[PATCH 1/2] rust: alloc: extend safety requirements of Vec::set_len()

[Danilo Krummrich <dakr@kernel.org>]

Extend the safety requirements of set_len() to consider the case when
the new length is smaller than the old length.

Fixes: 2aac4cd7dae3 ("rust: alloc: implement kernel `Vec` type")
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 rust/kernel/alloc/kvec.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/rust/kernel/alloc/kvec.rs b/rust/kernel/alloc/kvec.rs
index ae9d072741ce..8540d9e2b717 100644
--- a/rust/kernel/alloc/kvec.rs
+++ b/rust/kernel/alloc/kvec.rs
@@ -189,7 +189,9 @@ pub fn len(&self) -> usize {
     ///
     /// - `new_len` must be less than or equal to [`Self::capacity`].
     /// - If `new_len` is greater than `self.len`, all elements within the interval
-    ///   [`self.len`,`new_len`) must be initialized.
+    ///   [`self.len`,`new_len`) must be initialized,
+    /// - if `new_len` is smaller than `self.len`, all elements within the interval
+    ///   [`new_len`, `self.len`) must either be dropped or copied and taken ownership of.
     #[inline]
     pub unsafe fn set_len(&mut self, new_len: usize) {
         debug_assert!(new_len <= self.capacity());

base-commit: 80e54e84911a923c40d7bee33a34c1b4be148d7a
-- 
2.48.1