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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341// SPDX-License-Identifier: GPL-2.0// Copyright (C) 2025 Google LLC.
//! Traits for rendering or updating values exported to DebugFS.
use crate::{ alloc::Allocator, fmt, fs::file, prelude::*, sync::{ atomic::{ Atomic, AtomicBasicOps, AtomicType, Relaxed, // }, Arc, Mutex, // }, transmute::{ AsBytes, FromBytes, // }, uaccess::{ UserSliceReader, UserSliceWriter, // },};
use core::{ ops::{ Deref, DerefMut, // }, str::FromStr,};
/// A trait for types that can be written into a string.////// This works very similarly to `Debug`, and is automatically implemented if `Debug` is/// implemented for a type. It is also implemented for any writable type inside a `Mutex`.////// The derived implementation of `Debug` [may/// change](https://doc.rust-lang.org/std/fmt/trait.Debug.html#stability)/// between Rust versions, so if stability is key for your use case, please implement `Writer`/// explicitly instead.pub trait Writer { /// Formats the value using the given formatter. fn write(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result;}
impl<T: Writer> Writer for Mutex<T> { fn write(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { self.lock().write(f) }}
impl<T: fmt::Debug> Writer for T { fn write(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { writeln!(f, "{self:?}") }}
/// Trait for types that can be written out as binary.pub trait BinaryWriter { /// Writes the binary form of `self` into `writer`. /// /// `offset` is the requested offset into the binary representation of `self`. /// /// On success, returns the number of bytes written in to `writer`. fn write_to_slice( &self, writer: &mut UserSliceWriter, offset: &mut file::Offset, ) -> Result<usize>;}
// Base implementation for any `T: AsBytes`.impl<T: AsBytes> BinaryWriter for T { fn write_to_slice( &self, writer: &mut UserSliceWriter, offset: &mut file::Offset, ) -> Result<usize> { writer.write_slice_file(self.as_bytes(), offset) }}
// Delegate for `Mutex<T>`: Support a `T` with an outer mutex.impl<T: BinaryWriter> BinaryWriter for Mutex<T> { fn write_to_slice( &self, writer: &mut UserSliceWriter, offset: &mut file::Offset, ) -> Result<usize> { let guard = self.lock();
guard.write_to_slice(writer, offset) }}
// Delegate for `Box<T, A>`: Support a `Box<T, A>` with no lock or an inner lock.impl<T, A> BinaryWriter for Box<T, A>where T: BinaryWriter, A: Allocator,{ fn write_to_slice( &self, writer: &mut UserSliceWriter, offset: &mut file::Offset, ) -> Result<usize> { self.deref().write_to_slice(writer, offset) }}
// Delegate for `Pin<Box<T, A>>`: Support a `Pin<Box<T, A>>` with no lock or an inner lock.impl<T, A> BinaryWriter for Pin<Box<T, A>>where T: BinaryWriter, A: Allocator,{ fn write_to_slice( &self, writer: &mut UserSliceWriter, offset: &mut file::Offset, ) -> Result<usize> { self.deref().write_to_slice(writer, offset) }}
// Delegate for `Arc<T>`: Support a `Arc<T>` with no lock or an inner lock.impl<T> BinaryWriter for Arc<T>where T: BinaryWriter,{ fn write_to_slice( &self, writer: &mut UserSliceWriter, offset: &mut file::Offset, ) -> Result<usize> { self.deref().write_to_slice(writer, offset) }}
// Delegate for `Vec<T, A>`.impl<T, A> BinaryWriter for Vec<T, A>where T: AsBytes, A: Allocator,{ fn write_to_slice( &self, writer: &mut UserSliceWriter, offset: &mut file::Offset, ) -> Result<usize> { let slice = self.as_slice();
// SAFETY: `T: AsBytes` allows us to treat `&[T]` as `&[u8]`. let buffer = unsafe { core::slice::from_raw_parts(slice.as_ptr().cast(), core::mem::size_of_val(slice)) };
writer.write_slice_file(buffer, offset) }}
/// A trait for types that can be updated from a user slice.////// This works similarly to `FromStr`, but operates on a `UserSliceReader` rather than a &str.////// It is automatically implemented for all atomic integers, or any type that implements `FromStr`/// wrapped in a `Mutex`.pub trait Reader { /// Updates the value from the given user slice. fn read_from_slice(&self, reader: &mut UserSliceReader) -> Result;}
