From 6a152af23cb49a3bcbb8c4457a612ffa27d54693 Mon Sep 17 00:00:00 2001 From: Danilo Krummrich Date: Mon, 24 Mar 2025 16:01:00 +0100 Subject: [PATCH] rust: dma: add `Send` implementation for `CoherentAllocation` Stephen found a future build failure in linux-next [1]: error[E0277]: `*mut MyStruct` cannot be sent between threads safely --> samples/rust/rust_dma.rs:47:22 | 47 | impl pci::Driver for DmaSampleDriver { | ^^^^^^^^^^^^^^^ `*mut MyStruct` cannot be sent between threads safely It is caused by the interaction between commit 935e1d90bf6f ("rust: pci: require Send for Driver trait implementers") from the driver-core tree, which fixes a missing concurrency requirement, and commit 9901addae63b ("samples: rust: add Rust dma test sample driver") which adds a sample that does not satisfy that requirement. Add a `Send` implementation to `CoherentAllocation`, which allows the sample (and other future users) to satisfy it. Reported-by: Stephen Rothwell Link: https://lore.kernel.org/linux-next/20250324215702.1515ba92@canb.auug.org.au/ Signed-off-by: Danilo Krummrich Signed-off-by: Miguel Ojeda --- rust/kernel/dma.rs | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/rust/kernel/dma.rs b/rust/kernel/dma.rs index 9d00f9c49f47..18de693c4924 100644 --- a/rust/kernel/dma.rs +++ b/rust/kernel/dma.rs @@ -301,6 +301,10 @@ fn drop(&mut self) { } } +// SAFETY: It is safe to send a `CoherentAllocation` to another thread if `T` +// can be send to another thread. +unsafe impl Send for CoherentAllocation {} + /// Reads a field of an item from an allocated region of structs. /// /// # Examples -- 2.49.0