@@ -36,6 +36,18 @@ config ANDROID_BINDERFS
It can be used to dynamically allocate new binder IPC devices via
ioctls.
+config ANDROID_BINDERFS_RUST
+ bool "Android Binderfs filesystem in Rust"
+ depends on ANDROID_BINDER_IPC_RUST
+ default n
+ help
+ Binderfs is a pseudo-filesystem for the Android Binder IPC driver
+ which can be mounted per-ipc namespace allowing to run multiple
+ instances of Android.
+ Each binderfs mount initially only contains a binder-control device.
+ It can be used to dynamically allocate new binder IPC devices via
+ ioctls.
+
config ANDROID_BINDER_DEVICES
string "Android Binder devices"
depends on ANDROID_BINDER_IPC
@@ -48,6 +60,18 @@ config ANDROID_BINDER_DEVICES
created. Each binder device has its own context manager, and is
therefore logically separated from the other devices.
+config ANDROID_BINDER_DEVICES_RUST
+ string "Android Binder devices in Rust"
+ depends on ANDROID_BINDER_IPC_RUST
+ default "binder,hwbinder,vndbinder"
+ help
+ Default value for the binder.devices parameter.
+
+ The binder.devices parameter is a comma-separated list of strings
+ that specifies the names of the binder device nodes that will be
+ created. Each binder device has its own context manager, and is
+ therefore logically separated from the other devices.
+
config ANDROID_BINDER_IPC_SELFTEST
bool "Android Binder IPC Driver Selftest"
depends on ANDROID_BINDER_IPC
@@ -5,3 +5,4 @@ obj-$(CONFIG_ANDROID_BINDERFS) += binderfs.o
obj-$(CONFIG_ANDROID_BINDER_IPC) += binder.o binder_alloc.o
obj-$(CONFIG_ANDROID_BINDER_IPC_SELFTEST) += binder_alloc_selftest.o
obj-$(CONFIG_ANDROID_BINDER_IPC_RUST) += rust_binder.o
+obj-$(CONFIG_ANDROID_BINDERFS_RUST) += rust_binderfs.o
new file mode 100644
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{
+ list::{HasListLinks, List, ListArc, ListArcSafe, ListItem, ListLinks},
+ prelude::*,
+ str::{CStr, CString},
+ sync::{Arc, Mutex},
+};
+
+use crate::process::Process;
+
+// This module defines the global variable containing the list of contexts. Since the
+// `kernel::sync` bindings currently don't support mutexes in globals, we use a temporary
+// workaround.
+//
+// TODO: Once `kernel::sync` has support for mutexes in globals, remove this module.
+mod context_global {
+ use super::ContextList;
+ use core::cell::UnsafeCell;
+ use core::mem::MaybeUninit;
+ use kernel::init::PinInit;
+ use kernel::list::List;
+ use kernel::sync::lock::mutex::{Mutex, MutexBackend};
+ use kernel::sync::lock::Guard;
+
+ /// A temporary wrapper used to define a mutex in a global.
+ pub(crate) struct Contexts {
+ inner: UnsafeCell<MaybeUninit<Mutex<ContextList>>>,
+ }
+
+ impl Contexts {
+ /// Called when the module is initialized.
+ pub(crate) fn init(&self) {
+ // SAFETY: This is only called during initialization of the binder module, so we know
+ // that the global is currently uninitialized and that nobody else is using it yet.
+ unsafe {
+ let ptr = self.inner.get() as *mut Mutex<ContextList>;
+ let init = kernel::new_mutex!(ContextList { list: List::new() }, "ContextList");
+ match init.__pinned_init(ptr) {
+ Ok(()) => {}
+ Err(e) => match e {},
+ }
+ }
+ }
+
+ pub(crate) fn lock(&self) -> Guard<'_, ContextList, MutexBackend> {
+ // SAFETY: The `init` method is called during initialization of the binder module, so the
+ // mutex is always initialized when this method is called.
+ unsafe {
+ let ptr = self.inner.get() as *const Mutex<ContextList>;
+ (*ptr).lock()
+ }
+ }
+ }
+
+ unsafe impl Send for Contexts {}
+ unsafe impl Sync for Contexts {}
+
+ pub(crate) static CONTEXTS: Contexts = Contexts {
+ inner: UnsafeCell::new(MaybeUninit::uninit()),
+ };
+}
+
+pub(crate) use self::context_global::CONTEXTS;
+
+pub(crate) struct ContextList {
+ list: List<Context>,
+}
+
+/// This struct keeps track of the processes using this context, and which process is the context
+/// manager.
+struct Manager {
+ all_procs: List<Process>,
+}
+
+/// There is one context per binder file (/dev/binder, /dev/hwbinder, etc)
+#[pin_data]
+pub(crate) struct Context {
+ #[pin]
+ manager: Mutex<Manager>,
+ pub(crate) name: CString,
+ #[pin]
+ links: ListLinks,
+}
+
+kernel::list::impl_has_list_links! {
+ impl HasListLinks<0> for Context { self.links }
+}
+kernel::list::impl_list_arc_safe! {
+ impl ListArcSafe<0> for Context { untracked; }
+}
+kernel::list::impl_list_item! {
+ impl ListItem<0> for Context {
+ using ListLinks;
+ }
+}
+
+impl Context {
+ pub(crate) fn new(name: &CStr) -> Result<Arc<Self>> {
+ let name = CString::try_from(name)?;
+ let list_ctx = ListArc::pin_init(pin_init!(Context {
+ name,
+ links <- ListLinks::new(),
+ manager <- kernel::new_mutex!(Manager {
+ all_procs: List::new(),
+ }, "Context::manager"),
+ }))?;
+
+ let ctx = list_ctx.clone_arc();
+ CONTEXTS.lock().list.push_back(list_ctx);
+
+ Ok(ctx)
+ }
+
+ /// Called when the file for this context is unlinked.
+ ///
+ /// No-op if called twice.
+ pub(crate) fn deregister(&self) {
+ // SAFETY: We never add the context to any other linked list than this one, so it is either
+ // in this list, or not in any list.
+ unsafe {
+ CONTEXTS.lock().list.remove(self);
+ }
+ }
+
+ pub(crate) fn register_process(self: &Arc<Self>, proc: ListArc<Process>) {
+ if !Arc::ptr_eq(self, &proc.ctx) {
+ pr_err!("Context::register_process called on the wrong context.");
+ return;
+ }
+ self.manager.lock().all_procs.push_back(proc);
+ }
+
+ pub(crate) fn deregister_process(self: &Arc<Self>, proc: &Process) {
+ if !Arc::ptr_eq(self, &proc.ctx) {
+ pr_err!("Context::deregister_process called on the wrong context.");
+ return;
+ }
+ // SAFETY: We just checked that this is the right list.
