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[2003:df:bf22:3c00:bd7d:4644:53b7:3323]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-64750a90caasm6159605a12.11.2025.11.28.22.46.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 28 Nov 2025 22:46:43 -0800 (PST) Message-ID: <071c5fcf-bd7d-40da-ad7c-c0edbe780671@gmail.com> Date: Sat, 29 Nov 2025 07:46:40 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] rust: miscdevice: use `pin_init::zeroed()` for C type initialization To: Atharv Dubey , arnd@arndb.de, gregkh@linuxfoundation.org Cc: ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, lossin@kernel.org, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu, dakr@kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org References: <20251128162337.12082-1-atharvd440@gmail.com> Content-Language: de-AT-frami From: Dirk Behme In-Reply-To: <20251128162337.12082-1-atharvd440@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 28.11.25 17:23, 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 > --- > rust/kernel/miscdevice.rs | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs > index d698cddcb4a5..e168e9da8f4a 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)] > @@ -33,7 +33,7 @@ impl MiscDeviceOptions { > /// Create a raw `struct miscdev` ready for registration. > pub const fn into_raw(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(); While getting rid of the `unsafe`what's about dropping the `SAFETY` comment as well? As done by Benno in [1]? Cheers Dirk [1] https://lore.kernel.org/all/20250814093046.2071971-4-lossin@kernel.org/ > 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::::build(); > @@ -421,7 +421,7 @@ impl MiscdeviceVTable { > 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 {