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Sun, 02 Feb 2025 04:20:54 -0800 (PST) From: Tamir Duberstein Date: Sun, 02 Feb 2025 07:20:46 -0500 Subject: [PATCH v6 1/4] rust: move BStr,CStr Display impls behind method Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250202-cstr-core-v6-1-8469cd6d29fd@gmail.com> References: <20250202-cstr-core-v6-0-8469cd6d29fd@gmail.com> In-Reply-To: <20250202-cstr-core-v6-0-8469cd6d29fd@gmail.com> To: Michal Rostecki , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Tamir Duberstein X-Mailer: b4 0.15-dev There are two reasons for doing this: - Moving the Display impl behind a display method matches the style used in the standard library for printing non-Unicode data. - The standard library's core::ffi::CStr doesn't implement Display; moving Display to a helper struct is a necessary step toward using it. Signed-off-by: Tamir Duberstein --- rust/kernel/kunit.rs | 9 ++-- rust/kernel/str.rs | 120 +++++++++++++++++++++++++++++++++++------------= ---- 2 files changed, 89 insertions(+), 40 deletions(-) diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 824da0e9738a..630b947c708c 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -56,6 +56,7 @@ macro_rules! kunit_assert { break 'out; } =20 + static NAME: &'static $crate::str::CStr =3D $crate::c_str!($na= me); static FILE: &'static $crate::str::CStr =3D $crate::c_str!($fi= le); static LINE: i32 =3D core::line!() as i32 - $diff; static CONDITION: &'static $crate::str::CStr =3D $crate::c_str= !(stringify!($condition)); @@ -71,11 +72,13 @@ macro_rules! kunit_assert { // // This mimics KUnit's failed assertion format. $crate::kunit::err(format_args!( - " # {}: ASSERTION FAILED at {FILE}:{LINE}\n", - $name + " # {NAME}: ASSERTION FAILED at {FILE}:{LINE}\n", + NAME =3D NAME.display(), + FILE =3D FILE.display(), )); $crate::kunit::err(format_args!( - " Expected {CONDITION} to be true, but is false\n" + " Expected {CONDITION} to be true, but is false\n", + CONDITION =3D CONDITION.display(), )); $crate::kunit::err(format_args!( " Failure not reported to KUnit since this is a non= -KUnit task\n" diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index 28e2201604d6..53450c956a6a 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -31,29 +31,76 @@ pub const fn from_bytes(bytes: &[u8]) -> &Self { // SAFETY: `BStr` is transparent to `[u8]`. unsafe { &*(bytes as *const [u8] as *const BStr) } } -} =20 -impl fmt::Display for BStr { - /// Formats printable ASCII characters, escaping the rest. + /// Returns an object that implements [`Display`] for safely printing = a [`BStr`] that may + /// contain non-Unicode data. If you would like an implementation whic= h escapes the [`BStr`] + /// please use [`Debug`] instead. + /// + /// [`Display`]: fmt::Display + /// [`Debug`]: fmt::Debug + /// + /// # Examples /// /// ``` - /// # use kernel::{fmt, b_str, str::{BStr, CString}}; + /// # use kernel::{fmt, b_str, str::CString}; /// let ascii =3D b_str!("Hello, BStr!"); - /// let s =3D CString::try_from_fmt(fmt!("{}", ascii))?; + /// let s =3D CString::try_from_fmt(fmt!("{}", ascii.display()))?; /// assert_eq!(s.as_bytes(), "Hello, BStr!".as_bytes()); /// /// let non_ascii =3D b_str!("=F0=9F=A6=80"); - /// let s =3D CString::try_from_fmt(fmt!("{}", non_ascii))?; + /// let s =3D CString::try_from_fmt(fmt!("{}", non_ascii.display()))?; /// assert_eq!(s.as_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes()); /// # Ok::<(), kernel::error::Error>(()) /// ``` + #[inline] + pub fn display(&self) -> Display<'_> { + Display { + inner: self, + escape_common: true, + } + } +} + +/// Helper struct for safely printing a [`BStr`] with [`fmt!`] and `{}`. +/// +/// A [`BStr`] might contain non-Unicode data. This `struct` implements th= e [`Display`] trait in a +/// way that mitigates that. It is created by the [`display`](BStr::displa= y) method on [`BStr`]. +/// +/// If you would like an implementation which escapes the string please us= e [`Debug`] instead. +/// +/// # Examples +/// +/// ``` +/// # use kernel::{fmt, b_str, str::CString}; +/// let ascii =3D b_str!("Hello, BStr!"); +/// let s =3D CString::try_from_fmt(fmt!("{}", ascii.display()))?; +/// assert_eq!(s.as_bytes(), "Hello, BStr!".as_bytes()); +/// +/// let non_ascii =3D b_str!("=F0=9F=A6=80"); +/// let s =3D CString::try_from_fmt(fmt!("{}", non_ascii.display()))?; +/// assert_eq!(s.as_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes()); +/// # Ok::<(), kernel::error::Error>(()) +/// ``` +/// +/// [`Debug`]: fmt::Debug +/// [`Display`]: fmt::Display +pub struct Display<'a> { + inner: &'a BStr, + escape_common: bool, +} + +impl fmt::Display for Display<'_> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - for &b in &self.0 { + let Self { + inner: BStr(b), + escape_common, + } =3D self; + for &b in b { match b { // Common escape codes. - b'\t' =3D> f.write_str("\\t")?, - b'\n' =3D> f.write_str("\\n")?, - b'\r' =3D> f.write_str("\\r")?, + b'\t' if *escape_common =3D> f.write_str("\\t")?, + b'\n' if *escape_common =3D> f.write_str("\\n")?, + b'\r' if *escape_common =3D> f.write_str("\\r")?, // Printable characters. 0x20..=3D0x7e =3D> f.write_char(b as char)?, _ =3D> write!(f, "\\x{:02x}", b)?, @@ -68,7 +115,7 @@ impl fmt::Debug for BStr { /// escaping the rest. /// /// ``` - /// # use kernel::{fmt, b_str, str::{BStr, CString}}; + /// # use kernel::{fmt, b_str, str::CString}; /// // Embedded double quotes are escaped. /// let ascii =3D b_str!("Hello, \"BStr\"!"); /// let s =3D CString::try_from_fmt(fmt!("{:?