[PATCH v2] rust: miscdevice: use `pin_init::zeroed()` for C type initialization

[PATCH v2] rust: miscdevice: use `pin_init::zeroed()` for C type initialization

[Atharv Dubey]

Replace manual zero-initialization using
`MaybeUninit::zeroed().assume_init()` with `pin_init::zeroed()`.
The `pin_init` helper provides a safer and clearer API for
zero-initializing C structs without requiring an `unsafe` block.

Link: https://github.com/Rust-for-Linux/linux/issues/1189
Signed-off-by: Atharv Dubey <atharvd440@gmail.com>
---
Changes in v2:
  - Remove the Unwanted Comments.

 rust/kernel/miscdevice.rs | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs
index d698cddcb4a5..ba64c8a858f0 100644
--- a/rust/kernel/miscdevice.rs
+++ b/rust/kernel/miscdevice.rs
@@ -20,7 +20,7 @@
     seq_file::SeqFile,
     types::{ForeignOwnable, Opaque},
 };
-use core::{marker::PhantomData, mem::MaybeUninit, pin::Pin};
+use core::{marker::PhantomData, pin::Pin};
 
 /// Options for creating a misc device.
 #[derive(Copy, Clone)]
@@ -32,8 +32,7 @@ pub struct MiscDeviceOptions {
 impl MiscDeviceOptions {
     /// Create a raw `struct miscdev` ready for registration.
     pub const fn into_raw<T: MiscDevice>(self) -> bindings::miscdevice {
-        // SAFETY: All zeros is valid for this C type.
-        let mut result: bindings::miscdevice = unsafe { MaybeUninit::zeroed().assume_init() };
+        let mut result: bindings::miscdevice = pin_init::zeroed();
         result.minor = bindings::MISC_DYNAMIC_MINOR as ffi::c_int;
         result.name = crate::str::as_char_ptr_in_const_context(self.name);
         result.fops = MiscdeviceVTable::<T>::build();
@@ -420,8 +419,7 @@ impl<T: MiscDevice> MiscdeviceVTable<T> {
         } else {
             None
         },
-        // SAFETY: All zeros is a valid value for `bindings::file_operations`.
-        ..unsafe { MaybeUninit::zeroed().assume_init() }
+        ..pin_init::zeroed()
     };
 
     const fn build() -> &'static bindings::file_operations {
-- 
2.43.0

Re: [PATCH v2] rust: miscdevice: use `pin_init::zeroed()` for C type initialization

[Alexandre Courbot]

On Sat Nov 29, 2025 at 9:15 PM JST, Atharv Dubey wrote:
> Replace manual zero-initialization using
> `MaybeUninit::zeroed().assume_init()` with `pin_init::zeroed()`.
> The `pin_init` helper provides a safer and clearer API for
> zero-initializing C structs without requiring an `unsafe` block.
>
> Link: https://github.com/Rust-for-Linux/linux/issues/1189
> Signed-off-by: Atharv Dubey <atharvd440@gmail.com>

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>