asterinas/kernel/src/fs/procfs/pid/task/uid_map.rs

48 lines
1.4 KiB
Rust

// SPDX-License-Identifier: MPL-2.0
use aster_util::printer::VmPrinter;
use super::TidDirOps;
use crate::{
fs::{
procfs::template::{FileOps, ProcFileBuilder},
utils::{Inode, mkmod},
},
prelude::*,
process::{Process, Uid},
};
/// Represents the inode at `/proc/[pid]/task/[tid]/uid_map` (and also `/proc/[pid]/uid_map`).
#[expect(dead_code)]
pub struct UidMapFileOps(Arc<Process>);
impl UidMapFileOps {
pub fn new_inode(dir: &TidDirOps, parent: Weak<dyn Inode>) -> Arc<dyn Inode> {
let process_ref = dir.process_ref.clone();
// Reference: <https://elixir.bootlin.com/linux/v6.16.5/source/fs/proc/base.c#L3402>
ProcFileBuilder::new(Self(process_ref), mkmod!(a+r, u+w))
.parent(parent)
.build()
.unwrap()
}
}
impl FileOps for UidMapFileOps {
fn read_at(&self, offset: usize, writer: &mut VmWriter) -> Result<usize> {
let mut printer = VmPrinter::new_skip(writer, offset);
// This is the default UID map for the initial user namespace.
// TODO: Retrieve the UID map from the user namespace of the current process
// instead of returning this hard-coded value.
writeln!(
printer,
"{:>10} {:>10} {:>10}",
0,
0,
u32::from(Uid::INVALID)
)?;
Ok(printer.bytes_written())
}
}