2024-01-16 16:03:18

by Valentin Obst

Subject: [PATCH 02/13] rust: error: move unsafe block into function call

The `from_err_ptr` function is safe. There is no need for the call to it
to be inside the unsafe block.

Signed-off-by: Valentin Obst <[email protected]>
---
rust/kernel/error.rs | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 4f0c1edd63b7..6f6676bc0eb9 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -265,12 +265,7 @@ pub fn to_result(err: core::ffi::c_int) -> Result {
/// index: u32,
/// ) -> Result<*mut core::ffi::c_void> {
/// // SAFETY: FFI call.
-/// unsafe {
-/// from_err_ptr(bindings::devm_platform_ioremap_resource(
-/// pdev.to_ptr(),
-/// index,
-/// ))
-/// }
+/// from_err_ptr(unsafe { bindings::devm_platform_ioremap_resource(pdev.to_ptr(), index) })
/// }
/// ```
// TODO: Remove `dead_code` marker once an in-kernel client is available.
--
2.43.0

2024-01-18 00:31:47

by Trevor Gross

Subject: Re: [PATCH 02/13] rust: error: move unsafe block into function call

On Tue, Jan 16, 2024 at 11:05 AM Valentin Obst <kernel@valentinobstde> wrote:
>
> The `from_err_ptr` function is safe. There is no need for the call to it
> to be inside the unsafe block.
>
> Signed-off-by: Valentin Obst <[email protected]>
> ---
> rust/kernel/error.rs | 7 +------
> 1 file changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
> index 4f0c1edd63b7..6f6676bc0eb9 100644
> --- a/rust/kernel/error.rs
> +++ b/rust/kernel/error.rs
> @@ -265,12 +265,7 @@ pub fn to_result(err: core::ffi::c_int) -> Result {
> /// index: u32,
> /// ) -> Result<*mut core::ffi::c_void> {
> /// // SAFETY: FFI call.
> -/// unsafe {
> -/// from_err_ptr(bindings::devm_platform_ioremap_resource(
> -/// pdev.to_ptr(),
> -/// index,
> -/// ))
> -/// }
> +/// from_err_ptr(unsafe { bindings::devm_platform_ioremap_resource(pdev.to_ptr(), index) })
> /// }
> /// ```
> // TODO: Remove `dead_code` marker once an in-kernel client is available.
> --
> 2.43.0
>
>

If you're up for it, that safety comment could also be improved. Something like

// SAFETY: `pdev` points to a valid platform device

But that is noncritical.

Reviewed-by: Trevor Gross <[email protected]>

2024-01-18 08:56:33

by Valentin Obst

Subject: Re: [PATCH 02/13] rust: error: move unsafe block into function call

> If you're up for it, that safety comment could also be improved.
> Something like
>
> // SAFETY: `pdev` points to a valid platform device

Thanks, will include something like that in a v2.

Just to make sure I got it correctly: Index is bounds checked [1] and
thus there is no need to include it in the comment. Please object if
that is wrong.

[1]: https://elixir.bootlin.com/linux/v6.7/source/drivers/base/platform.c#L63