+ unsafe {
+ self.manager.lock().all_procs.remove(proc);
+ }
+ }
+}
new file mode 100644
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use core::ops::{Deref, DerefMut};
+use kernel::{
+ bindings,
+ io_buffer::{ReadableFromBytes, WritableToBytes},
+};
+
+macro_rules! decl_wrapper {
+ ($newname:ident, $wrapped:ty) => {
+ #[derive(Copy, Clone, Default)]
+ #[repr(transparent)]
+ pub(crate) struct $newname($wrapped);
+ // SAFETY: This macro is only used with types where this is ok.
+ unsafe impl ReadableFromBytes for $newname {}
+ unsafe impl WritableToBytes for $newname {}
+ impl Deref for $newname {
+ type Target = $wrapped;
+ fn deref(&self) -> &Self::Target {
+ &self.0
+ }
+ }
+ impl DerefMut for $newname {
+ fn deref_mut(&mut self) -> &mut Self::Target {
+ &mut self.0
+ }
+ }
+ };
+}
+
+decl_wrapper!(BinderVersion, bindings::binder_version);
+
+impl BinderVersion {
+ pub(crate) fn current() -> Self {
+ Self(bindings::binder_version {
+ protocol_version: bindings::BINDER_CURRENT_PROTOCOL_VERSION as _,
+ })
+ }
+}
new file mode 100644
@@ -0,0 +1,251 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! This module defines the `Process` type, which represents a process using a particular binder
+//! context.
+//!
+//! The `Process` object keeps track of all of the resources that this process owns in the binder
+//! context.
+//!
+//! There is one `Process` object for each binder fd that a process has opened, so processes using
+//! several binder contexts have several `Process` objects. This ensures that the contexts are
+//! fully separated.
+
+use kernel::{
+ bindings,
+ cred::Credential,
+ file::{File, PollTable},
+ io_buffer::IoBufferWriter,
+ list::{HasListLinks, ListArc, ListArcSafe, ListItem, ListLinks},
+ mm,
+ prelude::*,
+ sync::{Arc, ArcBorrow, SpinLock},
+ task::Task,
+ types::ARef,
+ user_ptr::{UserSlicePtr, UserSlicePtrReader},
+ workqueue::{self, Work},
+};
+
+use crate::{context::Context, defs::*};
+
+const PROC_DEFER_FLUSH: u8 = 1;
+const PROC_DEFER_RELEASE: u8 = 2;
+
+/// The fields of `Process` protected by the spinlock.
+pub(crate) struct ProcessInner {
+ is_dead: bool,
+
+ /// Bitmap of deferred work to do.
+ defer_work: u8,
+}
+
+impl ProcessInner {
+ fn new() -> Self {
+ Self {
+ is_dead: false,
+ defer_work: 0,
+ }
+ }
+}
+
+/// A process using binder.
+///
+/// Strictly speaking, there can be multiple of these per process. There is one for each binder fd
+/// that a process has opened, so processes using several binder contexts have several `Process`
+/// objects. This ensures that the contexts are fully separated.
+#[pin_data]
+pub(crate) struct Process {
+ pub(crate) ctx: Arc<Context>,
+
+ // The task leader (process).
+ pub(crate) task: ARef<Task>,
+
+ // Credential associated with file when `Process` is created.
+ pub(crate) cred: ARef<Credential>,
+
+ #[pin]
+ pub(crate) inner: SpinLock<ProcessInner>,
+
+ // Work node for deferred work item.
+ #[pin]
+ defer_work: Work<Process>,
+
+ // Links for process list in Context.
+ #[pin]
+ links: ListLinks,
+}
+
+kernel::impl_has_work! {
+ impl HasWork<Process> for Process { self.defer_work }
+}
+
+kernel::list::impl_has_list_links! {
+ impl HasListLinks<0> for Process { self.links }
+}
+kernel::list::impl_list_arc_safe! {
+ impl ListArcSafe<0> for Process { untracked; }
+}
+kernel::list::impl_list_item! {
+ impl ListItem<0> for Process {
+ using ListLinks;
+ }
+}
+
+impl workqueue::WorkItem for Process {
+ type Pointer = Arc<Process>;
+
+ fn run(me: Arc<Self>) {
+ let defer;
+ {
+ let mut inner = me.inner.lock();
+ defer = inner.defer_work;
+ inner.defer_work = 0;
+ }
+
+ if defer & PROC_DEFER_FLUSH != 0 {
+ me.deferred_flush();
+ }
+ if defer & PROC_DEFER_RELEASE != 0 {
+ me.deferred_release();
+ }
+ }
+}
+
+impl Process {
+ fn new(ctx: Arc<Context>, cred: ARef<Credential>) -> Result<Arc<Self>> {
+ let list_process = ListArc::pin_init(pin_init!(Process {
+ ctx,
+ cred,
+ inner <- kernel::new_spinlock!(ProcessInner::new(), "Process::inner"),
+ task: kernel::current!().group_leader().into(),
+ defer_work <- kernel::new_work!("Process::defer_work"),
+ links <- ListLinks::new(),
+ }))?;
+
+ let process = list_process.clone_arc();
+ process.ctx.register_process(list_process);
+
+ Ok(process)
+ }
+
+ fn version(&self, data: UserSlicePtr) -> Result {
+ data.writer().write(&BinderVersion::current())
+ }
+
+ fn deferred_flush(&self) {
+ // NOOP for now.
+ }
+
+ fn deferred_release(self: Arc<Self>) {
+ self.inner.lock().is_dead = true;
+
+ self.ctx.deregister_process(&self);
+ }
+
+ pub(crate) fn flush(this: ArcBorrow<'_, Process>) -> Result {
+ let should_schedule;
+ {
+ let mut inner = this.inner.lock();
+ should_schedule = inner.defer_work == 0;
+ inner.defer_work |= PROC_DEFER_FLUSH;
+ }
+
+ if should_schedule {
+ // Ignore failures to schedule to the workqueue. Those just mean that we're already
+ // scheduled for execution.
+ let _ = workqueue::system().enqueue(Arc::from(this));
+ }
+ Ok(())
+ }
+}
+
+/// The ioctl handler.
+impl Process {
+ fn write(
+ _this: ArcBorrow<'_, Process>,
+ _file: &File,
+ _cmd: u32,
+ _reader: &mut UserSlicePtrReader,
+ ) -> Result<i32> {
+ Err(EINVAL)
+ }
+
+ fn read_write(
+ this: ArcBorrow<'_, Process>,
+ _file: &File,
+ cmd: u32,
+ data: UserSlicePtr,
+ ) -> Result<i32> {
+ match cmd {
+ bindings::BINDER_VERSION => this.version(data)?,
+ _ => return Err(EINVAL),
+ }
+ Ok(0)
+ }
+}
+
+/// The file operations supported by `Process`.
