diff mbox series

[v3,01/16] rust: init: introduce `Opaque::try_ffi_init`

Message ID 20241022213221.2383-2-dakr@kernel.org (mailing list archive)
State Handled Elsewhere
Delegated to: Bjorn Helgaas
Headers show
Series Device / Driver PCI / Platform Rust abstractions | expand

Commit Message

Danilo Krummrich Oct. 22, 2024, 9:31 p.m. UTC 
From: Wedson Almeida Filho <walmeida@microsoft.com>

This is the same as `Opaque::ffi_init`, but returns a `Result`.

This is used by subsequent patches to implement the FFI init of static
driver structures on registration.

Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 rust/kernel/types.rs | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

Comments

Alice Ryhl Oct. 29, 2024, 12:42 p.m. UTC | #1 
On Tue, Oct 22, 2024 at 11:32 PM Danilo Krummrich <dakr@kernel.org> wrote:
>
> From: Wedson Almeida Filho <walmeida@microsoft.com>
>
> This is the same as `Opaque::ffi_init`, but returns a `Result`.
>
> This is used by subsequent patches to implement the FFI init of static
> driver structures on registration.
>
> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
> Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Just as an FYI, try_ffi_init is landing through char-misc-next for 6.13.

Alice
diff mbox series

Patch

diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index ced143600eb1..236e8de5844b 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -239,14 +239,22 @@  pub const fn uninit() -> Self {
     /// uninitialized. Additionally, access to the inner `T` requires `unsafe`, so the caller needs
     /// to verify at that point that the inner value is valid.
     pub fn ffi_init(init_func: impl FnOnce(*mut T)) -> impl PinInit<Self> {
+        Self::try_ffi_init(move |slot| {
+            init_func(slot);
+            Ok(())
+        })
+    }
+
+    /// Similar to [`Self::ffi_init`], except that the closure can fail.
+    ///
+    /// To avoid leaks on failure, the closure must drop any fields it has initialised before the
+    /// failure.
+    pub fn try_ffi_init<E>(
+        init_func: impl FnOnce(*mut T) -> Result<(), E>,
+    ) -> impl PinInit<Self, E> {
         // SAFETY: We contain a `MaybeUninit`, so it is OK for the `init_func` to not fully
         // initialize the `T`.
-        unsafe {
-            init::pin_init_from_closure::<_, ::core::convert::Infallible>(move |slot| {
-                init_func(Self::raw_get(slot));
-                Ok(())
-            })
-        }
+        unsafe { init::pin_init_from_closure(|slot| init_func(Self::raw_get(slot))) }
     }
 
     /// Returns a raw pointer to the opaque data.