diff options
Diffstat (limited to 'rust/kernel/debugfs')
| -rw-r--r-- | rust/kernel/debugfs/callback_adapters.rs | 7 | ||||
| -rw-r--r-- | rust/kernel/debugfs/entry.rs | 2 | ||||
| -rw-r--r-- | rust/kernel/debugfs/file_ops.rs | 146 | ||||
| -rw-r--r-- | rust/kernel/debugfs/traits.rs | 307 |
4 files changed, 408 insertions, 54 deletions
diff --git a/rust/kernel/debugfs/callback_adapters.rs b/rust/kernel/debugfs/callback_adapters.rs index 6c024230f676..a260d8dee051 100644 --- a/rust/kernel/debugfs/callback_adapters.rs +++ b/rust/kernel/debugfs/callback_adapters.rs @@ -5,10 +5,9 @@ //! than a trait implementation. If provided, it will override the trait implementation. use super::{Reader, Writer}; +use crate::fmt; use crate::prelude::*; use crate::uaccess::UserSliceReader; -use core::fmt; -use core::fmt::Formatter; use core::marker::PhantomData; use core::ops::Deref; @@ -76,9 +75,9 @@ impl<D, F> Deref for FormatAdapter<D, F> { impl<D, F> Writer for FormatAdapter<D, F> where - F: Fn(&D, &mut Formatter<'_>) -> fmt::Result + 'static, + F: Fn(&D, &mut fmt::Formatter<'_>) -> fmt::Result + 'static, { - fn write(&self, fmt: &mut Formatter<'_>) -> fmt::Result { + fn write(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { // SAFETY: FormatAdapter<_, F> can only be constructed if F is inhabited let f: &F = unsafe { materialize_zst() }; f(&self.inner, fmt) diff --git a/rust/kernel/debugfs/entry.rs b/rust/kernel/debugfs/entry.rs index f99402cd3ba0..706cb7f73d6c 100644 --- a/rust/kernel/debugfs/entry.rs +++ b/rust/kernel/debugfs/entry.rs @@ -3,7 +3,7 @@ use crate::debugfs::file_ops::FileOps; use crate::ffi::c_void; -use crate::str::CStr; +use crate::str::{CStr, CStrExt as _}; use crate::sync::Arc; use core::marker::PhantomData; diff --git a/rust/kernel/debugfs/file_ops.rs b/rust/kernel/debugfs/file_ops.rs index 50fead17b6f3..8a0442d6dd7a 100644 --- a/rust/kernel/debugfs/file_ops.rs +++ b/rust/kernel/debugfs/file_ops.rs @@ -1,13 +1,14 @@ // SPDX-License-Identifier: GPL-2.0 // Copyright (C) 2025 Google LLC. -use super::{Reader, Writer}; +use super::{BinaryReader, BinaryWriter, Reader, Writer}; use crate::debugfs::callback_adapters::Adapter; +use crate::fmt; +use crate::fs::file; use crate::prelude::*; use crate::seq_file::SeqFile; use crate::seq_print; use crate::uaccess::UserSlice; -use core::fmt::{Display, Formatter, Result}; use core::marker::PhantomData; #[cfg(CONFIG_DEBUG_FS)] @@ -65,8 +66,8 @@ impl<T> Deref for FileOps<T> { struct WriterAdapter<T>(T); -impl<'a, T: Writer> Display for WriterAdapter<&'a T> { - fn fmt(&self, f: &mut Formatter<'_>) -> Result { +impl<'a, T: Writer> fmt::Display for WriterAdapter<&'a T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { self.0.write(f) } } @@ -245,3 +246,140 @@ impl<T: Reader + Sync> WriteFile<T> for T { unsafe { FileOps::new(operations, 0o200) } }; } + +extern "C" fn blob_read<T: BinaryWriter>( + file: *mut bindings::file, + buf: *mut c_char, + count: usize, + ppos: *mut bindings::loff_t, +) -> isize { + // SAFETY: + // - `file` is a valid pointer to a `struct file`. + // - The type invariant of `FileOps` guarantees that `private_data` points to a valid `T`. + let this = unsafe { &*((*file).private_data.cast::<T>()) }; + + // SAFETY: + // - `ppos` is a valid `file::Offset` pointer. + // - We have exclusive access to `ppos`. + let pos: &mut file::Offset = unsafe { &mut *ppos }; + + let mut writer = UserSlice::new(UserPtr::from_ptr(buf.cast()), count).writer(); + + let ret = || -> Result<isize> { + let written = this.write_to_slice(&mut writer, pos)?; + + Ok(written.try_into()?) + }(); + + match ret { + Ok(n) => n, + Err(e) => e.to_errno() as isize, + } +} + +/// Representation of [`FileOps`] for read only binary files. +pub(crate) trait BinaryReadFile<T> { + const FILE_OPS: FileOps<T>; +} + +impl<T: BinaryWriter + Sync> BinaryReadFile<T> for T { + const FILE_OPS: FileOps<T> = { + let operations = bindings::file_operations { + read: Some(blob_read::<T>), + llseek: Some(bindings::default_llseek), + open: Some(bindings::simple_open), + // SAFETY: `file_operations` supports zeroes in all fields. + ..unsafe { core::mem::zeroed() } + }; + + // SAFETY: + // - The private data of `struct inode` does always contain a pointer to a valid `T`. + // - `simple_open()` stores the `struct inode`'s private data in the private data of the + // corresponding `struct file`. + // - `blob_read()` re-creates a reference to `T` from the `struct file`'s private data. + // - `default_llseek()` does not access the `struct file`'s private data. + unsafe { FileOps::new(operations, 0o400) } + }; +} + +extern "C" fn blob_write<T: BinaryReader>( + file: *mut bindings::file, + buf: *const c_char, + count: usize, + ppos: *mut bindings::loff_t, +) -> isize { + // SAFETY: + // - `file` is a valid pointer to a `struct file`. + // - The type invariant of `FileOps` guarantees that `private_data` points to a valid `T`. + let this = unsafe { &*((*file).private_data.cast::<T>()) }; + + // SAFETY: + // - `ppos` is a valid `file::Offset` pointer. + // - We have exclusive access to `ppos`. + let pos: &mut file::Offset = unsafe { &mut *ppos }; + + let mut reader = UserSlice::new(UserPtr::from_ptr(buf.cast_mut().cast()), count).reader(); + + let ret = || -> Result<isize> { + let read = this.read_from_slice(&mut reader, pos)?; + + Ok(read.try_into()?) + }(); + + match ret { + Ok(n) => n, + Err(e) => e.to_errno() as isize, + } +} + +/// Representation of [`FileOps`] for write only binary files. +pub(crate) trait BinaryWriteFile<T> { + const FILE_OPS: FileOps<T>; +} + +impl<T: BinaryReader + Sync> BinaryWriteFile<T> for T { + const FILE_OPS: FileOps<T> = { + let operations = bindings::file_operations { + write: Some(blob_write::<T>), + llseek: Some(bindings::default_llseek), + open: Some(bindings::simple_open), + // SAFETY: `file_operations` supports zeroes in all fields. + ..unsafe { core::mem::zeroed() } + }; + + // SAFETY: + // - The private data of `struct inode` does always contain a pointer to a valid `T`. + // - `simple_open()` stores the `struct inode`'s private data in the private data of the + // corresponding `struct file`. + // - `blob_write()` re-creates a reference to `T` from the `struct file`'s private data. + // - `default_llseek()` does not access the `struct file`'s private data. + unsafe { FileOps::new(operations, 0o200) } + }; +} + +/// Representation of [`FileOps`] for read/write binary files. +pub(crate) trait BinaryReadWriteFile<T> { + const FILE_OPS: FileOps<T>; +} + +impl<T: BinaryWriter + BinaryReader + Sync> BinaryReadWriteFile<T> for T { + const FILE_OPS: FileOps<T> = { + let operations = bindings::file_operations { + read: Some(blob_read::<T>), + write: Some(blob_write::<T>), + llseek: