[PATCH] binder: replace unsafe NewAllocation transmute with field move

[PATCH] binder: replace unsafe NewAllocation transmute with field move

[Thorsten Blum]

NewAllocation does not implement Drop and success() can return its
Allocation field directly. Also remove the now-unused transparent
representation.

Signed-off-by: Thorsten Blum <blum@kernel.org>
---
 drivers/android/binder/allocation.rs | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/android/binder/allocation.rs b/drivers/android/binder/allocation.rs
index 165cb797eb1e..be405f2596ae 100644
--- a/drivers/android/binder/allocation.rs
+++ b/drivers/android/binder/allocation.rs
@@ -298,17 +298,13 @@ fn drop(&mut self) {
 /// A wrapper around `Allocation` that is being created.
 ///
 /// If the allocation is destroyed while wrapped in this wrapper, then the allocation will be
-/// considered to be part of a failed transaction. Successful transactions avoid that by calling
-/// `success`, which skips the destructor.
-#[repr(transparent)]
+/// considered to be part of a failed transaction. Successful transactions call `success` and
+/// store the returned `Allocation` in the new transaction.
 pub(crate) struct NewAllocation(pub(crate) Allocation);
 
 impl NewAllocation {
     pub(crate) fn success(self) -> Allocation {
-        // This skips the destructor.
-        //
-        // SAFETY: This type is `#[repr(transparent)]`, so the layout matches.
-        unsafe { core::mem::transmute(self) }
+        self.0
     }
 }
 

Re: [PATCH] binder: replace unsafe NewAllocation transmute with field move

[Alice Ryhl]

On Thu, Oct 08, 2026 at 11:29:05AM +0200, Thorsten Blum wrote:
> NewAllocation does not implement Drop and success() can return its
> Allocation field directly. Also remove the now-unused transparent
> representation.
> 
> Signed-off-by: Thorsten Blum <blum@kernel.org>

The NewAllocation type implements Drop as of commit e2e4a4527d18
("rust_binder: allocation: call trace_transaction_failed_buffer_release()").

See: https://patch.msgid.link/20260927125622.676342-3-sagartaunk@proton.me

Alice