diff options
author | Miguel Ojeda <ojeda@kernel.org> | 2024-09-04 16:42:29 +0200 |
---|---|---|
committer | Miguel Ojeda <ojeda@kernel.org> | 2024-09-04 23:11:31 +0200 |
commit | ab309b6e084c70a29f9fa3cee797572bd2340901 (patch) | |
tree | d0dc23bdee49dd40bc2c40e4204d54991137522f /rust | |
parent | 68d3b6aa08708bb3907c2c13eaf4b3ccf4805160 (diff) |
rust: avoid `box_uninit_write` feature
Like commit 0903b9e2a46c ("rust: alloc: eschew
`Box<MaybeUninit<T>>::write`"), but for the new `rbtree` and `alloc` code.
That is, `feature(new_uninit)` [1] got partially stabilized [2]
for Rust 1.82.0 (expected to be released on 2024-10-17), but it
did not include `Box<MaybeUninit<T>>::write`, which got split into
`feature(box_uninit_write)` [3].
To avoid relying on a new unstable feature, rewrite the `write` +
`assume_init` pair manually.
Link: https://github.com/rust-lang/rust/issues/63291 [1]
Link: https://github.com/rust-lang/rust/pull/129401 [2]
Link: https://github.com/rust-lang/rust/issues/129397 [3]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240904144229.18592-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'rust')
-rw-r--r-- | rust/kernel/alloc/box_ext.rs | 6 | ||||
-rw-r--r-- | rust/kernel/rbtree.rs | 17 |
2 files changed, 12 insertions, 11 deletions
diff --git a/rust/kernel/alloc/box_ext.rs b/rust/kernel/alloc/box_ext.rs index b68ade26a42d..5b1550d620fd 100644 --- a/rust/kernel/alloc/box_ext.rs +++ b/rust/kernel/alloc/box_ext.rs @@ -26,9 +26,11 @@ pub trait BoxExt<T>: Sized { /// use kernel::alloc::{flags, box_ext::BoxExt}; /// let value = Box::new([0; 32], flags::GFP_KERNEL)?; /// assert_eq!(*value, [0; 32]); - /// let value = Box::drop_contents(value); + /// let mut value = Box::drop_contents(value); /// // Now we can re-use `value`: - /// let value = Box::write(value, [1; 32]); + /// value.write([1; 32]); + /// // SAFETY: We just wrote to it. + /// let value = unsafe { value.assume_init() }; /// assert_eq!(*value, [1; 32]); /// # Ok::<(), Error>(()) /// ``` diff --git a/rust/kernel/rbtree.rs b/rust/kernel/rbtree.rs index 48ceb9560bf5..25eb36fd1cdc 100644 --- a/rust/kernel/rbtree.rs +++ b/rust/kernel/rbtree.rs @@ -1059,15 +1059,14 @@ impl<K, V> RBTreeNodeReservation<K, V> { /// Initialises a node reservation. /// /// It then becomes an [`RBTreeNode`] that can be inserted into a tree. - pub fn into_node(self, key: K, value: V) -> RBTreeNode<K, V> { - let node = Box::write( - self.node, - Node { - key, - value, - links: bindings::rb_node::default(), - }, - ); + pub fn into_node(mut self, key: K, value: V) -> RBTreeNode<K, V> { + self.node.write(Node { + key, + value, + links: bindings::rb_node::default(), + }); + // SAFETY: We just wrote to it. + let node = unsafe { self.node.assume_init() }; RBTreeNode { node } } } |