The following commit has been merged into the locking/core branch of tip:
Commit-ID: 36dbde71fcece19699cef0d01bd2123a6d3142f4
Gitweb: https://git.kernel.org/tip/36dbde71fcece19699cef0d01bd2123a6d3142f4
Author: Alice Ryhl <aliceryhl@xxxxxxxxxx>
AuthorDate: Wed, 05 Feb 2025 10:54:50
Committer: Boqun Feng <boqun.feng@xxxxxxxxx>
CommitterDate: Sun, 23 Feb 2025 18:24:46 -08:00
rust: sync: Add accessor for the lock behind a given guard
In order to assert a particular `Guard` is associated with a particular
`Lock`, add an accessor to obtain a reference to the underlying `Lock`
of a `Guard`.
Binder needs this assertion to ensure unsafe list operations are done
with the correct lock held.
[Boqun: Capitalize the title and reword the commit log]
Signed-off-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>
Reviewed-by: Fiona Behrens <me@xxxxxxxxxx>
Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx>
Link: https://lore.kernel.org/r/20250205-guard-get-lock-v2-1-ba32a8c1d5b7@xxxxxxxxxx
---
rust/kernel/sync/lock.rs | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
index eb80048..8e7e6d5 100644
--- a/rust/kernel/sync/lock.rs
+++ b/rust/kernel/sync/lock.rs
@@ -199,7 +199,12 @@ pub struct Guard<'a, T: ?Sized, B: Backend> {
// SAFETY: `Guard` is sync when the data protected by the lock is also sync.
unsafe impl<T: Sync + ?Sized, B: Backend> Sync for Guard<'_, T, B> {}
-impl<T: ?Sized, B: Backend> Guard<'_, T, B> {
+impl<'a, T: ?Sized, B: Backend> Guard<'a, T, B> {
+ /// Returns the lock that this guard originates from.
+ pub fn lock_ref(&self) -> &'a Lock<T, B> {
+ self.lock
+ }
+
pub(crate) fn do_unlocked<U>(&mut self, cb: impl FnOnce() -> U) -> U {
// SAFETY: The caller owns the lock, so it is safe to unlock it.
unsafe { B::unlock(self.lock.state.get(), &self.state) };
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