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From: Alice Ryhl <aliceryhl@google.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Carlos Llamas <cmllamas@google.com>,
	 Miguel Ojeda <ojeda@kernel.org>
Cc: "Arve Hjønnevåg" <arve@android.com>,
	"Todd Kjos" <tkjos@android.com>,
	"Martijn Coenen" <maco@android.com>,
	"Joel Fernandes" <joelagnelf@nvidia.com>,
	"Christian Brauner" <brauner@kernel.org>,
	"Suren Baghdasaryan" <surenb@google.com>,
	"Boqun Feng" <boqun.feng@gmail.com>,
	"Gary Guo" <gary@garyguo.net>,
	"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
	"Benno Lossin" <lossin@kernel.org>,
	"Andreas Hindborg" <a.hindborg@kernel.org>,
	"Trevor Gross" <tmgross@umich.edu>,
	"Danilo Krummrich" <dakr@kernel.org>,
	linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org,
	"Alice Ryhl" <aliceryhl@google.com>
Subject: [PATCH 3/3] rust: list: add warning to List::remove docs about mem::take
Date: Tue, 11 Nov 2025 14:23:34 +0000	[thread overview]
Message-ID: <20251111-binder-fix-list-remove-v1-3-8ed14a0da63d@google.com> (raw)
In-Reply-To: <20251111-binder-fix-list-remove-v1-0-8ed14a0da63d@google.com>

The previous patches in this series illustrate why the List::remove
method is really dangerous. I think the real takeaway here is to replace
the linked lists with a different data structure without this unsafe
footgun, but for now we fix the bugs and add a warning to the docs.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
 rust/kernel/list.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/rust/kernel/list.rs b/rust/kernel/list.rs
index 7355bbac16a7fe7feeb8bc6408671817b186b21d..8349ff32fc37ff7141fb7c62d26653bda6507f91 100644
--- a/rust/kernel/list.rs
+++ b/rust/kernel/list.rs
@@ -576,6 +576,9 @@ pub fn pop_front(&mut self) -> Option<ListArc<T, ID>> {
     /// This returns `None` if the item is not in the list. (Note that by the safety requirements,
     /// this means that the item is not in any list.)
     ///
+    /// When using this method, be careful with using `mem::take` on the same list as that may
+    /// result in violating the safety requirements of this method.
+    ///
     /// # Safety
     ///
     /// `item` must not be in a different linked list (with the same id).

-- 
2.51.2.1041.gc1ab5b90ca-goog


  parent reply	other threads:[~2025-11-11 14:23 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-11 14:23 [PATCH 0/3] rust_binder: fix unsoundness due to combining List::remove with mem:take Alice Ryhl
2025-11-11 14:23 ` [PATCH 1/3] rust_binder: fix race condition on death_list Alice Ryhl
2025-11-11 14:23 ` [PATCH 2/3] rust_binder: avoid mem::take on delivered_deaths Alice Ryhl
2025-11-11 14:23 ` Alice Ryhl [this message]
2025-11-12 10:21   ` [PATCH 3/3] rust: list: add warning to List::remove docs about mem::take Miguel Ojeda
2025-11-12 10:22 ` [PATCH 0/3] rust_binder: fix unsoundness due to combining List::remove with mem:take Miguel Ojeda
2025-11-12 11:03   ` Greg Kroah-Hartman

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