Struct UserPtr

pub struct UserPtr<'a, T: Sized, R: Copy + Repr<T> = *const T> { /* private fields */ }

A pointer to readable userspace memory with a defined in-memory representation.

This exists primarily for use in defining safe ioctl/etc request types, to ensure that only valid addresses can be assigned to a field from safe Rust.

If a struct type used with an ioctl request has a field containing an address that the kernel only reads from then defining that field as a UserPtr ensures that it can only have a valid address assigned to it unless the caller uses the unsafe Self::from_ptr.

The in-memory representation of this type is guaranteed to match that of type parameter R, which defaults to being a pointer to T.

Implementations

impl<'a, T: Sized, R: Copy + Repr<T>> UserPtr<'a, T, R>

pub unsafe fn from_ptr(ptr: *const T) -> Self

Create a representation of the given pointer.

Safety

The pointer must remain valid for the lifetime of the result.

pub fn from_ref(r: &'a T) -> Self

Create a representation of a pointer referring to the same object as the given reference.

pub fn repr(&self) -> R

Get the in-memory representation of the pointer.