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

49 lines
1.4 KiB
Rust

// SPDX-License-Identifier: MPL-2.0
use crate::{
fs::{
procfs::template::{FileOps, ProcFileBuilder},
utils::{mkmod, Inode},
},
prelude::*,
process::Process,
};
/// Represents the inode at `/proc/[pid]/task/[tid]/comm` (and also `/proc/[pid]/comm`).
pub struct CommFileOps(Arc<Process>);
impl CommFileOps {
pub fn new_inode(process_ref: Arc<Process>, parent: Weak<dyn Inode>) -> Arc<dyn Inode> {
// Reference: <https://elixir.bootlin.com/linux/v6.16.5/source/fs/proc/base.c#L3336>
ProcFileBuilder::new(Self(process_ref), mkmod!(a+r, u+w))
.parent(parent)
.build()
.unwrap()
}
}
impl FileOps for CommFileOps {
fn data(&self) -> Result<Vec<u8>> {
let mut comm_output = {
let exe_path = self.0.executable_path();
let last_component = exe_path.rsplit('/').next().unwrap_or(&exe_path);
let mut comm = last_component.as_bytes().to_vec();
comm.push(b'\0');
comm.truncate(TASK_COMM_LEN);
comm
};
comm_output.push(b'\n');
Ok(comm_output)
}
fn write_at(&self, _offset: usize, _reader: &mut VmReader) -> Result<usize> {
warn!("writing to `/proc/[pid]/comm` is not supported");
return_errno_with_message!(
Errno::EOPNOTSUPP,
"writing to `/proc/[pid]/comm` is not supported"
);
}
}
const TASK_COMM_LEN: usize = 16;