impl<T: FromStr + Unpin> Reader for Mutex<T> { fn read_from_slice(&self, reader: &mut UserSliceReader) -> Result { let mut buf = [0u8; 128]; if reader.len() > buf.len() { return Err(EINVAL); } let n = reader.len(); reader.read_slice(&mut buf[..n])?;
let s = core::str::from_utf8(&buf[..n]).map_err(|_| EINVAL)?; let val = s.trim().parse::<T>().map_err(|_| EINVAL)?; *self.lock() = val; Ok(()) }}
impl<T: AtomicType + FromStr> Reader for Atomic<T>where T::Repr: AtomicBasicOps,{ fn read_from_slice(&self, reader: &mut UserSliceReader) -> Result { let mut buf = [0u8; 21]; // Enough for a 64-bit number. if reader.len() > buf.len() { return Err(EINVAL); } let n = reader.len(); reader.read_slice(&mut buf[..n])?;
let s = core::str::from_utf8(&buf[..n]).map_err(|_| EINVAL)?; let val = s.trim().parse::<T>().map_err(|_| EINVAL)?; self.store(val, Relaxed); Ok(()) }}
/// Trait for types that can be constructed from a binary representation.////// See also [`BinaryReader`] for interior mutability.pub trait BinaryReaderMut { /// Reads the binary form of `self` from `reader`. /// /// Same as [`BinaryReader::read_from_slice`], but takes a mutable reference. /// /// `offset` is the requested offset into the binary representation of `self`. /// /// On success, returns the number of bytes read from `reader`. fn read_from_slice_mut( &mut self, reader: &mut UserSliceReader, offset: &mut file::Offset, ) -> Result<usize>;}
// Base implementation for any `T: AsBytes + FromBytes`.impl<T: AsBytes + FromBytes> BinaryReaderMut for T { fn read_from_slice_mut( &mut self, reader: &mut UserSliceReader, offset: &mut file::Offset, ) -> Result<usize> { reader.read_slice_file(self.as_bytes_mut(), offset) }}
// Delegate for `Box<T, A>`: Support a `Box<T, A>` with an outer lock.impl<T: ?Sized + BinaryReaderMut, A: Allocator> BinaryReaderMut for Box<T, A> { fn read_from_slice_mut( &mut self, reader: &mut UserSliceReader, offset: &mut file::Offset, ) -> Result<usize> { self.deref_mut().read_from_slice_mut(reader, offset) }}
// Delegate for `Vec<T, A>`: Support a `Vec<T, A>` with an outer lock.impl<T, A> BinaryReaderMut for Vec<T, A>where T: AsBytes + FromBytes, A: Allocator,{ fn read_from_slice_mut( &mut self, reader: &mut UserSliceReader, offset: &mut file::Offset, ) -> Result<usize> { let slice = self.as_mut_slice();
// SAFETY: `T: AsBytes + FromBytes` allows us to treat `&mut [T]` as `&mut [u8]`. let buffer = unsafe { core::slice::from_raw_parts_mut( slice.as_mut_ptr().cast(), core::mem::size_of_val(slice), ) };
reader.read_slice_file(buffer, offset) }}
/// Trait for types that can be constructed from a binary representation.////// See also [`BinaryReaderMut`] for the mutable version.pub trait BinaryReader { /// Reads the binary form of `self` from `reader`. /// /// `offset` is the requested offset into the binary representation of `self`. /// /// On success, returns the number of bytes read from `reader`. fn read_from_slice( &self, reader: &mut UserSliceReader, offset: &mut file::Offset, ) -> Result<usize>;}
// Delegate for `Mutex<T>`: Support a `T` with an outer `Mutex`.impl<T: BinaryReaderMut + Unpin> BinaryReader for Mutex<T> { fn read_from_slice( &self, reader: &mut UserSliceReader, offset: &mut file::Offset, ) -> Result<usize> { let mut this = self.lock();
this.read_from_slice_mut(reader, offset) }}
// Delegate for `Box<T, A>`: Support a `Box<T, A>` with an inner lock.impl<T: ?Sized + BinaryReader, A: Allocator> BinaryReader for Box<T, A> { fn read_from_slice( &self, reader: &mut UserSliceReader, offset: &mut file::Offset, ) -> Result<usize> { self.deref().read_from_slice(reader, offset) }}
// Delegate for `Pin<Box<T, A>>`: Support a `Pin<Box<T, A>>` with an inner lock.impl<T: ?Sized + BinaryReader, A: Allocator> BinaryReader for Pin<Box<T, A>> { fn read_from_slice( &self, reader: &mut UserSliceReader, offset: &mut file::Offset, ) -> Result<usize> { self.deref().read_from_slice(reader, offset) }}
// Delegate for `Arc<T>`: Support an `Arc<T>` with an inner lock.impl<T: ?Sized + BinaryReader> BinaryReader for Arc<T> { fn read_from_slice( &self, reader: &mut UserSliceReader, offset: &mut file::Offset, ) -> Result<usize> { self.deref().read_from_slice(reader, offset) }}