because we may not know on which kernel version an application will be
@@ -90,6 +92,11 @@ the ABI.
case 2:
/* Removes LANDLOCK_ACCESS_FS_TRUNCATE for ABI < 3 */
ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_TRUNCATE;
+ __attribute__((fallthrough));
+ case 3:
+ /* Removes LANDLOCK_ACCESS_FS_{CHMOD, CHGRP} for ABI < 4 */
+ ruleset_attr.handled_access_fs &= ~(LANDLOCK_ACCESS_FS_CHMOD |
+ LANDLOCK_ACCESS_FS_CHGRP);
}

This enables to create an inclusive ruleset that will contain our rules.
--
2.17.1