+impl Process {
+ pub(crate) fn open(ctx: ArcBorrow<'_, Context>, file: &File) -> Result<Arc<Process>> {
+ Self::new(ctx.into(), ARef::from(file.cred()))
+ }
+
+ pub(crate) fn release(this: Arc<Process>, _file: &File) {
+ let should_schedule;
+ {
+ let mut inner = this.inner.lock();
+ should_schedule = inner.defer_work == 0;
+ inner.defer_work |= PROC_DEFER_RELEASE;
+ }
+
+ if should_schedule {
+ // Ignore failures to schedule to the workqueue. Those just mean that we're already
+ // scheduled for execution.
+ let _ = workqueue::system().enqueue(this);
+ }
+ }
+
+ pub(crate) fn ioctl(
+ this: ArcBorrow<'_, Process>,
+ file: &File,
+ cmd: u32,
+ arg: *mut core::ffi::c_void,
+ ) -> Result<i32> {
+ use kernel::ioctl::{_IOC_DIR, _IOC_SIZE};
+ use kernel::uapi::{_IOC_READ, _IOC_WRITE};
+
+ let user_slice = UserSlicePtr::new(arg, _IOC_SIZE(cmd));
+
+ const _IOC_READ_WRITE: u32 = _IOC_READ | _IOC_WRITE;
+
+ match _IOC_DIR(cmd) {
+ _IOC_WRITE => Self::write(this, file, cmd, &mut user_slice.reader()),
+ _IOC_READ_WRITE => Self::read_write(this, file, cmd, user_slice),
+ _ => Err(EINVAL),
+ }
+ }
+
+ pub(crate) fn compat_ioctl(
+ this: ArcBorrow<'_, Process>,
+ file: &File,
+ cmd: u32,
+ arg: *mut core::ffi::c_void,
+ ) -> Result<i32> {
+ Self::ioctl(this, file, cmd, arg)
+ }
+
+ pub(crate) fn mmap(
+ _this: ArcBorrow<'_, Process>,
+ _file: &File,
+ _vma: &mut mm::virt::Area,
+ ) -> Result {
+ Err(EINVAL)
+ }
+
+ pub(crate) fn poll(
+ _this: ArcBorrow<'_, Process>,
+ _file: &File,
+ _table: &mut PollTable,
+ ) -> Result<u32> {
+ Err(EINVAL)
+ }
+}
@@ -2,7 +2,19 @@
//! Binder -- the Android IPC mechanism.
-use kernel::prelude::*;
+use kernel::{
+ bindings::{self, seq_file},
+ file::{File, PollTable},
+ prelude::*,
+ sync::Arc,
+ types::ForeignOwnable,
+};
+
+use crate::{context::Context, process::Process};
+
+mod context;
+mod defs;
+mod process;
module! {
type: BinderModule,
@@ -16,6 +28,188 @@ struct BinderModule {}
impl kernel::Module for BinderModule {
fn init(_module: &'static kernel::ThisModule) -> Result<Self> {
+ crate::context::CONTEXTS.init();
+
+ // SAFETY: The module is being loaded, so we can initialize binderfs.
+ #[cfg(CONFIG_ANDROID_BINDERFS_RUST)]
+ unsafe {
+ kernel::error::to_result(bindings::init_rust_binderfs())?;
+ }
+
Ok(Self {})
}
}
+
+/// Makes the inner type Sync.
+#[repr(transparent)]
+pub struct AssertSync<T>(T);
+// SAFETY: Used only to insert `file_operations` into a global, which is safe.
+unsafe impl<T> Sync for AssertSync<T> {}
+
+/// File operations that rust_binderfs.c can use.
+#[no_mangle]
+#[used]
+pub static rust_binder_fops: AssertSync<kernel::bindings::file_operations> = {
+ // SAFETY: All zeroes is safe for the `file_operations` type.
+ let zeroed_ops = unsafe { core::mem::MaybeUninit::zeroed().assume_init() };
+
+ let ops = kernel::bindings::file_operations {
+ owner: THIS_MODULE.as_ptr(),
+ poll: Some(rust_binder_poll),
+ unlocked_ioctl: Some(rust_binder_unlocked_ioctl),
+ compat_ioctl: Some(rust_binder_compat_ioctl),
+ mmap: Some(rust_binder_mmap),
+ open: Some(rust_binder_open),
+ release: Some(rust_binder_release),
+ mmap_supported_flags: 0,
+ flush: Some(rust_binder_flush),
+ ..zeroed_ops
+ };
+ AssertSync(ops)
+};
+
+#[no_mangle]
+unsafe extern "C" fn rust_binder_new_device(
+ name: *const core::ffi::c_char,
+) -> *mut core::ffi::c_void {
+ // SAFETY: The caller will always provide a valid c string here.
+ let name = unsafe { kernel::str::CStr::from_char_ptr(name) };
+ match Context::new(name) {
+ Ok(ctx) => Arc::into_foreign(ctx).cast_mut(),
+ Err(_err) => core::ptr::null_mut(),
+ }
+}
+
+#[no_mangle]
+unsafe extern "C" fn rust_binder_remove_device(device: *mut core::ffi::c_void) {
+ if !device.is_null() {
+ // SAFETY: The caller ensures that the `device` pointer came from a previous call to
+ // `rust_binder_new_device`.
+ let ctx = unsafe { Arc::<Context>::from_foreign(device) };
+ ctx.deregister();
+ drop(ctx);
+ }
+}
+
+unsafe extern "C" fn rust_binder_open(
+ inode: *mut bindings::inode,
+ file_ptr: *mut bindings::file,
+) -> core::ffi::c_int {
+ // SAFETY: The `rust_binderfs.c` file ensures that `i_private` is set to the return value of a
+ // successful call to `rust_binder_new_device`.
+ let ctx = unsafe { Arc::<Context>::borrow((*inode).i_private) };
+
+ // SAFETY: The caller provides a valid file pointer to a new `struct file`.
+ let file = unsafe { File::from_ptr(file_ptr) };
+ let process = match Process::open(ctx, file) {
+ Ok(process) => process,
+ Err(err) => return err.to_errno(),
+ };
+ // SAFETY: This file is associated with Rust binder, so we own the `private_data` field.
+ unsafe {
+ (*file_ptr).private_data = process.into_foreign().cast_mut();
+ }
+ 0
+}
+
+unsafe extern "C" fn rust_binder_release(
+ _inode: *mut bindings::inode,
+ file: *mut bindings::file,
+) -> core::ffi::c_int {
+ // SAFETY: We previously set `private_data` in `rust_binder_open`.
