Tamir Duberstein
2025-May-30 12:27 UTC
[PATCH v11 0/5] rust: replace kernel::str::CStr w/ core::ffi::CStr
This picks up from Michal Rostecki's work[0]. Per Michal's guidance I
have omitted Co-authored tags, as the end result is quite different.
Link: https://lore.kernel.org/rust-for-linux/20240819153656.28807-2-vadorovsky
at protonmail.com/t/#u [0]
Closes: https://github.com/Rust-for-Linux/linux/issues/1075
Signed-off-by: Tamir Duberstein <tamird at gmail.com>
---
Changes in v11:
- Use `quote_spanned!` to avoid `use<'a, T>` and generally reduce
manual
token construction.
- Add a commit to simplify `quote_spanned!`.
- Drop first commit in favor of
https://lore.kernel.org/rust-for-linux/20240906164448.2268368-1-paddymills at
proton.me/.
(Miguel Ojeda)
- Correctly handle expressions such as `pr_info!("{a}", a = a = a)`.
(Benno Lossin)
- Avoid dealing with `}}` escapes, which is not needed. (Benno Lossin)
- Revert some unnecessary changes. (Benno Lossin)
- Rename `c_str_avoid_literals!` to `str_to_cstr!`. (Benno Lossin &
Alice Ryhl).
- Link to v10: https://lore.kernel.org/r/20250524-cstr-core-v10-0-6412a94d9d75
at gmail.com
Changes in v10:
- Rebase on cbeaa41dfe26b72639141e87183cb23e00d4b0dd.
- Implement Alice's suggestion to use a proc macro to work around orphan
rules otherwise preventing `core::ffi::CStr` to be directly printed
with `{}`.
- Link to v9: https://lore.kernel.org/r/20250317-cstr-core-v9-0-51d6cc522f62 at
gmail.com
Changes in v9:
- Rebase on rust-next.
- Restore `impl Display for BStr` which exists upstream[1].
- Link:
https://doc.rust-lang.org/nightly/std/bstr/struct.ByteStr.html#impl-Display-for-ByteStr
[1]
- Link to v8: https://lore.kernel.org/r/20250203-cstr-core-v8-0-cb3f26e78686 at
gmail.com
Changes in v8:
- Move `{from,as}_char_ptr` back to `CStrExt`. This reduces the diff
some.
- Restore `from_bytes_with_nul_unchecked_mut`, `to_cstring`.
- Link to v7: https://lore.kernel.org/r/20250202-cstr-core-v7-0-da1802520438 at
gmail.com
Changes in v7:
- Rebased on mainline.
- Restore functionality added in commit a321f3ad0a5d ("rust: str: add
{make,to}_{upper,lower}case() to CString").
- Used `diff.algorithm patience` to improve diff readability.
- Link to v6: https://lore.kernel.org/r/20250202-cstr-core-v6-0-8469cd6d29fd at
gmail.com
Changes in v6:
- Split the work into several commits for ease of review.
- Restore `{from,as}_char_ptr` to allow building on ARM (see commit
message).
- Add `CStrExt` to `kernel::prelude`. (Alice Ryhl)
- Remove `CStrExt::from_bytes_with_nul_unchecked_mut` and restore
`DerefMut for CString`. (Alice Ryhl)
- Rename and hide `kernel::c_str!` to encourage use of C-String
literals.
- Drop implementation and invocation changes in kunit.rs. (Trevor Gross)
- Drop docs on `Display` impl. (Trevor Gross)
- Rewrite docs in the style of the standard library.
- Restore the `test_cstr_debug` unit tests to demonstrate that the
implementation has changed.
Changes in v5:
- Keep the `test_cstr_display*` unit tests.
Changes in v4:
- Provide the `CStrExt` trait with `display()` method, which returns a
`CStrDisplay` wrapper with `Display` implementation. This addresses
the lack of `Display` implementation for `core::ffi::CStr`.
- Provide `from_bytes_with_nul_unchecked_mut()` method in `CStrExt`,
which might be useful and is going to prevent manual, unsafe casts.
- Fix a typo (s/preffered/prefered/).
Changes in v3:
- Fix the commit message.
- Remove redundant braces in `use`, when only one item is imported.
Changes in v2:
- Do not remove `c_str` macro. While it's preferred to use C-string
literals, there are two cases where `c_str` is helpful:
- When working with macros, which already return a Rust string literal
(e.g. `stringify!`).
- When building macros, where we want to take a Rust string literal as an
argument (for caller's convenience), but still use it as a C-string
internally.
- Use Rust literals as arguments in macros (`new_mutex`, `new_condvar`,
`new_mutex`). Use the `c_str` macro to convert these literals to C-string
literals.
- Use `c_str` in kunit.rs for converting the output of `stringify!` to a
`CStr`.
- Remove `DerefMut` implementation for `CString`.
---
Tamir Duberstein (5):
rust: macros: reduce collections in `quote!` macro
rust: support formatting of foreign types
rust: replace `CStr` with `core::ffi::CStr`
rust: replace `kernel::c_str!` with C-Strings
rust: remove core::ffi::CStr reexport
drivers/block/rnull.rs | 4 +-
drivers/gpu/drm/drm_panic_qr.rs | 5 +-
drivers/gpu/nova-core/driver.rs | 2 +-
drivers/gpu/nova-core/firmware.rs | 2 +-
drivers/net/phy/ax88796b_rust.rs | 8 +-
drivers/net/phy/qt2025.rs | 6 +-
rust/kernel/block/mq.rs | 2 +-
rust/kernel/device.rs | 9 +-
rust/kernel/devres.rs | 2 +-
rust/kernel/driver.rs | 4 +-
rust/kernel/error.rs | 10 +-
rust/kernel/faux.rs | 5 +-
rust/kernel/firmware.rs | 16 +-
rust/kernel/fmt.rs | 77 ++++++
rust/kernel/kunit.rs | 21 +-
rust/kernel/lib.rs | 3 +-
rust/kernel/miscdevice.rs | 5 +-
rust/kernel/net/phy.rs | 12 +-
rust/kernel/of.rs | 5 +-
rust/kernel/pci.rs | 2 +-
rust/kernel/platform.rs | 6 +-
rust/kernel/prelude.rs | 5 +-
rust/kernel/print.rs | 4 +-
rust/kernel/seq_file.rs | 6 +-
rust/kernel/str.rs | 443 ++++++++++-------------------------
rust/kernel/sync.rs | 7 +-
rust/kernel/sync/condvar.rs | 4 +-
rust/kernel/sync/lock.rs | 4 +-
rust/kernel/sync/lock/global.rs | 6 +-
rust/kernel/sync/poll.rs | 1 +
rust/kernel/workqueue.rs | 9 +-
rust/macros/fmt.rs | 99 ++++++++
rust/macros/kunit.rs | 10 +-
rust/macros/lib.rs | 19 ++
rust/macros/module.rs | 2 +-
rust/macros/quote.rs | 111 ++++-----
samples/rust/rust_driver_faux.rs | 4 +-
samples/rust/rust_driver_pci.rs | 4 +-
samples/rust/rust_driver_platform.rs | 4 +-
samples/rust/rust_misc_device.rs | 3 +-
scripts/rustdoc_test_gen.rs | 6 +-
41 files changed, 485 insertions(+), 472 deletions(-)
---
base-commit: 7a17bbc1d952057898cb0739e60665908fbb8c72
change-id: 20250201-cstr-core-d4b9b69120cf
Best regards,
--
Tamir Duberstein <tamird at gmail.com>
Tamir Duberstein
2025-May-30 12:27 UTC
[PATCH v11 1/5] rust: macros: reduce collections in `quote!` macro
Remove a handful of unncessary intermediate vectors and token streams;
mainly the top-level stream can be directly extended with the notable
exception of groups.
Remove an unnecessary `#[allow(dead_code)]` added in commit dbd5058ba60c
("rust: make pin-init its own crate").
Signed-off-by: Tamir Duberstein <tamird at gmail.com>
---
rust/macros/quote.rs | 104 ++++++++++++++++++++++++---------------------------
1 file changed, 49 insertions(+), 55 deletions(-)
diff --git a/rust/macros/quote.rs b/rust/macros/quote.rs
index 92cacc4067c9..acc140c18653 100644
--- a/rust/macros/quote.rs
+++ b/rust/macros/quote.rs
@@ -2,7 +2,6 @@
use proc_macro::{TokenStream, TokenTree};
-#[allow(dead_code)]
pub(crate) trait ToTokens {
fn to_tokens(&self, tokens: &mut TokenStream);
}
@@ -47,121 +46,116 @@ fn to_tokens(&self, tokens: &mut TokenStream) {
/// `quote` crate but provides only just enough functionality needed by the
current `macros` crate.
macro_rules! quote_spanned {
($span:expr => $($tt:tt)*) => {{
- let mut tokens: ::std::vec::Vec<::proc_macro::TokenTree>;
- #[allow(clippy::vec_init_then_push)]
+ let mut tokens = ::proc_macro::TokenStream::new();
{
- tokens = ::std::vec::Vec::new();
let span = $span;
quote_spanned!(@proc tokens span $($tt)*);
}
- ::proc_macro::TokenStream::from_iter(tokens)
+ tokens
}};
(@proc $v:ident $span:ident) => {};
(@proc $v:ident $span:ident #$id:ident $($tt:tt)*) => {
- let mut ts = ::proc_macro::TokenStream::new();
- $crate::quote::ToTokens::to_tokens(&$id, &mut ts);
- $v.extend(ts);
+ $crate::quote::ToTokens::to_tokens(&$id, &mut $v);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident #(#$id:ident)* $($tt:tt)*) => {
for token in $id {
- let mut ts = ::proc_macro::TokenStream::new();
- $crate::quote::ToTokens::to_tokens(&token, &mut ts);
- $v.extend(ts);
+ $crate::quote::ToTokens::to_tokens(&token, &mut $v);
}
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident ( $($inner:tt)* ) $($tt:tt)*) => {
#[allow(unused_mut)]
- let mut tokens =
::std::vec::Vec::<::proc_macro::TokenTree>::new();
+ let mut tokens = ::proc_macro::TokenStream::new();
quote_spanned!(@proc tokens $span $($inner)*);
- $v.push(::proc_macro::TokenTree::Group(::proc_macro::Group::new(
+ $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
::proc_macro::Delimiter::Parenthesis,
- ::proc_macro::TokenStream::from_iter(tokens)
- )));
+ tokens,
+ ))]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident [ $($inner:tt)* ] $($tt:tt)*) => {
- let mut tokens = ::std::vec::Vec::new();
+ let mut tokens = ::proc_macro::TokenStream::new();
quote_spanned!(@proc tokens $span $($inner)*);
- $v.push(::proc_macro::TokenTree::Group(::proc_macro::Group::new(
+ $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
::proc_macro::Delimiter::Bracket,
- ::proc_macro::TokenStream::from_iter(tokens)
- )));
+ tokens,
+ ))]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident { $($inner:tt)* } $($tt:tt)*) => {
- let mut tokens = ::std::vec::Vec::new();
+ let mut tokens = ::proc_macro::TokenStream::new();
quote_spanned!(@proc tokens $span $($inner)*);
- $v.push(::proc_macro::TokenTree::Group(::proc_macro::Group::new(
+ $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
::proc_macro::Delimiter::Brace,
- ::proc_macro::TokenStream::from_iter(tokens)
- )));
+ tokens,
+ ))]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident :: $($tt:tt)*) => {
- $v.push(::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new(':',
::proc_macro::Spacing::Joint)
- ));
- $v.push(::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new(':',
::proc_macro::Spacing::Alone)
- ));
+ $v.extend([::proc_macro::Spacing::Joint,
::proc_macro::Spacing::Alone].map(|spacing| {
+
::proc_macro::TokenTree::Punct(::proc_macro::Punct::new(':', spacing))
+ }));
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident : $($tt:tt)*) => {
- $v.push(::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new(':',
::proc_macro::Spacing::Alone)
- ));
+ $v.extend([::proc_macro::TokenTree::Punct(
+ ::proc_macro::Punct::new(':',
::proc_macro::Spacing::Alone),
+ )]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident , $($tt:tt)*) => {
- $v.push(::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new(',',
::proc_macro::Spacing::Alone)
- ));
+ $v.extend([::proc_macro::TokenTree::Punct(
+ ::proc_macro::Punct::new(',',
::proc_macro::Spacing::Alone),
+ )]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident @ $($tt:tt)*) => {
- $v.push(::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new('@',
::proc_macro::Spacing::Alone)
- ));
+ $v.extend([::proc_macro::TokenTree::Punct(
+ ::proc_macro::Punct::new('@',
::proc_macro::Spacing::Alone),
+ )]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident ! $($tt:tt)*) => {
- $v.push(::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new('!',
::proc_macro::Spacing::Alone)
- ));
+ $v.extend([::proc_macro::TokenTree::Punct(
+ ::proc_macro::Punct::new('!',
::proc_macro::Spacing::Alone),
+ )]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident ; $($tt:tt)*) => {
- $v.push(::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new(';',
::proc_macro::Spacing::Alone)
- ));
+ $v.extend([::proc_macro::TokenTree::Punct(
+ ::proc_macro::Punct::new(';',
::proc_macro::Spacing::Alone),
+ )]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident + $($tt:tt)*) => {
- $v.push(::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new('+',
::proc_macro::Spacing::Alone)
- ));
+ $v.extend([::proc_macro::TokenTree::Punct(
+ ::proc_macro::Punct::new('+',
::proc_macro::Spacing::Alone),
+ )]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident = $($tt:tt)*) => {
- $v.push(::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new('=',
::proc_macro::Spacing::Alone)
- ));
+ $v.extend([::proc_macro::TokenTree::Punct(
+ ::proc_macro::Punct::new('=',
::proc_macro::Spacing::Alone),
+ )]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident # $($tt:tt)*) => {
- $v.push(::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new('#',
::proc_macro::Spacing::Alone)
- ));
+ $v.extend([::proc_macro::TokenTree::Punct(
+ ::proc_macro::Punct::new('#',
::proc_macro::Spacing::Alone),
+ )]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident _ $($tt:tt)*) => {
-
$v.push(::proc_macro::TokenTree::Ident(::proc_macro::Ident::new("_",
$span)));
+ $v.extend([::proc_macro::TokenTree::Ident(
+ ::proc_macro::Ident::new("_", $span),
+ )]);
quote_spanned!(@proc $v $span $($tt)*);
};
(@proc $v:ident $span:ident $id:ident $($tt:tt)*) => {
-
$v.push(::proc_macro::TokenTree::Ident(::proc_macro::Ident::new(stringify!($id),
$span)));
+ $v.extend([::proc_macro::TokenTree::Ident(
+ ::proc_macro::Ident::new(stringify!($id), $span),
+ )]);
quote_spanned!(@proc $v $span $($tt)*);
};
}
--
2.49.0
Tamir Duberstein
2025-May-30 12:27 UTC
[PATCH v11 2/5] rust: support formatting of foreign types
Introduce a `fmt!` macro which wraps all arguments in
`kernel::fmt::Adapter` This enables formatting of foreign types (like
`core::ffi::CStr`) that do not implement `fmt::Display` due to concerns
around lossy conversions which do not apply in the kernel.
