From: Andreas Hindborg <a.hindborg@kernel.org>
Date: Sun, 9 Mar 2025 15:19:00 +0000 (+0100)
Subject: rust: alloc: add `Box::into_pin`
X-Git-Tag: v6.15-rc1~93^2^2~4
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b4fecceee29e2a6453ac746e70c16fe7f70babf9;p=thirdparty%2Fkernel%2Flinux.git

rust: alloc: add `Box::into_pin`

Add an associated function to convert a `Box<T>` into a `Pin<Box<T>>`.

Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-9-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---

diff --git a/rust/kernel/alloc/kbox.rs b/rust/kernel/alloc/kbox.rs
index cb4ebea3b0742..9da4a32e60bc3 100644
--- a/rust/kernel/alloc/kbox.rs
+++ b/rust/kernel/alloc/kbox.rs
@@ -245,6 +245,12 @@ where
         Ok(Self::new(x, flags)?.into())
     }
 
+    /// Convert a [`Box<T,A>`] to a [`Pin<Box<T,A>>`]. If `T` does not implement
+    /// [`Unpin`], then `x` will be pinned in memory and can't be moved.
+    pub fn into_pin(this: Self) -> Pin<Self> {
+        this.into()
+    }
+
     /// Forgets the contents (does not run the destructor), but keeps the allocation.
     fn forget_contents(this: Self) -> Box<MaybeUninit<T>, A> {
         let ptr = Self::into_raw(this);