}", ascii))?; @@ -376,35 +423,35 @@ pub fn to_ascii_uppercase(&self) -> Result { =20 Ok(s) } -} =20 -impl fmt::Display for CStr { - /// Formats printable ASCII characters, escaping the rest. + /// Returns an object that implements [`Display`] for safely printing = a [`CStr`] that may + /// contain non-Unicode data. If you would like an implementation whic= h escapes the [`CStr`] + /// please use [`Debug`] instead. + /// + /// [`Display`]: fmt::Display + /// [`Debug`]: fmt::Debug + /// + /// # Examples /// /// ``` /// # use kernel::c_str; /// # use kernel::fmt; - /// # use kernel::str::CStr; /// # use kernel::str::CString; /// let penguin =3D c_str!("=F0=9F=90=A7"); - /// let s =3D CString::try_from_fmt(fmt!("{}", penguin))?; + /// let s =3D CString::try_from_fmt(fmt!("{}", penguin.display()))?; /// assert_eq!(s.as_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_byte= s()); /// /// let ascii =3D c_str!("so \"cool\""); - /// let s =3D CString::try_from_fmt(fmt!("{}", ascii))?; + /// let s =3D CString::try_from_fmt(fmt!("{}", ascii.display()))?; /// 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 { - for &c in self.as_bytes() { - if (0x20..0x7f).contains(&c) { - // Printable character. - f.write_char(c as char)?; - } else { - write!(f, "\\x{:02x}", c)?; - } + #[inline] + pub fn display(&self) -> Display<'_> { + Display { + inner: self, + escape_common: false, } - Ok(()) } } =20 @@ -414,7 +461,6 @@ impl fmt::Debug for CStr { /// ``` /// # use kernel::c_str; /// # use kernel::fmt; - /// # use kernel::str::CStr; /// # use kernel::str::CString; /// let penguin =3D c_str!("=F0=9F=90=A7"); /// let s =3D CString::try_from_fmt(fmt!("{:?}", penguin))?; @@ -595,13 +641,13 @@ fn test_cstr_as_str_unchecked() { #[test] fn test_cstr_display() { let hello_world =3D CStr::from_bytes_with_nul(b"hello, world!\0").= unwrap(); - assert_eq!(format!("{}", hello_world), "hello, world!"); + assert_eq!(format!("{}", hello_world.display()), "hello, world!"); let non_printables =3D CStr::from_bytes_with_nul(b"\x01\x09\x0a\0"= ).unwrap(); - assert_eq!(format!("{}", non_printables), "\\x01\\x09\\x0a"); + assert_eq!(format!("{}", non_printables.display()), "\\x01\\x09\\x= 0a"); let non_ascii =3D CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").un= wrap(); - assert_eq!(format!("{}", non_ascii), "d\\xe9j\\xe0 vu"); + assert_eq!(format!("{}", non_ascii.display()), "d\\xe9j\\xe0 vu"); let good_bytes =3D CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0"= ).unwrap(); - assert_eq!(format!("{}", good_bytes), "\\xf0\\x9f\\xa6\\x80"); + assert_eq!(format!("{}", good_bytes.display()), "\\xf0\\x9f\\xa6\\= x80"); } =20 #[test] @@ -612,7 +658,7 @@ fn test_cstr_display_all_bytes() { bytes[i as usize] =3D i.wrapping_add(1); } let cstr =3D CStr::from_bytes_with_nul(&bytes).unwrap(); - assert_eq!(format!("{}", cstr), ALL_ASCII_CHARS); + assert_eq!(format!("{}", cstr.display()), ALL_ASCII_CHARS); } =20 #[test] @@ -630,15 +676,15 @@ fn test_cstr_debug() { #[test] fn test_bstr_display() { let hello_world =3D BStr::from_bytes(b"hello, world!"); - assert_eq!(format!("{}", hello_world), "hello, world!"); + assert_eq!(format!("{}", hello_world.display()), "hello, world!"); let escapes =3D BStr::from_bytes(b"_\t_\n_\r_\\_\'_\"_"); - assert_eq!(format!("{}", escapes), "_\\t_\\n_\\r_\\_'_\"_"); 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Sun, 02 Feb 2025 04:20:58 -0800 (PST) Received: from tamird-mac.local ([2600:4041:5be7:7c00:f07f:fb14:288d:6f1e]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-46fdf1728efsm37700331cf.62.2025.02.02.04.20.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 02 Feb 2025 04:20:57 -0800 (PST) From: Tamir Duberstein Date: Sun, 02 Feb 2025 07:20:47 -0500 Subject: [PATCH v6 2/4] rust: replace `CStr` with `core::ffi::CStr` Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250202-cstr-core-v6-2-8469cd6d29fd@gmail.com> References: <20250202-cstr-core-v6-0-8469cd6d29fd@gmail.com> In-Reply-To: <20250202-cstr-core-v6-0-8469cd6d29fd@gmail.com> To: Michal Rostecki , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Tamir Duberstein X-Mailer: b4 0.15-dev `std::ffi::CStr` was moved to `core::ffi::CStr` in Rust 1.64. Replace `kernel::str::CStr` with `core::ffi::CStr` now that we can. `kernel::str::CStr::{from,as}_char_ptr` live on as free functions in `kernel::str` to paper over the difference between `core::ffi::c_char` and `kernel::ffi::char`; see the code comment on the latter type for details. C-String literals were added in Rust 1.77. Opportunistically replace instances of `kernel::c_str!` with C-String literals where other code changes were already necessary; the rest will be done in a later commit. Signed-off-by: Tamir Duberstein --- drivers/gpu/drm/drm_panic_qr.rs | 2 +- rust/kernel/device.rs | 5 +- rust/kernel/error.rs | 4 +- rust/kernel/firmware.rs | 2 +- rust/kernel/kunit.rs | 4 +- rust/kernel/miscdevice.rs | 2 +- rust/kernel/net/phy.rs | 2 +- rust/kernel/prelude.rs | 5 +- rust/kernel/seq_file.rs | 4 +- rust/kernel/str.rs | 449 ++++++------------------------------= ---- rust/kernel/sync/condvar.rs | 2 +- rust/kernel/sync/lock.rs | 2 +- rust/kernel/sync/lock/global.rs | 2 +- rust/kernel/workqueue.rs | 2 +- 14 files changed, 88 insertions(+), 399 deletions(-) diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_qr= .rs index bcf248f69252..ef294017888e 100644 --- a/drivers/gpu/drm/drm_panic_qr.rs +++ b/drivers/gpu/drm/drm_panic_qr.rs @@ -958,7 +958,7 @@ fn draw_all(&mut self, data: impl Iterator= ) { } else { // SAFETY: The caller ensures that `url` is a valid pointer to a // nul-terminated string. - let url_cstr: &CStr =3D unsafe { CStr::from_char_ptr(url) }; + let url_cstr: &CStr =3D unsafe { kernel::str::from_char_ptr(url) }; let segments =3D &[ &Segment::Binary(url_cstr.as_bytes()), &Segment::Numeric(&data_slice[0..data_len]), diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs index d5e6a19ff6b7..f97c409aaba9 100644 --- a/rust/kernel/device.rs +++ b/rust/kernel/device.rs @@ -10,9 +10,6 @@ }; use core::{fmt, ptr}; =20 -#[cfg(CONFIG_PRINTK)] -use crate::c_str; - /// A reference-counted device. /// /// This structure represents the Rust abstraction for a C `struct device`= . This implementation @@ -175,7 +172,7 @@ unsafe fn printk(&self, klevel: &[u8], msg: fmt::Argume= nts<'_>) { bindings::_dev_printk( klevel as *const _ as *const crate::ffi::c_char, self.as_raw(), - c_str!