1 files changed, 63 insertions, 2 deletions

diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs
index 6373fe183b27..d698cddcb4a5 100644
--- a/rust/kernel/miscdevice.rs
+++ b/rust/kernel/miscdevice.rs
@@ -13,7 +13,8 @@ use crate::{
     device::Device,
     error::{to_result, Error, Result, VTABLE_DEFAULT_ERROR},
     ffi::{c_int, c_long, c_uint, c_ulong},
-    fs::File,
+    fs::{File, Kiocb},
+    iov::{IovIterDest, IovIterSource},
     mm::virt::VmaNew,
     prelude::*,
     seq_file::SeqFile,
@@ -34,7 +35,7 @@ impl MiscDeviceOptions {
         // SAFETY: All zeros is valid for this C type.
         let mut result: bindings::miscdevice = unsafe { MaybeUninit::zeroed().assume_init() };
         result.minor = bindings::MISC_DYNAMIC_MINOR as ffi::c_int;
-        result.name = self.name.as_char_ptr();
+        result.name = crate::str::as_char_ptr_in_const_context(self.name);
         result.fops = MiscdeviceVTable::<T>::build();
         result
     }
@@ -141,6 +142,16 @@ pub trait MiscDevice: Sized {
         build_error!(VTABLE_DEFAULT_ERROR)
     }
 
+    /// Read from this miscdevice.
+    fn read_iter(_kiocb: Kiocb<'_, Self::Ptr>, _iov: &mut IovIterDest<'_>) -> Result<usize> {
+        build_error!(VTABLE_DEFAULT_ERROR)
+    }
+
+    /// Write to this miscdevice.
+    fn write_iter(_kiocb: Kiocb<'_, Self::Ptr>, _iov: &mut IovIterSource<'_>) -> Result<usize> {
+        build_error!(VTABLE_DEFAULT_ERROR)
+    }
+
     /// Handler for ioctls.
     ///
     /// The `cmd` argument is usually manipulated using the utilities in [`kernel::ioctl`].
@@ -247,6 +258,46 @@ impl<T: MiscDevice> MiscdeviceVTable<T> {
 
     /// # Safety
     ///
+    /// `kiocb` must be correspond to a valid file that is associated with a
+    /// `MiscDeviceRegistration<T>`. `iter` must be a valid `struct iov_iter` for writing.
+    unsafe extern "C" fn read_iter(
+        kiocb: *mut bindings::kiocb,
+        iter: *mut bindings::iov_iter,
+    ) -> isize {
+        // SAFETY: The caller provides a valid `struct kiocb` associated with a
+        // `MiscDeviceRegistration<T>` file.
+        let kiocb = unsafe { Kiocb::from_raw(kiocb) };
+        // SAFETY: This is a valid `struct iov_iter` for writing.
+        let iov = unsafe { IovIterDest::from_raw(iter) };
+
+        match T::read_iter(kiocb, iov) {
+            Ok(res) => res as isize,
+            Err(err) => err.to_errno() as isize,
+        }
+    }
+
+    /// # Safety
+    ///
+    /// `kiocb` must be correspond to a valid file that is associated with a
+    /// `MiscDeviceRegistration<T>`. `iter` must be a valid `struct iov_iter` for writing.
+    unsafe extern "C" fn write_iter(
+        kiocb: *mut bindings::kiocb,
+        iter: *mut bindings::iov_iter,
+    ) -> isize {
+        // SAFETY: The caller provides a valid `struct kiocb` associated with a
+        // `MiscDeviceRegistration<T>` file.
+        let kiocb = unsafe { Kiocb::from_raw(kiocb) };
+        // SAFETY: This is a valid `struct iov_iter` for reading.
+        let iov = unsafe { IovIterSource::from_raw(iter) };
+
+        match T::write_iter(kiocb, iov) {
+            Ok(res) => res as isize,
+            Err(err) => err.to_errno() as isize,
+        }
+    }
+
+    /// # Safety
+    ///
     /// `file` must be a valid file that is associated with a `MiscDeviceRegistration<T>`.
     /// `vma` must be a vma that is currently being mmap'ed with this file.
     unsafe extern "C" fn mmap(
@@ -341,6 +392,16 @@ impl<T: MiscDevice> MiscdeviceVTable<T> {
         open: Some(Self::open),
         release: Some(Self::release),
         mmap: if T::HAS_MMAP { Some(Self::mmap) } else { None },
+        read_iter: if T::HAS_READ_ITER {
+            Some(Self::read_iter)
+        } else {
+            None
+        },
+        write_iter: if T::HAS_WRITE_ITER {
+            Some(Self::write_iter)
+        } else {
+            None
+        },
         unlocked_ioctl: if T::HAS_IOCTL {
             Some(Self::ioctl)
         } else {