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Merged
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Nov 17, 2021
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Use generic associated types (GATs) to implement PointerWrapper. #556

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43 changes: 30 additions & 13 deletions drivers/android/process.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@ use kernel::{
pages::Pages,
prelude::*,
rbtree::RBTree,
sync::{GuardMut, Mutex, Ref, UniqueRef},
sync::{GuardMut, Mutex, Ref, RefBorrow, UniqueRef},
task::Task,
user_ptr::{UserSlicePtr, UserSlicePtrReader},
};
Expand Down Expand Up @@ -307,7 +307,7 @@ impl Process {
Either::Right(Registration::new(self, thread, &mut inner))
}

fn get_thread(self: &Ref<Self>, id: i32) -> Result<Ref<Thread>> {
fn get_thread(self: RefBorrow<'_, Self>, id: i32) -> Result<Ref<Thread>> {
// TODO: Consider using read/write locks here instead.
{
let inner = self.inner.lock();
Expand All @@ -317,7 +317,7 @@ impl Process {
}

// Allocate a new `Thread` without holding any locks.
let ta = Thread::new(id, self.clone())?;
let ta = Thread::new(id, self.into())?;
let node = RBTree::try_allocate_node(id, ta.clone())?;

let mut inner = self.inner.lock();
Expand All @@ -335,7 +335,11 @@ impl Process {
self.inner.lock().push_work(work)
}

fn set_as_manager(self: &Ref<Self>, info: Option<FlatBinderObject>, thread: &Thread) -> Result {
fn set_as_manager(
self: RefBorrow<'_, Self>,
info: Option<FlatBinderObject>,
thread: &Thread,
) -> Result {
let (ptr, cookie, flags) = if let Some(obj) = info {
(
// SAFETY: The object type for this ioctl is implicitly `BINDER_TYPE_BINDER`, so it
Expand All @@ -359,7 +363,7 @@ impl Process {
}

pub(crate) fn get_node(
self: &Ref<Self>,
self: RefBorrow<'_, Self>,
ptr: usize,
cookie: usize,
flags: u32,
Expand All @@ -375,7 +379,7 @@ impl Process {
}

// Allocate the node before reacquiring the lock.
let node = Ref::try_new(Node::new(ptr, cookie, flags, self.clone()))?;
let node = Ref::try_new(Node::new(ptr, cookie, flags, self.into()))?;
let rbnode = RBTree::try_allocate_node(ptr, node.clone())?;

let mut inner = self.inner.lock();
Expand Down Expand Up @@ -758,10 +762,10 @@ impl Process {
}

impl IoctlHandler for Process {
type Target = Ref<Process>;
type Target<'a> = RefBorrow<'a, Process>;

fn write(
this: &Ref<Process>,
this: RefBorrow<'_, Process>,
_file: &File,
cmd: u32,
reader: &mut UserSlicePtrReader,
Expand All @@ -779,7 +783,12 @@ impl IoctlHandler for Process {
Ok(0)
}

fn read_write(this: &Ref<Process>, file: &File, cmd: u32, data: UserSlicePtr) -> Result<i32> {
fn read_write(
this: RefBorrow<'_, Process>,
file: &File,
cmd: u32,
data: UserSlicePtr,
) -> Result<i32> {
let thread = this.get_thread(Task::current().pid())?;
match cmd {
bindings::BINDER_WRITE_READ => thread.write_read(data, file.is_blocking())?,
Expand Down Expand Up @@ -879,15 +888,23 @@ impl FileOperations for Process {
}
}

fn ioctl(this: &Ref<Process>, file: &File, cmd: &mut IoctlCommand) -> Result<i32> {
fn ioctl(this: RefBorrow<'_, Process>, file: &File, cmd: &mut IoctlCommand) -> Result<i32> {
cmd.dispatch::<Self>(this, file)
}