Some(bindings::default_llseek), + open: Some(bindings::simple_open), + // SAFETY: `file_operations` supports zeroes in all fields. + ..unsafe { core::mem::zeroed() } + }; + + // SAFETY: + // - The private data of `struct inode` does always contain a pointer to a valid `T`. + // - `simple_open()` stores the `struct inode`'s private data in the private data of the + // corresponding `struct file`. + // - `blob_read()` re-creates a reference to `T` from the `struct file`'s private data. + // - `blob_write()` re-creates a reference to `T` from the `struct file`'s private data. + // - `default_llseek()` does not access the `struct file`'s private data. + unsafe { FileOps::new(operations, 0o600) } + }; +} diff --git a/rust/kernel/debugfs/traits.rs b/rust/kernel/debugfs/traits.rs index ab009eb254b3..3eee60463fd5 100644 --- a/rust/kernel/debugfs/traits.rs +++ b/rust/kernel/debugfs/traits.rs @@ -3,15 +3,17 @@ //! Traits for rendering or updating values exported to DebugFS. +use crate::alloc::Allocator; +use crate::fmt; +use crate::fs::file; use crate::prelude::*; +use crate::sync::atomic::{Atomic, AtomicBasicOps, AtomicType, Relaxed}; +use crate::sync::Arc; use crate::sync::Mutex; -use crate::uaccess::UserSliceReader; -use core::fmt::{self, Debug, Formatter}; +use crate::transmute::{AsBytes, FromBytes}; +use crate::uaccess::{UserSliceReader, UserSliceWriter}; +use core::ops::{Deref, DerefMut}; use core::str::FromStr; -use core::sync::atomic::{ - AtomicI16, AtomicI32, AtomicI64, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU64, - AtomicU8, AtomicUsize, Ordering, -}; /// A trait for types that can be written into a string. /// @@ -24,21 +26,125 @@ use core::sync::atomic::{ /// explicitly instead. pub trait Writer { /// Formats the value using the given formatter. - fn write(&self, f: &mut Formatter<'_>) -> fmt::Result; + fn write(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result; } impl<T: Writer> Writer for Mutex<T> { - fn write(&self, f: &mut Formatter<'_>) -> fmt::Result { + fn write(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { self.lock().write(f) } } -impl<T: Debug> Writer for T { - fn write(&self, f: &mut Formatter<'_>) -> fmt::Result { +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. @@ -50,7 +156,7 @@ pub trait Reader { fn read_from_slice(&self, reader: &mut UserSliceReader) -> Result; } -impl<T: FromStr> Reader for Mutex<T> { +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() { @@ -66,37 +172,148 @@ impl<T: FromStr> Reader for Mutex<T> { } } -macro_rules! impl_reader_for_atomic { - ($(($atomic_type:ty, $int_type:ty)),*) => { - $( - impl Reader for $atomic_type { - fn read_from_slice(&self, reader: &mut UserSliceReader) -> Result { - let mut buf = [0u8; 21]; // Enough for a 64-bit number. - if reader.len() > buf.len() { - return Err(EINVAL); - } - let n = reader.len(); - reader.read_slice(&mut buf[..n])?; - - let s = core::str::from_utf8(&buf[..n]).map_err(|_| EINVAL)?; - let val = s.trim().parse::<$int_type>().map_err(|_| EINVAL)?; - self.store(val, Ordering::Relaxed); - Ok(()) - } - } - )* - }; -} - -impl_reader_for_atomic!( - (AtomicI16, i16), - (AtomicI32, i32), - (AtomicI64, i64), - (AtomicI8, i8), - (AtomicIsize, isize), - (AtomicU16, u16), - (AtomicU32, u32), - (AtomicU64, u64), - (AtomicU8, u8), - (AtomicUsize, usize) -); +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) + } +} |