Replace all direct calls to `format_args!` with `fmt!`.
In preparation for replacing our `CStr` with `core::ffi::CStr`, move its
`fmt::Display` implementation to `kernel::fmt::Adapter<&CStr>`.
Suggested-by: Alice Ryhl <aliceryhl at google.com>
Link:
https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/Custom.20formatting/with/516476467
Signed-off-by: Tamir Duberstein <tamird at gmail.com>
---
drivers/block/rnull.rs | 2 +-
rust/kernel/block/mq.rs | 2 +-
rust/kernel/device.rs | 2 +-
rust/kernel/fmt.rs | 77 +++++++++++++++++++++++++++++++++++
rust/kernel/kunit.rs | 6 +--
rust/kernel/lib.rs | 1 +
rust/kernel/prelude.rs | 3 +-
rust/kernel/print.rs | 4 +-
rust/kernel/seq_file.rs | 2 +-
rust/kernel/str.rs | 23 +++++------
rust/macros/fmt.rs | 99 +++++++++++++++++++++++++++++++++++++++++++++
rust/macros/lib.rs | 19 +++++++++
rust/macros/quote.rs | 7 ++++
scripts/rustdoc_test_gen.rs | 2 +-
14 files changed, 223 insertions(+), 26 deletions(-)
diff --git a/drivers/block/rnull.rs b/drivers/block/rnull.rs
index d07e76ae2c13..6366da12c5a5 100644
--- a/drivers/block/rnull.rs
+++ b/drivers/block/rnull.rs
@@ -51,7 +51,7 @@ fn init(_module: &'static ThisModule) -> impl
PinInit<Self, Error> {
.logical_block_size(4096)?
.physical_block_size(4096)?
.rotational(false)
- .build(format_args!("rnullb{}", 0), tagset)
+ .build(fmt!("rnullb{}", 0), tagset)
})();
try_pin_init!(Self {
diff --git a/rust/kernel/block/mq.rs b/rust/kernel/block/mq.rs
index fb0f393c1cea..842be88aa1cf 100644
--- a/rust/kernel/block/mq.rs
+++ b/rust/kernel/block/mq.rs
@@ -82,7 +82,7 @@
//! Arc::pin_init(TagSet::new(1, 256, 1), flags::GFP_KERNEL)?;
//! let mut disk = gen_disk::GenDiskBuilder::new()
//! .capacity_sectors(4096)
-//! .build(format_args!("myblk"), tagset)?;
+//! .build(fmt!("myblk"), tagset)?;
//!
//! # Ok::<(), kernel::error::Error>(())
//! ```
diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
index 539888465cc6..99d99a76934c 100644
--- a/rust/kernel/device.rs
+++ b/rust/kernel/device.rs
@@ -240,7 +240,7 @@ impl DeviceContext for Normal {}
macro_rules! dev_printk {
($method:ident, $dev:expr, $($f:tt)*) => {
{
- ($dev).$method(::core::format_args!($($f)*));
+ ($dev).$method($crate::prelude::fmt!($($f)*));
}
}
}
diff --git a/rust/kernel/fmt.rs b/rust/kernel/fmt.rs
new file mode 100644
index 000000000000..12b08debc3b3
--- /dev/null
+++ b/rust/kernel/fmt.rs
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Formatting utilities.
+
+use core::fmt;
+
+/// Internal adapter used to route allow implementations of formatting traits
for foreign types.
+///
+/// It is inserted automatically by the [`fmt!`] macro and is not meant to be
used directly.
+///
+/// [`fmt!`]: crate::prelude::fmt!
+#[doc(hidden)]
+pub struct Adapter<T>(pub T);
+
+macro_rules! impl_fmt_adapter_forward {
+ ($($trait:ident),* $(,)?) => {
+ $(
+ impl<T: fmt::$trait> fmt::$trait for Adapter<T> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>)
-> fmt::Result {
+ let Self(t) = self;
+ fmt::$trait::fmt(t, f)
+ }
+ }
+ )*
+ };
+}
+
+impl_fmt_adapter_forward!(Debug, LowerHex, UpperHex, Octal, Binary, Pointer,
LowerExp, UpperExp);
+
+macro_rules! impl_display_forward {
+ ($(
+ $( { $($generics:tt)* } )? $ty:ty $( { where $($where:tt)* } )?
+ ),* $(,)?) => {
+ $(
+ impl$($($generics)*)? fmt::Display for Adapter<&$ty>
+ $(where $($where)*)? {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>)
-> fmt::Result {
+ let Self(t) = self;
+ fmt::Display::fmt(t, f)
+ }
+ }
+ )*
+ };
+}
+
+impl<T: ?Sized> fmt::Display for Adapter<&&T>
+where
+ for<'a> Adapter<&'a T>: fmt::Display,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
+ let Self(t) = self;
+ Adapter::<&T>(**t).fmt(f)
+ }
+}
+
+impl_display_forward!(
+ bool,
+ char,
+ core::panic::PanicInfo<'_>,
+ crate::str::BStr,
+ fmt::Arguments<'_>,
+ i128,
+ i16,
+ i32,
+ i64,
+ i8,
+ isize,
+ str,
+ u128,
+ u16,
+ u32,
+ u64,
+ u8,
+ usize,
+ {<T: ?Sized>} crate::sync::Arc<T> {where
crate::sync::Arc<T>: fmt::Display},
+ {<T: ?Sized>} crate::sync::UniqueArc<T> {where
crate::sync::UniqueArc<T>: fmt::Display},
+);
diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs
index 4b8cdcb21e77..20ae65c2a18e 100644
--- a/rust/kernel/kunit.rs
+++ b/rust/kernel/kunit.rs
@@ -71,14 +71,14 @@ macro_rules! kunit_assert {
// mistake (it is hidden to prevent that).
//
// This mimics KUnit's failed assertion format.
- $crate::kunit::err(format_args!(
+ $crate::kunit::err($crate::prelude::fmt!(
" # {}: ASSERTION FAILED at {FILE}:{LINE}\n",
$name
));
- $crate::kunit::err(format_args!(
+ $crate::kunit::err($crate::prelude::fmt!(
" Expected {CONDITION} to be true, but is
false\n"
));
- $crate::kunit::err(format_args!(
+ $crate::kunit::err($crate::prelude::fmt!(
" Failure not reported to KUnit since this is a
non-KUnit task\n"
));
break 'out;
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 7e227b52b4d8..6e8eb57fb225 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -66,6 +66,7 @@
pub mod faux;
#[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)]
pub mod firmware;
+pub mod fmt;
pub mod fs;
pub mod init;
pub mod io;
diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index 2f30a398dddd..41cebd906c4c 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -22,7 +22,7 @@
pub use crate::alloc::{flags::*, Box, KBox, KVBox, KVVec, KVec, VBox, VVec,
Vec};
#[doc(no_inline)]
-pub use macros::{export, kunit_tests, module, vtable};
+pub use macros::{export, fmt, kunit_tests, module, vtable};
pub use pin_init::{init, pin_data, pin_init, pinned_drop, InPlaceWrite, Init,
PinInit, Zeroable};
@@ -31,7 +31,6 @@
// `super::std_vendor` is hidden, which makes the macro inline for some reason.
#[doc(no_inline)]
pub use super::dbg;
-pub use super::fmt;
pub use super::{dev_alert, dev_crit, dev_dbg, dev_emerg, dev_err, dev_info,
dev_notice, dev_warn};
pub use super::{pr_alert, pr_crit, pr_debug, pr_emerg, pr_err, pr_info,
pr_notice, pr_warn};
diff --git a/rust/kernel/print.rs b/rust/kernel/print.rs
index 9783d960a97a..0f5e15128005 100644
--- a/rust/kernel/print.rs
+++ b/rust/kernel/print.rs
@@ -149,7 +149,7 @@ macro_rules! print_macro (
// takes borrows on the arguments, but does not extend the scope of
temporaries.
// Therefore, a `match` expression is used to keep them around, since
// the scrutinee is kept until the end of the `match`.
- match format_args!($($arg)+) {
+ match $crate::prelude::fmt!($($arg)+) {
// SAFETY: This hidden macro should only be called by the
documented
// printing macros which ensure the format string is one of the
fixed
// ones. All `__LOG_PREFIX`s are null-terminated as they are
generated
@@ -168,7 +168,7 @@ macro_rules! print_macro (
// The `CONT` case.
($format_string:path, true, $($arg:tt)+) => (
$crate::print::call_printk_cont(
- format_args!($($arg)+),
+ $crate::prelude::fmt!($($arg)+),
);
);
);
diff --git a/rust/kernel/seq_file.rs b/rust/kernel/seq_file.rs
index 7a9403eb6e5b..627bc2f7b3d2 100644
--- a/rust/kernel/seq_file.rs
+++ b/rust/kernel/seq_file.rs
@@ -47,7 +47,7 @@ pub fn call_printf(&self, args:
core::fmt::Arguments<'_>) {
#[macro_export]
macro_rules! seq_print {
($m:expr, $($arg:tt)+) => (
- $m.call_printf(format_args!($($arg)+))
+ $m.call_printf($crate::prelude::fmt!($($arg)+))
);
}
pub use seq_print;
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index a927db8e079c..1115b47c7618 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -54,7 +54,7 @@ impl fmt::Display for BStr {
/// Formats printable ASCII characters, escaping the rest.
///
/// ```
- /// # use kernel::{fmt, b_str, str::{BStr, CString}};
+ /// # use kernel::{prelude::fmt, b_str, str::{BStr, CString}};
/// let ascii = b_str!("Hello, BStr!");
/// let s = CString::try_from_fmt(fmt!("{}", ascii))?;
/// assert_eq!(s.as_bytes(), "Hello, BStr!".as_bytes());
@@ -85,7 +85,7 @@ impl fmt::Debug for BStr {
/// escaping the rest.
///
/// ```
- /// # use kernel::{fmt, b_str, str::{BStr, CString}};
+ /// # use kernel::{prelude::fmt, b_str, str::{BStr, CString}};
/// // Embedded double quotes are escaped.
/// let ascii = b_str!("Hello, \"BStr\"!");
/// let s = CString::try_from_fmt(fmt!("{:?}", ascii))?;
@@ -424,12 +424,12 @@ pub fn to_ascii_uppercase(&self) ->
Result<CString, AllocError> {
}
}
-impl fmt::Display for CStr {
+impl fmt::Display for crate::fmt::Adapter<&CStr> {
/// Formats printable ASCII characters, escaping the rest.
///
/// ```
/// # use kernel::c_str;
- /// # use kernel::fmt;
+ /// # use kernel::prelude::fmt;
/// # use kernel::str::CStr;
/// # use kernel::str::CString;
/// let penguin = c_str!("?");
@@ -442,7 +442,8 @@ impl fmt::Display for CStr {
/// # Ok::<(), kernel::error::Error>(())
/// ```
fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
- for &c in self.as_bytes() {
+ let Self(cstr) = self;
+ for &c in cstr.as_bytes() {
if (0x20..0x7f).contains(&c) {
// Printable character.
f.write_char(c as char)?;
@@ -459,7 +460,7 @@ impl fmt::Debug for CStr {
///
/// ```
/// # use kernel::c_str;
- /// # use kernel::fmt;
+ /// # use kernel::prelude::fmt;
/// # use kernel::str::CStr;
/// # use kernel::str::CString;
/// let penguin = c_str!("?");
@@ -578,7 +579,7 @@ mod tests {
macro_rules! format {
($($f:tt)*) => ({
- CString::try_from_fmt(::kernel::fmt!($($f)*))?.to_str()?
+ CString::try_from_fmt(crate::prelude::fmt!($($f)*))?.to_str()?
})
}
@@ -840,7 +841,7 @@ fn write_str(&mut self, s: &str) -> fmt::Result {
/// # Examples
///
/// ```
-/// use kernel::{str::CString, fmt};
+/// use kernel::{str::CString, prelude::fmt};
///
/// let s = CString::try_from_fmt(fmt!("{}{}{}", "abc", 10,
20))?;
/// assert_eq!(s.as_bytes_with_nul(), "abc1020\0".as_bytes());
@@ -930,9 +931,3 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>)
-> fmt::Result {
fmt::Debug::fmt(&**self, f)
}
}
-
-/// A convenience alias for [`core::format_args`].
-#[macro_export]
-macro_rules! fmt {
- ($($f:tt)*) => ( ::core::format_args!($($f)*) )
-}
diff --git a/rust/macros/fmt.rs b/rust/macros/fmt.rs
new file mode 100644
index 000000000000..edc37c220a89
--- /dev/null
+++ b/rust/macros/fmt.rs
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use proc_macro::{Ident, TokenStream, TokenTree};
+use std::collections::BTreeSet;
+
+/// Please see [`crate::fmt`] for documentation.
+pub(crate) fn fmt(input: TokenStream) -> TokenStream {
+ let mut input = input.into_iter();
+
+ let first_opt = input.next();
+ let first_owned_str;
+ let mut names = BTreeSet::new();
+ let first_lit = {
+ let Some((mut first_str, first_lit)) = (match first_opt.as_ref() {
+ Some(TokenTree::Literal(first_lit)) => {
+ first_owned_str = first_lit.to_string();
+ Some(first_owned_str.as_str()).and_then(|first| {
+ let first = first.strip_prefix('"')?;
+ let first = first.strip_suffix('"')?;
+ Some((first, first_lit))
+ })
+ }
+ _ => None,
+ }) else {
+ return first_opt.into_iter().chain(input).collect();
+ };
+ while let Some((_, rest)) = first_str.split_once('{') {
+ first_str = rest;
+ if let Some(rest) = first_str.strip_prefix('{') {
+ first_str = rest;
+ continue;
+ }
+ if let Some((name, rest)) = first_str.split_once('}') {
+ first_str = rest;
+ let name = name.split_once(':').map_or(name, |(name,
_)| name);
+ if !name.is_empty() && !name.chars().all(|c|
c.is_ascii_digit()) {
+ names.insert(name);
+ }
+ }
+ }
+ first_lit
+ };
+
+ let first_span = first_lit.span();
+ let adapter = quote_spanned! {
+ first_span => ::kernel::fmt::Adapter
+ };
+
+ let mut args = TokenStream::from_iter(first_opt);
+ {
+ let mut flush = |args: &mut TokenStream, current: &mut
TokenStream| {
+ let current = std::mem::take(current);
+ if !current.is_empty() {
+ let (lhs, rhs) = (|| {
+ let mut current = current.into_iter();
+ let mut acc = TokenStream::new();
+ while let Some(tt) = current.next() {
+ // Split on `=` only once to handle cases like `a = b =
c`.
