[PATCH v3 18/25] rust: treewide: switch to the kernel `Vec` type

Danilo Krummrich
2024-08-01T00:08:31Z

Now that we got the kernel `Vec` in place, convert all existing `Vec`
users to make use of it.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
rust/kernel/str.rs | 12 +++++-------
rust/kernel/sync/locked_by.rs | 2 +-
rust/kernel/types.rs | 2 +-
rust/kernel/uaccess.rs | 15 ++++++---------
samples/rust/rust_minimal.rs | 4 ++--
5 files changed, 15 insertions(+), 20 deletions(-)

diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index bb8d4f41475b..0b6ffbade521 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -2,8 +2,7 @@

//! String representations.

-use crate::alloc::{flags::*, vec_ext::VecExt, AllocError};
-use alloc::vec::Vec;
+use crate::alloc::{flags::*, AllocError, KVec};
use core::fmt::{self, Write};
use core::ops::{self, Deref, DerefMut, Index};

@@ -790,7 +789,7 @@ fn write_str(&mut self, s: &str) -> fmt::Result {
/// assert_eq!(s.is_ok(), false);
/// ```
pub struct CString {
- buf: Vec<u8>,
+ buf: KVec<u8>,
}

impl CString {
@@ -803,7 +802,7 @@ pub fn try_from_fmt(args: fmt::Arguments<'_>) -> Result<Self, Error> {
let size = f.bytes_written();

// Allocate a vector with the required number of bytes, and write to it.
- let mut buf = <Vec<_> as VecExt<_>>::with_capacity(size, GFP_KERNEL)?;
+ let mut buf = KVec::with_capacity(size, GFP_KERNEL)?;
// SAFETY: The buffer stored in `buf` is at least of size `size` and is valid for writes.
let mut f = unsafe { Formatter::from_buffer(buf.as_mut_ptr(), size) };
f.write_fmt(args)?;
@@ -850,10 +849,9 @@ impl<'a> TryFrom<&'a CStr> for CString {
type Error = AllocError;

fn try_from(cstr: &'a CStr) -> Result<CString, AllocError> {
- let mut buf = Vec::new();
+ let mut buf = KVec::new();

- <Vec<_> as VecExt<_>>::extend_from_slice(&mut buf, cstr.as_bytes_with_nul(), GFP_KERNEL)
- .map_err(|_| AllocError)?;
+ KVec::extend_from_slice(&mut buf, cstr.as_bytes_with_nul(), GFP_KERNEL)?;

// INVARIANT: The `CStr` and `CString` types have the same invariants for
// the string data, and we copied it over without changes.
diff --git a/rust/kernel/sync/locked_by.rs b/rust/kernel/sync/locked_by.rs
index babc731bd5f6..b94517231fcc 100644
--- a/rust/kernel/sync/locked_by.rs
+++ b/rust/kernel/sync/locked_by.rs
@@ -43,7 +43,7 @@
/// struct InnerDirectory {
/// /// The sum of the bytes used by all files.
/// bytes_used: u64,
-/// _files: Vec<File>,
+/// _files: KVec<File>,
/// }
///
/// struct Directory {
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index 809653b9d945..1d90d2c68f74 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -158,7 +158,7 @@ unsafe fn from_foreign(_: *const core::ffi::c_void) -> Self {}
/// # use kernel::types::ScopeGuard;
/// fn example3(arg: bool) -> Result {
/// let mut vec =
-/// ScopeGuard::new_with_data(Vec::new(), |v| pr_info!("vec had {} elements\n", v.len()));
+/// ScopeGuard::new_with_data(KVec::new(), |v| pr_info!("vec had {} elements\n", v.len()));
///
/// vec.push(10u8, GFP_KERNEL)?;
/// if arg {
diff --git a/rust/kernel/uaccess.rs b/rust/kernel/uaccess.rs
index e9347cff99ab..d19002308636 100644
--- a/rust/kernel/uaccess.rs
+++ b/rust/kernel/uaccess.rs
@@ -11,7 +11,6 @@
prelude::*,
types::{AsBytes, FromBytes},
};
-use alloc::vec::Vec;
use core::ffi::{c_ulong, c_void};
use core::mem::{size_of, MaybeUninit};

