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References: <20240116160141.165951-1-kernel@valentinobst.de> <20240116160141.165951-3-kernel@valentinobst.de>
In-Reply-To: <20240116160141.165951-3-kernel@valentinobst.de>
From: Trevor Gross <tmgross@umich.edu>
Date: Wed, 17 Jan 2024 19:31:24 -0500
Message-ID: <CALNs47vgfs+cFhYsTZU_RE5WxFZ4euMAhuKESJE6m7PFy0JTzQ@mail.gmail.com>
Subject: Re: [PATCH 02/13] rust: error: move unsafe block into function call
To: Valentin Obst <kernel@valentinobst.de>
Cc: Miguel Ojeda <ojeda@kernel.org>, Alex Gaynor <alex.gaynor@gmail.com>, 
	Wedson Almeida Filho <wedsonaf@gmail.com>, Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>, 
	=?UTF-8?Q?Bj=C3=B6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>, 
	Benno Lossin <benno.lossin@proton.me>, Andreas Hindborg <a.hindborg@samsung.com>, 
	Alice Ryhl <aliceryhl@google.com>, rust-for-linux@vger.kernel.org, 
	linux-kernel@vger.kernel.org
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On Tue, Jan 16, 2024 at 11:05=E2=80=AFAM Valentin Obst <kernel@valentinobst=
de> 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 <kernel@valentinobst.de>
> ---
>  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(p=
dev.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 <tmgross@umich.edu>