+ if matches!(&tt, TokenTree::Punct(p) if p.as_char()
== '=') {
+ names.remove(acc.to_string().as_str());
+ // Include the `=` itself to keep the handling
below uniform.
+ acc.extend([tt]);
+ return (Some(acc),
current.collect::<TokenStream>());
+ }
+ acc.extend([tt]);
+ }
+ (None, acc)
+ })();
+ args.extend(quote_spanned! {
+ first_span => #lhs #adapter(&#rhs)
+ });
+ }
+ };
+
+ let mut current = TokenStream::new();
+ for tt in input {
+ match &tt {
+ TokenTree::Punct(p) if p.as_char() == ',' => {
+ flush(&mut args, &mut current);
+ &mut args
+ }
+ _ => &mut current,
+ }
+ .extend([tt]);
+ }
+ flush(&mut args, &mut current);
+ }
+
+ for name in names {
+ let name = Ident::new(name, first_span);
+ args.extend(quote_spanned! {
+ first_span => , #name = #adapter(&#name)
+ });
+ }
+
+ quote_spanned! {
+ first_span => ::core::format_args!(#args)
+ }
+}
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index fa847cf3a9b5..980e70d253e4 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -15,6 +15,7 @@
mod quote;
mod concat_idents;
mod export;
+mod fmt;
mod helpers;
mod kunit;
mod module;
@@ -201,6 +202,24 @@ pub fn export(attr: TokenStream, ts: TokenStream) ->
TokenStream {
export::export(attr, ts)
}
+/// Like [`core::format_args!`], but automatically wraps arguments in
[`kernel::fmt::Adapter`].
+///
+/// This macro allows generating `core::fmt::Arguments` while ensuring that
each argument is wrapped
+/// with `::kernel::fmt::Adapter`, which customizes formatting behavior for
kernel logging.
+///
+/// Named arguments used in the format string (e.g. `{foo}`) are detected and
resolved from local
+/// bindings. All positional and named arguments are automatically wrapped.
+///
+/// This macro is an implementation detail of other kernel logging macros like
[`pr_info!`] and
+/// should not typically be used directly.
+///
+/// [`kernel::fmt::Adapter`]: ../kernel/fmt/struct.Adapter.html
+/// [`pr_info!`]: ../kernel/macro.pr_info.html
+#[proc_macro]
+pub fn fmt(input: TokenStream) -> TokenStream {
+ fmt::fmt(input)
+}
+
/// Concatenate two identifiers.
///
/// This is useful in macros that need to declare or reference items with names
diff --git a/rust/macros/quote.rs b/rust/macros/quote.rs
index acc140c18653..ddfc21577539 100644
--- a/rust/macros/quote.rs
+++ b/rust/macros/quote.rs
@@ -48,6 +48,7 @@ macro_rules! quote_spanned {
($span:expr => $($tt:tt)*) => {{
let mut tokens = ::proc_macro::TokenStream::new();
{
+ #[allow(unused_variables)]
let span = $span;
quote_spanned!(@proc tokens span $($tt)*);
}
@@ -146,6 +147,12 @@ macro_rules! quote_spanned {
)]);
quote_spanned!(@proc $v $span $($tt)*);
};
+ (@proc $v:ident $span:ident & $($tt:tt)*) => {
+ $v.extend([::proc_macro::TokenTree::Punct(
+ ::proc_macro::Punct::new('&',
::proc_macro::Spacing::Alone),
+ )]);
+ quote_spanned!(@proc $v $span $($tt)*);
+ };
(@proc $v:ident $span:ident _ $($tt:tt)*) => {
$v.extend([::proc_macro::TokenTree::Ident(
::proc_macro::Ident::new("_", $span),
diff --git a/scripts/rustdoc_test_gen.rs b/scripts/rustdoc_test_gen.rs
index 1ca253594d38..507d36875196 100644
--- a/scripts/rustdoc_test_gen.rs
+++ b/scripts/rustdoc_test_gen.rs
@@ -201,7 +201,7 @@ macro_rules! assert_eq {{
// This follows the syntax for declaring test metadata in the proposed KTAP
v2 spec, which may
// be used for the proposed KUnit test attributes API. Thus hopefully this
will make migration
// easier later on.
- ::kernel::kunit::info(format_args!(" # {kunit_name}.location:
{real_path}:{line}\n"));
+ ::kernel::kunit::info(fmt!(" # {kunit_name}.location:
{real_path}:{line}\n"));
/// The anchor where the test code body starts.
#[allow(unused)]
--
2.49.0
Tamir Duberstein
2025-May-30 12:27 UTC
[PATCH v11 3/5] rust: replace `CStr` with `core::ffi::CStr`
`kernel::ffi::CStr` was introduced in commit d126d2380131 ("rust: str:
add `CStr` type") in November 2022 as an upstreaming of earlier work
that was done in May 2021[0]. That earlier work, having predated the
inclusion of `CStr` in `core`, largely duplicated the implementation of
`std::ffi::CStr`.
`std::ffi::CStr` was moved to `core::ffi::CStr` in Rust 1.64 in
September 2022. Hence replace `kernel::str::CStr` with `core::ffi::CStr`
to reduce our custom code footprint, and retain needed custom
functionality through an extension trait.
C-String literals were added in Rust 1.77, while our MSRV is 1.78. Thus
opportunistically replace instances of `kernel::c_str!` with C-String
literals where other code changes were already necessary or where
existing code triggered clippy lints; the rest will be done in a later
commit.
Link:
https://github.com/Rust-for-Linux/linux/commit/faa3cbcca03d0dec8f8e43f1d8d5c0860d98a23f
[0]
Signed-off-by: Tamir Duberstein <tamird at gmail.com>
---
drivers/gpu/drm/drm_panic_qr.rs | 2 +-
rust/kernel/device.rs | 4 +-
rust/kernel/error.rs | 4 +-
rust/kernel/firmware.rs | 11 +-
rust/kernel/kunit.rs | 6 +-
rust/kernel/miscdevice.rs | 2 +-
rust/kernel/net/phy.rs | 2 +-
rust/kernel/of.rs | 2 +-
rust/kernel/prelude.rs | 5 +-
rust/kernel/seq_file.rs | 4 +-
rust/kernel/str.rs | 394 +++++++++++-----------------------------
rust/kernel/sync/condvar.rs | 2 +-
rust/kernel/sync/lock.rs | 2 +-
rust/kernel/sync/lock/global.rs | 2 +-
14 files changed, 132 insertions(+), 310 deletions(-)
diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_qr.rs
index f2a99681b998..d8192a9bef63 100644
--- a/drivers/gpu/drm/drm_panic_qr.rs
+++ b/drivers/gpu/drm/drm_panic_qr.rs
@@ -922,7 +922,7 @@ fn draw_all(&mut self, data: impl Iterator<Item =
u8>) {
// nul-terminated string.
let url_cstr: &CStr = unsafe { CStr::from_char_ptr(url) };
let segments = &[
- &Segment::Binary(url_cstr.as_bytes()),
+ &Segment::Binary(url_cstr.to_bytes()),
&Segment::Numeric(&data_slice[0..data_len]),
];
match EncodedMsg::new(segments, tmp_slice) {
diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
index 99d99a76934c..9074322c79e8 100644
--- a/rust/kernel/device.rs
+++ b/rust/kernel/device.rs
@@ -12,7 +12,7 @@
use core::{fmt, ptr};
#[cfg(CONFIG_PRINTK)]
-use crate::c_str;
+use crate::str::CStrExt as _;
/// A reference-counted device.
///
@@ -176,7 +176,7 @@ unsafe fn printk(&self, klevel: &[u8], msg:
fmt::Arguments<'_>) {
bindings::_dev_printk(
klevel as *const _ as *const crate::ffi::c_char,
self.as_raw(),
- c_str!("%pA").as_char_ptr(),
+ c"%pA".as_char_ptr(),
&msg as *const _ as *const crate::ffi::c_void,
)
};
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 3dee3139fcd4..933c048c04f1 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -164,6 +164,8 @@ pub fn name(&self) -> Option<&'static
CStr> {
if ptr.is_null() {
None
} else {
+ use crate::str::CStrExt as _;
+
// SAFETY: The string returned by `errname` is static and
`NUL`-terminated.
Some(unsafe { CStr::from_char_ptr(ptr) })
}
@@ -188,7 +190,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>)
-> fmt::Result {
Some(name) => f
.debug_tuple(
// SAFETY: These strings are ASCII-only.
- unsafe { core::str::from_utf8_unchecked(name) },
+ unsafe { core::str::from_utf8_unchecked(name.to_bytes()) },
)
.finish(),
}
diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs
index 2494c96e105f..582ab648b14c 100644
--- a/rust/kernel/firmware.rs
+++ b/rust/kernel/firmware.rs
@@ -4,7 +4,14 @@
//!
//! C header: [`include/linux/firmware.h`](srctree/include/linux/firmware.h)
-use crate::{bindings, device::Device, error::Error, error::Result, ffi,
str::CStr};
+use crate::{
+ bindings,
+ device::Device,
+ error::Error,
+ error::Result,
+ ffi,
+ str::{CStr, CStrExt as _},
+};
use core::ptr::NonNull;
/// # Invariants
@@ -290,7 +297,7 @@ const fn push_module_name(self) -> Self {
let module_name = this.module_name;
if !this.module_name.is_empty() {
- this = this.push_internal(module_name.as_bytes_with_nul());
+ this = this.push_internal(module_name.to_bytes_with_nul());
if N != 0 {
// Re-use the space taken by the NULL terminator and swap it
with the '.' separator.
diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs
index 20ae65c2a18e..4927aa0b656e 100644
--- a/rust/kernel/kunit.rs
+++ b/rust/kernel/kunit.rs
@@ -99,12 +99,12 @@ unsafe impl Sync for Location {}
unsafe impl Sync for UnaryAssert {}
static LOCATION: Location = Location($crate::bindings::kunit_loc {
- file: FILE.as_char_ptr(),
+ file: $crate::str::as_char_ptr_in_const_context(FILE),
line: LINE,
});
static ASSERTION: UnaryAssert =
UnaryAssert($crate::bindings::kunit_unary_assert {
assert: $crate::bindings::kunit_assert {},
- condition: CONDITION.as_char_ptr(),
+ condition:
$crate::str::as_char_ptr_in_const_context(CONDITION),
expected_true: true,
});
@@ -199,7 +199,7 @@ pub const fn kunit_case(
) -> kernel::bindings::kunit_case {
kernel::bindings::kunit_case {
run_case: Some(run_case),
- name: name.as_char_ptr(),
+ name: kernel::str::as_char_ptr_in_const_context(name),
attr: kernel::bindings::kunit_attributes {
speed: kernel::bindings::kunit_speed_KUNIT_SPEED_NORMAL,
},
diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs
index b4c5f74de23d..d684ec4ef4d0 100644
--- a/rust/kernel/miscdevice.rs
+++ b/rust/kernel/miscdevice.rs
@@ -34,7 +34,7 @@ pub const fn into_raw<T: MiscDevice>(self) ->
bindings::miscdevice {
// SAFETY: All zeros is valid for this C type.
let mut result: bindings::miscdevice = unsafe {
MaybeUninit::zeroed().assume_init() };
result.minor = bindings::MISC_DYNAMIC_MINOR as _;
- result.name = self.name.as_char_ptr();
+ result.name = crate::str::as_char_ptr_in_const_context(self.name);
result.fops = MiscdeviceVTable::<T>::build();
result
}
diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs
index a59469c785e3..652e060e47bd 100644
--- a/rust/kernel/net/phy.rs
+++ b/rust/kernel/net/phy.rs
@@ -504,7 +504,7 @@ unsafe impl Sync for DriverVTable {}
pub const fn create_phy_driver<T: Driver>() -> DriverVTable {
// INVARIANT: All the fields of `struct phy_driver` are initialized
properly.
DriverVTable(Opaque::new(bindings::phy_driver {
- name: T::NAME.as_char_ptr().cast_mut(),
+ name: crate::str::as_char_ptr_in_const_context(T::NAME).cast_mut(),
flags: T::FLAGS,
phy_id: T::PHY_DEVICE_ID.id,
phy_id_mask: T::PHY_DEVICE_ID.mask_as_int(),
diff --git a/rust/kernel/of.rs b/rust/kernel/of.rs
index 04f2d8ef29cb..12ea65df46de 100644
--- a/rust/kernel/of.rs
+++ b/rust/kernel/of.rs
@@ -29,7 +29,7 @@ fn index(&self) -> usize {
impl DeviceId {
/// Create a new device id from an OF 'compatible' string.
pub const fn new(compatible: &'static CStr) -> Self {
- let src = compatible.as_bytes_with_nul();
+ let src = compatible.to_bytes_with_nul();
// Replace with `bindings::of_device_id::default()` once stabilized for
`const`.
// SAFETY: FFI type is valid to be zero-initialized.
let mut of: bindings::of_device_id = unsafe { core::mem::zeroed() };
diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index 41cebd906c4c..244b660fa835 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -40,7 +40,10 @@
pub use super::error::{code::*, Error, Result};
-pub use super::{str::CStr, ThisModule};
+pub use super::{
+ str::{CStr, CStrExt as _},
+ ThisModule,
+};
pub use super::init::InPlaceInit;
diff --git a/rust/kernel/seq_file.rs b/rust/kernel/seq_file.rs
index 627bc2f7b3d2..1011743dd0ce 100644
--- a/rust/kernel/seq_file.rs
+++ b/rust/kernel/seq_file.rs
@@ -4,7 +4,7 @@
//!
//! C header: [`include/linux/seq_file.h`](srctree/include/linux/seq_file.h)
-use crate::{bindings, c_str, types::NotThreadSafe, types::Opaque};
+use crate::{bindings, str::CStrExt as _, types::NotThreadSafe, types::Opaque};
/// A utility for generating the contents of a seq file.
#[repr(transparent)]
@@ -36,7 +36,7 @@ pub fn call_printf(&self, args:
core::fmt::Arguments<'_>) {
unsafe {
bindings::seq_printf(
self.inner.get(),
- c_str!("%pA").as_char_ptr(),
+ c"%pA".as_char_ptr(),
&args as *const _ as *const crate::ffi::c_void,
);
}
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index 1115b47c7618..f8164fd23f61 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -4,7 +4,7 @@
use crate::alloc::{flags::*, AllocError, KVec};
use core::fmt::{self, Write};
-use core::ops::{self, Deref, DerefMut, Index};
+use core::ops::{Deref, DerefMut, Index};
use crate::prelude::*;
@@ -57,11 +57,11 @@ impl fmt::Display for BStr {
/// # use kernel::{prelude::fmt, b_str, str::{BStr, CString}};
/// let ascii = b_str!("Hello, BStr!");
/// let s = CString::try_from_fmt(fmt!("{}", ascii))?;
- /// assert_eq!(s.as_bytes(), "Hello, BStr!".as_bytes());
+ /// assert_eq!(s.to_bytes(), "Hello, BStr!".as_bytes());
///
/// let non_ascii = b_str!("?");
/// let s = CString::try_from_fmt(fmt!("{}", non_ascii))?;
- /// assert_eq!(s.as_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes());
+ /// assert_eq!(s.to_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes());
/// # Ok::<(), kernel::error::Error>(())
/// ```
fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
@@ -89,11 +89,11 @@ impl fmt::Debug for BStr {
/// // Embedded double quotes are escaped.
