diff options
Diffstat (limited to 'rust/kernel/alloc/kbox.rs')
| -rw-r--r-- | rust/kernel/alloc/kbox.rs | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/rust/kernel/alloc/kbox.rs b/rust/kernel/alloc/kbox.rs index 9da4a32e60bc..14eb9c546683 100644 --- a/rust/kernel/alloc/kbox.rs +++ b/rust/kernel/alloc/kbox.rs @@ -15,8 +15,9 @@ use core::pin::Pin; use core::ptr::NonNull; use core::result::Result; -use crate::init::{InPlaceInit, InPlaceWrite, Init, PinInit}; +use crate::init::InPlaceInit; use crate::types::ForeignOwnable; +use pin_init::{InPlaceWrite, Init, PinInit, ZeroableOption}; /// The kernel's [`Box`] type -- a heap allocation for a single value of type `T`. /// @@ -99,6 +100,12 @@ pub type VBox<T> = Box<T, super::allocator::Vmalloc>; /// ``` pub type KVBox<T> = Box<T, super::allocator::KVmalloc>; +// SAFETY: All zeros is equivalent to `None` (option layout optimization guarantee). +// +// In this case we are allowed to use `T: ?Sized`, since all zeros is the `None` variant and there +// is no problem with a VTABLE pointer being null. +unsafe impl<T: ?Sized, A: Allocator> ZeroableOption for Box<T, A> {} + // SAFETY: `Box` is `Send` if `T` is `Send` because the `Box` owns a `T`. unsafe impl<T, A> Send for Box<T, A> where |