From a0c6fa8b8a59f8901e182fada6ac0e1f65beaa00 Mon Sep 17 00:00:00 2001 From: Andreas Hindborg Date: Sun, 9 Mar 2025 16:18:53 +0100 Subject: [PATCH] rust: sync: add `Arc::as_ptr` Add a method to get a pointer to the data contained in an `Arc`. Reviewed-by: Lyude Paul Reviewed-by: Alice Ryhl Reviewed-by: Benno Lossin Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-2-73586e2bd5f1@kernel.org Signed-off-by: Andreas Hindborg --- rust/kernel/sync/arc.rs | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs index 3cefda7a4372..1dfa75714f9d 100644 --- a/rust/kernel/sync/arc.rs +++ b/rust/kernel/sync/arc.rs @@ -246,6 +246,15 @@ impl Arc { unsafe { core::ptr::addr_of!((*ptr).data) } } + /// Return a raw pointer to the data in this arc. + pub fn as_ptr(this: &Self) -> *const T { + let ptr = this.ptr.as_ptr(); + + // SAFETY: As `ptr` points to a valid allocation of type `ArcInner`, + // field projection to `data`is within bounds of the allocation. + unsafe { core::ptr::addr_of!((*ptr).data) } + } + /// Recreates an [`Arc`] instance previously deconstructed via [`Arc::into_raw`]. /// /// # Safety @@ -539,11 +548,11 @@ impl ArcBorrow<'_, T> { } /// Creates an [`ArcBorrow`] to an [`Arc`] that has previously been deconstructed with - /// [`Arc::into_raw`]. + /// [`Arc::into_raw`] or [`Arc::as_ptr`]. /// /// # Safety /// - /// * The provided pointer must originate from a call to [`Arc::into_raw`]. + /// * The provided pointer must originate from a call to [`Arc::into_raw`] or [`Arc::as_ptr`]. /// * For the duration of the lifetime annotated on this `ArcBorrow`, the reference count must /// not hit zero. /// * For the duration of the lifetime annotated on this `ArcBorrow`, there must not be a -- 2.50.1