/// let ascii = b_str!("Hello, \"BStr\"!");
/// let s = CString::try_from_fmt(fmt!("{:?}", ascii))?;
- /// assert_eq!(s.as_bytes(), "\"Hello,
\\\"BStr\\\"!\"".as_bytes());
+ /// assert_eq!(s.to_bytes(), "\"Hello,
\\\"BStr\\\"!\"".as_bytes());
///
/// let non_ascii = b_str!("?");
/// let s = CString::try_from_fmt(fmt!("{:?}", non_ascii))?;
- /// assert_eq!(s.as_bytes(),
"\"\\xf0\\x9f\\x98\\xba\"".as_bytes());
+ /// assert_eq!(s.to_bytes(),
"\"\\xf0\\x9f\\x98\\xba\"".as_bytes());
/// # Ok::<(), kernel::error::Error>(())
/// ```
fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
@@ -175,55 +175,19 @@ macro_rules! b_str {
}};
}
-/// Possible errors when using conversion functions in [`CStr`].
-#[derive(Debug, Clone, Copy)]
-pub enum CStrConvertError {
- /// Supplied bytes contain an interior `NUL`.
- InteriorNul,
+pub use core::ffi::CStr;
- /// Supplied bytes are not terminated by `NUL`.
- NotNulTerminated,
+/// Returns a C pointer to the string.
+// It is a free function rather than a method on an extension trait because:
+//
+// - error[E0379]: functions in trait impls cannot be declared const
+#[inline]
+pub const fn as_char_ptr_in_const_context(c_str: &CStr) -> *const
crate::ffi::c_char {
+ c_str.as_ptr().cast()
}
-impl From<CStrConvertError> for Error {
- #[inline]
- fn from(_: CStrConvertError) -> Error {
- EINVAL
- }
-}
-
-/// A string that is guaranteed to have exactly one `NUL` byte, which is at the
-/// end.
-///
-/// Used for interoperability with kernel APIs that take C strings.
-#[repr(transparent)]
-pub struct CStr([u8]);
-
-impl CStr {
- /// Returns the length of this string excluding `NUL`.
- #[inline]
- pub const fn len(&self) -> usize {
- self.len_with_nul() - 1
- }
-
- /// Returns the length of this string with `NUL`.
- #[inline]
- pub const fn len_with_nul(&self) -> usize {
- if self.0.is_empty() {
- // SAFETY: This is one of the invariant of `CStr`.
- // We add a `unreachable_unchecked` here to hint the optimizer that
- // the value returned from this function is non-zero.
- unsafe { core::hint::unreachable_unchecked() };
- }
- self.0.len()
- }
-
- /// Returns `true` if the string only includes `NUL`.
- #[inline]
- pub const fn is_empty(&self) -> bool {
- self.len() == 0
- }
-
+/// Extensions to [`CStr`].
+pub trait CStrExt {
/// Wraps a raw C string pointer.
///
/// # Safety
@@ -231,54 +195,9 @@ pub const fn is_empty(&self) -> bool {
/// `ptr` must be a valid pointer to a `NUL`-terminated C string, and it
must
/// last at least `'a`. When `CStr` is alive, the memory pointed by
`ptr`
/// must not be mutated.
- #[inline]
- pub unsafe fn from_char_ptr<'a>(ptr: *const crate::ffi::c_char)
-> &'a Self {
- // SAFETY: The safety precondition guarantees `ptr` is a valid pointer
- // to a `NUL`-terminated C string.
- let len = unsafe { bindings::strlen(ptr) } + 1;
- // SAFETY: Lifetime guaranteed by the safety precondition.
- let bytes = unsafe { core::slice::from_raw_parts(ptr as _, len) };
- // SAFETY: As `len` is returned by `strlen`, `bytes` does not contain
interior `NUL`.
- // As we have added 1 to `len`, the last byte is known to be `NUL`.
- unsafe { Self::from_bytes_with_nul_unchecked(bytes) }
- }
-
- /// Creates a [`CStr`] from a `[u8]`.
- ///
- /// The provided slice must be `NUL`-terminated, does not contain any
- /// interior `NUL` bytes.
- pub const fn from_bytes_with_nul(bytes: &[u8]) ->
Result<&Self, CStrConvertError> {
- if bytes.is_empty() {
- return Err(CStrConvertError::NotNulTerminated);
- }
- if bytes[bytes.len() - 1] != 0 {
- return Err(CStrConvertError::NotNulTerminated);
- }
- let mut i = 0;
- // `i + 1 < bytes.len()` allows LLVM to optimize away bounds
checking,
- // while it couldn't optimize away bounds checks for `i <
bytes.len() - 1`.
- while i + 1 < bytes.len() {
- if bytes[i] == 0 {
- return Err(CStrConvertError::InteriorNul);
- }
- i += 1;
- }
- // SAFETY: We just checked that all properties hold.
- Ok(unsafe { Self::from_bytes_with_nul_unchecked(bytes) })
- }
-
- /// Creates a [`CStr`] from a `[u8]` without performing any additional
- /// checks.
- ///
- /// # Safety
- ///
- /// `bytes` *must* end with a `NUL` byte, and should only have a single
- /// `NUL` byte (or the string will be truncated).
- #[inline]
- pub const unsafe fn from_bytes_with_nul_unchecked(bytes: &[u8]) ->
&CStr {
- // SAFETY: Properties of `bytes` guaranteed by the safety precondition.
- unsafe { core::mem::transmute(bytes) }
- }
+ // This function exists to paper over the fact that `CStr::from_ptr` takes
a `*const
+ // core::ffi::c_char` rather than a `*const crate::ffi::c_char`.
+ unsafe fn from_char_ptr<'a>(ptr: *const crate::ffi::c_char) ->
&'a Self;
/// Creates a mutable [`CStr`] from a `[u8]` without performing any
/// additional checks.
@@ -287,77 +206,16 @@ pub const fn from_bytes_with_nul(bytes: &[u8]) ->
Result<&Self, CStrConvertError
///
/// `bytes` *must* end with a `NUL` byte, and should only have a single
/// `NUL` byte (or the string will be truncated).
- #[inline]
- pub unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) ->
&mut CStr {
- // SAFETY: Properties of `bytes` guaranteed by the safety precondition.
- unsafe { &mut *(bytes as *mut [u8] as *mut CStr) }
- }
+ unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) ->
&mut Self;
/// Returns a C pointer to the string.
- #[inline]
- pub const fn as_char_ptr(&self) -> *const crate::ffi::c_char {
- self.0.as_ptr()
- }
-
- /// Convert the string to a byte slice without the trailing `NUL` byte.
- #[inline]
- pub fn as_bytes(&self) -> &[u8] {
- &self.0[..self.len()]
- }
-
- /// Convert the string to a byte slice containing the trailing `NUL` byte.
- #[inline]
- pub const fn as_bytes_with_nul(&self) -> &[u8] {
- &self.0
- }
-
- /// Yields a [`&str`] slice if the [`CStr`] contains valid UTF-8.
- ///
- /// If the contents of the [`CStr`] are valid UTF-8 data, this
- /// function will return the corresponding [`&str`] slice. Otherwise,
- /// it will return an error with details of where UTF-8 validation failed.
- ///
- /// # Examples
- ///
- /// ```
- /// # use kernel::str::CStr;
- /// let cstr = CStr::from_bytes_with_nul(b"foo\0")?;
- /// assert_eq!(cstr.to_str(), Ok("foo"));
- /// # Ok::<(), kernel::error::Error>(())
- /// ```
- #[inline]
- pub fn to_str(&self) -> Result<&str, core::str::Utf8Error>
{
- core::str::from_utf8(self.as_bytes())
- }
-
- /// Unsafely convert this [`CStr`] into a [`&str`], without checking
for
- /// valid UTF-8.
- ///
- /// # Safety
- ///
- /// The contents must be valid UTF-8.
- ///
- /// # Examples
- ///
- /// ```
- /// # use kernel::c_str;
- /// # use kernel::str::CStr;
- /// let bar = c_str!("?");
- /// // SAFETY: String literals are guaranteed to be valid UTF-8
- /// // by the Rust compiler.
- /// assert_eq!(unsafe { bar.as_str_unchecked() }, "?");
- /// ```
- #[inline]
- pub unsafe fn as_str_unchecked(&self) -> &str {
- // SAFETY: TODO.
- unsafe { core::str::from_utf8_unchecked(self.as_bytes()) }
- }
+ // This function exists to paper over the fact that `CStr::as_ptr` returns
a `*const
+ // core::ffi::c_char` rather than a `*const crate::ffi::c_char`.
+ fn as_char_ptr(&self) -> *const crate::ffi::c_char;
/// Convert this [`CStr`] into a [`CString`] by allocating memory and
/// copying over the string data.
- pub fn to_cstring(&self) -> Result<CString, AllocError> {
- CString::try_from(self)
- }
+ fn to_cstring(&self) -> Result<CString, AllocError>;
/// Converts this [`CStr`] to its ASCII lower case equivalent in-place.
///
@@ -368,11 +226,7 @@ pub fn to_cstring(&self) -> Result<CString,
AllocError> {
/// [`to_ascii_lowercase()`].
///
/// [`to_ascii_lowercase()`]: #method.to_ascii_lowercase
- pub fn make_ascii_lowercase(&mut self) {
- // INVARIANT: This doesn't introduce or remove NUL bytes in the C
- // string.
- self.0.make_ascii_lowercase();
- }
+ fn make_ascii_lowercase(&mut self);
/// Converts this [`CStr`] to its ASCII upper case equivalent in-place.
///
@@ -383,11 +237,7 @@ pub fn make_ascii_lowercase(&mut self) {
/// [`to_ascii_uppercase()`].
///
/// [`to_ascii_uppercase()`]: #method.to_ascii_uppercase
- pub fn make_ascii_uppercase(&mut self) {
- // INVARIANT: This doesn't introduce or remove NUL bytes in the C
- // string.
- self.0.make_ascii_uppercase();
- }
+ fn make_ascii_uppercase(&mut self);
/// Returns a copy of this [`CString`] where each character is mapped to
its
/// ASCII lower case equivalent.
@@ -398,13 +248,7 @@ pub fn make_ascii_uppercase(&mut self) {
/// To lowercase the value in-place, use [`make_ascii_lowercase`].
///
/// [`make_ascii_lowercase`]: str::make_ascii_lowercase
- pub fn to_ascii_lowercase(&self) -> Result<CString,
AllocError> {
- let mut s = self.to_cstring()?;
-
- s.make_ascii_lowercase();
-
- Ok(s)
- }
+ fn to_ascii_lowercase(&self) -> Result<CString, AllocError>;
/// Returns a copy of this [`CString`] where each character is mapped to
its
/// ASCII upper case equivalent.
@@ -415,13 +259,7 @@ pub fn to_ascii_lowercase(&self) ->
Result<CString, AllocError> {
/// To uppercase the value in-place, use [`make_ascii_uppercase`].
///
/// [`make_ascii_uppercase`]: str::make_ascii_uppercase
- pub fn to_ascii_uppercase(&self) -> Result<CString,
AllocError> {
- let mut s = self.to_cstring()?;
-
- s.make_ascii_uppercase();
-
- Ok(s)
- }
+ fn to_ascii_uppercase(&self) -> Result<CString, AllocError>;
}
impl fmt::Display for crate::fmt::Adapter<&CStr> {
@@ -434,16 +272,16 @@ impl fmt::Display for crate::fmt::Adapter<&CStr>
{
/// # use kernel::str::CString;
/// let penguin = c_str!("?");
/// let s = CString::try_from_fmt(fmt!("{}", penguin))?;
- /// assert_eq!(s.as_bytes_with_nul(),
"\\xf0\\x9f\\x90\\xa7\0".as_bytes());
+ /// assert_eq!(s.to_bytes_with_nul(),
"\\xf0\\x9f\\x90\\xa7\0".as_bytes());
///
/// let ascii = c_str!("so \"cool\"");
/// let s = CString::try_from_fmt(fmt!("{}", ascii))?;
- /// assert_eq!(s.as_bytes_with_nul(), "so
\"cool\"\0".as_bytes());
+ /// assert_eq!(s.to_bytes_with_nul(), "so
\"cool\"\0".as_bytes());
/// # Ok::<(), kernel::error::Error>(())
/// ```
fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
let Self(cstr) = self;
- for &c in cstr.as_bytes() {
+ for &c in cstr.to_bytes() {
if (0x20..0x7f).contains(&c) {
// Printable character.
f.write_char(c as char)?;
@@ -455,98 +293,75 @@ fn fmt(&self, f: &mut
fmt::Formatter<'_>) -> fmt::Result {
}
}
-impl fmt::Debug for CStr {
- /// Formats printable ASCII characters with a double quote on either end,
escaping the rest.
- ///
- /// ```
- /// # use kernel::c_str;
- /// # use kernel::prelude::fmt;
- /// # use kernel::str::CStr;
- /// # use kernel::str::CString;
- /// let penguin = c_str!("?");
- /// let s = CString::try_from_fmt(fmt!("{:?}", penguin))?;
- /// assert_eq!(s.as_bytes_with_nul(),
"\"\\xf0\\x9f\\x90\\xa7\"\0".as_bytes());
- ///
- /// // Embedded double quotes are escaped.
- /// let ascii = c_str!("so \"cool\"");
- /// let s = CString::try_from_fmt(fmt!("{:?}", ascii))?;
- /// assert_eq!(s.as_bytes_with_nul(), "\"so
\\\"cool\\\"\"\0".as_bytes());
- /// # Ok::<(), kernel::error::Error>(())
- /// ```
- fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
- f.write_str("\"")?;
- for &c in self.as_bytes() {
- match c {
- // Printable characters.
- b'\"' => f.write_str("\\\"")?,
- 0x20..=0x7e => f.write_char(c as char)?,
- _ => write!(f, "\\x{c:02x}")?,
- }
- }
- f.write_str("\"")
- }
+/// Converts a mutable C string to a mutable byte slice.
+///
+/// # Safety
+///
+/// The caller must ensure that the slice ends in a NUL byte and contains no
other NUL bytes before
+/// the borrow ends and the underlying [`CStr`] is used.
