linux-kernel - [PATCH v3 02/12] rust: error: improve unsafe code in example

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240131-doc-fixes-v3-v3-2-0c8af94ed7de@valentinobst.de>
Date: Wed, 31 Jan 2024 21:23:24 +0100
From: Valentin Obst via B4 Relay <devnull+kernel.valentinobst.de@...nel.org>
To: Miguel Ojeda <ojeda@...nel.org>, Alex Gaynor <alex.gaynor@...il.com>, 
 Wedson Almeida Filho <wedsonaf@...il.com>, 
 Boqun Feng <boqun.feng@...il.com>, Gary Guo <gary@...yguo.net>, 
 Björn Roy Baron <bjorn3_gh@...tonmail.com>, 
 Benno Lossin <benno.lossin@...ton.me>, 
 Andreas Hindborg <a.hindborg@...sung.com>, 
 Alice Ryhl <aliceryhl@...gle.com>
Cc: rust-for-linux@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Valentin Obst <kernel@...entinobst.de>, 
 Martin Rodriguez Reboredo <yakoyoku@...il.com>
Subject: [PATCH v3 02/12] rust: error: improve unsafe code in example

From: Valentin Obst <kernel@...entinobst.de>

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

Reword the SAFETY comment to provide a better justification of why the
FFI call is safe.

Signed-off-by: Valentin Obst <kernel@...entinobst.de>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@...il.com>
Reviewed-by: Alice Ryhl <aliceryhl@...gle.com>
---
 rust/kernel/error.rs | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 4f0c1edd63b7..4786d3ee1e92 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -264,13 +264,9 @@ pub fn to_result(err: core::ffi::c_int) -> Result {
 ///     pdev: &mut PlatformDevice,
 ///     index: u32,
 /// ) -> Result<*mut core::ffi::c_void> {
-///     // SAFETY: FFI call.
-///     unsafe {
-///         from_err_ptr(bindings::devm_platform_ioremap_resource(
-///             pdev.to_ptr(),
-///             index,
-///         ))
-///     }
+///     // SAFETY: `pdev` points to a valid platform device. There are no safety requirements
+///     // on `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