@@ -46,7 +45,6 @@
/// every byte in the region.
///
/// ```no_run
-/// use alloc::vec::Vec;
/// use core::ffi::c_void;
/// use kernel::error::Result;
/// use kernel::uaccess::{UserPtr, UserSlice};
@@ -54,7 +52,7 @@
/// fn bytes_add_one(uptr: UserPtr, len: usize) -> Result<()> {
/// let (read, mut write) = UserSlice::new(uptr, len).reader_writer();
///
-/// let mut buf = Vec::new();
+/// let mut buf = KVec::new();
/// read.read_all(&mut buf, GFP_KERNEL)?;
///
/// for b in &mut buf {
@@ -69,7 +67,6 @@
/// Example illustrating a TOCTOU (time-of-check to time-of-use) bug.
///
/// ```no_run
-/// use alloc::vec::Vec;
/// use core::ffi::c_void;
/// use kernel::error::{code::EINVAL, Result};
/// use kernel::uaccess::{UserPtr, UserSlice};
@@ -78,14 +75,14 @@
/// fn is_valid(uptr: UserPtr, len: usize) -> Result<bool> {
/// let read = UserSlice::new(uptr, len).reader();
///
-/// let mut buf = Vec::new();
+/// let mut buf = KVec::new();
/// read.read_all(&mut buf, GFP_KERNEL)?;
///
/// todo!()
/// }
///
/// /// Returns the bytes behind this user pointer if they are valid.
-/// fn get_bytes_if_valid(uptr: UserPtr, len: usize) -> Result<Vec<u8>> {
+/// fn get_bytes_if_valid(uptr: UserPtr, len: usize) -> Result<KVec<u8>> {
/// if !is_valid(uptr, len)? {
/// return Err(EINVAL);
/// }
@@ -130,7 +127,7 @@ pub fn new(ptr: UserPtr, length: usize) -> Self {
/// Reads the entirety of the user slice, appending it to the end of the provided buffer.
///
/// Fails with [`EFAULT`] if the read happens on a bad address.
- pub fn read_all(self, buf: &mut Vec<u8>, flags: Flags) -> Result {
+ pub fn read_all(self, buf: &mut KVec<u8>, flags: Flags) -> Result {
self.reader().read_all(buf, flags)
}

@@ -291,9 +288,9 @@ pub fn read<T: FromBytes>(&mut self) -> Result<T> {
/// Reads the entirety of the user slice, appending it to the end of the provided buffer.
///
/// Fails with [`EFAULT`] if the read happens on a bad address.
- pub fn read_all(mut self, buf: &mut Vec<u8>, flags: Flags) -> Result {
+ pub fn read_all(mut self, buf: &mut KVec<u8>, flags: Flags) -> Result {
let len = self.length;
- VecExt::<u8>::reserve(buf, len, flags)?;
+ KVec::<u8>::reserve(buf, len, flags)?;

// The call to `try_reserve` was successful, so the spare capacity is at least `len` bytes
// long.
diff --git a/samples/rust/rust_minimal.rs b/samples/rust/rust_minimal.rs
index 2a9eaab62d1c..4aaf117bf8e3 100644
--- a/samples/rust/rust_minimal.rs
+++ b/samples/rust/rust_minimal.rs
@@ -13,7 +13,7 @@
}

struct RustMinimal {
- numbers: Vec<i32>,
+ numbers: KVec<i32>,
}

impl kernel::Module for RustMinimal {
@@ -21,7 +21,7 @@ fn init(_module: &'static ThisModule) -> Result<Self> {
pr_info!("Rust minimal sample (init)\n");
pr_info!("Am I built-in? {}\n", !cfg!(MODULE));

- let mut numbers = Vec::new();
+ let mut numbers = KVec::new();
numbers.push(72, GFP_KERNEL)?;
numbers.push(108, GFP_KERNEL)?;
numbers.push(200, GFP_KERNEL)?;
--
2.45.2