+unsafe fn to_bytes_mut(s: &mut CStr) -> &mut [u8] {
+ // SAFETY: the cast from `&CStr` to `&[u8]` is safe since `CStr`
has the same layout as `&[u8]`
+ // (this is technically not guaranteed, but we rely on it here). The
pointer dereference is
+ // safe since it comes from a mutable reference which is guaranteed to be
valid for writes.
+ unsafe { &mut *(s as *mut CStr as *mut [u8]) }
}
-impl AsRef<BStr> for CStr {
+impl CStrExt for CStr {
#[inline]
- fn as_ref(&self) -> &BStr {
- BStr::from_bytes(self.as_bytes())
+ unsafe fn from_char_ptr<'a>(ptr: *const crate::ffi::c_char) ->
&'a Self {
+ // SAFETY: The safety preconditions are the same as for
`CStr::from_ptr`.
+ unsafe { CStr::from_ptr(ptr.cast()) }
}
-}
-impl Deref for CStr {
- type Target = BStr;
+ #[inline]
+ unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) ->
&mut Self {
+ // SAFETY: the cast from `&[u8]` to `&CStr` is safe since the
properties of `bytes` are
+ // guaranteed by the safety precondition and `CStr` has the same layout
as `&[u8]` (this is
+ // technically not guaranteed, but we rely on it here). The pointer
dereference is safe
+ // since it comes from a mutable reference which is guaranteed to be
valid for writes.
+ unsafe { &mut *(bytes as *mut [u8] as *mut CStr) }
+ }
#[inline]
- fn deref(&self) -> &Self::Target {
- self.as_ref()
+ fn as_char_ptr(&self) -> *const crate::ffi::c_char {
+ self.as_ptr().cast()
}
-}
-impl Index<ops::RangeFrom<usize>> for CStr {
- type Output = CStr;
+ fn to_cstring(&self) -> Result<CString, AllocError> {
+ CString::try_from(self)
+ }
- #[inline]
- fn index(&self, index: ops::RangeFrom<usize>) ->
&Self::Output {
- // Delegate bounds checking to slice.
- // Assign to _ to mute clippy's unnecessary operation warning.
- let _ = &self.as_bytes()[index.start..];
- // SAFETY: We just checked the bounds.
- unsafe {
Self::from_bytes_with_nul_unchecked(&self.0[index.start..]) }
+ fn make_ascii_lowercase(&mut self) {
+ // SAFETY: This doesn't introduce or remove NUL bytes in the C
string.
+ unsafe { to_bytes_mut(self) }.make_ascii_lowercase();
}
-}
-impl Index<ops::RangeFull> for CStr {
- type Output = CStr;
+ fn make_ascii_uppercase(&mut self) {
+ // SAFETY: This doesn't introduce or remove NUL bytes in the C
string.
+ unsafe { to_bytes_mut(self) }.make_ascii_uppercase();
+ }
- #[inline]
- fn index(&self, _index: ops::RangeFull) -> &Self::Output {
- self
+ fn to_ascii_lowercase(&self) -> Result<CString, AllocError> {
+ let mut s = self.to_cstring()?;
+
+ s.make_ascii_lowercase();
+
+ Ok(s)
}
-}
-mod private {
- use core::ops;
+ fn to_ascii_uppercase(&self) -> Result<CString, AllocError> {
+ let mut s = self.to_cstring()?;
- // Marker trait for index types that can be forward to `BStr`.
- pub trait CStrIndex {}
+ s.make_ascii_uppercase();
- impl CStrIndex for usize {}
- impl CStrIndex for ops::Range<usize> {}
- impl CStrIndex for ops::RangeInclusive<usize> {}
- impl CStrIndex for ops::RangeToInclusive<usize> {}
+ Ok(s)
+ }
}
-impl<Idx> Index<Idx> for CStr
-where
- Idx: private::CStrIndex,
- BStr: Index<Idx>,
-{
- type Output = <BStr as Index<Idx>>::Output;
-
+impl AsRef<BStr> for CStr {
#[inline]
- fn index(&self, index: Idx) -> &Self::Output {
- &self.as_ref()[index]
+ fn as_ref(&self) -> &BStr {
+ BStr::from_bytes(self.to_bytes())
}
}
@@ -577,6 +392,13 @@ macro_rules! c_str {
mod tests {
use super::*;
+ impl From<core::ffi::FromBytesWithNulError> for Error {
+ #[inline]
+ fn from(_: core::ffi::FromBytesWithNulError) -> Error {
+ EINVAL
+ }
+ }
+
macro_rules! format {
($($f:tt)*) => ({
CString::try_from_fmt(crate::prelude::fmt!($($f)*))?.to_str()?
@@ -599,40 +421,28 @@ macro_rules! format {
#[test]
fn test_cstr_to_str() -> Result {
- let good_bytes = b"\xf0\x9f\xa6\x80\0";
- let checked_cstr = CStr::from_bytes_with_nul(good_bytes)?;
- let checked_str = checked_cstr.to_str()?;
+ let cstr = c"\xf0\x9f\xa6\x80";
+ let checked_str = cstr.to_str()?;
assert_eq!(checked_str, "?");
Ok(())
}
#[test]
fn test_cstr_to_str_invalid_utf8() -> Result {
- let bad_bytes = b"\xc3\x28\0";
- let checked_cstr = CStr::from_bytes_with_nul(bad_bytes)?;
- assert!(checked_cstr.to_str().is_err());
- Ok(())
- }
-
- #[test]
- fn test_cstr_as_str_unchecked() -> Result {
- let good_bytes = b"\xf0\x9f\x90\xA7\0";
- let checked_cstr = CStr::from_bytes_with_nul(good_bytes)?;
- // SAFETY: The contents come from a string literal which contains valid
UTF-8.
- let unchecked_str = unsafe { checked_cstr.as_str_unchecked() };
- assert_eq!(unchecked_str, "?");
+ let cstr = c"\xc3\x28";
+ assert!(cstr.to_str().is_err());
Ok(())
}
#[test]
fn test_cstr_display() -> Result {
- let hello_world = CStr::from_bytes_with_nul(b"hello,
world!\0")?;
+ let hello_world = c"hello, world!";
assert_eq!(format!("{hello_world}"), "hello,
world!");
- let non_printables =
CStr::from_bytes_with_nul(b"\x01\x09\x0a\0")?;
+ let non_printables = c"\x01\x09\x0a";
assert_eq!(format!("{non_printables}"),
"\\x01\\x09\\x0a");
- let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0
vu\0")?;
+ let non_ascii = c"d\xe9j\xe0 vu";
assert_eq!(format!("{non_ascii}"), "d\\xe9j\\xe0
vu");
- let good_bytes =
CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0")?;
+ let good_bytes = c"\xf0\x9f\xa6\x80";
assert_eq!(format!("{good_bytes}"),
"\\xf0\\x9f\\xa6\\x80");
Ok(())
}
@@ -651,13 +461,13 @@ fn test_cstr_display_all_bytes() -> Result {
#[test]
fn test_cstr_debug() -> Result {
- let hello_world = CStr::from_bytes_with_nul(b"hello,
world!\0")?;
+ let hello_world = c"hello, world!";
assert_eq!(format!("{hello_world:?}"), "\"hello,
world!\"");
- let non_printables =
CStr::from_bytes_with_nul(b"\x01\x09\x0a\0")?;
- assert_eq!(format!("{non_printables:?}"),
"\"\\x01\\x09\\x0a\"");
- let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0
vu\0")?;
+ let non_printables = c"\x01\x09\x0a";
+ assert_eq!(format!("{non_printables:?}"),
"\"\\x01\\t\\n\"");
+ let non_ascii = c"d\xe9j\xe0 vu";
assert_eq!(format!("{non_ascii:?}"),
"\"d\\xe9j\\xe0 vu\"");
- let good_bytes =
CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0")?;
+ let good_bytes = c"\xf0\x9f\xa6\x80";
assert_eq!(format!("{good_bytes:?}"),
"\"\\xf0\\x9f\\xa6\\x80\"");
Ok(())
}
@@ -844,11 +654,11 @@ fn write_str(&mut self, s: &str) -> fmt::Result
{
/// use kernel::{str::CString, prelude::fmt};
///
/// let s = CString::try_from_fmt(fmt!("{}{}{}", "abc", 10,
20))?;
-/// assert_eq!(s.as_bytes_with_nul(), "abc1020\0".as_bytes());
+/// assert_eq!(s.to_bytes_with_nul(), "abc1020\0".as_bytes());
///
/// let tmp = "testing";
/// let s = CString::try_from_fmt(fmt!("{tmp}{}", 123))?;
-/// assert_eq!(s.as_bytes_with_nul(), "testing123\0".as_bytes());
+/// assert_eq!(s.to_bytes_with_nul(), "testing123\0".as_bytes());
///
/// // This fails because it has an embedded `NUL` byte.
/// let s = CString::try_from_fmt(fmt!("a\0b{}", 123));
@@ -918,7 +728,7 @@ impl<'a> TryFrom<&'a CStr> for
CString {
fn try_from(cstr: &'a CStr) -> Result<CString, AllocError>
{
let mut buf = KVec::new();
- buf.extend_from_slice(cstr.as_bytes_with_nul(), GFP_KERNEL)?;
+ buf.extend_from_slice(cstr.to_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/condvar.rs b/rust/kernel/sync/condvar.rs
index caebf03f553b..0b6bc7f2878d 100644
--- a/rust/kernel/sync/condvar.rs
+++ b/rust/kernel/sync/condvar.rs
@@ -8,7 +8,7 @@
use super::{lock::Backend, lock::Guard, LockClassKey};
use crate::{
ffi::{c_int, c_long},
- str::CStr,
+ str::{CStr, CStrExt as _},
task::{
MAX_SCHEDULE_TIMEOUT, TASK_FREEZABLE, TASK_INTERRUPTIBLE, TASK_NORMAL,
TASK_UNINTERRUPTIBLE,
},
diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
index e82fa5be289c..a777a22976e0 100644
--- a/rust/kernel/sync/lock.rs
+++ b/rust/kernel/sync/lock.rs
@@ -7,7 +7,7 @@
use super::LockClassKey;
use crate::{
- str::CStr,
+ str::{CStr, CStrExt as _},
types::{NotThreadSafe, Opaque, ScopeGuard},
};
use core::{cell::UnsafeCell, marker::PhantomPinned, pin::Pin};
diff --git a/rust/kernel/sync/lock/global.rs b/rust/kernel/sync/lock/global.rs
index d65f94b5caf2..79d0ef7fda86 100644
--- a/rust/kernel/sync/lock/global.rs
+++ b/rust/kernel/sync/lock/global.rs
@@ -5,7 +5,7 @@
//! Support for defining statics containing locks.
use crate::{
- str::CStr,
+ str::{CStr, CStrExt as _},
sync::lock::{Backend, Guard, Lock},
sync::{LockClassKey, LockedBy},
types::Opaque,
--
2.49.0
Tamir Duberstein
2025-May-30 12:28 UTC
[PATCH v11 4/5] rust: replace `kernel::c_str!` with C-Strings
C-String literals were added in Rust 1.77. Replace instances of
`kernel::c_str!` with C-String literals where possible and rename
`kernel::c_str!` to `str_to_cstr!` to clarify its intended use.
Closes: https://github.com/Rust-for-Linux/linux/issues/1075
Signed-off-by: Tamir Duberstein <tamird at gmail.com>
---
drivers/block/rnull.rs | 2 +-
drivers/gpu/nova-core/driver.rs | 2 +-
drivers/net/phy/ax88796b_rust.rs | 7 +++----
drivers/net/phy/qt2025.rs | 5 ++---
rust/kernel/devres.rs | 2 +-
rust/kernel/firmware.rs | 6 +++---
rust/kernel/kunit.rs | 7 ++++---
rust/kernel/net/phy.rs | 6 ++----
rust/kernel/platform.rs | 4 ++--
rust/kernel/str.rs | 24 ++++++++++++++++--------
rust/kernel/sync.rs | 7 +++----
rust/kernel/sync/lock/global.rs | 3 ++-
rust/kernel/workqueue.rs | 8 ++++----
rust/macros/kunit.rs | 10 +++++-----
rust/macros/module.rs | 2 +-
samples/rust/rust_driver_faux.rs | 4 ++--
samples/rust/rust_driver_pci.rs | 4 ++--
samples/rust/rust_driver_platform.rs | 4 ++--
samples/rust/rust_misc_device.rs | 3 +--
scripts/rustdoc_test_gen.rs | 4 ++--
20 files changed, 59 insertions(+), 55 deletions(-)
diff --git a/drivers/block/rnull.rs b/drivers/block/rnull.rs
index 6366da12c5a5..9aa79b862b63 100644
--- a/drivers/block/rnull.rs
+++ b/drivers/block/rnull.rs
@@ -55,7 +55,7 @@ fn init(_module: &'static ThisModule) -> impl
PinInit<Self, Error> {
})();
try_pin_init!(Self {
- _disk <- new_mutex!(disk?, "nullb:disk"),
+ _disk <- new_mutex!(disk?, c"nullb:disk"),
})
}
}
diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs
index a08fb6599267..776970049974 100644
--- a/drivers/gpu/nova-core/driver.rs
+++ b/drivers/gpu/nova-core/driver.rs
@@ -33,7 +33,7 @@ fn probe(pdev: &pci::Device<Core>, _info:
&Self::IdInfo) -> Result<Pin<KBox<Self
pdev.enable_device_mem()?;
pdev.set_master();
- let bar = pdev.iomap_region_sized::<BAR0_SIZE>(0,
c_str!("nova-core/bar0"))?;
+ let bar = pdev.iomap_region_sized::<BAR0_SIZE>(0,
c"nova-core/bar0")?;
let this = KBox::pin_init(
try_pin_init!(Self {
diff --git a/drivers/net/phy/ax88796b_rust.rs b/drivers/net/phy/ax88796b_rust.rs
index bc73ebccc2aa..2d24628a4e58 100644
--- a/drivers/net/phy/ax88796b_rust.rs
+++ b/drivers/net/phy/ax88796b_rust.rs
@@ -5,7 +5,6 @@
//!
