[PATCH locking 10/11] rust: lockdep: Remove support for dynamically allocated LockClassKeys
From: Mitchell Levy levymitchell0@gmail.com
Currently, dynamically allocated LockCLassKeys can be used from the Rust side without having them registered. This is a soundness issue, so remove them.
Suggested-by: Alice Ryhl aliceryhl@google.com Link: https://lore.kernel.org/rust-for-linux/20240815074519.2684107-3-nmi@metaspac... Cc: stable@vger.kernel.org Fixes: 6ea5aa08857a ("rust: sync: introduce `LockClassKey`") Reviewed-by: Benno Lossin benno.lossin@proton.me Signed-off-by: Mitchell Levy levymitchell0@gmail.com Signed-off-by: Boqun Feng boqun.feng@gmail.com Link: https://lore.kernel.org/r/20250207-rust-lockdep-v4-1-7a50a7e88656@gmail.com --- rust/kernel/sync.rs | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-)
diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs index 3498fb344dc9..16eab9138b2b 100644 --- a/rust/kernel/sync.rs +++ b/rust/kernel/sync.rs @@ -30,28 +30,20 @@ unsafe impl Sync for LockClassKey {}
impl LockClassKey { - /// Creates a new lock class key. - pub const fn new() -> Self { - Self(Opaque::uninit()) - } - pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key { self.0.get() } }
-impl Default for LockClassKey { - fn default() -> Self { - Self::new() - } -} - /// Defines a new static lock class and returns a pointer to it. #[doc(hidden)] #[macro_export] macro_rules! static_lock_class { () => {{ - static CLASS: $crate::sync::LockClassKey = $crate::sync::LockClassKey::new(); + static CLASS: $crate::sync::LockClassKey = + // SAFETY: lockdep expects uninitialized memory when it's handed a statically allocated + // lock_class_key + unsafe { ::core::mem::MaybeUninit::uninit().assume_init() }; &CLASS }}; }
The following commit has been merged into the locking/core branch of tip:
Commit-ID: 966944f3711665db13e214fef6d02982c49bb972 Gitweb: https://git.kernel.org/tip/966944f3711665db13e214fef6d02982c49bb972 Author: Mitchell Levy levymitchell0@gmail.com AuthorDate: Fri, 07 Mar 2025 15:27:00 -08:00 Committer: Ingo Molnar mingo@kernel.org CommitterDate: Sat, 08 Mar 2025 00:52:00 +01:00
rust: lockdep: Remove support for dynamically allocated LockClassKeys
Currently, dynamically allocated LockCLassKeys can be used from the Rust side without having them registered. This is a soundness issue, so remove them.
Fixes: 6ea5aa08857a ("rust: sync: introduce `LockClassKey`") Suggested-by: Alice Ryhl aliceryhl@google.com Signed-off-by: Mitchell Levy levymitchell0@gmail.com Signed-off-by: Boqun Feng boqun.feng@gmail.com Signed-off-by: Ingo Molnar mingo@kernel.org Reviewed-by: Benno Lossin benno.lossin@proton.me Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250307232717.1759087-11-boqun.feng@gmail.com --- rust/kernel/sync.rs | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-)
diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs index 3498fb3..16eab91 100644 --- a/rust/kernel/sync.rs +++ b/rust/kernel/sync.rs @@ -30,28 +30,20 @@ pub struct LockClassKey(Opaquebindings::lock_class_key); unsafe impl Sync for LockClassKey {}
impl LockClassKey { - /// Creates a new lock class key. - pub const fn new() -> Self { - Self(Opaque::uninit()) - } - pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key { self.0.get() } }
-impl Default for LockClassKey { - fn default() -> Self { - Self::new() - } -} - /// Defines a new static lock class and returns a pointer to it. #[doc(hidden)] #[macro_export] macro_rules! static_lock_class { () => {{ - static CLASS: $crate::sync::LockClassKey = $crate::sync::LockClassKey::new(); + static CLASS: $crate::sync::LockClassKey = + // SAFETY: lockdep expects uninitialized memory when it's handed a statically allocated + // lock_class_key + unsafe { ::core::mem::MaybeUninit::uninit().assume_init() }; &CLASS }}; }
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