("%pA").as_char_ptr(), + crate::str::as_char_ptr(c"%pA"), &msg as *const _ as *const crate::ffi::c_void, ) }; diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs index f6ecf09cb65f..51c5e0f0a0bc 100644 --- a/rust/kernel/error.rs +++ b/rust/kernel/error.rs @@ -164,7 +164,7 @@ pub fn name(&self) -> Option<&'static CStr> { None } else { // SAFETY: The string returned by `errname` is static and `NUL= `-terminated. - Some(unsafe { CStr::from_char_ptr(ptr) }) + Some(unsafe { crate::str::from_char_ptr(ptr) }) } } =20 @@ -187,7 +187,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Resul= t { Some(name) =3D> 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 c5162fdc95ff..e75db4d825ce 100644 --- a/rust/kernel/firmware.rs +++ b/rust/kernel/firmware.rs @@ -61,7 +61,7 @@ fn request_internal(name: &CStr, dev: &Device, func: FwFu= nc) -> Result { =20 // SAFETY: `pfw` is a valid pointer to a NULL initialized `binding= s::firmware` pointer. // `name` and `dev` are valid as by their type invariants. - let ret =3D unsafe { func.0(pfw as _, name.as_char_ptr(), dev.as_r= aw()) }; + let ret =3D unsafe { func.0(pfw as _, crate::str::as_char_ptr(name= ), dev.as_raw()) }; if ret !=3D 0 { return Err(Error::from_errno(ret)); } diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 630b947c708c..9f40ea744fc2 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -101,12 +101,12 @@ unsafe impl Sync for Location {} unsafe impl Sync for UnaryAssert {} =20 static LOCATION: Location =3D Location($crate::bindings::kunit= _loc { - file: FILE.as_char_ptr(), + file: $crate::str::as_char_ptr(FILE), line: LINE, }); static ASSERTION: UnaryAssert =3D UnaryAssert($crate::bindings= ::kunit_unary_assert { assert: $crate::bindings::kunit_assert {}, - condition: CONDITION.as_char_ptr(), + condition: $crate::str::as_char_ptr(CONDITION), expected_true: true, }); =20 diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs index b3a6cc50b240..2dd20e981e9b 100644 --- a/rust/kernel/miscdevice.rs +++ b/rust/kernel/miscdevice.rs @@ -31,7 +31,7 @@ pub const fn into_raw(self) -> bindings::m= iscdevice { // SAFETY: All zeros is valid for this C type. let mut result: bindings::miscdevice =3D unsafe { MaybeUninit::zer= oed().assume_init() }; result.minor =3D bindings::MISC_DYNAMIC_MINOR as _; - result.name =3D self.name.as_char_ptr(); + result.name =3D crate::str::as_char_ptr(self.name); result.fops =3D create_vtable::(); result } diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs index d7da29f95e43..9e410de3c3a3 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() -> DriverVTable { // INVARIANT: All the fields of `struct phy_driver` are initialized pr= operly. DriverVTable(Opaque::new(bindings::phy_driver { - name: T::NAME.as_char_ptr().cast_mut(), + name: crate::str::as_char_ptr(T::NAME), 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/prelude.rs b/rust/kernel/prelude.rs index dde2e0649790..96e7029c27da 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -34,7 +34,10 @@ =20 pub use super::error::{code::*, Error, Result}; =20 -pub use super::{str::CStr, ThisModule}; +pub use super::{ + str::{CStr, CStrExt as _}, + ThisModule, +}; =20 pub use super::init::{InPlaceInit, InPlaceWrite, Init, PinInit}; =20 diff --git a/rust/kernel/seq_file.rs b/rust/kernel/seq_file.rs index 04947c672979..bb3c49fd4ef3 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) =20 -use crate::{bindings, c_str, types::NotThreadSafe, types::Opaque}; +use crate::{bindings, types::NotThreadSafe, types::Opaque}; =20 /// A utility for generating the contents of a seq file. #[repr(transparent)] @@ -35,7 +35,7 @@ pub fn call_printf(&self, args: core::fmt::Arguments<'_>)= { unsafe { bindings::seq_printf( self.inner.get(), - c_str!("%pA").as_char_ptr(), + crate::str::as_char_ptr(c"%pA"), &args as *const _ as *const crate::ffi::c_void, ); } diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index 53450c956a6a..2b63cfaaa981 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -4,7 +4,7 @@ =20 use crate::alloc::{flags::*, AllocError, KVec}; use core::fmt::{self, Write}; -use core::ops::{self, Deref, DerefMut, Index}; +use core::ops::{Deref, DerefMut}; =20 use crate::error::{code::*, Error}; =20 @@ -45,11 +45,11 @@ pub const fn from_bytes(bytes: &[u8]) -> &Self { /// # use kernel::{fmt, b_str, str::CString}; /// let ascii =3D b_str!("Hello, BStr!"); /// let s =3D CString::try_from_fmt(fmt!("{}", ascii.display()))?; - /// assert_eq!(s.as_bytes(), "Hello, BStr!".as_bytes()); + /// assert_eq!(s.to_bytes(), "Hello, BStr!".as_bytes()); /// /// let non_ascii =3D b_str!("=F0=9F=A6=80"); /// let s =3D CString::try_from_fmt(fmt!("{}", non_ascii.display()))?; - /// 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>(()) /// ``` #[inline] @@ -74,11 +74,11 @@ pub fn display(&self) -> Display<'_> { /// # use kernel::{fmt, b_str, str::CString}; /// let ascii =3D b_str!("Hello, BStr!"); /// let s =3D CString::try_from_fmt(fmt!("{}", ascii.display()))?; -/// assert_eq!(s.as_bytes(), "Hello, BStr!".as_bytes()); +/// assert_eq!(s.to_bytes(), "Hello, BStr!".as_bytes()); /// /// let non_ascii =3D b_str!("=F0=9F=A6=80"); /// let s =3D CString::try_from_fmt(fmt!("{}", non_ascii.display()))?; -/// 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>(()) /// ``` /// @@ -119,11 +119,11 @@ impl fmt::Debug for BStr { /// // Embedded double quotes are escaped. /// let ascii =3D b_str!("Hello, \"BStr\"!"); /// let s =3D 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 =3D b_str!