[PATCH v2 3/3] landlock: Document LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVS

Document atomically setting no_new_privs with ruleset enforcement,
following the same compatibility section style as previous ABI
additions.

Signed-off-by: Justin Suess <[email protected]>
---
 Documentation/userspace-api/landlock.rst | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst
index 5a63d4476c1c..ec87d35f4715 100644
--- a/Documentation/userspace-api/landlock.rst
+++ b/Documentation/userspace-api/landlock.rst
@@ -8,7 +8,7 @@ Landlock: unprivileged access control
 =====================================
 
 :Author: Mickaël Salaün
-:Date: June 2026
+:Date: July 2026
 
 The goal of Landlock is to enable restriction of ambient rights (e.g. global
 filesystem or network access) for a set of processes.  Because Landlock
@@ -789,6 +789,18 @@ when at least one sys_landlock_add_rule() call is made for it with the
 ``LANDLOCK_ADD_RULE_QUIET`` flag, additional add-rule calls for the same
 object without this flag do not clear it.
 
+Atomic no_new_privs (ABI < 11)
+------------------------------
+
+Starting with the Landlock ABI version 11, sys_landlock_restrict_self()
+accepts the ``LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVS`` flag, which sets the
+no_new_privs attribute of the calling thread atomically with the enforcement
+of the ruleset: no_new_privs is set if and only if the call succeeds.  This
+removes the need for a prior :manpage:`prctl(2)` ``PR_SET_NO_NEW_PRIVS``
+call, and with it the ``CAP_SYS_ADMIN`` requirement.  When combined with
+``LANDLOCK_RESTRICT_SELF_TSYNC``, no_new_privs is set on all threads of the
+process.
+
 .. _kernel_support:
 
 Kernel support
-- 
2.54.0