+ let process = unsafe { Arc::<Process>::from_foreign((*file).private_data) };
+ // SAFETY: The caller ensures that the file is valid.
+ let file = unsafe { File::from_ptr(file) };
+ Process::release(process, file);
+ 0
+}
+
+unsafe extern "C" fn rust_binder_compat_ioctl(
+ file: *mut bindings::file,
+ cmd: core::ffi::c_uint,
+ arg: core::ffi::c_ulong,
+) -> core::ffi::c_long {
+ // SAFETY: We previously set `private_data` in `rust_binder_open`.
+ let f = unsafe { Arc::<Process>::borrow((*file).private_data) };
+ // SAFETY: The caller ensures that the file is valid.
+ match Process::compat_ioctl(f, unsafe { File::from_ptr(file) }, cmd as _, arg as _) {
+ Ok(ret) => ret.into(),
+ Err(err) => err.to_errno().into(),
+ }
+}
+
+unsafe extern "C" fn rust_binder_unlocked_ioctl(
+ file: *mut bindings::file,
+ cmd: core::ffi::c_uint,
+ arg: core::ffi::c_ulong,
+) -> core::ffi::c_long {
+ // SAFETY: We previously set `private_data` in `rust_binder_open`.
+ let f = unsafe { Arc::<Process>::borrow((*file).private_data) };
+ // SAFETY: The caller ensures that the file is valid.
+ match Process::ioctl(f, unsafe { File::from_ptr(file) }, cmd as _, arg as _) {
+ Ok(ret) => ret.into(),
+ Err(err) => err.to_errno().into(),
+ }
+}
+
+unsafe extern "C" fn rust_binder_mmap(
+ file: *mut bindings::file,
+ vma: *mut bindings::vm_area_struct,
+) -> core::ffi::c_int {
+ // SAFETY: We previously set `private_data` in `rust_binder_open`.
+ let f = unsafe { Arc::<Process>::borrow((*file).private_data) };
+ // SAFETY: The caller ensures that the vma is valid.
+ let area = unsafe { kernel::mm::virt::Area::from_ptr_mut(vma) };
+ // SAFETY: The caller ensures that the file is valid.
+ match Process::mmap(f, unsafe { File::from_ptr(file) }, area) {
+ Ok(()) => 0,
+ Err(err) => err.to_errno(),
+ }
+}
+
+unsafe extern "C" fn rust_binder_poll(
+ file: *mut bindings::file,
+ wait: *mut bindings::poll_table_struct,
+) -> bindings::__poll_t {
+ // SAFETY: We previously set `private_data` in `rust_binder_open`.
+ let f = unsafe { Arc::<Process>::borrow((*file).private_data) };
+ // SAFETY: The caller ensures that the file is valid.
+ let fileref = unsafe { File::from_ptr(file) };
+ // SAFETY: The caller ensures that the `PollTable` is valid.
+ match Process::poll(f, fileref, unsafe { PollTable::from_ptr(wait) }) {
+ Ok(v) => v,
+ Err(_) => bindings::POLLERR,
+ }
+}
+
+unsafe extern "C" fn rust_binder_flush(
+ file: *mut bindings::file,
+ _id: bindings::fl_owner_t,
+) -> core::ffi::c_int {
+ // SAFETY: We previously set `private_data` in `rust_binder_open`.
+ let f = unsafe { Arc::<Process>::borrow((*file).private_data) };
+ match Process::flush(f) {
+ Ok(()) => 0,
+ Err(err) => err.to_errno(),
+ }
+}
+
+#[no_mangle]
+unsafe extern "C" fn rust_binder_stats_show(_: *mut seq_file) -> core::ffi::c_int {
+ 0
+}
+
+#[no_mangle]
+unsafe extern "C" fn rust_binder_state_show(_: *mut seq_file) -> core::ffi::c_int {
+ 0
+}
+
+#[no_mangle]
+unsafe extern "C" fn rust_binder_transactions_show(_: *mut seq_file) -> core::ffi::c_int {
+ 0
+}
+
+#[no_mangle]
+unsafe extern "C" fn rust_binder_transaction_log_show(_: *mut seq_file) -> core::ffi::c_int {
+ 0
+}
new file mode 100644
@@ -0,0 +1,866 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/compiler_types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/fsnotify.h>
+#include <linux/gfp.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/ipc_namespace.h>
+#include <linux/kdev_t.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/namei.h>
+#include <linux/magic.h>
+#include <linux/major.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/mount.h>
+#include <linux/fs_parser.h>
+#include <linux/rust_binder.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/spinlock_types.h>
+#include <linux/stddef.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/user_namespace.h>
+#include <linux/xarray.h>
+#include <uapi/asm-generic/errno-base.h>
+#include <uapi/linux/android/binder.h>
+#include <uapi/linux/android/binderfs.h>
+
+#include "binder_internal.h"
+
+#define FIRST_INODE 1
+#define SECOND_INODE 2
+#define INODE_OFFSET 3
+#define BINDERFS_MAX_MINOR (1U << MINORBITS)
+/* Ensure that the initial ipc namespace always has devices available. */
+#define BINDERFS_MAX_MINOR_CAPPED (BINDERFS_MAX_MINOR - 4)
+
+/* === DEFINED IN RUST === */
+extern int rust_binder_stats_show(struct seq_file *m, void *unused);
+DEFINE_SHOW_ATTRIBUTE(rust_binder_stats);
+
+extern int rust_binder_state_show(struct seq_file *m, void *unused);
+DEFINE_SHOW_ATTRIBUTE(rust_binder_state);
+
+extern int rust_binder_transactions_show(struct seq_file *m, void *unused);
+DEFINE_SHOW_ATTRIBUTE(rust_binder_transactions);
+
+extern int rust_binder_transaction_log_show(struct seq_file *m, void *unused);
+DEFINE_SHOW_ATTRIBUTE(rust_binder_transaction_log);
+
+extern const struct file_operations rust_binder_fops;
+extern rust_binder_device rust_binder_new_device(char *name);
+extern void rust_binder_remove_device(rust_binder_device device);
+/* === END DEFINED IN RUST === */
+
+char *rust_binder_devices_param = CONFIG_ANDROID_BINDER_DEVICES_RUST;
+module_param_named(rust_devices, rust_binder_devices_param, charp, 0444);
+
+static dev_t binderfs_dev;
+static DEFINE_MUTEX(binderfs_minors_mutex);
+static DEFINE_IDA(binderfs_minors);
+
+enum binderfs_param {
+ Opt_max,
+ Opt_stats_mode,
+};
+
+enum binderfs_stats_mode {
+ binderfs_stats_mode_unset,
+ binderfs_stats_mode_global,
+};
+
+struct binder_features {
+ bool oneway_spam_detection;
+ bool extended_error;
+};
+
+static const struct constant_table binderfs_param_stats[] = {
+ { "global", binderfs_stats_mode_global },
+ {}
+};
+
+static const struct fs_parameter_spec binderfs_fs_parameters[] = {
+ fsparam_u32("max", Opt_max),
+ fsparam_enum("stats", Opt_stats_mode, binderfs_param_stats),
+ {}
+};
+
+static struct binder_features binder_features = {
+ .oneway_spam_detection = true,
+ .extended_error = true,
+};
+
+static inline struct binderfs_info *BINDERFS_SB(const struct super_block *sb)
+{
+ return sb->s_fs_info;
+}
+
+bool is_rust_binderfs_device(const struct inode *inode)
+{
+ if (inode->i_sb->s_magic == RUST_BINDERFS_SUPER_MAGIC)
+ return true;
+
+ return false;
+}
+
+/**
+ * binderfs_binder_device_create - allocate inode from super block of a
+ * binderfs mount
+ * @ref_inode: inode from wich the super block will be taken
+ * @userp: buffer to copy information about new device for userspace to
+ * @req: struct binderfs_device as copied from userspace
+ *
+ * This function allocates a new binder_device and reserves a new minor
+ * number for it.