fn compat_ioctl(this: &Ref<Process>, file: &File, cmd: &mut IoctlCommand) -> Result<i32> {
fn compat_ioctl(
this: RefBorrow<'_, Process>,
file: &File,
cmd: &mut IoctlCommand,
) -> Result<i32> {
cmd.dispatch::<Self>(this, file)
}

fn mmap(this: &Ref<Process>, _file: &File, vma: &mut bindings::vm_area_struct) -> Result {
fn mmap(
this: RefBorrow<'_, Process>,
_file: &File,
vma: &mut bindings::vm_area_struct,
) -> Result {
// We don't allow mmap to be used in a different process.
if !Task::current().group_leader().eq(&this.task) {
return Err(Error::EINVAL);
Expand All @@ -908,7 +925,7 @@ impl FileOperations for Process {
this.create_mapping(vma)
}

fn poll(this: &Ref<Process>, file: &File, table: &PollTable) -> Result<u32> {
fn poll(this: RefBorrow<'_, Process>, file: &File, table: &PollTable) -> Result<u32> {
let thread = this.get_thread(Task::current().pid())?;
let (from_proc, mut mask) = thread.poll(file, table);
if mask == 0 && from_proc && !this.inner.lock().work.is_empty() {
Expand Down
8 changes: 7 additions & 1 deletion drivers/android/rust_binder.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,13 @@
//! TODO: This module is a work in progress.

#![no_std]
#![feature(global_asm, try_reserve, allocator_api, concat_idents)]
#![feature(
global_asm,
try_reserve,
allocator_api,
concat_idents,
generic_associated_types
)]

use kernel::{
io_buffer::IoBufferWriter,
Expand Down
10 changes: 7 additions & 3 deletions drivers/android/thread.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -395,9 +395,13 @@ impl Thread {
let ptr = unsafe { obj.__bindgen_anon_1.binder } as _;
let cookie = obj.cookie as _;
let flags = obj.flags as _;
let node = self
.process
.get_node(ptr, cookie, flags, strong, Some(self))?;
let node = self.process.as_ref_borrow().get_node(
ptr,
cookie,
flags,
strong,
Some(self),
)?;
security::binder_transfer_binder(&self.process.task, &view.alloc.process.task)?;
Ok(node)
})?;
Expand Down
56 changes: 30 additions & 26 deletions rust/kernel/file_operations.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,7 @@
//! C header: [`include/linux/fs.h`](../../../../include/linux/fs.h)

use core::convert::{TryFrom, TryInto};
use core::{marker, mem, ops::Deref, ptr};
use core::{marker, mem, ptr};

use alloc::boxed::Box;

