[PATCH v2 02/12] rust: error: improve unsafe code in example

Valentin Obst
2024-01-23T15:06:46Z

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@valentinobst.de>
---
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