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[PATCH v5] rust: str: Use `core::CStr`, remove the custom `CStr` implementation

by Michal Rostecki

`CStr` became a part of `core` library in Rust 1.75. This change replaces the custom `CStr` implementation with the one from `core`. `core::CStr` behaves generally the same as the removed implementation, with the following differences: - It does not implement `Display`. - It does not provide `from_bytes_with_nul_unchecked_mut` method. - It has `as_ptr()` method instead of `as_char_ptr()`, which also returns `*const c_char`. The first two differences are handled by providing the `CStrExt` trait, with `display()` and `from_bytes_with_nul_unchecked_mut()` methods. `display()` returns a `CStrDisplay` wrapper, with a custom `Display` implementation. `DerefMut` implementation for `CString` is removed here, as it's not being used anywhere. Signed-off-by: Michal Rostecki <vadorovsky(a)gmail.com> --- v1 -> 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`. v2 -> v3: - Fix the commit message. - Remove redundant braces in `use`, when only one item is imported. v3 -> 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/). v4 -> v5: - Keep the `test_cstr_display*` unit tests. rust/kernel/error.rs | 7 +- rust/kernel/kunit.rs | 18 +- rust/kernel/net/phy.rs | 2 +- rust/kernel/prelude.rs | 4 +- rust/kernel/str.rs | 501 ++++++------------------------------ rust/kernel/sync/condvar.rs | 5 +- rust/kernel/sync/lock.rs | 6 +- rust/kernel/workqueue.rs | 2 +- scripts/rustdoc_test_gen.rs | 4 +- 9 files changed, 111 insertions(+), 438 deletions(-) diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs index 55280ae9fe40..18808b29604d 100644 --- a/rust/kernel/error.rs +++ b/rust/kernel/error.rs @@ -4,10 +4,11 @@ //! //! C header: [`include/uapi/asm-generic/errno-base.h`](srctree/include/uapi/asm-generic/errno-base.h) -use crate::{alloc::AllocError, str::CStr}; +use crate::alloc::AllocError; use alloc::alloc::LayoutError; +use core::ffi::CStr; use core::fmt; use core::num::TryFromIntError; use core::str::Utf8Error; @@ -142,7 +143,7 @@ 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 { CStr::from_ptr(ptr) }) } } @@ -164,7 +165,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { None => f.debug_tuple("Error").field(&-self.0).finish(), // SAFETY: These strings are ASCII-only. Some(name) => f - .debug_tuple(unsafe { core::str::from_utf8_unchecked(name) }) + .debug_tuple(unsafe { core::str::from_utf8_unchecked(name.to_bytes()) }) .finish(), } } diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 0ba77276ae7e..79a50ab59af0 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -56,13 +56,15 @@ macro_rules! kunit_assert { break 'out; } - static FILE: &'static $crate::str::CStr = $crate::c_str!($file); + static FILE: &'static core::ffi::CStr = $file; static LINE: i32 = core::line!() as i32 - $diff; - static CONDITION: &'static $crate::str::CStr = $crate::c_str!(stringify!($condition)); + static CONDITION: &'static core::ffi::CStr = $crate::c_str!(stringify!($condition)); // SAFETY: FFI call without safety requirements. let kunit_test = unsafe { $crate::bindings::kunit_get_current_test() }; if kunit_test.is_null() { + use kernel::str::CStrExt; + // The assertion failed but this task is not running a KUnit test, so we cannot call // KUnit, but at least print an error to the kernel log. This may happen if this // macro is called from an spawned thread in a test (see @@ -71,11 +73,13 @@ macro_rules! kunit_assert { // // This mimics KUnit's failed assertion format. $crate::kunit::err(format_args!( - " # {}: ASSERTION FAILED at {FILE}:{LINE}\n", - $name + " # {}: ASSERTION FAILED at {}:{LINE}\n", + $name.display(), + FILE.display(), )); $crate::kunit::err(format_args!( - " Expected {CONDITION} to be true, but is false\n" + " Expected {} to be true, but is false\n", + CONDITION.display(), )); $crate::kunit::err(format_args!( " Failure not reported to KUnit since this is a non-KUnit task\n" @@ -98,12 +102,12 @@ unsafe impl Sync for Location {} unsafe impl Sync for UnaryAssert {} static LOCATION: Location = Location($crate::bindings::kunit_loc { - file: FILE.as_char_ptr(), + file: FILE.as_ptr(), line: LINE, }); static ASSERTION: UnaryAssert = UnaryAssert($crate::bindings::kunit_unary_assert { assert: $crate::bindings::kunit_assert {}, - condition: CONDITION.as_char_ptr(), + condition: CONDITION.as_ptr(), expected_true: true, }); diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs index fd40b703d224..19f45922ec42 100644 --- a/rust/kernel/net/phy.rs +++ b/rust/kernel/net/phy.rs @@ -502,7 +502,7 @@ 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: T::NAME.as_ptr().