Expand Down Expand Up @@ -122,7 +122,7 @@ unsafe extern "C" fn read_callback<T: FileOperations>(
let f = unsafe { T::Wrapper::borrow((*file).private_data) };
// No `FMODE_UNSIGNED_OFFSET` support, so `offset` must be in [0, 2^63).
// See discussion in https://github.com/fishinabarrel/linux-kernel-module-rust/pull/113
let read = T::read(&f, unsafe { &FileRef::from_ptr(file) }, &mut data, unsafe { *offset }.try_into()?)?;
let read = T::read(f, unsafe { &FileRef::from_ptr(file) }, &mut data, unsafe { *offset }.try_into()?)?;
unsafe { (*offset) += bindings::loff_t::try_from(read).unwrap() };
Ok(read as _)
}
Expand All @@ -141,7 +141,7 @@ unsafe extern "C" fn read_iter_callback<T: FileOperations>(
// callback, which the C API guarantees that will be called only when all references to
// `file` have been released, so we know it can't be called while this function is running.
let f = unsafe { T::Wrapper::borrow((*file).private_data) };
let read = T::read(&f, unsafe { &FileRef::from_ptr(file) }, &mut iter, offset.try_into()?)?;
let read = T::read(f, unsafe { &FileRef::from_ptr(file) }, &mut iter, offset.try_into()?)?;
unsafe { (*iocb).ki_pos += bindings::loff_t::try_from(read).unwrap() };
Ok(read as _)
}
Expand All @@ -162,7 +162,7 @@ unsafe extern "C" fn write_callback<T: FileOperations>(
let f = unsafe { T::Wrapper::borrow((*file).private_data) };
// No `FMODE_UNSIGNED_OFFSET` support, so `offset` must be in [0, 2^63).
// See discussion in https://github.com/fishinabarrel/linux-kernel-module-rust/pull/113
let written = T::write(&f, unsafe { &FileRef::from_ptr(file) }, &mut data, unsafe { *offset }.try_into()?)?;
let written = T::write(f, unsafe { &FileRef::from_ptr(file) }, &mut data, unsafe { *offset }.try_into()?)?;
unsafe { (*offset) += bindings::loff_t::try_from(written).unwrap() };
Ok(written as _)
}
Expand All @@ -181,7 +181,7 @@ unsafe extern "C" fn write_iter_callback<T: FileOperations>(
// callback, which the C API guarantees that will be called only when all references to
// `file` have been released, so we know it can't be called while this function is running.
let f = unsafe { T::Wrapper::borrow((*file).private_data) };
let written = T::write(&f, unsafe { &FileRef::from_ptr(file) }, &mut iter, offset.try_into()?)?;
let written = T::write(f, unsafe { &FileRef::from_ptr(file) }, &mut iter, offset.try_into()?)?;
unsafe { (*iocb).ki_pos += bindings::loff_t::try_from(written).unwrap() };
Ok(written as _)
}
Expand Down Expand Up @@ -215,7 +215,7 @@ unsafe extern "C" fn llseek_callback<T: FileOperations>(
// callback, which the C API guarantees that will be called only when all references to
// `file` have been released, so we know it can't be called while this function is running.
let f = unsafe { T::Wrapper::borrow((*file).private_data) };
let off = T::seek(&f, unsafe { &FileRef::from_ptr(file) }, off)?;
let off = T::seek(f, unsafe { &FileRef::from_ptr(file) }, off)?;
Ok(off as bindings::loff_t)
}
}
Expand All @@ -232,7 +232,7 @@ unsafe extern "C" fn unlocked_ioctl_callback<T: FileOperations>(
// `file` have been released, so we know it can't be called while this function is running.
let f = unsafe { T::Wrapper::borrow((*file).private_data) };
let mut cmd = IoctlCommand::new(cmd as _, arg as _);
let ret = T::ioctl(&f, unsafe { &FileRef::from_ptr(file) }, &mut cmd)?;
let ret = T::ioctl(f, unsafe { &FileRef::from_ptr(file) }, &mut cmd)?;
Ok(ret as _)
}
}
Expand All @@ -249,7 +249,7 @@ unsafe extern "C" fn compat_ioctl_callback<T: FileOperations>(
// `file` have been released, so we know it can't be called while this function is running.
let f = unsafe { T::Wrapper::borrow((*file).private_data) };
let mut cmd = IoctlCommand::new(cmd as _, arg as _);
let ret = T::compat_ioctl(&f, unsafe { &FileRef::from_ptr(file) }, &mut cmd)?;
let ret = T::compat_ioctl(f, unsafe { &FileRef::from_ptr(file) }, &mut cmd)?;
Ok(ret as _)
}
}
Expand All @@ -264,7 +264,7 @@ unsafe extern "C" fn mmap_callback<T: FileOperations>(
// callback, which the C API guarantees that will be called only when all references to
// `file` have been released, so we know it can't be called while this function is running.
let f = unsafe { T::Wrapper::borrow((*file).private_data) };
T::mmap(&f, unsafe { &FileRef::from_ptr(file) }, unsafe { &mut *vma })?;
T::mmap(f, unsafe { &FileRef::from_ptr(file) }, unsafe { &mut *vma })?;
Ok(0)
}
}
Expand All @@ -284,7 +284,7 @@ unsafe extern "C" fn fsync_callback<T: FileOperations>(
// callback, which the C API guarantees that will be called only when all references to
// `file` have been released, so we know it can't be called while this function is running.
let f = unsafe { T::Wrapper::borrow((*file).private_data) };
let res = T::fsync(&f, unsafe { &FileRef::from_ptr(file) }, start, end, datasync)?;
let res = T::fsync(f, unsafe { &FileRef::from_ptr(file) }, start, end, datasync)?;
Ok(res.try_into().unwrap())
}
}
Expand All @@ -298,7 +298,7 @@ unsafe extern "C" fn poll_callback<T: FileOperations>(
// callback, which the C API guarantees that will be called only when all references to `file`
// have been released, so we know it can't be called while this function is running.
let f = unsafe { T::Wrapper::borrow((*file).private_data) };
match T::poll(&f, unsafe { &FileRef::from_ptr(file) }, unsafe {
match T::poll(f, unsafe { &FileRef::from_ptr(file) }, unsafe {
&PollTable::from_ptr(wait)
}) {
Ok(v) => v,
Expand Down Expand Up @@ -463,17 +463,17 @@ macro_rules! declare_file_operations {
/// For each macro, there is a handler function that takes the appropriate types as arguments.
pub trait IoctlHandler: Sync {
/// The type of the first argument to each associated function.
type Target;
type Target<'a>;