+ * Minor numbers are limited and tracked globally in binderfs_minors. The
+ * function will stash a struct binder_device for the specific binder
+ * device in i_private of the inode.
+ * It will go on to allocate a new inode from the super block of the
+ * filesystem mount, stash a struct binder_device in its i_private field
+ * and attach a dentry to that inode.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+static int binderfs_binder_device_create(struct inode *ref_inode,
+ struct binderfs_device __user *userp,
+ struct binderfs_device *req)
+{
+ int minor, ret;
+ struct dentry *dentry, *root;
+ rust_binder_device device = NULL;
+ char *name = NULL;
+ size_t name_len;
+ struct inode *inode = NULL;
+ struct super_block *sb = ref_inode->i_sb;
+ struct binderfs_info *info = sb->s_fs_info;
+#if defined(CONFIG_IPC_NS)
+ bool use_reserve = (info->ipc_ns == &init_ipc_ns);
+#else
+ bool use_reserve = true;
+#endif
+
+ /* Reserve new minor number for the new device. */
+ mutex_lock(&binderfs_minors_mutex);
+ if (++info->device_count <= info->mount_opts.max)
+ minor = ida_alloc_max(&binderfs_minors,
+ use_reserve ? BINDERFS_MAX_MINOR :
+ BINDERFS_MAX_MINOR_CAPPED,
+ GFP_KERNEL);
+ else
+ minor = -ENOSPC;
+ if (minor < 0) {
+ --info->device_count;
+ mutex_unlock(&binderfs_minors_mutex);
+ return minor;
+ }
+ mutex_unlock(&binderfs_minors_mutex);
+
+ ret = -ENOMEM;
+ req->name[BINDERFS_MAX_NAME] = '\0'; /* NUL-terminate */
+ name_len = strlen(req->name);
+ /* Make sure to include terminating NUL byte */
+ name = kmemdup(req->name, name_len + 1, GFP_KERNEL);
+ if (!name)
+ goto err;
+
+ device = rust_binder_new_device(name);
+ if (!device)
+ goto err;
+
+ inode = new_inode(sb);
+ if (!inode)
+ goto err;
+
+ inode->i_ino = minor + INODE_OFFSET;
+ simple_inode_init_ts(inode);
+ init_special_inode(inode, S_IFCHR | 0600,
+ MKDEV(MAJOR(binderfs_dev), minor));
+ inode->i_fop = &rust_binder_fops;
+ inode->i_uid = info->root_uid;
+ inode->i_gid = info->root_gid;
+
+ req->major = MAJOR(binderfs_dev);
+ req->minor = minor;
+
+ if (userp && copy_to_user(userp, req, sizeof(*req))) {
+ ret = -EFAULT;
+ goto err;
+ }
+
+ root = sb->s_root;
+ inode_lock(d_inode(root));
+
+ /* look it up */
+ dentry = lookup_one_len(name, root, name_len);
+ if (IS_ERR(dentry)) {
+ inode_unlock(d_inode(root));
+ ret = PTR_ERR(dentry);
+ goto err;
+ }
+
+ if (d_really_is_positive(dentry)) {
+ /* already exists */
+ dput(dentry);
+ inode_unlock(d_inode(root));
+ ret = -EEXIST;
+ goto err;
+ }
+
+ inode->i_private = device;
+ d_instantiate(dentry, inode);
+ fsnotify_create(root->d_inode, dentry);
+ inode_unlock(d_inode(root));
+
+ return 0;
+
+err:
+ kfree(name);
+ rust_binder_remove_device(device);
+ mutex_lock(&binderfs_minors_mutex);
+ --info->device_count;
+ ida_free(&binderfs_minors, minor);
+ mutex_unlock(&binderfs_minors_mutex);
+ iput(inode);
+
+ return ret;
+}
+
+/**
+ * binder_ctl_ioctl - handle binder device node allocation requests
+ *
+ * The request handler for the binder-control device. All requests operate on
+ * the binderfs mount the binder-control device resides in:
+ * - BINDER_CTL_ADD
+ * Allocate a new binder device.
+ *
+ * Return: %0 on success, negative errno on failure.
