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[v9,3/6] rust: enable `clippy::as_ptr_cast_mut` lint

Message ID 20250416-ptr-as-ptr-v9-3-18ec29b1b1f3@gmail.com
State Superseded
Headers show
Series rust: reduce `as` casts, enable related lints | expand

Commit Message

Tamir Duberstein April 16, 2025, 5:36 p.m. UTC
In Rust 1.66.0, Clippy introduced the `as_ptr_cast_mut` lint [1]:

> Since `as_ptr` takes a `&self`, the pointer won’t have write
> permissions unless interior mutability is used, making it unlikely
> that having it as a mutable pointer is correct.

There is only one affected callsite, and the change amounts to replacing
`as _` with `.cast_mut().cast()`. This doesn't change the semantics, but
is more descriptive of what's going on.

Apply this change and enable the lint -- no functional change intended.

Link: https://rust-lang.github.io/rust-clippy/master/index.html#as_ptr_cast_mut [1]
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
---
 Makefile              | 1 +
 rust/kernel/devres.rs | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

Comments

Boqun Feng April 17, 2025, 5:13 p.m. UTC | #1
On Wed, Apr 16, 2025 at 01:36:07PM -0400, Tamir Duberstein wrote:
> In Rust 1.66.0, Clippy introduced the `as_ptr_cast_mut` lint [1]:
> 
> > Since `as_ptr` takes a `&self`, the pointer won’t have write
> > permissions unless interior mutability is used, making it unlikely
> > that having it as a mutable pointer is correct.
> 
> There is only one affected callsite, and the change amounts to replacing
> `as _` with `.cast_mut().cast()`. This doesn't change the semantics, but
> is more descriptive of what's going on.
> 
> Apply this change and enable the lint -- no functional change intended.
> 
> Link: https://rust-lang.github.io/rust-clippy/master/index.html#as_ptr_cast_mut [1]
> Reviewed-by: Benno Lossin <benno.lossin@proton.me>
> Signed-off-by: Tamir Duberstein <tamird@gmail.com>

Reviewed-by: Boqun Feng <boqun.feng@gmail.com>

Regards,
Boqun

> ---
>  Makefile              | 1 +
>  rust/kernel/devres.rs | 2 +-
>  2 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/Makefile b/Makefile
> index 7b85b2a8d371..04a5246171f9 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -474,6 +474,7 @@ export rust_common_flags := --edition=2021 \
>  			    -Wrust_2018_idioms \
>  			    -Wunreachable_pub \
>  			    -Wclippy::all \
> +			    -Wclippy::as_ptr_cast_mut \
>  			    -Wclippy::ignored_unit_patterns \
>  			    -Wclippy::mut_mut \
>  			    -Wclippy::needless_bitwise_bool \
> diff --git a/rust/kernel/devres.rs b/rust/kernel/devres.rs
> index 9e649d70716a..f7e8f5f53622 100644
> --- a/rust/kernel/devres.rs
> +++ b/rust/kernel/devres.rs
> @@ -143,7 +143,7 @@ fn remove_action(this: &Arc<Self>) {
>              bindings::devm_remove_action_nowarn(
>                  this.dev.as_raw(),
>                  Some(this.callback),
> -                this.as_ptr() as _,
> +                this.as_ptr().cast_mut().cast(),
>              )
>          };
>  
> 
> -- 
> 2.49.0
>
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index 7b85b2a8d371..04a5246171f9 100644
--- a/Makefile
+++ b/Makefile
@@ -474,6 +474,7 @@  export rust_common_flags := --edition=2021 \
 			    -Wrust_2018_idioms \
 			    -Wunreachable_pub \
 			    -Wclippy::all \
+			    -Wclippy::as_ptr_cast_mut \
 			    -Wclippy::ignored_unit_patterns \
 			    -Wclippy::mut_mut \
 			    -Wclippy::needless_bitwise_bool \
diff --git a/rust/kernel/devres.rs b/rust/kernel/devres.rs
index 9e649d70716a..f7e8f5f53622 100644
--- a/rust/kernel/devres.rs
+++ b/rust/kernel/devres.rs
@@ -143,7 +143,7 @@  fn remove_action(this: &Arc<Self>) {
             bindings::devm_remove_action_nowarn(
                 this.dev.as_raw(),
                 Some(this.callback),
-                this.as_ptr() as _,
+                this.as_ptr().cast_mut().cast(),
             )
         };