("=F0=9F=98=BA"); /// let s =3D 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 { @@ -176,254 +176,10 @@ macro_rules! b_str { }}; } =20 -/// Possible errors when using conversion functions in [`CStr`]. -#[derive(Debug, Clone, Copy)] -pub enum CStrConvertError { - /// Supplied bytes contain an interior `NUL`. - InteriorNul, - - /// Supplied bytes are not terminated by `NUL`. - NotNulTerminated, -} - -impl From for Error { - #[inline] - fn from(_: CStrConvertError) -> Error { - EINVAL - } -} - -/// A string that is guaranteed to have exactly one `NUL` byte, which is a= t 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() =3D=3D 0 - } - - /// Wraps a raw C string pointer. - /// - /// # Safety - /// - /// `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 `p= tr` - /// 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 poi= nter - // to a `NUL`-terminated C string. - let len =3D unsafe { bindings::strlen(ptr) } + 1; - // SAFETY: Lifetime guaranteed by the safety precondition. - let bytes =3D unsafe { core::slice::from_raw_parts(ptr as _, len) = }; - // SAFETY: As `len` is returned by `strlen`, `bytes` does not cont= ain 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, CStrCo= nvertError> { - if bytes.is_empty() { - return Err(CStrConvertError::NotNulTerminated); - } - if bytes[bytes.len() - 1] !=3D 0 { - return Err(CStrConvertError::NotNulTerminated); - } - let mut i =3D 0; - // `i + 1 < bytes.len()` allows LLVM to optimize away bounds check= ing, - // while it couldn't optimize away bounds checks for `i < bytes.le= n() - 1`. - while i + 1 < bytes.len() { - if bytes[i] =3D=3D 0 { - return Err(CStrConvertError::InteriorNul); - } - i +=3D 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]) -> &CS= tr { - // SAFETY: Properties of `bytes` guaranteed by the safety precondi= tion. - unsafe { core::mem::transmute(bytes) } - } - - /// Creates a mutable [`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 unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) -> &= mut CStr { - // SAFETY: Properties of `bytes` guaranteed by the safety precondi= tion. - unsafe { &mut *(bytes as *mut [u8] as *mut CStr) } - } - - /// 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` b= yte. - #[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 fai= led. - /// - /// # Examples - /// - /// ``` - /// # use kernel::str::CStr; - /// let cstr =3D 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 f= or - /// valid UTF-8. - /// - /// # Safety - /// - /// The contents must be valid UTF-8. - /// - /// # Examples - /// - /// ``` - /// # use kernel::c_str; - /// # use kernel::str::CStr; - /// let bar =3D c_str!("=E3=83=84"); - /// // SAFETY: String literals are guaranteed to be valid UTF-8 - /// // by the Rust compiler. - /// assert_eq!(unsafe { bar.as_str_unchecked() }, "=E3=83=84"); - /// ``` - #[inline] - pub unsafe fn as_str_unchecked(&self) -> &str { - // SAFETY: TODO. - unsafe { core::str::from_utf8_unchecked(self.as_bytes()) } - } - - /// Convert this [`CStr`] into a [`CString`] by allocating memory and - /// copying over the string data. - pub fn to_cstring(&self) -> Result { - CString::try_from(self) - } - - /// Converts this [`CStr`] to its ASCII lower case equivalent in-place. - /// - /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z', - /// but non-ASCII letters are unchanged. - /// - /// To return a new lowercased value without modifying the existing on= e, use - /// [`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(); - } - - /// Converts this [`CStr`] to its ASCII upper case equivalent in-place. - /// - /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', - /// but non-ASCII letters are unchanged. - /// - /// To return a new uppercased value without modifying the existing on= e, use - /// [`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(); - } - - /// Returns a copy of this [`CString`] where each character is mapped = to its - /// ASCII lower case equivalent. - /// - /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z', - /// but non-ASCII letters are unchanged. - /// - /// To lowercase the value in-place, use [`make_ascii_lowercase`]. - /// - /// [`make_ascii_lowercase`]: str::make_ascii_lowercase - pub fn to_ascii_lowercase(&self) -> Result { - let mut s =3D self.to_cstring()?; - - s.make_ascii_lowercase(); - - Ok(s) - } - - /// Returns a copy of this [`CString`] where each character is mapped = to its - /// ASCII upper case equivalent. - /// - /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', - /// but non-ASCII letters are unchanged. - /// - /// To uppercase the value in-place, use [`make_ascii_uppercase`]. - /// - /// [`make_ascii_uppercase`]: str::make_ascii_uppercase - pub fn to_ascii_uppercase(&self) -> Result { - let mut s =3D self.to_cstring()?; - - s.make_ascii_uppercase(); - - Ok(s) - } +pub use core::ffi::CStr; =20 +/// Extensions to [`CStr`]. +pub trait CStrExt { /// Returns an object that implements [`Display`] for safely printing = a [`CStr`] that may /// contain non-Unicode data. If you would like an implementation whic= h escapes the [`CStr`] /// please use [`Debug`] instead. @@ -439,114 +195,59 @@ pub fn to_ascii_uppercase(&self) -> Result { /// # use kernel::str::CString; /// let penguin =3D c_str!("=F0=9F=90=A7"); /// let s =3D CString::try_from_fmt(fmt!("{}", penguin.display()))?; - /// assert_eq!(s.as_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_byte= s()); + /// assert_eq!(s.to_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_byte= s()); /// /// let ascii =3D c_str!("so \"cool\""); /// let s =3D CString::try_from_fmt(fmt!