/// Handles ioctls defined with the `_IO` macro, that is, with no buffer as argument.
fn pure(_this: &Self::Target, _file: &File, _cmd: u32, _arg: usize) -> Result<i32> {
fn pure(_this: Self::Target<'_>, _file: &File, _cmd: u32, _arg: usize) -> Result<i32> {
Err(Error::EINVAL)
}

/// Handles ioctls defined with the `_IOR` macro, that is, with an output buffer provided as
/// argument.
fn read(
_this: &Self::Target,
_this: Self::Target<'_>,
_file: &File,
_cmd: u32,
_writer: &mut UserSlicePtrWriter,
Expand All @@ -484,7 +484,7 @@ pub trait IoctlHandler: Sync {
/// Handles ioctls defined with the `_IOW` macro, that is, with an input buffer provided as
/// argument.
fn write(
_this: &Self::Target,
_this: Self::Target<'_>,
_file: &File,
_cmd: u32,
_reader: &mut UserSlicePtrReader,
Expand All @@ -495,7 +495,7 @@ pub trait IoctlHandler: Sync {
/// Handles ioctls defined with the `_IOWR` macro, that is, with a buffer for both input and
/// output provided as argument.
fn read_write(
_this: &Self::Target,
_this: Self::Target<'_>,
_file: &File,
_cmd: u32,
_data: UserSlicePtr,
Expand Down Expand Up @@ -535,7 +535,11 @@ impl IoctlCommand {
///
/// It is meant to be used in implementations of [`FileOperations::ioctl`] and
/// [`FileOperations::compat_ioctl`].
pub fn dispatch<T: IoctlHandler>(&mut self, handler: &T::Target, file: &File) -> Result<i32> {
pub fn dispatch<T: IoctlHandler>(
&mut self,
handler: T::Target<'_>,
file: &File,
) -> Result<i32> {
let dir = (self.cmd >> bindings::_IOC_DIRSHIFT) & bindings::_IOC_DIRMASK;
if dir == bindings::_IOC_NONE {
return T::pure(handler, file, self.cmd, self.arg);
Expand Down Expand Up @@ -604,7 +608,7 @@ impl<T: FileOperations<Wrapper = Box<T>> + Default> FileOpener<()> for T {
/// File descriptors may be used from multiple threads/processes concurrently, so your type must be
/// [`Sync`]. It must also be [`Send`] because [`FileOperations::release`] will be called from the
/// thread that decrements that associated file's refcount to zero.
pub trait FileOperations: Send + Sync + Sized {
pub trait FileOperations: Send + Sync + Sized + 'static {
/// The methods to use to populate [`struct file_operations`].
const TO_USE: ToUse;

