linux-kernel - [PATCH v2 1/4] rust: sync: reword the `Arc` safety comment for `Send`

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: <20230523144418.1250547-2-aliceryhl@google.com>
Date:   Tue, 23 May 2023 14:44:15 +0000
From:   Alice Ryhl <aliceryhl@...gle.com>
To:     Miguel Ojeda <ojeda@...nel.org>,
        Wedson Almeida Filho <wedsonaf@...il.com>,
        Alex Gaynor <alex.gaynor@...il.com>
Cc:     Boqun Feng <boqun.feng@...il.com>, Gary Guo <gary@...yguo.net>,
        "Björn Roy Baron" <bjorn3_gh@...tonmail.com>,
        Benno Lossin <benno.lossin@...ton.me>,
        Alice Ryhl <aliceryhl@...gle.com>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Will Deacon <will@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        rust-for-linux@...r.kernel.org, linux-kernel@...r.kernel.org,
        patches@...ts.linux.dev, Andreas Hindborg <a.hindborg@...sung.com>
Subject: [PATCH v2 1/4] rust: sync: reword the `Arc` safety comment for `Send`

The safety comment on `impl Send for Arc` talks about "directly"
accessing the value, when it really means "accessing the value with a
mutable reference". This commit clarifies that.

Suggested-by: Boqun Feng <boqun.feng@...il.com>
Signed-off-by: Alice Ryhl <aliceryhl@...gle.com>
Reviewed-by: Andreas Hindborg <a.hindborg@...sung.com>
Reviewed-by: Boqun Feng <boqun.feng@...il.com>
---
 rust/kernel/sync/arc.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index e6d206242465..87a4c9ed712b 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -146,8 +146,8 @@ impl<T: ?Sized + Unsize<U>, U: ?Sized> core::ops::DispatchFromDyn<Arc<U>> for Ar
 
 // SAFETY: It is safe to send `Arc<T>` to another thread when the underlying `T` is `Sync` because
 // it effectively means sharing `&T` (which is safe because `T` is `Sync`); additionally, it needs
-// `T` to be `Send` because any thread that has an `Arc<T>` may ultimately access `T` directly, for
-// example, when the reference count reaches zero and `T` is dropped.
+// `T` to be `Send` because any thread that has an `Arc<T>` may ultimately access `T` using a
+// mutable reference, for example, when the reference count reaches zero and `T` is dropped.
 unsafe impl<T: ?Sized + Sync + Send> Send for Arc<T> {}
 
 // SAFETY: It is safe to send `&Arc<T>` to another thread when the underlying `T` is `Sync` for the
-- 
2.40.1.698.g37aff9b760-goog