Mailing List Archive: [PATCH v3 03/13] rust: types: add `Opaque::raw

[PATCH v3 03/13] rust: types: add `Opaque::raw_get`

Mar 29, 2023, 4:15 PM

Post #1 of 4 (10 views)

From: Benno Lossin <y86-dev@protonmail.com>

This function mirrors `UnsafeCell::raw_get`. It avoids creating a
reference and allows solely using raw pointers.
The `pin-init` API will be using this, since uninitialized memory
requires raw pointers.

Signed-off-by: Benno Lossin <y86-dev@protonmail.com>
---
rust/kernel/types.rs | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index 9d0fdbc55843..ff2b2fac951d 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -238,6 +238,14 @@ impl<T> Opaque<T> {
pub fn get(&self) -> *mut T {
UnsafeCell::raw_get(self.0.as_ptr())
}
+
+ /// Gets the value behind `this`.
+ ///
+ /// This function is useful to get access to the value without creating intermediate
+ /// references.
+ pub const fn raw_get(this: *const Self) -> *mut T {
+ UnsafeCell::raw_get(this.cast::<UnsafeCell<T>>())
+ }
}

/// A sum type that always holds either a value of type `L` or `R`.
--
2.39.2

Re: [PATCH v3 03/13] rust: types: add `Opaque::raw_get` [ In reply to ]

gary at garyguo

Mar 30, 2023, 4:15 AM

Post #2 of 4 (10 views)

Permalink

On Wed, 29 Mar 2023 22:33:03 +0000
y86-dev@protonmail.com wrote:

> From: Benno Lossin <y86-dev@protonmail.com>
>
> This function mirrors `UnsafeCell::raw_get`. It avoids creating a
> reference and allows solely using raw pointers.
> The `pin-init` API will be using this, since uninitialized memory
> requires raw pointers.
>
> Signed-off-by: Benno Lossin <y86-dev@protonmail.com>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
> rust/kernel/types.rs | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
> index 9d0fdbc55843..ff2b2fac951d 100644
> --- a/rust/kernel/types.rs
> +++ b/rust/kernel/types.rs
> @@ -238,6 +238,14 @@ impl<T> Opaque<T> {
> pub fn get(&self) -> *mut T {
> UnsafeCell::raw_get(self.0.as_ptr())
> }
> +
> + /// Gets the value behind `this`.
> + ///
> + /// This function is useful to get access to the value without creating intermediate
> + /// references.
> + pub const fn raw_get(this: *const Self) -> *mut T {
> + UnsafeCell::raw_get(this.cast::<UnsafeCell<T>>())
> + }
> }
>
> /// A sum type that always holds either a value of type `L` or `R`.
> --
> 2.39.2
>
>

Re: [PATCH v3 03/13] rust: types: add `Opaque::raw_get` [ In reply to ]

nmi at metaspace

Mar 30, 2023, 6:15 AM

Post #3 of 4 (10 views)

Permalink

y86-dev@protonmail.com writes:

> From: Benno Lossin <y86-dev@protonmail.com>
>
> This function mirrors `UnsafeCell::raw_get`. It avoids creating a
> reference and allows solely using raw pointers.
> The `pin-init` API will be using this, since uninitialized memory
> requires raw pointers.
>
> Signed-off-by: Benno Lossin <y86-dev@protonmail.com>
> ---

Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>

> rust/kernel/types.rs | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
> index 9d0fdbc55843..ff2b2fac951d 100644
> --- a/rust/kernel/types.rs
> +++ b/rust/kernel/types.rs
> @@ -238,6 +238,14 @@ impl<T> Opaque<T> {
> pub fn get(&self) -> *mut T {
> UnsafeCell::raw_get(self.0.as_ptr())
> }
> +
> + /// Gets the value behind `this`.
> + ///
> + /// This function is useful to get access to the value without creating intermediate
> + /// references.
> + pub const fn raw_get(this: *const Self) -> *mut T {
> + UnsafeCell::raw_get(this.cast::<UnsafeCell<T>>())
> + }
> }
>
> /// A sum type that always holds either a value of type `L` or `R`.

Re: [PATCH v3 03/13] rust: types: add `Opaque::raw_get` [ In reply to ]

alice at ryhl

Mar 30, 2023, 8:15 AM

Post #4 of 4 (10 views)

Permalink

On 3/30/23 00:33, y86-dev@protonmail.com wrote:
> From: Benno Lossin <y86-dev@protonmail.com>
>
> This function mirrors `UnsafeCell::raw_get`. It avoids creating a
> reference and allows solely using raw pointers.
> The `pin-init` API will be using this, since uninitialized memory
> requires raw pointers.
>
> Signed-off-by: Benno Lossin <y86-dev@protonmail.com>

Reviewed-by: Alice Ryhl <aliceryhl@google.com>