("{}", ascii.display()))?; - /// 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 display(&self) -> Display<'_>; +} + +impl CStrExt for CStr { #[inline] - pub fn display(&self) -> Display<'_> { + fn display(&self) -> Display<'_> { Display { - inner: self, + inner: BStr::from_bytes(self.to_bytes()), escape_common: false, } } } =20 -impl fmt::Debug for CStr { - /// Formats printable ASCII characters with a double quote on either e= nd, escaping the rest. - /// - /// ``` - /// # use kernel::c_str; - /// # use kernel::fmt; - /// # use kernel::str::CString; - /// let penguin =3D c_str!("=F0=9F=90=A7"); - /// let s =3D 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 =3D c_str!("so \"cool\""); - /// let s =3D 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'\"' =3D> f.write_str("\\\"")?, - 0x20..=3D0x7e =3D> f.write_char(c as char)?, - _ =3D> write!(f, "\\x{:02x}", c)?, - } - } - f.write_str("\"") - } -} - -impl AsRef for CStr { - #[inline] - fn as_ref(&self) -> &BStr { - BStr::from_bytes(self.as_bytes()) - } -} - -impl Deref for CStr { - type Target =3D BStr; - - #[inline] - fn deref(&self) -> &Self::Target { - self.as_ref() - } -} - -impl Index> for CStr { - type Output =3D CStr; - - #[inline] - fn index(&self, index: ops::RangeFrom) -> &Self::Output { - // Delegate bounds checking to slice. - // Assign to _ to mute clippy's unnecessary operation warning. - let _ =3D &self.as_bytes()[index.start..]; - // SAFETY: We just checked the bounds. - unsafe { Self::from_bytes_with_nul_unchecked(&self.0[index.start..= ]) } - } -} - -impl Index for CStr { - type Output =3D CStr; - - #[inline] - fn index(&self, _index: ops::RangeFull) -> &Self::Output { - self - } -} - -mod private { - use core::ops; - - // Marker trait for index types that can be forward to `BStr`. - pub trait CStrIndex {} - - impl CStrIndex for usize {} - impl CStrIndex for ops::Range {} - impl CStrIndex for ops::RangeInclusive {} - impl CStrIndex for ops::RangeToInclusive {} +/// Wraps a raw C string with a safe C string wrapper. +/// +/// # Safety +/// +/// * The memory pointed to by `ptr` must contain a valid nul terminator a= t the end of the string. +/// +/// * `ptr` must be [valid] for reads of bytes up to and including the nul= terminator. This means in +/// particular: +/// +/// * The entire memory range of this `CStr` must be contained within = a single allocated object! +/// * `ptr` must be non-null even for a zero-length cstr. +/// +/// * The memory referenced by the returned `CStr` must not be mutated for= the duration of lifetime +/// `'a`. +/// +/// * The nul terminator must be within `isize::MAX` from `ptr` +// 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`. +#[inline] +pub unsafe fn from_char_ptr<'a>(ptr: *const crate::ffi::c_char) -> &'a CSt= r { + // SAFETY: The safety preconditions are the same as for `from_ptr`. + unsafe { CStr::from_ptr(ptr.cast()) } } =20 -impl Index for CStr -where - Idx: private::CStrIndex, - BStr: Index, -{ - type Output =3D >::Output; - - #[inline] - fn index(&self, index: Idx) -> &Self::Output { - &self.as_ref()[index] - } +/// Returns a C pointer to the string. +// 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`. It is a f= ree 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(c_str: &CStr) -> *const crate::ffi::c_char { + c_str.as_ptr().cast() } =20 /// Creates a new [`CStr`] from a string literal. @@ -629,25 +330,15 @@ fn test_cstr_to_str_panic() { checked_cstr.to_str().unwrap(); } =20 - #[test] - fn test_cstr_as_str_unchecked() { - let good_bytes =3D b"\xf0\x9f\x90\xA7\0"; - let checked_cstr =3D CStr::from_bytes_with_nul(good_bytes).unwrap(= ); - // SAFETY: The contents come from a string literal which contains = valid UTF-8. - let unchecked_str =3D unsafe { checked_cstr.as_str_unchecked() }; - assert_eq!(unchecked_str, "=F0=9F=90=A7"); - } - #[test] fn test_cstr_display() { - let hello_world =3D CStr::from_bytes_with_nul(b"hello, world!\0").= unwrap(); - assert_eq!(format!("{}", hello_world.display()), "hello, world!"); - let non_printables =3D CStr::from_bytes_with_nul(b"\x01\x09\x0a\0"= ).unwrap(); - assert_eq!(format!("{}", non_printables.display()), "\\x01\\x09\\x= 0a"); - let non_ascii =3D CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").un= wrap(); - assert_eq!(format!("{}", non_ascii.display()), "d\\xe9j\\xe0 vu"); - let good_bytes =3D CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0"= ).unwrap(); - assert_eq!(format!("{}", good_bytes.display()), "\\xf0\\x9f\\xa6\\= x80"); + assert_eq!(format!("{}", c"hello, world!".display()), "hello, worl= d!"); + assert_eq!(format!("{}", c"\x01\x09\x0a".display()), "\\x01\\x09\\= x0a"); + assert_eq!(format!("{}", c"d\xe9j\xe0 vu".display()), "d\\xe9j\\xe= 0 vu"); + assert_eq!( + format!("{}", c"\xf0\x9f\xa6\x80".display()), + "\\xf0\\x9f\\xa6\\x80" + ); } =20 #[test] @@ -663,14 +354,13 @@ fn test_cstr_display_all_bytes() { =20 #[test] fn test_cstr_debug() { - let hello_world =3D CStr::from_bytes_with_nul(b"hello, world!\0").= unwrap(); - assert_eq!(format!("{:?}", hello_world), "\"hello, world!\""); - let non_printables =3D CStr::from_bytes_with_nul(b"\x01\x09\x0a\0"= ).unwrap(); - assert_eq!(format!("{:?}", non_printables), "\"\\x01\\x09\\x0a\""); - let non_ascii =3D CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").un= wrap(); - assert_eq!(format!("{:?}", non_ascii), "\"d\\xe9j\\xe0 vu\""); - let good_bytes =3D CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0"= ).unwrap(); - assert_eq!(format!("{:?}", good_bytes), "\"\\xf0\\x9f\\xa6\\x80\""= ); + assert_eq!(format!("{:?}", c"hello, world!"), "\"hello, world!\""); + assert_eq!(format!("{:?}", c"\x01\x09\x0a"), "\"\\x01\\t\\n\""); + assert_eq!(format!("{:?}", c"d\xe9j\xe0 vu"), "\"d\\xe9j\\xe0 vu\"= "); + assert_eq!( + format!("{:?