Expand All @@ -623,7 +627,7 @@ pub trait FileOperations: Send + Sync + Sized {
///
/// Corresponds to the `read` and `read_iter` function pointers in `struct file_operations`.
fn read(
_this: &<<Self::Wrapper as PointerWrapper>::Borrowed as Deref>::Target,
_this: <Self::Wrapper as PointerWrapper>::Borrowed<'_>,
_file: &File,
_data: &mut impl IoBufferWriter,
_offset: u64,
Expand All @@ -635,7 +639,7 @@ pub trait FileOperations: Send + Sync + Sized {
///
/// Corresponds to the `write` and `write_iter` function pointers in `struct file_operations`.
fn write(
_this: &<<Self::Wrapper as PointerWrapper>::Borrowed as Deref>::Target,
_this: <Self::Wrapper as PointerWrapper>::Borrowed<'_>,
_file: &File,
_data: &mut impl IoBufferReader,
_offset: u64,
Expand All @@ -647,7 +651,7 @@ pub trait FileOperations: Send + Sync + Sized {
///
/// Corresponds to the `llseek` function pointer in `struct file_operations`.
fn seek(
_this: &<<Self::Wrapper as PointerWrapper>::Borrowed as Deref>::Target,
_this: <Self::Wrapper as PointerWrapper>::Borrowed<'_>,
_file: &File,
_offset: SeekFrom,
) -> Result<u64> {
Expand All @@ -658,7 +662,7 @@ pub trait FileOperations: Send + Sync + Sized {
///
/// Corresponds to the `unlocked_ioctl` function pointer in `struct file_operations`.
fn ioctl(
_this: &<<Self::Wrapper as PointerWrapper>::Borrowed as Deref>::Target,
_this: <Self::Wrapper as PointerWrapper>::Borrowed<'_>,
_file: &File,
_cmd: &mut IoctlCommand,
) -> Result<i32> {
Expand All @@ -669,7 +673,7 @@ pub trait FileOperations: Send + Sync + Sized {
///
/// Corresponds to the `compat_ioctl` function pointer in `struct file_operations`.
fn compat_ioctl(
_this: &<<Self::Wrapper as PointerWrapper>::Borrowed as Deref>::Target,
_this: <Self::Wrapper as PointerWrapper>::Borrowed<'_>,
_file: &File,
_cmd: &mut IoctlCommand,
) -> Result<i32> {
Expand All @@ -680,7 +684,7 @@ pub trait FileOperations: Send + Sync + Sized {
///
/// Corresponds to the `fsync` function pointer in `struct file_operations`.
fn fsync(
_this: &<<Self::Wrapper as PointerWrapper>::Borrowed as Deref>::Target,
_this: <Self::Wrapper as PointerWrapper>::Borrowed<'_>,
_file: &File,
_start: u64,
_end: u64,
Expand All @@ -694,7 +698,7 @@ pub trait FileOperations: Send + Sync + Sized {
/// Corresponds to the `mmap` function pointer in `struct file_operations`.
/// TODO: wrap `vm_area_struct` so that we don't have to expose it.
fn mmap(
_this: &<<Self::Wrapper as PointerWrapper>::Borrowed as Deref>::Target,
_this: <Self::Wrapper as PointerWrapper>::Borrowed<'_>,
_file: &File,
_vma: &mut bindings::vm_area_struct,
) -> Result {
Expand All @@ -706,7 +710,7 @@ pub trait FileOperations: Send + Sync + Sized {
///
/// Corresponds to the `poll` function pointer in `struct file_operations`.
fn poll(
_this: &<<Self::Wrapper as PointerWrapper>::Borrowed as Deref>::Target,
_this: <Self::Wrapper as PointerWrapper>::Borrowed<'_>,
_file: &File,
_table: &PollTable,
) -> Result<u32> {
Expand Down
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