linux-kernel - [PATCH v2 1/2] rust: clk: implement Send and Sync

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250910-clk-type-state-v2-1-1b97c11bb631@collabora.com>
Date: Wed, 10 Sep 2025 14:28:27 -0300
From: Daniel Almeida <daniel.almeida@...labora.com>
To: Michael Turquette <mturquette@...libre.com>, 
 Stephen Boyd <sboyd@...nel.org>, Miguel Ojeda <ojeda@...nel.org>, 
 Alex Gaynor <alex.gaynor@...il.com>, Boqun Feng <boqun.feng@...il.com>, 
 Gary Guo <gary@...yguo.net>, 
 Björn Roy Baron <bjorn3_gh@...tonmail.com>, 
 Benno Lossin <lossin@...nel.org>, Andreas Hindborg <a.hindborg@...nel.org>, 
 Alice Ryhl <aliceryhl@...gle.com>, Trevor Gross <tmgross@...ch.edu>, 
 Danilo Krummrich <dakr@...nel.org>, "Rafael J. Wysocki" <rafael@...nel.org>, 
 Viresh Kumar <viresh.kumar@...aro.org>
Cc: linux-clk@...r.kernel.org, rust-for-linux@...r.kernel.org, 
 linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org, 
 Daniel Almeida <daniel.almeida@...labora.com>
Subject: [PATCH v2 1/2] rust: clk: implement Send and Sync

From: Alice Ryhl <aliceryhl@...gle.com>

These traits are required for drivers to embed the Clk type in their own
data structures because driver data structures are usually required to
be Send. See e.g. [1] for the kind of workaround that drivers currently
need due to lacking this annotation.

Link: https://lore.kernel.org/rust-for-linux/20250812-tyr-v2-1-9e0f3dc9da95@collabora.com/ [1]
Signed-off-by: Daniel Almeida <daniel.almeida@...labora.com>
Signed-off-by: Alice Ryhl <aliceryhl@...gle.com>
Reviewed-by: Danilo Krummrich <dakr@...nel.org>
Acked-by: Viresh Kumar <viresh.kumar@...aro.org>
Reviewed-by: Daniel Almeida <daniel.almeida@...labora.com>
---
 rust/kernel/clk.rs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/rust/kernel/clk.rs b/rust/kernel/clk.rs
index 1e6c8c42fb3a321951e275101848b35e1ae5c2a8..0a290202da69669d670ddad2b6762a1d5f1d912e 100644
--- a/rust/kernel/clk.rs
+++ b/rust/kernel/clk.rs
@@ -129,6 +129,13 @@ mod common_clk {
     #[repr(transparent)]
     pub struct Clk(*mut bindings::clk);

+    // SAFETY: It is safe to call `clk_put` on another thread than where `clk_get` was called.
+    unsafe impl Send for Clk {}
+
+    // SAFETY: It is safe to call any combination of the `&self` methods in parallel, as the
+    // methods are synchronized internally.
+    unsafe impl Sync for Clk {}
+
     impl Clk {
         /// Gets [`Clk`] corresponding to a [`Device`] and a connection id.
         ///

-- 
2.51.0