}", c"\xf0\x9f\xa6\x80"), + "\"\\xf0\\x9f\\xa6\\x80\"" + ); } =20 #[test] @@ -850,14 +540,14 @@ fn write_str(&mut self, s: &str) -> fmt::Result { /// # Examples /// /// ``` -/// use kernel::{str::CString, fmt}; +/// use kernel::{fmt, str::CString}; /// /// let s =3D 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 =3D "testing"; /// let s =3D 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 =3D CString::try_from_fmt(fmt!("a\0b{}", 123)); @@ -915,9 +605,8 @@ fn deref(&self) -> &Self::Target { =20 impl DerefMut for CString { fn deref_mut(&mut self) -> &mut Self::Target { - // SAFETY: A `CString` is always NUL-terminated and contains no ot= her - // NUL bytes. - unsafe { CStr::from_bytes_with_nul_unchecked_mut(self.buf.as_mut_s= lice()) } + // SAFETY: Properties of `bytes` guaranteed by the safety precondi= tion. + unsafe { &mut *(self.buf.as_mut_slice() as *mut [u8] as *mut CStr)= } } } =20 @@ -927,7 +616,7 @@ impl<'a> TryFrom<&'a CStr> for CString { fn try_from(cstr: &'a CStr) -> Result { let mut buf =3D KVec::new(); =20 - buf.extend_from_slice(cstr.as_bytes_with_nul(), GFP_KERNEL)?; + buf.extend_from_slice(cstr.to_bytes_with_nul(), GFP_KERNEL)?; =20 // INVARIANT: The `CStr` and `CString` types have the same invaria= nts 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 7df565038d7d..7bf3df980433 100644 --- a/rust/kernel/sync/condvar.rs +++ b/rust/kernel/sync/condvar.rs @@ -107,7 +107,7 @@ pub fn new(name: &'static CStr, key: &'static LockClass= Key) -> impl PinInit impl PinIni // SAFETY: `slot` is valid while the closure is called and bot= h `name` and `key` have // static lifetimes so they live indefinitely. state <- Opaque::ffi_init(|slot| unsafe { - B::init(slot, name.as_char_ptr(), key.as_ptr()) + B::init(slot, crate::str::as_char_ptr(name), key.as_ptr()) }), }) } diff --git a/rust/kernel/sync/lock/global.rs b/rust/kernel/sync/lock/global= .rs index 480ee724e3cc..4c4d60a51c1f 100644 --- a/rust/kernel/sync/lock/global.rs +++ b/rust/kernel/sync/lock/global.rs @@ -69,7 +69,7 @@ pub unsafe fn init(&'static self) { unsafe { B::Backend::init( self.inner.state.get(), - B::NAME.as_char_ptr(), + crate::str::as_char_ptr(B::NAME), B::get_lock_class().as_ptr(), ) } diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs index 1dcd53478edd..284b9a739c01 100644 --- a/rust/kernel/workqueue.rs +++ b/rust/kernel/workqueue.rs @@ -382,7 +382,7 @@ pub fn new(name: &'static CStr, key: &'static LockClass= Key) -> impl PinInit Date: Sun, 02 Feb 2025 07:20:48 -0500 Subject: [PATCH v6 3/4] rust: replace `kernel::c_str!` with C-Strings Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250202-cstr-core-v6-3-8469cd6d29fd@gmail.com> References: <20250202-cstr-core-v6-0-8469cd6d29fd@gmail.com> In-Reply-To: <20250202-cstr-core-v6-0-8469cd6d29fd@gmail.com> To: Michal Rostecki , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Tamir Duberstein X-Mailer: b4 0.15-dev 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 `c_str_avoid_literals` to clarify its intended use. Closes: https://github.com/Rust-for-Linux/linux/issues/1075 Signed-off-by: Tamir Duberstein --- drivers/net/phy/ax88796b_rust.rs | 7 +++---- drivers/net/phy/qt2025.rs | 5 ++--- rust/kernel/firmware.rs | 4 ++-- rust/kernel/kunit.rs | 7 ++++--- rust/kernel/net/phy.rs | 6 ++---- rust/kernel/str.rs | 37 ++++++++++++++++++++++++------------- rust/kernel/sync.rs | 4 ++-- rust/kernel/sync/lock/global.rs | 3 ++- 8 files changed, 41 insertions(+), 32 deletions(-) diff --git a/drivers/net/phy/ax88796b_rust.rs b/drivers/net/phy/ax88796b_ru= st.rs index 8c7eb009d9fc..b07d36f45a43 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 =3D phy::flags::IS_INTERNAL; - const NAME: &'static CStr =3D c_str!("Asix Electronics AX88772A"); + const NAME: &'static CStr =3D c"Asix Electronics AX88772A"; const PHY_DEVICE_ID: DeviceId =3D DeviceId::new_with_exact_mask(0x003b= 1861); =20 // 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 =3D phy::flags::IS_INTERNAL; - const NAME: &'static CStr =3D c_str!("Asix Electronics AX88772C"); + const NAME: &'static CStr =3D c"Asix Electronics AX88772C"; const PHY_DEVICE_ID: DeviceId =3D DeviceId::new_with_exact_mask(0x003b= 1881); =20 fn suspend(dev: &mut phy::Device) -> Result { @@ -125,7 +124,7 @@ fn soft_reset(dev: &mut phy::Device) -> Result { =20 #[vtable] impl Driver for PhyAX88796B { - const NAME: &'static CStr =3D c_str!("Asix Electronics AX88796B"); + const NAME: &'static CStr =3D c"Asix Electronics AX88796B"; const PHY_DEVICE_ID: DeviceId =3D DeviceId::new_with_model_mask(0x003b= 1841); =20 fn soft_reset(dev: &mut phy::Device) -> Result { diff --git a/drivers/net/phy/qt2025.rs b/drivers/net/phy/qt2025.rs index 1ab065798175..2f4ba85a0d73 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. =20 -use kernel::c_str; use kernel::error::code; use kernel::firmware::Firmware; use kernel::net::phy::{ @@ -36,7 +35,7 @@ =20 #[vtable] impl Driver for PhyQT2025 { - const NAME: &'static CStr =3D c_str!("QT2025 10Gpbs SFP+"); + const NAME: &'static CStr =3D c"QT2025 10Gpbs SFP+"; const PHY_DEVICE_ID: phy::DeviceId =3D phy::DeviceId::new_with_exact_m= ask(0x0043a400); =20 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)?; =20 - let fw =3D Firmware::request(c_str!("qt2025-2.0.3.3.fw"), dev.as_r= ef())?; + let fw =3D 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/firmware.rs b/rust/kernel/firmware.rs index e75db4d825ce..93e375e75ca0 100644 --- a/rust/kernel/firmware.rs +++ b/rust/kernel/firmware.rs @@ -40,13 +40,13 @@ 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`= instance /// # let dev =3D unsafe { Device::get_device(core::ptr::null_mut()) }; /// -/// let fw =3D Firmware::request(c_str!("path/to/firmware.bin"), &dev)?; +/// let fw =3D Firmware::request(c"path/to/firmware.bin", &dev)?; /// let blob =3D fw.data(); /// /// # Ok(()) diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 9f40ea744fc2..3d812edec057 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -56,10 +56,11 @@ macro_rules! kunit_assert { break 'out; } =20 - static NAME: &'static $crate::str::CStr =3D $crate::c_str!