+ */
+static long binder_ctl_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int ret = -EINVAL;
+ struct inode *inode = file_inode(file);
+ struct binderfs_device __user *device = (struct binderfs_device __user *)arg;
+ struct binderfs_device device_req;
+
+ switch (cmd) {
+ case BINDER_CTL_ADD:
+ ret = copy_from_user(&device_req, device, sizeof(device_req));
+ if (ret) {
+ ret = -EFAULT;
+ break;
+ }
+
+ ret = binderfs_binder_device_create(inode, device, &device_req);
+ break;
+ default:
+ break;
+ }
+
+ return ret;
+}
+
+static void binderfs_evict_inode(struct inode *inode)
+{
+ rust_binder_device device = inode->i_private;
+ struct binderfs_info *info = BINDERFS_SB(inode->i_sb);
+ int minor = inode->i_ino - INODE_OFFSET;
+
+ clear_inode(inode);
+
+ if (!S_ISCHR(inode->i_mode) || !device)
+ return;
+
+ mutex_lock(&binderfs_minors_mutex);
+ --info->device_count;
+ ida_free(&binderfs_minors, minor);
+ mutex_unlock(&binderfs_minors_mutex);
+
+ rust_binder_remove_device(device);
+}
+
+static int binderfs_fs_context_parse_param(struct fs_context *fc,
+ struct fs_parameter *param)
+{
+ int opt;
+ struct binderfs_mount_opts *ctx = fc->fs_private;
+ struct fs_parse_result result;
+
+ opt = fs_parse(fc, binderfs_fs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_max:
+ if (result.uint_32 > BINDERFS_MAX_MINOR)
+ return invalfc(fc, "Bad value for '%s'", param->key);
+
+ ctx->max = result.uint_32;
+ break;
+ case Opt_stats_mode:
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ ctx->stats_mode = result.uint_32;
+ break;
+ default:
+ return invalfc(fc, "Unsupported parameter '%s'", param->key);
+ }
+
+ return 0;
+}
+
+static int binderfs_fs_context_reconfigure(struct fs_context *fc)
+{
+ struct binderfs_mount_opts *ctx = fc->fs_private;
+ struct binderfs_info *info = BINDERFS_SB(fc->root->d_sb);
+
+ if (info->mount_opts.stats_mode != ctx->stats_mode)
+ return invalfc(fc, "Binderfs stats mode cannot be changed during a remount");
+
+ info->mount_opts.stats_mode = ctx->stats_mode;
+ info->mount_opts.max = ctx->max;
+ return 0;
+}
+
+static int binderfs_show_options(struct seq_file *seq, struct dentry *root)
+{
+ struct binderfs_info *info = BINDERFS_SB(root->d_sb);
+
+ if (info->mount_opts.max <= BINDERFS_MAX_MINOR)
+ seq_printf(seq, ",max=%d", info->mount_opts.max);
+
+ switch (info->mount_opts.stats_mode) {
+ case binderfs_stats_mode_unset:
+ break;
+ case binderfs_stats_mode_global:
+ seq_printf(seq, ",stats=global");
+ break;
+ }
+
+ return 0;
+}
+
+static const struct super_operations binderfs_super_ops = {
+ .evict_inode = binderfs_evict_inode,
+ .show_options = binderfs_show_options,
+ .statfs = simple_statfs,
+};
+
+static inline bool is_binderfs_control_device(const struct dentry *dentry)
+{
+ struct binderfs_info *info = dentry->d_sb->s_fs_info;
+
+ return info->control_dentry == dentry;
+}
+
+static int binderfs_rename(struct mnt_idmap *idmap,
+ struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry,
+ unsigned int flags)
+{
+ if (is_binderfs_control_device(old_dentry) ||
+ is_binderfs_control_device(new_dentry))
+ return -EPERM;
+
+ return simple_rename(idmap, old_dir, old_dentry, new_dir,
+ new_dentry, flags);
+}
+
+static int binderfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ if (is_binderfs_control_device(dentry))
+ return -EPERM;
+
+ return simple_unlink(dir, dentry);
+}
+
+static const struct file_operations binder_ctl_fops = {
+ .owner = THIS_MODULE,
+ .open = nonseekable_open,
+ .unlocked_ioctl = binder_ctl_ioctl,
+ .compat_ioctl = binder_ctl_ioctl,
+ .llseek = noop_llseek,
+};
+
+/**
+ * binderfs_binder_ctl_create - create a new binder-control device
+ * @sb: super block of the binderfs mount
+ *
+ * This function creates a new binder-control device node in the binderfs mount
+ * referred to by @sb.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+static int binderfs_binder_ctl_create(struct super_block *sb)
+{
+ int minor, ret;
+ struct dentry *dentry;
+ struct binder_device *device;
+ struct inode *inode = NULL;
+ struct dentry *root = sb->s_root;
+ struct binderfs_info *info = sb->s_fs_info;
+#if defined(CONFIG_IPC_NS)
+ bool use_reserve = (info->ipc_ns == &init_ipc_ns);
+#else
+ bool use_reserve = true;
+#endif
+
+ device = kzalloc(sizeof(*device), GFP_KERNEL);
+ if (!device)
+ return -ENOMEM;
+
+ /* If we have already created a binder-control node, return. */
+ if (info->control_dentry) {
+ ret = 0;
+ goto out;
+ }
+
+ ret = -ENOMEM;
+ inode = new_inode(sb);
+ if (!inode)
+ goto out;
+
+ /* Reserve a new minor number for the new device. */
+ mutex_lock(&binderfs_minors_mutex);
+ minor = ida_alloc_max(&binderfs_minors,
+ use_reserve ? BINDERFS_MAX_MINOR :
+ BINDERFS_MAX_MINOR_CAPPED,
+ GFP_KERNEL);
+ mutex_unlock(&binderfs_minors_mutex);
+ if (minor < 0) {
+ ret = minor;
+ goto out;
+ }
+
+ inode->i_ino = SECOND_INODE;
+ simple_inode_init_ts(inode);
+ init_special_inode(inode, S_IFCHR | 0600,
+ MKDEV(MAJOR(binderfs_dev), minor));
+ inode->i_fop = &binder_ctl_fops;
+ inode->i_uid = info->root_uid;
+ inode->i_gid = info->root_gid;
+
+ refcount_set(&device->ref, 1);
+ device->binderfs_inode = inode;
+ device->miscdev.minor = minor;
+
+ dentry = d_alloc_name(root, "binder-control");
+ if (!dentry)
+ goto out;
+
+ inode->i_private = device;
+ info->control_dentry = dentry;
+ d_add(dentry, inode);
+
+ return 0;
+
+out:
+ kfree(device);
+ iput(inode);
+
+ return ret;
+}
+
+static const struct inode_operations binderfs_dir_inode_operations = {
+ .lookup = simple_lookup,
+ .rename = binderfs_rename,
+ .unlink = binderfs_unlink,
+};
+
+static struct inode *binderfs_make_inode(struct super_block *sb, int mode)
+{