//! C version of this driver: [`drivers/net/phy/ax88796b.c`](./ax88796b.c)
use kernel::{
- c_str,
net::phy::{self, reg::C22, DeviceId, Driver},
prelude::*,
uapi,
@@ -41,7 +40,7 @@ fn asix_soft_reset(dev: &mut phy::Device) -> Result {
#[vtable]
impl Driver for PhyAX88772A {
const FLAGS: u32 = phy::flags::IS_INTERNAL;
- const NAME: &'static CStr = c_str!("Asix Electronics
AX88772A");
+ const NAME: &'static CStr = c"Asix Electronics AX88772A";
const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_exact_mask(0x003b1861);
// AX88772A is not working properly with some old switches (NETGEAR EN
108TP):
@@ -105,7 +104,7 @@ fn link_change_notify(dev: &mut phy::Device) {
#[vtable]
impl Driver for PhyAX88772C {
const FLAGS: u32 = phy::flags::IS_INTERNAL;
- const NAME: &'static CStr = c_str!("Asix Electronics
AX88772C");
+ const NAME: &'static CStr = c"Asix Electronics AX88772C";
const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_exact_mask(0x003b1881);
fn suspend(dev: &mut phy::Device) -> Result {
@@ -125,7 +124,7 @@ fn soft_reset(dev: &mut phy::Device) -> Result {
#[vtable]
impl Driver for PhyAX88796B {
- const NAME: &'static CStr = c_str!("Asix Electronics
AX88796B");
+ const NAME: &'static CStr = c"Asix Electronics AX88796B";
const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_model_mask(0x003b1841);
fn soft_reset(dev: &mut phy::Device) -> Result {
diff --git a/drivers/net/phy/qt2025.rs b/drivers/net/phy/qt2025.rs
index 0b9400dcb4c1..9ccc75f70219 100644
--- a/drivers/net/phy/qt2025.rs
+++ b/drivers/net/phy/qt2025.rs
@@ -9,7 +9,6 @@
//!
//! The QT2025 PHY integrates an Intel 8051 micro-controller.
-use kernel::c_str;
use kernel::error::code;
use kernel::firmware::Firmware;
use kernel::net::phy::{
@@ -36,7 +35,7 @@
#[vtable]
impl Driver for PhyQT2025 {
- const NAME: &'static CStr = c_str!("QT2025 10Gpbs SFP+");
+ const NAME: &'static CStr = c"QT2025 10Gpbs SFP+";
const PHY_DEVICE_ID: phy::DeviceId =
phy::DeviceId::new_with_exact_mask(0x0043a400);
fn probe(dev: &mut phy::Device) -> Result<()> {
@@ -69,7 +68,7 @@ fn probe(dev: &mut phy::Device) -> Result<()> {
// The micro-controller will start running from the boot ROM.
dev.write(C45::new(Mmd::PCS, 0xe854), 0x00c0)?;
- let fw = Firmware::request(c_str!("qt2025-2.0.3.3.fw"),
dev.as_ref())?;
+ let fw = Firmware::request(c"qt2025-2.0.3.3.fw",
dev.as_ref())?;
if fw.data().len() > SZ_16K + SZ_8K {
return Err(code::EFBIG);
}
diff --git a/rust/kernel/devres.rs b/rust/kernel/devres.rs
index ddb1ce4a78d9..8735b227f0d3 100644
--- a/rust/kernel/devres.rs
+++ b/rust/kernel/devres.rs
@@ -45,7 +45,7 @@ struct DevresInner<T> {
/// # Example
///
/// ```no_run
-/// # use kernel::{bindings, c_str, device::Device, devres::Devres, io::{Io,
IoRaw}};
+/// # use kernel::{bindings, device::Device, devres::Devres, io::{Io, IoRaw}};
/// # use core::ops::Deref;
///
/// // See also [`pci::Bar`] for a real example.
diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs
index 582ab648b14c..09fd3a27bcf0 100644
--- a/rust/kernel/firmware.rs
+++ b/rust/kernel/firmware.rs
@@ -51,13 +51,13 @@ fn request_nowarn() -> Self {
/// # Examples
///
/// ```no_run
-/// # use kernel::{c_str, device::Device, firmware::Firmware};
+/// # use kernel::{device::Device, firmware::Firmware};
///
/// # fn no_run() -> Result<(), Error> {
/// # // SAFETY: *NOT* safe, just for the example to get an
`ARef<Device>` instance
/// # let dev = unsafe { Device::get_device(core::ptr::null_mut()) };
///
-/// let fw = Firmware::request(c_str!("path/to/firmware.bin"),
&dev)?;
+/// let fw = Firmware::request(c"path/to/firmware.bin", &dev)?;
/// let blob = fw.data();
///
/// # Ok(())
@@ -203,7 +203,7 @@ macro_rules! module_firmware {
($($builder:tt)*) => {
const _: () = {
const __MODULE_FIRMWARE_PREFIX: &'static $crate::str::CStr
= if cfg!(MODULE) {
- $crate::c_str!("")
+ c""
} else {
<LocalModule as $crate::ModuleMetadata>::NAME
};
diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs
index 4927aa0b656e..2bab61910f1e 100644
--- a/rust/kernel/kunit.rs
+++ b/rust/kernel/kunit.rs
@@ -57,9 +57,10 @@ macro_rules! kunit_assert {
break 'out;
}
- static FILE: &'static $crate::str::CStr =
$crate::c_str!($file);
+ static FILE: &'static $crate::str::CStr = $file;
static LINE: i32 = ::core::line!() as i32 - $diff;
- static CONDITION: &'static $crate::str::CStr =
$crate::c_str!(stringify!($condition));
+ static CONDITION: &'static $crate::str::CStr +
$crate::str_to_cstr!(stringify!($condition));
// SAFETY: FFI call without safety requirements.
let kunit_test = unsafe {
$crate::bindings::kunit_get_current_test() };
@@ -246,7 +247,7 @@ pub const fn kunit_case_null() ->
kernel::bindings::kunit_case {
/// }
///
/// static mut KUNIT_TEST_CASES: [kernel::bindings::kunit_case; 2] = [
-/// kernel::kunit::kunit_case(kernel::c_str!("name"), test_fn),
+/// kernel::kunit::kunit_case(c"name", test_fn),
/// kernel::kunit::kunit_case_null(),
/// ];
/// kernel::kunit_unsafe_test_suite!(suite_name, KUNIT_TEST_CASES);
diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs
index 652e060e47bd..8129419a3931 100644
--- a/rust/kernel/net/phy.rs
+++ b/rust/kernel/net/phy.rs
@@ -780,7 +780,6 @@ const fn as_int(&self) -> u32 {
///
/// ```
/// # mod module_phy_driver_sample {
-/// use kernel::c_str;
/// use kernel::net::phy::{self, DeviceId};
/// use kernel::prelude::*;
///
@@ -799,7 +798,7 @@ const fn as_int(&self) -> u32 {
///
/// #[vtable]
/// impl phy::Driver for PhySample {
-/// const NAME: &'static CStr = c_str!("PhySample");
+/// const NAME: &'static CStr = c"PhySample";
/// const PHY_DEVICE_ID: phy::DeviceId =
phy::DeviceId::new_with_exact_mask(0x00000001);
/// }
/// # }
@@ -808,7 +807,6 @@ const fn as_int(&self) -> u32 {
/// This expands to the following code:
///
/// ```ignore
-/// use kernel::c_str;
/// use kernel::net::phy::{self, DeviceId};
/// use kernel::prelude::*;
///
@@ -828,7 +826,7 @@ const fn as_int(&self) -> u32 {
///
/// #[vtable]
/// impl phy::Driver for PhySample {
-/// const NAME: &'static CStr = c_str!("PhySample");
+/// const NAME: &'static CStr = c"PhySample";
/// const PHY_DEVICE_ID: phy::DeviceId =
phy::DeviceId::new_with_exact_mask(0x00000001);
/// }
///
diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index a02ae5b25b74..65916b5936e6 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -124,7 +124,7 @@ macro_rules! module_platform_driver {
/// # Example
///
///```
-/// # use kernel::{bindings, c_str, device::Core, of, platform};
+/// # use kernel::{bindings, device::Core, of, platform};
///
/// struct MyDriver;
///
@@ -133,7 +133,7 @@ macro_rules! module_platform_driver {
/// MODULE_OF_TABLE,
/// <MyDriver as platform::Driver>::IdInfo,
/// [
-/// (of::DeviceId::new(c_str!("test,device")), ())
+/// (of::DeviceId::new(c"test,device"), ())
/// ]
/// );
///
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index f8164fd23f61..ff5ae125be0d 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -266,15 +266,14 @@ impl fmt::Display for crate::fmt::Adapter<&CStr>
{
/// Formats printable ASCII characters, escaping the rest.
///
/// ```
- /// # use kernel::c_str;
/// # use kernel::prelude::fmt;
/// # use kernel::str::CStr;
/// # use kernel::str::CString;
- /// let penguin = c_str!("?");
+ /// let penguin = c"?";
/// let s = CString::try_from_fmt(fmt!("{}", penguin))?;
/// assert_eq!(s.to_bytes_with_nul(),
"\\xf0\\x9f\\x90\\xa7\0".as_bytes());
///
- /// let ascii = c_str!("so \"cool\"");
+ /// let ascii = c"so \"cool\"";
/// let s = CString::try_from_fmt(fmt!("{}", ascii))?;
/// assert_eq!(s.to_bytes_with_nul(), "so
\"cool\"\0".as_bytes());
/// # Ok::<(), kernel::error::Error>(())
@@ -365,19 +364,28 @@ fn as_ref(&self) -> &BStr {
}
}
-/// Creates a new [`CStr`] from a string literal.
+/// Creates a static C string wrapper at compile time.
///
-/// The string literal should not contain any `NUL` bytes.
+/// Rust supports C string literals since Rust 1.77, and they should be used
instead of this macro
+/// where possible. This macro exists to allow static *non-literal* C strings
to be created at
+/// compile time. This is most often used in other macros.
+///
+/// # Panics
+///
+/// This macro panics if the operand contains an interior `NUL` byte.
///
/// # Examples
///
/// ```
-/// # use kernel::c_str;
+/// # use kernel::str_to_cstr;
/// # use kernel::str::CStr;
-/// const MY_CSTR: &CStr = c_str!("My awesome CStr!");
+/// const MY_CSTR: &CStr = str_to_cstr!(concat!(file!(), ":",
line!(), ": My CStr!"));
/// ```
#[macro_export]
-macro_rules! c_str {
+macro_rules! str_to_cstr {
+ // NB: we could write `($str:lit) => compile_error!("use a C string
literal instead");` here but
+ // that would trigger when the literal is at the top of several macro
expansions. That would be
+ // too limiting to macro authors, so we rely on the name as a hint instead.
($str:expr) => {{
const S: &str = concat!($str, "\0");
const C: &$crate::str::CStr = match
$crate::str::CStr::from_bytes_with_nul(S.as_bytes()) {
diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs
index 36a719015583..e38629147f42 100644
--- a/rust/kernel/sync.rs
+++ b/rust/kernel/sync.rs
@@ -41,7 +41,6 @@ impl LockClassKey {
///
/// # Example
/// ```
- /// # use kernel::c_str;
/// # use kernel::alloc::KBox;
/// # use kernel::types::ForeignOwnable;
/// # use kernel::sync::{LockClassKey, SpinLock};
@@ -53,7 +52,7 @@ impl LockClassKey {
/// {
/// stack_pin_init!(let num: SpinLock<u32> = SpinLock::new(
/// 0,
- /// c_str!("my_spinlock"),
+ /// c"my_spinlock",
/// // SAFETY: `key_ptr` is returned by the above `into_foreign()`,
whose
/// // `from_foreign()` has not yet been called.
/// unsafe { <Pin<KBox<LockClassKey>> as
ForeignOwnable>::borrow(key_ptr) }
@@ -106,9 +105,9 @@ macro_rules! static_lock_class {
#[macro_export]
macro_rules! optional_name {
() => {
- $crate::c_str!(::core::concat!(::core::file!(), ":",
::core::line!()))
+ $crate::str_to_cstr!(::core::concat!(::core::file!(), ":",
::core::line!()))
};
($name:literal) => {
- $crate::c_str!($name)
+ $name
};
}
diff --git a/rust/kernel/sync/lock/global.rs b/rust/kernel/sync/lock/global.rs
index 79d0ef7fda86..9caa9b419f09 100644
--- a/rust/kernel/sync/lock/global.rs
+++ b/rust/kernel/sync/lock/global.rs
@@ -267,7 +267,8 @@ macro_rules! global_lock {
$pub enum $name {}
impl $crate::sync::lock::GlobalLockBackend for $name {
- const NAME: &'static $crate::str::CStr =
$crate::c_str!(::core::stringify!($name));
+ const NAME: &'static $crate::str::CStr +
$crate::str_to_cstr!(::core::stringify!($name));
type Item = $valuety;
type Backend = $crate::global_lock_inner!(backend $kind);
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index d092112d843f..dbec533fd31f 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -51,7 +51,7 @@
//! fn new(value: i32) -> Result<Arc<Self>> {
//! Arc::pin_init(pin_init!(MyStruct {
//! value,
-//! work <- new_work!("MyStruct::work"),
+//! work <- new_work!(c"MyStruct::work"),
//! }), GFP_KERNEL)
//! }
//! }
@@ -98,8 +98,8 @@
//! Arc::pin_init(pin_init!(MyStruct {
//! value_1,
//! value_2,
-//! work_1 <- new_work!("MyStruct::work_1"),
-//! work_2 <- new_work!("MyStruct::work_2"),
+//! work_1 <- new_work!(c"MyStruct::work_1"),
+//! work_2 <- new_work!(c"MyStruct::work_2"),
//! }), GFP_KERNEL)
//! }
//! }
@@ -215,7 +215,7 @@ pub fn try_spawn<T: 'static + Send + FnOnce()>(
func: T,
) -> Result<(), AllocError> {
let init = pin_init!(ClosureWork {
- work <- new_work!("Queue::try_spawn"),
+ work <- new_work!(c"Queue::try_spawn"),
func: Some(func),
});
diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
index 81d18149a0cc..c64df1a01b9d 100644
--- a/rust/macros/kunit.rs
+++ b/rust/macros/kunit.rs
@@ -89,8 +89,8 @@ pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream)
-> TokenStream {
// unsafe extern "C" fn kunit_rust_wrapper_bar(_test: *mut
::kernel::bindings::kunit) { bar(); }
//
// static mut TEST_CASES: [::kernel::bindings::kunit_case; 3] = [
- // ::kernel::kunit::kunit_case(::kernel::c_str!("foo"),
kunit_rust_wrapper_foo),
- // ::kernel::kunit::kunit_case(::kernel::c_str!("bar"),
kunit_rust_wrapper_bar),
+ // ::kernel::kunit::kunit_case(c"foo",
kunit_rust_wrapper_foo),
+ // ::kernel::kunit::kunit_case(c"bar",
kunit_rust_wrapper_bar),
// ::kernel::kunit::kunit_case_null(),
// ];
//
@@ -109,7 +109,7 @@ pub(crate) fn kunit_tests(attr: TokenStream, ts:
TokenStream) -> TokenStream {
writeln!(kunit_macros, "{kunit_wrapper}").unwrap();
writeln!(
test_cases,
- "
::kernel::kunit::kunit_case(::kernel::c_str!(\"{test}\"),
{kunit_wrapper_fn_name}),"
+ " ::kernel::kunit::kunit_case(c\"{test}\",
{kunit_wrapper_fn_name}),"
)
.unwrap();
writeln!(
@@ -119,7 +119,7 @@ pub(crate) fn kunit_tests(attr: TokenStream, ts:
TokenStream) -> TokenStream {
#[allow(unused)]
macro_rules! assert {{
($cond:expr $(,)?) => {{{{
- kernel::kunit_assert!("{test}", "{path}", 0,
$cond);
+ kernel::kunit_assert!("{test}", c"{path}", 0,
$cond);
}}}}
}}
@@ -127,7 +127,7 @@ macro_rules! assert {{
#[allow(unused)]
macro_rules! assert_eq {{
($left:expr, $right:expr $(,)?) => {{{{
- kernel::kunit_assert_eq!("{test}", "{path}", 0,
$left, $right);
+ kernel::kunit_assert_eq!("{test}", c"{path}", 0,
$left, $right);
}}}}
}}
"#
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index de9304498a97..ef1906285a55 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -232,7 +232,7 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream {
type LocalModule = {type_};
impl ::kernel::ModuleMetadata for {type_} {{
- const NAME: &'static ::kernel::str::CStr =
::kernel::c_str!(\"{name}\");
+ const NAME: &'static ::kernel::str::CStr =
c\"{name}\";
}}
// Double nested modules, since then nobody can access the public
items inside.
diff --git a/samples/rust/rust_driver_faux.rs b/samples/rust/rust_driver_faux.rs
index ecc9fd378cbd..23add3160693 100644
--- a/samples/rust/rust_driver_faux.rs
+++ b/samples/rust/rust_driver_faux.rs
@@ -2,7 +2,7 @@
//! Rust faux device sample.