($na= me); - static FILE: &'static $crate::str::CStr =3D $crate::c_str!($fi= le); + static NAME: &'static $crate::str::CStr =3D $crate::c_str_avoi= d_literals!($name); + static FILE: &'static $crate::str::CStr =3D $crate::c_str_avoi= d_literals!($file); static LINE: i32 =3D core::line!() as i32 - $diff; - static CONDITION: &'static $crate::str::CStr =3D $crate::c_str= !(stringify!($condition)); + static CONDITION: &'static $crate::str::CStr =3D + $crate::c_str_avoid_literals!(stringify!($condition)); =20 // SAFETY: FFI call without safety requirements. let kunit_test =3D unsafe { $crate::bindings::kunit_get_curren= t_test() }; diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs index 9e410de3c3a3..5fb9b0e1c9b1 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 =3D c_str!("PhySample"); +/// const NAME: &'static CStr =3D c"PhySample"; /// const PHY_DEVICE_ID: phy::DeviceId =3D phy::DeviceId::new_with_exa= ct_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 =3D c_str!("PhySample"); +/// const NAME: &'static CStr =3D c"PhySample"; /// const PHY_DEVICE_ID: phy::DeviceId =3D phy::DeviceId::new_with_exa= ct_mask(0x00000001); /// } /// diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index 2b63cfaaa981..20d852aa8b3c 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -190,14 +190,13 @@ pub trait CStrExt { /// # Examples /// /// ``` - /// # use kernel::c_str; /// # use kernel::fmt; /// # use kernel::str::CString; - /// let penguin =3D c_str!("=F0=9F=90=A7"); + /// let penguin =3D c"=F0=9F=90=A7"; /// let s =3D CString::try_from_fmt(fmt!("{}", penguin.display()))?; /// assert_eq!(s.to_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_byte= s()); /// - /// let ascii =3D c_str!("so \"cool\""); + /// let ascii =3D c"so \"cool\""; /// let s =3D CString::try_from_fmt(fmt!("{}", ascii.display()))?; /// assert_eq!(s.to_bytes_with_nul(), "so \"cool\"\0".as_bytes()); /// # Ok::<(), kernel::error::Error>(()) @@ -250,25 +249,37 @@ pub const fn as_char_ptr(c_str: &CStr) -> *const crat= e::ffi::c_char { c_str.as_ptr().cast() } =20 -/// 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 us= ed instead of this macro +/// where possible. This macro exists to allow static *non-literal* C stri= ngs 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::c_str_avoid_literals; /// # use kernel::str::CStr; -/// const MY_CSTR: &CStr =3D c_str!("My awesome CStr!"); +/// const MY_CSTR: &CStr =3D c_str_avoid_literals!(concat!(file!(), ":", l= ine!(), ": My CStr!")); /// ``` #[macro_export] -macro_rules! c_str { +macro_rules! c_str_avoid_literals { + // NB: we could write `($str:lit) =3D> 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 ins= tead. ($str:expr) =3D> {{ - const S: &str =3D concat!($str, "\0"); - const C: &$crate::str::CStr =3D match $crate::str::CStr::from_byte= s_with_nul(S.as_bytes()) { - Ok(v) =3D> v, - Err(_) =3D> panic!("string contains interior NUL"), - }; + const S: &'static str =3D concat!($str, "\0"); + const C: &'static $crate::str::CStr =3D + match $crate::str::CStr::from_bytes_with_nul(S.as_bytes()) { + Ok(v) =3D> v, + Err(core::ffi::FromBytesWithNulError { .. }) =3D> { + panic!("string contains interior NUL") + } + }; C }}; } diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs index 1eab7ebf25fd..ec7f80a924c3 100644 --- a/rust/kernel/sync.rs +++ b/rust/kernel/sync.rs @@ -61,9 +61,9 @@ macro_rules! static_lock_class { #[macro_export] macro_rules! optional_name { () =3D> { - $crate::c_str!(::core::concat!(::core::file!(), ":", ::core::line!= ())) + $crate::c_str_avoid_literals!(::core::concat!(::core::file!(), ":"= , ::core::line!())) }; ($name:literal) =3D> { - $crate::c_str!($name) + $crate::c_str_avoid_literals!($name) }; 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Sun, 02 Feb 2025 04:21:02 -0800 (PST) Received: from tamird-mac.local ([2600:4041:5be7:7c00:f07f:fb14:288d:6f1e]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-46fdf1728efsm37700331cf.62.2025.02.02.04.21.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 02 Feb 2025 04:21:02 -0800 (PST) From: Tamir Duberstein Date: Sun, 02 Feb 2025 07:20:49 -0500 Subject: [PATCH v6 4/4] rust: remove core::ffi::CStr reexport Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250202-cstr-core-v6-4-8469cd6d29fd@gmail.com> References: <20250202-cstr-core-v6-0-8469cd6d29fd@gmail.com> In-Reply-To: <20250202-cstr-core-v6-0-8469cd6d29fd@gmail.com> To: Michal Rostecki , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Tamir Duberstein X-Mailer: b4 0.15-dev Clean up references to `kernel::str::CStr`. Signed-off-by: Tamir Duberstein --- rust/kernel/error.rs | 6 ++---- rust/kernel/firmware.rs | 3 ++- rust/kernel/kunit.rs | 6 +++--- rust/kernel/miscdevice.rs | 3 +-- rust/kernel/prelude.rs | 5 +---- rust/kernel/str.rs | 19 +++++++++---------- rust/kernel/sync/condvar.rs | 2 +- rust/kernel/sync/lock.rs | 3 +-- rust/kernel/sync/lock/global.rs | 4 ++-- rust/kernel/sync/poll.rs | 1 + rust/kernel/workqueue.rs | 1 + 11 files changed, 24 insertions(+), 29 deletions(-) diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs index 51c5e0f0a0bc..81972a8f695d 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/ua= pi/asm-generic/errno-base.h) =20 -use crate::{ - alloc::{layout::LayoutError, AllocError}, - str::CStr, -}; +use crate::alloc::{layout::LayoutError, AllocError}; =20 +use core::ffi::CStr; use core::fmt; use core::num::NonZeroI32; use core::num::TryFromIntError; diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs index 93e375e75ca0..86ed79cef211 100644 --- a/rust/kernel/firmware.rs +++ b/rust/kernel/firmware.rs @@ -4,7 +4,8 @@ //! //! C header: [`include/linux/firmware.h`](srctree/include/linux/firmware.