+ struct inode *ret;
+
+ ret = new_inode(sb);
+ if (ret) {
+ ret->i_ino = iunique(sb, BINDERFS_MAX_MINOR + INODE_OFFSET);
+ ret->i_mode = mode;
+ simple_inode_init_ts(ret);
+ }
+ return ret;
+}
+
+static struct dentry *binderfs_create_dentry(struct dentry *parent,
+ const char *name)
+{
+ struct dentry *dentry;
+
+ dentry = lookup_one_len(name, parent, strlen(name));
+ if (IS_ERR(dentry))
+ return dentry;
+
+ /* Return error if the file/dir already exists. */
+ if (d_really_is_positive(dentry)) {
+ dput(dentry);
+ return ERR_PTR(-EEXIST);
+ }
+
+ return dentry;
+}
+
+void rust_binderfs_remove_file(struct dentry *dentry)
+{
+ struct inode *parent_inode;
+
+ parent_inode = d_inode(dentry->d_parent);
+ inode_lock(parent_inode);
+ if (simple_positive(dentry)) {
+ dget(dentry);
+ simple_unlink(parent_inode, dentry);
+ d_delete(dentry);
+ dput(dentry);
+ }
+ inode_unlock(parent_inode);
+}
+
+struct dentry *rust_binderfs_create_file(struct dentry *parent, const char *name,
+ const struct file_operations *fops,
+ void *data)
+{
+ struct dentry *dentry;
+ struct inode *new_inode, *parent_inode;
+ struct super_block *sb;
+
+ parent_inode = d_inode(parent);
+ inode_lock(parent_inode);
+
+ dentry = binderfs_create_dentry(parent, name);
+ if (IS_ERR(dentry))
+ goto out;
+
+ sb = parent_inode->i_sb;
+ new_inode = binderfs_make_inode(sb, S_IFREG | 0444);
+ if (!new_inode) {
+ dput(dentry);
+ dentry = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ new_inode->i_fop = fops;
+ new_inode->i_private = data;
+ d_instantiate(dentry, new_inode);
+ fsnotify_create(parent_inode, dentry);
+
+out:
+ inode_unlock(parent_inode);
+ return dentry;
+}
+
+static struct dentry *binderfs_create_dir(struct dentry *parent,
+ const char *name)
+{
+ struct dentry *dentry;
+ struct inode *new_inode, *parent_inode;
+ struct super_block *sb;
+
+ parent_inode = d_inode(parent);
+ inode_lock(parent_inode);
+
+ dentry = binderfs_create_dentry(parent, name);
+ if (IS_ERR(dentry))
+ goto out;
+
+ sb = parent_inode->i_sb;
+ new_inode = binderfs_make_inode(sb, S_IFDIR | 0755);
+ if (!new_inode) {
+ dput(dentry);
+ dentry = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ new_inode->i_fop = &simple_dir_operations;
+ new_inode->i_op = &simple_dir_inode_operations;
+
+ set_nlink(new_inode, 2);
+ d_instantiate(dentry, new_inode);
+ inc_nlink(parent_inode);
+ fsnotify_mkdir(parent_inode, dentry);
+
+out:
+ inode_unlock(parent_inode);
+ return dentry;
+}
+
+static int binder_features_show(struct seq_file *m, void *unused)
+{
+ bool *feature = m->private;
+
+ seq_printf(m, "%d\n", *feature);
+
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(binder_features);
+
+static int init_binder_features(struct super_block *sb)
+{
+ struct dentry *dentry, *dir;
+
+ dir = binderfs_create_dir(sb->s_root, "features");
+ if (IS_ERR(dir))
+ return PTR_ERR(dir);
+
+ dentry = rust_binderfs_create_file(dir, "oneway_spam_detection",
+ &binder_features_fops,
+ &binder_features.oneway_spam_detection);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+
+ dentry = rust_binderfs_create_file(dir, "extended_error",
+ &binder_features_fops,
+ &binder_features.extended_error);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+
+ return 0;
+}
+
+static int init_binder_logs(struct super_block *sb)
+{
+ struct dentry *binder_logs_root_dir, *dentry, *proc_log_dir;
+ struct binderfs_info *info;
+ int ret = 0;
+
+ binder_logs_root_dir = binderfs_create_dir(sb->s_root,
+ "binder_logs");
+ if (IS_ERR(binder_logs_root_dir)) {
+ ret = PTR_ERR(binder_logs_root_dir);
+ goto out;
+ }
+
+ dentry = rust_binderfs_create_file(binder_logs_root_dir, "stats",
+ &rust_binder_stats_fops, NULL);
+ if (IS_ERR(dentry)) {
+ ret = PTR_ERR(dentry);
+ goto out;
+ }
+
+ dentry = rust_binderfs_create_file(binder_logs_root_dir, "state",
+ &rust_binder_state_fops, NULL);
+ if (IS_ERR(dentry)) {
+ ret = PTR_ERR(dentry);
+ goto out;
+ }
+
+ dentry = rust_binderfs_create_file(binder_logs_root_dir, "transactions",
+ &rust_binder_transactions_fops, NULL);
+ if (IS_ERR(dentry)) {
+ ret = PTR_ERR(dentry);
+ goto out;
+ }
+
+ dentry = rust_binderfs_create_file(binder_logs_root_dir,
+ "transaction_log",
+ &rust_binder_transaction_log_fops,
+ NULL);
+ if (IS_ERR(dentry)) {
+ ret = PTR_ERR(dentry);
+ goto out;
+ }
+
+ dentry = rust_binderfs_create_file(binder_logs_root_dir,
+ "failed_transaction_log",
+ &rust_binder_transaction_log_fops,
+ NULL);
+ if (IS_ERR(dentry)) {
+ ret = PTR_ERR(dentry);
+ goto out;
+ }
+
+ proc_log_dir = binderfs_create_dir(binder_logs_root_dir, "proc");
+ if (IS_ERR(proc_log_dir)) {
+ ret = PTR_ERR(proc_log_dir);
+ goto out;
+ }
+ info = sb->s_fs_info;
+ info->proc_log_dir = proc_log_dir;
+
+out:
+ return ret;
+}
+
+static int binderfs_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+ int ret;
+ struct binderfs_info *info;
+ struct binderfs_mount_opts *ctx = fc->fs_private;
+ struct inode *inode = NULL;
+ struct binderfs_device device_info = {};
+ const char *name;
+ size_t len;
+
+ sb->s_blocksize = PAGE_SIZE;
+ sb->s_blocksize_bits = PAGE_SHIFT;
+
+ /*
+ * The binderfs filesystem can be mounted by userns root in a
+ * non-initial userns. By default such mounts have the SB_I_NODEV flag
+ * set in s_iflags to prevent security issues where userns root can
+ * just create random device nodes via mknod() since it owns the
+ * filesystem mount. But binderfs does not allow to create any files
+ * including devices nodes. The only way to create binder devices nodes
+ * is through the binder-control device which userns root is explicitly
+ * allowed to do. So removing the SB_I_NODEV flag from s_iflags is both
+ * necessary and safe.
