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| author | Danilo Krummrich <dakr@kernel.org> | 2026-05-05 17:23:07 +0200 |
|---|---|---|
| committer | Danilo Krummrich <dakr@kernel.org> | 2026-05-11 15:26:12 +0200 |
| commit | abb21500e7e5dcf2d1b1a4a02b2ee77b3d5061b6 (patch) | |
| tree | 45ae516218ee82565cbae488336e627efd009459 /rust | |
| parent | 254f49634ee16a731174d2ae34bc50bd5f45e731 (diff) | |
| download | linux-next-history-abb21500e7e5dcf2d1b1a4a02b2ee77b3d5061b6.tar.gz | |
rust: alloc: add Box::zeroed()
Add Box::zeroed() for T: Zeroable types.
This allocates with __GFP_ZERO directly, letting the underlying
allocator deal with zeroing out the memory compared to
Box::new(T::zeroed(), flags).
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260505152400.3905096-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Diffstat (limited to 'rust')
| -rw-r--r-- | rust/kernel/alloc/kbox.rs | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/rust/kernel/alloc/kbox.rs b/rust/kernel/alloc/kbox.rs index bd6da02c7ab8f..c824ed6e15233 100644 --- a/rust/kernel/alloc/kbox.rs +++ b/rust/kernel/alloc/kbox.rs @@ -19,6 +19,7 @@ use crate::ffi::c_void; use crate::fmt; use crate::init::InPlaceInit; use crate::page::AsPageIter; +use crate::prelude::*; use crate::types::ForeignOwnable; use pin_init::{InPlaceWrite, Init, PinInit, ZeroableOption}; @@ -256,6 +257,27 @@ where Ok(Box(ptr.cast(), PhantomData)) } + /// Creates a new zero-initialized `Box<T, A>`. + /// + /// New memory is allocated with `A` and the [`__GFP_ZERO`] flag. The allocation may fail, in + /// which case an error is returned. For ZSTs no memory is allocated. + /// + /// # Examples + /// + /// ``` + /// let b = KBox::<[u8; 128]>::zeroed(GFP_KERNEL)?; + /// assert_eq!(*b, [0; 128]); + /// # Ok::<(), Error>(()) + /// ``` + pub fn zeroed(flags: Flags) -> Result<Self, AllocError> + where + T: Zeroable, + { + // SAFETY: `__GFP_ZERO` guarantees the memory is zeroed; `T: Zeroable` guarantees that + // all-zeroes is a valid bit pattern for `T`. + Ok(unsafe { Self::new_uninit(flags | __GFP_ZERO)?.assume_init() }) + } + /// Constructs a new `Pin<Box<T, A>>`. If `T` does not implement [`Unpin`], then `x` will be /// pinned in memory and can't be moved. #[inline] |