linux.git/rust/kernel/sync.rs, branch v6.6.131

rust: lockdep: Remove support for dynamically allocated LockClassKeys

2025-03-22T19:50:50+00:00

commit 966944f3711665db13e214fef6d02982c49bb972 upstream.

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 
Signed-off-by: Mitchell Levy 
Signed-off-by: Boqun Feng 
Signed-off-by: Ingo Molnar 
Reviewed-by: Benno Lossin 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250307232717.1759087-11-boqun.feng@gmail.com
Signed-off-by: Boqun Feng 
Signed-off-by: Greg Kroah-Hartman

rust: sync: introduce `CondVar`

2023-04-21T23:46:45+00:00

This is the traditional condition variable or monitor synchronisation
primitive. It is implemented with C's `wait_queue_head_t`.

It allows users to release a lock and go to sleep while guaranteeing
that notifications won't be missed. This is achieved by enqueuing a wait
entry before releasing the lock.

Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Will Deacon 
Cc: Waiman Long 
Reviewed-by: Martin Rodriguez Reboredo 
Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Alice Ryhl 
Link: https://lore.kernel.org/r/20230411054543.21278-12-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda

rust: sync: introduce `LockedBy`

2023-04-21T22:20:00+00:00

This allows us to have data protected by a lock despite not being
wrapped by it. Access is granted by providing evidence that the lock is
held by the caller.

Reviewed-by: Martin Rodriguez Reboredo 
Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20230411054543.21278-13-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda

rust: lock: introduce `SpinLock`

2023-04-21T22:20:00+00:00

This is the `spinlock_t` lock backend and allows Rust code to use the
kernel spinlock idiomatically.

Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Will Deacon 
Cc: Waiman Long 
Reviewed-by: Martin Rodriguez Reboredo 
Signed-off-by: Wedson Almeida Filho 
Link: https://lore.kernel.org/r/20230419174426.132207-1-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda

rust: lock: introduce `Mutex`

2023-04-21T22:20:00+00:00

This is the `struct mutex` lock backend and allows Rust code to use the
kernel mutex idiomatically.

Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Will Deacon 
Cc: Waiman Long 
Reviewed-by: Martin Rodriguez Reboredo 
Signed-off-by: Wedson Almeida Filho 
Link: https://lore.kernel.org/r/20230411054543.21278-3-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda

rust: sync: introduce `Lock` and `Guard`

2023-04-21T22:19:42+00:00

They are generic Rust implementations of a lock and a lock guard that
contain code that is common to all locks. Different backends will be
introduced in subsequent commits.

Reviewed-by: Martin Rodriguez Reboredo 
Suggested-by: Gary Guo 
Signed-off-by: Wedson Almeida Filho 
Link: https://lore.kernel.org/r/20230411054543.21278-2-wedsonaf@gmail.com
[ Fixed typo. ]
Signed-off-by: Miguel Ojeda

rust: sync: introduce `LockClassKey`

2023-04-20T22:35:26+00:00

It is a wrapper around C's `lock_class_key`, which is used by the
synchronisation primitives that are checked with lockdep. This is in
preparation for introducing Rust abstractions for these primitives.

Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Will Deacon 
Cc: Waiman Long 
Reviewed-by: Martin Rodriguez Reboredo 
Co-developed-by: Boqun Feng 
Signed-off-by: Boqun Feng 
Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Gary Guo 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20230411054543.21278-1-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda

rust: sync: introduce `UniqueArc`

2023-01-16T22:48:06+00:00

Since `Arc` does not allow mutating `T` directly (i.e., without inner
mutability), it is currently not possible to do some initialisation of
`T` post construction but before being shared.

`UniqueArc` addresses this problem essentially being an `Arc` that
has a refcount of 1 and is therefore writable. Once initialisation is
completed, it can be transitioned (without failure paths) into an
`Arc`.

Suggested-by: Gary Guo 
Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Alice Ryhl 
Reviewed-by: Gary Guo 
Reviewed-by: Vincenzo Palazzo 
Acked-by: Boqun Feng 
Signed-off-by: Miguel Ojeda

rust: sync: introduce `ArcBorrow`

2023-01-16T22:47:57+00:00

This allows us to create references to a ref-counted allocation without
double-indirection and that still allow us to increment the refcount to
a new `Arc`.

Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Alice Ryhl 
Acked-by: Boqun Feng 
Reviewed-by: Gary Guo 
Reviewed-by: Vincenzo Palazzo 
Signed-off-by: Miguel Ojeda

rust: sync: add `Arc` for ref-counted allocations

2023-01-16T21:20:03+00:00

This is a basic implementation of `Arc` backed by C's `refcount_t`. It
allows Rust code to idiomatically allocate memory that is ref-counted.

Cc: Will Deacon 
Cc: Peter Zijlstra 
Cc: Boqun Feng 
Cc: Mark Rutland 
Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Alice Ryhl 
Reviewed-by: Gary Guo 
Reviewed-by: Vincenzo Palazzo 
Acked-by: Boqun Feng 
Signed-off-by: Miguel Ojeda