= h) =20 -use crate::{bindings, device::Device, error::Error, error::Result, str::CS= tr}; +use crate::{bindings, device::Device, error::Error, error::Result}; +use core::ffi::CStr; use core::ptr::NonNull; =20 /// # Invariants diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 3d812edec057..f83988959257 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -56,10 +56,10 @@ macro_rules! kunit_assert { break 'out; } =20 - static NAME: &'static $crate::str::CStr =3D $crate::c_str_avoi= d_literals!($name); - static FILE: &'static $crate::str::CStr =3D $crate::c_str_avoi= d_literals!($file); + static NAME: &'static core::ffi::CStr =3D $crate::c_str_avoid_= literals!($name); + static FILE: &'static core::ffi::CStr =3D $crate::c_str_avoid_= literals!($file); static LINE: i32 =3D core::line!() as i32 - $diff; - static CONDITION: &'static $crate::str::CStr =3D + static CONDITION: &'static core::ffi::CStr =3D $crate::c_str_avoid_literals!(stringify!($condition)); =20 // SAFETY: FFI call without safety requirements. diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs index 2dd20e981e9b..26623d2c43c0 100644 --- a/rust/kernel/miscdevice.rs +++ b/rust/kernel/miscdevice.rs @@ -13,10 +13,9 @@ error::{to_result, Error, Result, VTABLE_DEFAULT_ERROR}, ffi::{c_int, c_long, c_uint, c_ulong}, prelude::*, - str::CStr, types::{ForeignOwnable, Opaque}, }; -use core::{marker::PhantomData, mem::MaybeUninit, pin::Pin}; +use core::{ffi::CStr, marker::PhantomData, mem::MaybeUninit, pin::Pin}; =20 /// Options for creating a misc device. #[derive(Copy, Clone)] diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs index 96e7029c27da..21fa7b3a68c3 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -34,10 +34,7 @@ =20 pub use super::error::{code::*, Error, Result}; =20 -pub use super::{ - str::{CStr, CStrExt as _}, - ThisModule, -}; +pub use super::{str::CStrExt as _, ThisModule}; =20 pub use super::init::{InPlaceInit, InPlaceWrite, Init, PinInit}; =20 diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index 20d852aa8b3c..c96ce2640ca1 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -3,6 +3,7 @@ //! String representations. =20 use crate::alloc::{flags::*, AllocError, KVec}; +use core::ffi::CStr; use core::fmt::{self, Write}; use core::ops::{Deref, DerefMut}; =20 @@ -176,8 +177,6 @@ macro_rules! b_str { }}; } =20 -pub use core::ffi::CStr; - /// Extensions to [`CStr`]. pub trait CStrExt { /// Returns an object that implements [`Display`] for safely printing = a [`CStr`] that may @@ -263,7 +262,7 @@ pub const fn as_char_ptr(c_str: &CStr) -> *const crate:= :ffi::c_char { /// /// ``` /// # use kernel::c_str_avoid_literals; -/// # use kernel::str::CStr; +/// # use core::ffi::CStr; /// const MY_CSTR: &CStr =3D c_str_avoid_literals!(concat!(file!(), ":", l= ine!(), ": My CStr!")); /// ``` #[macro_export] @@ -273,13 +272,13 @@ macro_rules! c_str_avoid_literals { // too limiting to macro authors, so we rely on the name as a hint ins= tead. ($str:expr) =3D> {{ const S: &'static str =3D concat!($str, "\0"); - const C: &'static $crate::str::CStr =3D - match $crate::str::CStr::from_bytes_with_nul(S.as_bytes()) { - Ok(v) =3D> v, - Err(core::ffi::FromBytesWithNulError { .. }) =3D> { - panic!("string contains interior NUL") - } - }; + const C: &'static core::ffi::CStr =3D match core::ffi::CStr::from_= bytes_with_nul(S.as_bytes()) + { + Ok(v) =3D> v, + Err(core::ffi::FromBytesWithNulError { .. }) =3D> { + panic!("string contains interior NUL") + } + }; C }}; } diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs index 7bf3df980433..3b82acdcd56c 100644 --- a/rust/kernel/sync/condvar.rs +++ b/rust/kernel/sync/condvar.rs @@ -10,11 +10,11 @@ ffi::{c_int, c_long}, init::PinInit, pin_init, - str::CStr, task::{MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE, TASK_NORMAL, TASK_UNI= NTERRUPTIBLE}, time::Jiffies, types::Opaque, }; +use core::ffi::CStr; use core::marker::PhantomPinned; use core::ptr; use macros::pin_data; diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs index 16bf3014f068..7b412f5049e5 100644 --- a/rust/kernel/sync/lock.rs +++ b/rust/kernel/sync/lock.rs @@ -9,10 +9,9 @@ use crate::{ init::PinInit, pin_init, - str::CStr, types::{NotThreadSafe, Opaque, ScopeGuard}, }; -use core::{cell::UnsafeCell, marker::PhantomPinned}; +use core::{cell::UnsafeCell, ffi::CStr, marker::PhantomPinned}; use macros::pin_data; =20 pub mod mutex; diff --git a/rust/kernel/sync/lock/global.rs b/rust/kernel/sync/lock/global= .rs index 732dde45024b..ee438654eb6c 100644 --- a/rust/kernel/sync/lock/global.rs +++ b/rust/kernel/sync/lock/global.rs @@ -5,13 +5,13 @@ //! Support for defining statics containing locks. =20 use crate::{ - str::CStr, sync::lock::{Backend, Guard, Lock}, sync::{LockClassKey, LockedBy}, types::Opaque, }; use core::{ cell::UnsafeCell, + ffi::CStr, marker::{PhantomData, PhantomPinned}, }; =20 @@ -266,7 +266,7 @@ macro_rules! global_lock { $pub enum $name {} =20 impl $crate::sync::lock::GlobalLockBackend for $name { - const NAME: &'static $crate::str::CStr =3D + const NAME: &'static core::ffi::CStr =3D $crate::c_str_avoid_literals!(::core::stringify!($name)); type Item =3D $valuety; type Backend =3D $crate::global_lock_inner!(backend $kind); diff --git a/rust/kernel/sync/poll.rs b/rust/kernel/sync/poll.rs index d5f17153b424..3349f48725f2 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; =20 /// 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 284b9a739c01..69bf6a1cba41 100644 --- a/rust/kernel/workqueue.rs +++ b/rust/kernel/workqueue.rs @@ -135,6 +135,7 @@ =20 use crate::alloc::{AllocError, Flags}; use crate::{prelude::*, sync::Arc, sync::LockClassKey, types::Opaque}; +use core::ffi::CStr; use core::marker::PhantomData; =20 /// Creates a [`Work`] initialiser with the given name and a newly-created= lock class. --=20 2.48.1