-use kernel::{c_str, faux, prelude::*, Module};
+use kernel::{faux, prelude::*, Module};
module! {
type: SampleModule,
@@ -20,7 +20,7 @@ impl Module for SampleModule {
fn init(_module: &'static ThisModule) -> Result<Self> {
pr_info!("Initialising Rust Faux Device Sample\n");
- let reg =
faux::Registration::new(c_str!("rust-faux-sample-device"), None)?;
+ let reg = faux::Registration::new(c"rust-faux-sample-device",
None)?;
dev_info!(reg.as_ref(), "Hello from faux device!\n");
diff --git a/samples/rust/rust_driver_pci.rs b/samples/rust/rust_driver_pci.rs
index 2bb260aebc9e..8da48c1c3c2d 100644
--- a/samples/rust/rust_driver_pci.rs
+++ b/samples/rust/rust_driver_pci.rs
@@ -4,7 +4,7 @@
//!
//! To make this driver probe, QEMU must be run with `-device pci-testdev`.
-use kernel::{bindings, c_str, device::Core, devres::Devres, pci, prelude::*,
types::ARef};
+use kernel::{bindings, device::Core, devres::Devres, pci, prelude::*,
types::ARef};
struct Regs;
@@ -73,7 +73,7 @@ fn probe(pdev: &pci::Device<Core>, info:
&Self::IdInfo) -> Result<Pin<KBox<Self>
pdev.enable_device_mem()?;
pdev.set_master();
- let bar = pdev.iomap_region_sized::<{ Regs::END }>(0,
c_str!("rust_driver_pci"))?;
+ let bar = pdev.iomap_region_sized::<{ Regs::END }>(0,
c"rust_driver_pci")?;
let drvdata = KBox::new(
Self {
diff --git a/samples/rust/rust_driver_platform.rs
b/samples/rust/rust_driver_platform.rs
index 8b42b3cfb363..e6487a970a59 100644
--- a/samples/rust/rust_driver_platform.rs
+++ b/samples/rust/rust_driver_platform.rs
@@ -2,7 +2,7 @@
//! Rust Platform driver sample.
-use kernel::{c_str, device::Core, of, platform, prelude::*, types::ARef};
+use kernel::{device::Core, of, platform, prelude::*, types::ARef};
struct SampleDriver {
pdev: ARef<platform::Device>,
@@ -14,7 +14,7 @@ struct SampleDriver {
OF_TABLE,
MODULE_OF_TABLE,
<SampleDriver as platform::Driver>::IdInfo,
- [(of::DeviceId::new(c_str!("test,rust-device")), Info(42))]
+ [(of::DeviceId::new(c"test,rust-device"), Info(42))]
);
impl platform::Driver for SampleDriver {
diff --git a/samples/rust/rust_misc_device.rs b/samples/rust/rust_misc_device.rs
index c881fd6dbd08..12b64296e912 100644
--- a/samples/rust/rust_misc_device.rs
+++ b/samples/rust/rust_misc_device.rs
@@ -98,7 +98,6 @@
use core::pin::Pin;
use kernel::{
- c_str,
device::Device,
fs::File,
ioctl::{_IO, _IOC_SIZE, _IOR, _IOW},
@@ -133,7 +132,7 @@ fn init(_module: &'static ThisModule) -> impl
PinInit<Self, Error> {
pr_info!("Initialising Rust Misc Device Sample\n");
let options = MiscDeviceOptions {
- name: c_str!("rust-misc-device"),
+ name: c"rust-misc-device",
};
try_pin_init!(Self {
diff --git a/scripts/rustdoc_test_gen.rs b/scripts/rustdoc_test_gen.rs
index 507d36875196..0e86bdf1b5b1 100644
--- a/scripts/rustdoc_test_gen.rs
+++ b/scripts/rustdoc_test_gen.rs
@@ -173,7 +173,7 @@ pub extern "C" fn {kunit_name}(__kunit_test: *mut
::kernel::bindings::kunit) {{
macro_rules! assert {{
($cond:expr $(,)?) => {{{{
::kernel::kunit_assert!(
- "{kunit_name}", "{real_path}",
__DOCTEST_ANCHOR - {line}, $cond
+ "{kunit_name}", c"{real_path}",
__DOCTEST_ANCHOR - {line}, $cond
);
}}}}
}}
@@ -183,7 +183,7 @@ macro_rules! assert {{
macro_rules! assert_eq {{
($left:expr, $right:expr $(,)?) => {{{{
::kernel::kunit_assert_eq!(
- "{kunit_name}", "{real_path}",
__DOCTEST_ANCHOR - {line}, $left, $right
+ "{kunit_name}", c"{real_path}",
__DOCTEST_ANCHOR - {line}, $left, $right
);
}}}}
}}
--
2.49.0
Tamir Duberstein
2025-May-30 12:28 UTC
[PATCH v11 5/5] rust: remove core::ffi::CStr reexport
Clean up references to `kernel::str::CStr`.
Signed-off-by: Tamir Duberstein <tamird at gmail.com>
---
drivers/gpu/drm/drm_panic_qr.rs | 3 ++-
drivers/gpu/nova-core/firmware.rs | 2 +-
drivers/net/phy/ax88796b_rust.rs | 1 +
drivers/net/phy/qt2025.rs | 1 +
rust/kernel/device.rs | 3 +--
rust/kernel/driver.rs | 4 ++--
rust/kernel/error.rs | 6 ++----
rust/kernel/faux.rs | 5 ++++-
rust/kernel/firmware.rs | 15 ++++-----------
rust/kernel/kunit.rs | 6 +++---
rust/kernel/lib.rs | 2 +-
rust/kernel/miscdevice.rs | 3 +--
rust/kernel/net/phy.rs | 4 +++-
rust/kernel/of.rs | 3 ++-
rust/kernel/pci.rs | 2 +-
rust/kernel/platform.rs | 2 +-
rust/kernel/prelude.rs | 5 +----
rust/kernel/str.rs | 8 +++-----
rust/kernel/sync/condvar.rs | 4 ++--
rust/kernel/sync/lock.rs | 4 ++--
rust/kernel/sync/lock/global.rs | 5 +++--
rust/kernel/sync/poll.rs | 1 +
rust/kernel/workqueue.rs | 1 +
rust/macros/module.rs | 2 +-
24 files changed, 44 insertions(+), 48 deletions(-)
diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_qr.rs
index d8192a9bef63..ba63238d352f 100644
--- a/drivers/gpu/drm/drm_panic_qr.rs
+++ b/drivers/gpu/drm/drm_panic_qr.rs
@@ -27,7 +27,8 @@
//! * <https://github.com/erwanvivien/fast_qr>
//! * <https://github.com/bjguillot/qr>
-use kernel::{prelude::*, str::CStr};
+use core::ffi::CStr;
+use kernel::prelude::*;
#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd)]
struct Version(usize);
diff --git a/drivers/gpu/nova-core/firmware.rs
b/drivers/gpu/nova-core/firmware.rs
index 6e6361c59ca1..0af1f0df2fa5 100644
--- a/drivers/gpu/nova-core/firmware.rs
+++ b/drivers/gpu/nova-core/firmware.rs
@@ -30,7 +30,7 @@ const fn make_entry_chipset(self, chipset: &str) ->
Self {
}
pub(crate) const fn create(
- module_name: &'static kernel::str::CStr,
+ module_name: &'static core::ffi::CStr,
) -> firmware::ModInfoBuilder<N> {
let mut this = Self(firmware::ModInfoBuilder::new(module_name));
let mut i = 0;
diff --git a/drivers/net/phy/ax88796b_rust.rs b/drivers/net/phy/ax88796b_rust.rs
index 2d24628a4e58..68b8e30ae296 100644
--- a/drivers/net/phy/ax88796b_rust.rs
+++ b/drivers/net/phy/ax88796b_rust.rs
@@ -4,6 +4,7 @@
//! Rust Asix PHYs driver
//!
//! C version of this driver: [`drivers/net/phy/ax88796b.c`](./ax88796b.c)
+use core::ffi::CStr;
use kernel::{
net::phy::{self, reg::C22, DeviceId, Driver},
prelude::*,
diff --git a/drivers/net/phy/qt2025.rs b/drivers/net/phy/qt2025.rs
index 9ccc75f70219..78ce2866f2b6 100644
--- a/drivers/net/phy/qt2025.rs
+++ b/drivers/net/phy/qt2025.rs
@@ -9,6 +9,7 @@
//!
//! The QT2025 PHY integrates an Intel 8051 micro-controller.
+use core::ffi::CStr;
use kernel::error::code;
use kernel::firmware::Firmware;
use kernel::net::phy::{
diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
index 9074322c79e8..2cf5903f7dde 100644
--- a/rust/kernel/device.rs
+++ b/rust/kernel/device.rs
@@ -6,10 +6,9 @@
use crate::{
bindings,
- str::CStr,
types::{ARef, Opaque},
};
-use core::{fmt, ptr};
+use core::{ffi::CStr, fmt, ptr};
#[cfg(CONFIG_PRINTK)]
use crate::str::CStrExt as _;
diff --git a/rust/kernel/driver.rs b/rust/kernel/driver.rs
index ec9166cedfa7..9926664d9ba2 100644
--- a/rust/kernel/driver.rs
+++ b/rust/kernel/driver.rs
@@ -6,8 +6,8 @@
//! register using the [`Registration`] class.
use crate::error::{Error, Result};
-use crate::{device, of, str::CStr, try_pin_init, types::Opaque, ThisModule};
-use core::pin::Pin;
+use crate::{device, of, try_pin_init, types::Opaque, ThisModule};
+use core::{ffi::CStr, pin::Pin};
use pin_init::{pin_data, pinned_drop, PinInit};
/// The [`RegistrationOps`] trait serves as generic interface for subsystems
(e.g., PCI, Platform,
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 933c048c04f1..b2b46d26f7b7 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -4,11 +4,9 @@
//!
//! C header:
[`include/uapi/asm-generic/errno-base.h`](srctree/include/uapi/asm-generic/errno-base.h)
-use crate::{
- alloc::{layout::LayoutError, AllocError},
- str::CStr,
-};
+use crate::alloc::{layout::LayoutError, AllocError};
+use core::ffi::CStr;
use core::fmt;
use core::num::NonZeroI32;
use core::num::TryFromIntError;
diff --git a/rust/kernel/faux.rs b/rust/kernel/faux.rs
index 8a50fcd4c9bb..d9e5cd265101 100644
--- a/rust/kernel/faux.rs
+++ b/rust/kernel/faux.rs
@@ -7,7 +7,10 @@
//! C header: [`include/linux/device/faux.h`]
use crate::{bindings, device, error::code::*, prelude::*};
-use core::ptr::{addr_of_mut, null, null_mut, NonNull};
+use core::{
+ ffi::CStr,
+ ptr::{addr_of_mut, null, null_mut, NonNull},
+};
/// The registration of a faux device.
///
diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs
index 09fd3a27bcf0..4ba5e5589d7b 100644
--- a/rust/kernel/firmware.rs
+++ b/rust/kernel/firmware.rs
@@ -4,15 +4,8 @@
//!
//! C header: [`include/linux/firmware.h`](srctree/include/linux/firmware.h)
-use crate::{
- bindings,
- device::Device,
- error::Error,
- error::Result,
- ffi,
- str::{CStr, CStrExt as _},
-};
-use core::ptr::NonNull;
+use crate::{bindings, device::Device, error::Error, error::Result, ffi,
str::CStrExt as _};
+use core::{ffi::CStr, ptr::NonNull};
/// # Invariants
///
@@ -168,7 +161,7 @@ unsafe impl Sync for Firmware {}
/// const DIR: &'static str = "vendor/chip/";
/// const FILES: [&'static str; 3] = [ "foo",
"bar", "baz" ];
///
-/// const fn create(module_name: &'static kernel::str::CStr) ->
firmware::ModInfoBuilder<N> {
+/// const fn create(module_name: &'static core::ffi::CStr) ->
firmware::ModInfoBuilder<N> {
/// let mut builder = firmware::ModInfoBuilder::new(module_name);
///
/// let mut i = 0;
@@ -202,7 +195,7 @@ macro_rules! module_firmware {
// this macro. Hence, we can neither use `expr` nor `ty`.
($($builder:tt)*) => {
const _: () = {
- const __MODULE_FIRMWARE_PREFIX: &'static $crate::str::CStr
= if cfg!(MODULE) {
+ const __MODULE_FIRMWARE_PREFIX: &'static ::core::ffi::CStr
= if cfg!(MODULE) {
c""
} else {
<LocalModule as $crate::ModuleMetadata>::NAME
diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs
index 2bab61910f1e..5504a6216d19 100644
--- a/rust/kernel/kunit.rs
+++ b/rust/kernel/kunit.rs
@@ -57,9 +57,9 @@ macro_rules! kunit_assert {
break 'out;
}
- static FILE: &'static $crate::str::CStr = $file;
+ static FILE: &'static ::core::ffi::CStr = $file;
static LINE: i32 = ::core::line!() as i32 - $diff;
- static CONDITION: &'static $crate::str::CStr +
static CONDITION: &'static ::core::ffi::CStr
$crate::str_to_cstr!(stringify!($condition));
// SAFETY: FFI call without safety requirements.
@@ -195,7 +195,7 @@ pub fn is_test_result_ok(t: impl TestResult) -> bool {
/// Use [`kunit_case_null`] to generate such a delimiter.