+ */
+ sb->s_iflags &= ~SB_I_NODEV;
+ sb->s_iflags |= SB_I_NOEXEC;
+ sb->s_magic = RUST_BINDERFS_SUPER_MAGIC;
+ sb->s_op = &binderfs_super_ops;
+ sb->s_time_gran = 1;
+
+ sb->s_fs_info = kzalloc(sizeof(struct binderfs_info), GFP_KERNEL);
+ if (!sb->s_fs_info)
+ return -ENOMEM;
+ info = sb->s_fs_info;
+
+ info->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns);
+
+ info->root_gid = make_kgid(sb->s_user_ns, 0);
+ if (!gid_valid(info->root_gid))
+ info->root_gid = GLOBAL_ROOT_GID;
+ info->root_uid = make_kuid(sb->s_user_ns, 0);
+ if (!uid_valid(info->root_uid))
+ info->root_uid = GLOBAL_ROOT_UID;
+ info->mount_opts.max = ctx->max;
+ info->mount_opts.stats_mode = ctx->stats_mode;
+
+ inode = new_inode(sb);
+ if (!inode)
+ return -ENOMEM;
+
+ inode->i_ino = FIRST_INODE;
+ inode->i_fop = &simple_dir_operations;
+ inode->i_mode = S_IFDIR | 0755;
+ simple_inode_init_ts(inode);
+ inode->i_op = &binderfs_dir_inode_operations;
+ set_nlink(inode, 2);
+
+ sb->s_root = d_make_root(inode);
+ if (!sb->s_root)
+ return -ENOMEM;
+
+ ret = binderfs_binder_ctl_create(sb);
+ if (ret)
+ return ret;
+
+ name = rust_binder_devices_param;
+ for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) {
+ strscpy(device_info.name, name, len + 1);
+ ret = binderfs_binder_device_create(inode, NULL, &device_info);
+ if (ret)
+ return ret;
+ name += len;
+ if (*name == ',')
+ name++;
+ }
+
+ ret = init_binder_features(sb);
+ if (ret)
+ return ret;
+
+ if (info->mount_opts.stats_mode == binderfs_stats_mode_global)
+ return init_binder_logs(sb);
+
+ return 0;
+}
+
+static int binderfs_fs_context_get_tree(struct fs_context *fc)
+{
+ return get_tree_nodev(fc, binderfs_fill_super);
+}
+
+static void binderfs_fs_context_free(struct fs_context *fc)
+{
+ struct binderfs_mount_opts *ctx = fc->fs_private;
+
+ kfree(ctx);
+}
+
+static const struct fs_context_operations binderfs_fs_context_ops = {
+ .free = binderfs_fs_context_free,
+ .get_tree = binderfs_fs_context_get_tree,
+ .parse_param = binderfs_fs_context_parse_param,
+ .reconfigure = binderfs_fs_context_reconfigure,
+};
+
+static int binderfs_init_fs_context(struct fs_context *fc)
+{
+ struct binderfs_mount_opts *ctx;
+
+ ctx = kzalloc(sizeof(struct binderfs_mount_opts), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->max = BINDERFS_MAX_MINOR;
+ ctx->stats_mode = binderfs_stats_mode_unset;
+
+ fc->fs_private = ctx;
+ fc->ops = &binderfs_fs_context_ops;
+
+ return 0;
+}
+
+static void binderfs_kill_super(struct super_block *sb)
+{
+ struct binderfs_info *info = sb->s_fs_info;
+
+ /*
+ * During inode eviction struct binderfs_info is needed.
+ * So first wipe the super_block then free struct binderfs_info.
+ */
+ kill_litter_super(sb);
+
+ if (info && info->ipc_ns)
+ put_ipc_ns(info->ipc_ns);
+
+ kfree(info);
+}
+
+static struct file_system_type binder_fs_type = {
+ .name = "binder",
+ .init_fs_context = binderfs_init_fs_context,
+ .parameters = binderfs_fs_parameters,
+ .kill_sb = binderfs_kill_super,
+ .fs_flags = FS_USERNS_MOUNT,
+};
+
+int init_rust_binderfs(void)
+{
+ int ret;
+ const char *name;
+ size_t len;
+
+ /* Verify that the default binderfs device names are valid. */
+ name = rust_binder_devices_param;
+ for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) {
+ if (len > BINDERFS_MAX_NAME)
+ return -E2BIG;
+ name += len;
+ if (*name == ',')
+ name++;
+ }
+
+ /* Allocate new major number for binderfs. */
+ ret = alloc_chrdev_region(&binderfs_dev, 0, BINDERFS_MAX_MINOR,
+ "rust_binder");
+ if (ret)
+ return ret;
+
+ ret = register_filesystem(&binder_fs_type);
+ if (ret) {
+ unregister_chrdev_region(binderfs_dev, BINDERFS_MAX_MINOR);
+ return ret;
+ }
+
+ return ret;
+}
new file mode 100644
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_RUST_BINDER_H
+#define _LINUX_RUST_BINDER_H
+
+#include <uapi/linux/android/binderfs.h>
+
+/*
+ * This typedef is used for Rust binder driver instances. The driver object is
+ * completely opaque from C and can only be accessed via calls into Rust, so we
+ * use a typedef.
+ */
+typedef void *rust_binder_device;
+
+int init_rust_binderfs(void);
+
+#endif
@@ -82,6 +82,7 @@
#define BINFMTFS_MAGIC 0x42494e4d
#define DEVPTS_SUPER_MAGIC 0x1cd1
#define BINDERFS_SUPER_MAGIC 0x6c6f6f70
+#define RUST_BINDERFS_SUPER_MAGIC 0x6c6f6f71
#define FUTEXFS_SUPER_MAGIC 0xBAD1DEA
#define PIPEFS_MAGIC 0x50495045
#define PROC_SUPER_MAGIC 0x9fa0
@@ -17,11 +17,13 @@
#include <linux/security.h>
#include <linux/slab.h>
#include <linux/refcount.h>
+#include <linux/rust_binder.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/task_work.h>
#include <linux/workqueue.h>
#include <uapi/linux/android/binder.h>
+#include <uapi/linux/android/binderfs.h>
/* `bindgen` gets confused at certain things. */
const size_t BINDINGS_ARCH_SLAB_MINALIGN = ARCH_SLAB_MINALIGN;
@@ -99,6 +99,13 @@ impl ThisModule {
pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
ThisModule(ptr)
}
+
+ /// Access the raw pointer for this module.
+ ///
+ /// It is up to the user to use it correctly.
+ pub const fn as_ptr(&self) -> *mut bindings::module {
+ self.0
+ }
}
#[cfg(not(any(testlib, test)))]
@@ -262,7 +262,7 @@ $(obj)/%.lst: $(src)/%.c FORCE
# Compile Rust sources (.rs)
# ---------------------------------------------------------------------------
-rust_allowed_features := new_uninit,offset_of
+rust_allowed_features := const_maybe_uninit_zeroed,new_uninit,offset_of
# `--out-dir` is required to avoid temporaries being created by `rustc` in the
# current working directory, which may be not accessible in the out-of-tree