Commit d4b83ba1 authored by Alice Ryhl's avatar Alice Ryhl Committed by Greg Kroah-Hartman
Browse files

rust_binder: use compat_ptr_ioctl 



Binder always treats the ioctl argument as a pointer. In this scenario,
the idiomatic way to implement compat_ioctl is to use compat_ptr_ioctl.
Thus update Rust Binder to do that.

Signed-off-by: default avatarAlice Ryhl <aliceryhl@google.com>
Acked-by: default avatarCarlos Llamas <cmllamas@google.com>
Link: https://patch.msgid.link/20251031-binder-compatptrioctl-v2-1-3d05b5cc058e@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a1fb84ab

drivers/android/binder/process.rs

+0 −9
Original line number Diff line number Diff line
@@ -1623,15 +1623,6 @@ pub(crate) fn ioctl(this: ArcBorrow<'_, Process>, file: &File, cmd: u32, arg: us 
        }

    }



    pub(crate) fn compat_ioctl(

        this: ArcBorrow<'_, Process>,

        file: &File,

        cmd: u32,

        arg: usize,

    ) -> Result {

        Self::ioctl(this, file, cmd, arg)

    }



    pub(crate) fn mmap(

        this: ArcBorrow<'_, Process>,

        _file: &File,

drivers/android/binder/rust_binder_main.rs

+3 −19
Original line number Diff line number Diff line
@@ -313,8 +313,8 @@ unsafe impl<T> Sync for AssertSync<T> {} 
    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),

        unlocked_ioctl: Some(rust_binder_ioctl),

        compat_ioctl: Some(bindings::compat_ptr_ioctl),

        mmap: Some(rust_binder_mmap),

        open: Some(rust_binder_open),

        release: Some(rust_binder_release),
@@ -402,23 +402,7 @@ unsafe impl<T> Sync for AssertSync<T> {} 


/// # Safety

/// Only called by binderfs.

unsafe extern "C" fn rust_binder_compat_ioctl(

    file: *mut bindings::file,

    cmd: kernel::ffi::c_uint,

    arg: kernel::ffi::c_ulong,

) -> kernel::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_raw_file(file) }, cmd as _, arg as _) {

        Ok(()) => 0,

        Err(err) => err.to_errno() as isize,

    }

}



/// # Safety

/// Only called by binderfs.

unsafe extern "C" fn rust_binder_unlocked_ioctl(

unsafe extern "C" fn rust_binder_ioctl(

    file: *mut bindings::file,

    cmd: kernel::ffi::c_uint,

    arg: kernel::ffi::c_ulong,