#[doc(hidden)]
pub const fn kunit_case(
- name: &'static kernel::str::CStr,
+ name: &'static core::ffi::CStr,
run_case: unsafe extern "C" fn(*mut kernel::bindings::kunit),
) -> kernel::bindings::kunit_case {
kernel::bindings::kunit_case {
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 6e8eb57fb225..1b162973b71d 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -152,7 +152,7 @@ fn init(module: &'static ThisModule) -> impl
pin_init::PinInit<Self, error::Erro
/// Metadata attached to a [`Module`] or [`InPlaceModule`].
pub trait ModuleMetadata {
/// The name of the module as specified in the `module!` macro.
- const NAME: &'static crate::str::CStr;
+ const NAME: &'static core::ffi::CStr;
}
/// Equivalent to `THIS_MODULE` in the C API.
diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs
index d684ec4ef4d0..47f718a9ceb5 100644
--- a/rust/kernel/miscdevice.rs
+++ b/rust/kernel/miscdevice.rs
@@ -16,10 +16,9 @@
fs::File,
prelude::*,
seq_file::SeqFile,
- str::CStr,
types::{ForeignOwnable, Opaque},
};
-use core::{marker::PhantomData, mem::MaybeUninit, pin::Pin};
+use core::{ffi::CStr, marker::PhantomData, mem::MaybeUninit, pin::Pin};
/// Options for creating a misc device.
#[derive(Copy, Clone)]
diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs
index 8129419a3931..72635af8f20e 100644
--- a/rust/kernel/net/phy.rs
+++ b/rust/kernel/net/phy.rs
@@ -7,7 +7,7 @@
//! C headers: [`include/linux/phy.h`](srctree/include/linux/phy.h).
use crate::{error::*, prelude::*, types::Opaque};
-use core::{marker::PhantomData, ptr::addr_of_mut};
+use core::{ffi::CStr, marker::PhantomData, ptr::addr_of_mut};
pub mod reg;
@@ -780,6 +780,7 @@ const fn as_int(&self) -> u32 {
///
/// ```
/// # mod module_phy_driver_sample {
+/// use core::ffi::CStr;
/// use kernel::net::phy::{self, DeviceId};
/// use kernel::prelude::*;
///
@@ -807,6 +808,7 @@ const fn as_int(&self) -> u32 {
/// This expands to the following code:
///
/// ```ignore
+/// use core::ffi::CStr;
/// use kernel::net::phy::{self, DeviceId};
/// use kernel::prelude::*;
///
diff --git a/rust/kernel/of.rs b/rust/kernel/of.rs
index 12ea65df46de..087ac8e05551 100644
--- a/rust/kernel/of.rs
+++ b/rust/kernel/of.rs
@@ -2,7 +2,8 @@
//! Device Tree / Open Firmware abstractions.
-use crate::{bindings, device_id::RawDeviceId, prelude::*};
+use crate::{bindings, device_id::RawDeviceId};
+use core::ffi::CStr;
/// IdTable type for OF drivers.
pub type IdTable<T> = &'static dyn
kernel::device_id::IdTable<DeviceId, T>;
diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index c17a32b76d74..86df366bf911 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -13,11 +13,11 @@
error::{to_result, Result},
io::Io,
io::IoRaw,
- str::CStr,
types::{ARef, ForeignOwnable, Opaque},
ThisModule,
};
use core::{
+ ffi::CStr,
marker::PhantomData,
ops::Deref,
ptr::{addr_of_mut, NonNull},
diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 65916b5936e6..272a7401c0dc 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -9,12 +9,12 @@
error::{to_result, Result},
of,
prelude::*,
- str::CStr,
types::{ARef, ForeignOwnable, Opaque},
ThisModule,
};
use core::{
+ ffi::CStr,
marker::PhantomData,
ops::Deref,
ptr::{addr_of_mut, NonNull},
diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index 244b660fa835..3f7ca5a95160 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -40,10 +40,7 @@
pub use super::error::{code::*, Error, Result};
-pub use super::{
- str::{CStr, CStrExt as _},
- ThisModule,
-};
+pub use super::{str::CStrExt as _, ThisModule};
pub use super::init::InPlaceInit;
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index ff5ae125be0d..cc882c5a8d67 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -3,6 +3,7 @@
//! String representations.
use crate::alloc::{flags::*, AllocError, KVec};
+use core::ffi::CStr;
use core::fmt::{self, Write};
use core::ops::{Deref, DerefMut, Index};
@@ -175,8 +176,6 @@ macro_rules! b_str {
}};
}
-pub use core::ffi::CStr;
-
/// Returns a C pointer to the string.
// It is a free function rather than a method on an extension trait because:
//
@@ -267,7 +266,6 @@ impl fmt::Display for crate::fmt::Adapter<&CStr> {
///
/// ```
/// # use kernel::prelude::fmt;
- /// # use kernel::str::CStr;
/// # use kernel::str::CString;
/// let penguin = c"?";
/// let s = CString::try_from_fmt(fmt!("{}", penguin))?;
@@ -377,8 +375,8 @@ fn as_ref(&self) -> &BStr {
/// # Examples
///
/// ```
+/// # use core::ffi::CStr;
/// # use kernel::str_to_cstr;
-/// # use kernel::str::CStr;
/// const MY_CSTR: &CStr = str_to_cstr!(concat!(file!(), ":",
line!(), ": My CStr!"));
/// ```
#[macro_export]
@@ -388,7 +386,7 @@ macro_rules! str_to_cstr {
// too limiting to macro authors, so we rely on the name as a hint instead.
($str:expr) => {{
const S: &str = concat!($str, "\0");
- const C: &$crate::str::CStr = match
$crate::str::CStr::from_bytes_with_nul(S.as_bytes()) {
+ const C: &core::ffi::CStr = match
core::ffi::CStr::from_bytes_with_nul(S.as_bytes()) {
Ok(v) => v,
Err(_) => panic!("string contains interior NUL"),
};
diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
index 0b6bc7f2878d..09bc35feb451 100644
--- a/rust/kernel/sync/condvar.rs
+++ b/rust/kernel/sync/condvar.rs
@@ -8,14 +8,14 @@
use super::{lock::Backend, lock::Guard, LockClassKey};
use crate::{
ffi::{c_int, c_long},
- str::{CStr, CStrExt as _},
+ str::CStrExt as _,
task::{
MAX_SCHEDULE_TIMEOUT, TASK_FREEZABLE, TASK_INTERRUPTIBLE, TASK_NORMAL,
TASK_UNINTERRUPTIBLE,
},
time::Jiffies,
types::Opaque,
};
-use core::{marker::PhantomPinned, pin::Pin, ptr};
+use core::{ffi::CStr, marker::PhantomPinned, pin::Pin, ptr};
use pin_init::{pin_data, pin_init, PinInit};
/// Creates a [`CondVar`] initialiser with the given name and a newly-created
lock class.
diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
index a777a22976e0..21deff0bb13b 100644
--- a/rust/kernel/sync/lock.rs
+++ b/rust/kernel/sync/lock.rs
@@ -7,10 +7,10 @@
use super::LockClassKey;
use crate::{
- str::{CStr, CStrExt as _},
+ str::CStrExt as _,
types::{NotThreadSafe, Opaque, ScopeGuard},
};
-use core::{cell::UnsafeCell, marker::PhantomPinned, pin::Pin};
+use core::{cell::UnsafeCell, ffi::CStr, marker::PhantomPinned, pin::Pin};
use pin_init::{pin_data, pin_init, PinInit};
pub mod mutex;
diff --git a/rust/kernel/sync/lock/global.rs b/rust/kernel/sync/lock/global.rs
index 9caa9b419f09..ab5a3947fdd6 100644
--- a/rust/kernel/sync/lock/global.rs
+++ b/rust/kernel/sync/lock/global.rs
@@ -5,13 +5,14 @@
//! Support for defining statics containing locks.
use crate::{
- str::{CStr, CStrExt as _},
+ str::CStrExt as _,
sync::lock::{Backend, Guard, Lock},
sync::{LockClassKey, LockedBy},
types::Opaque,
};
use core::{
cell::UnsafeCell,
+ ffi::CStr,
marker::{PhantomData, PhantomPinned},
pin::Pin,
};
@@ -267,7 +268,7 @@ macro_rules! global_lock {
$pub enum $name {}
impl $crate::sync::lock::GlobalLockBackend for $name {
- const NAME: &'static $crate::str::CStr + const
NAME: &'static ::core::ffi::CStr
$crate::str_to_cstr!(::core::stringify!($name));
type Item = $valuety;
type Backend = $crate::global_lock_inner!(backend $kind);
diff --git a/rust/kernel/sync/poll.rs b/rust/kernel/sync/poll.rs
index d7e6e59e124b..bf2fb24d04ea 100644
--- a/rust/kernel/sync/poll.rs
+++ b/rust/kernel/sync/poll.rs
@@ -11,6 +11,7 @@
sync::{CondVar, LockClassKey},
types::Opaque,
};
+use core::ffi::CStr;
use core::ops::Deref;
/// Creates a [`PollCondVar`] initialiser with the given name and a
newly-created lock class.
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index dbec533fd31f..bb3f917204f8 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -135,6 +135,7 @@
use crate::alloc::{AllocError, Flags};
use crate::{prelude::*, sync::Arc, sync::LockClassKey, types::Opaque};
+use core::ffi::CStr;
use core::marker::PhantomData;
/// Creates a [`Work`] initialiser with the given name and a newly-created lock
class.
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index ef1906285a55..1ec923eb9383 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -232,7 +232,7 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream {
type LocalModule = {type_};
impl ::kernel::ModuleMetadata for {type_} {{
- const NAME: &'static ::kernel::str::CStr =
c\"{name}\";
+ const NAME: &'static ::core::ffi::CStr =
c\"{name}\";
}}
// Double nested modules, since then nobody can access the public
items inside.
--
2.49.0
Benno Lossin
2025-Jun-01 16:24 UTC
[PATCH v11 1/5] rust: macros: reduce collections in `quote!` macro
On Fri May 30, 2025 at 2:27 PM CEST, Tamir Duberstein wrote:> Remove a handful of unncessary intermediate vectors and token streams; > mainly the top-level stream can be directly extended with the notable > exception of groups.What's the motivation for this? I wouldn't spend much effort on this file, as it'll go away when we add the `quote` crate. --- Cheers, Benno> Remove an unnecessary `#[allow(dead_code)]` added in commit dbd5058ba60c > ("rust: make pin-init its own crate"). > > Signed-off-by: Tamir Duberstein <tamird at gmail.com> > --- > rust/macros/quote.rs | 104 ++++++++++++++++++++++++--------------------------- > 1 file changed, 49 insertions(+), 55 deletions(-)
Alice Ryhl
2025-Jun-02 08:45 UTC
[PATCH v11 4/5] rust: replace `kernel::c_str!` with C-Strings
On Fri, May 30, 2025 at 08:27:45AM -0400, Tamir Duberstein wrote:> C-String literals were added in Rust 1.77. Replace instances of > `kernel::c_str!` with C-String literals where possible and rename > `kernel::c_str!` to `str_to_cstr!` to clarify its intended use. > > Closes: https://github.com/Rust-for-Linux/linux/issues/1075 > Signed-off-by: Tamir Duberstein <tamird at gmail.com>> -/// Creates a new [`CStr`] from a string literal. > +/// Creates a static C string wrapper at compile time.A C string *wrapper*? What do you mean? I would drop the word "wrapper" here.> -/// The string literal should not contain any `NUL` bytes. > +/// Rust supports C string literals since Rust 1.77, and they should be used instead of this macro > +/// where possible. This macro exists to allow static *non-literal* C strings to be created at > +/// compile time. This is most often used in other macros. > +/// > +/// # Panics > +/// > +/// This macro panics if the operand contains an interior `NUL` byte. > /// > /// # Examples > /// > /// ``` > -/// # use kernel::c_str; > +/// # use kernel::str_to_cstr; > /// # use kernel::str::CStr; > -/// const MY_CSTR: &CStr = c_str!("My awesome CStr!"); > +/// const MY_CSTR: &CStr = str_to_cstr!(concat!(file!(), ":", line!(), ": My CStr!")); > /// ``` > #[macro_export] > -macro_rules! c_str { > +macro_rules! str_to_cstr { > + // NB: we could write `($str:lit) => compile_error!("use a C string literal instead");` here but > + // that would trigger when the literal is at the top of several macro expansions. That would be > + // too limiting to macro authors, so we rely on the name as a hint instead. > ($str:expr) => {{ > const S: &str = concat!($str, "\0"); > const C: &$crate::str::CStr = match $crate::str::CStr::from_bytes_with_nul(S.as_bytes()) {Alice
Alice Ryhl
2025-Jun-02 08:46 UTC
[PATCH v11 3/5] rust: replace `CStr` with `core::ffi::CStr`
On Fri, May 30, 2025 at 08:27:44AM -0400, Tamir Duberstein wrote:> `kernel::ffi::CStr` was introduced in commit d126d2380131 ("rust: str: > add `CStr` type") in November 2022 as an upstreaming of earlier work > that was done in May 2021[0]. That earlier work, having predated the > inclusion of `CStr` in `core`, largely duplicated the implementation of > `std::ffi::CStr`. > > `std::ffi::CStr` was moved to `core::ffi::CStr` in Rust 1.64 in > September 2022. Hence replace `kernel::str::CStr` with `core::ffi::CStr` > to reduce our custom code footprint, and retain needed custom > functionality through an extension trait. > > C-String literals were added in Rust 1.77, while our MSRV is 1.78. Thus > opportunistically replace instances of `kernel::c_str!` with C-String > literals where other code changes were already necessary or where > existing code triggered clippy lints; the rest will be done in a later > commit. > > Link: https://github.com/Rust-for-Linux/linux/commit/faa3cbcca03d0dec8f8e43f1d8d5c0860d98a23f [0] > Signed-off-by: Tamir Duberstein <tamird at gmail.com>> diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs > index 2494c96e105f..582ab648b14c 100644 > --- a/rust/kernel/firmware.rs > +++ b/rust/kernel/firmware.rs > @@ -4,7 +4,14 @@ > //! > //! C header: [`include/linux/firmware.h`](srctree/include/linux/firmware.h) > > -use crate::{bindings, device::Device, error::Error, error::Result, ffi, str::CStr}; > +use crate::{ > + bindings, > + device::Device, > + error::Error, > + error::Result, > + ffi, > + str::{CStr, CStrExt as _}, > +};Did you not add CStrExt to the prelude?> --- a/rust/kernel/error.rs > +++ b/rust/kernel/error.rs > @@ -164,6 +164,8 @@ pub fn name(&self) -> Option<&'static CStr> { > if ptr.is_null() { > None > } else { > + use crate::str::CStrExt as _; > + > // SAFETY: The string returned by `errname` is static and `NUL`-terminated. > Some(unsafe { CStr::from_char_ptr(ptr) }) > }Ditto here. Alice