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/prelude.rs b/rust/kernel/prelude.rs index b37a0b3180fb..b0969ca78f10 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -12,7 +12,7 @@ //! ``` #[doc(no_inline)] -pub use core::pin::Pin; +pub use core::{ffi::CStr, pin::Pin}; pub use crate::alloc::{box_ext::BoxExt, flags::*, vec_ext::VecExt}; @@ -35,7 +35,7 @@ pub use super::error::{code::*, Error, Result}; -pub use super::{str::CStr, ThisModule}; +pub use super::ThisModule; pub use super::init::{InPlaceInit, Init, PinInit}; diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index bb8d4f41475b..f1acaa377694 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -4,8 +4,9 @@ use crate::alloc::{flags::*, vec_ext::VecExt, AllocError}; use alloc::vec::Vec; +use core::ffi::CStr; use core::fmt::{self, Write}; -use core::ops::{self, Deref, DerefMut, Index}; +use core::ops::Deref; use crate::error::{code::*, Error}; @@ -41,11 +42,11 @@ impl fmt::Display for BStr { /// # use kernel::{fmt, b_str, str::{BStr, CString}}; /// let ascii = b_str!("Hello, BStr!"); /// let s = CString::try_from_fmt(fmt!("{}", ascii)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes()); + /// assert_eq!(s.to_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes()); /// ``` fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { for &b in &self.0 { @@ -72,11 +73,11 @@ impl fmt::Debug for BStr { /// // Embedded double quotes are escaped. /// let ascii = b_str!("Hello, \"BStr\"!"); /// let s = CString::try_from_fmt(fmt!("{:?}", ascii)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes(), "\"\\xf0\\x9f\\x98\\xba\"".as_bytes()); + /// assert_eq!(s.to_bytes(), "\"\\xf0\\x9f\\x98\\xba\"".as_bytes()); /// ``` fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.write_char('"')?; @@ -128,271 +129,29 @@ 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, +/// Wrapper around [`CStr`] which implements [`Display`](core::fmt::Display). +pub struct CStrDisplay<'a>(&'a CStr); - /// Supplied bytes are not terminated by `NUL`. - NotNulTerminated, -} - -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 { - // 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. - if self.0.is_empty() { - 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 - } - - /// 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 `ptr` - /// must not be mutated. - #[inline] - pub unsafe fn from_char_ptr<'a>(ptr: *const core::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 as _) }; - // 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) } - } - - /// 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 precondition. - 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 core::ffi::c_char { - self.0.as_ptr() as _ - } - - /// 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").unwrap(); - /// assert_eq!(cstr.to_str(), Ok("foo")); - /// ``` - #[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. +impl fmt::Display for CStrDisplay<'_> { + /// Formats printable ASCII characters, escaping the rest. /// /// # Examples /// /// ``` - /// # use kernel::c_str; - /// # use kernel::str::CStr; - /// let bar = c_str!("ツ"); - /// // SAFETY: String literals are guaranteed to be valid UTF-8 - /// // by the Rust compiler. - /// assert_eq!(unsafe { bar.as_str_unchecked() }, "ツ"); - /// ``` - #[inline] - pub unsafe fn as_str_unchecked(&self) -> &str { - 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, AllocError> { - 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 one, 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 one, 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<CString, AllocError> { - let mut s = 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<CString, AllocError> { - let mut s = self.to_cstring()?; - - s.make_ascii_uppercase(); - - Ok(s) - } -} - -impl fmt::Display for CStr { - /// Formats printable ASCII characters, escaping the rest. - /// - /// ``` + /// # use core::ffi::CStr; /// # use kernel::c_str; /// # use kernel::fmt; - /// # use kernel::str::CStr; - /// # use kernel::str::CString; - /// let penguin = c_str!("🐧"); - /// let s = CString::try_from_fmt(fmt!("{}", penguin)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_bytes()); - /// - /// let ascii = c_str!("so \"cool\""); - /// let s = CString::try_from_fmt(fmt!("{}", ascii)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "so \"cool\"\0".as_bytes()); + /// # use kernel::str::{CStrExt, CString}; + /// let penguin = c"🐧"; + /// let s = CString::try_from_fmt(fmt!("{}", penguin.display())).unwrap(); + /// assert_eq!(s.to_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_bytes()); + /// + /// let ascii = c"so \"cool\""; + /// let s = CString::try_from_fmt(fmt!("{}", ascii.display())).unwrap(); + /// assert_eq!(s.to_bytes_with_nul(), "so \"cool\"\0".as_bytes()); /// ``` fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - for &c in self.as_bytes() { + for &c in self.0.to_bytes() { if (0x20..0x7f).contains(&c) { // Printable character. f.write_char(c as char)?; @@ -404,116 +163,70 @@ 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. +/// Extensions to [`CStr`]. +pub trait CStrExt { + /// Returns an object that implements [`Display`](core::fmt::Display) for + /// safely printing a [`CStr`] that may contain non-ASCII data, which are + /// escaped. + /// + /// # Examples /// /// ``` + /// # use core::ffi::CStr; /// # use kernel::c_str; /// # use kernel::fmt; - /// # use kernel::str::CStr; - /// # use kernel::str::CString; - /// let penguin = c_str!("🐧"); - /// let s = CString::try_from_fmt(fmt!("{:?}", penguin)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "\"so \\\"cool\\\"\"\0".as_bytes()); + /// # use kernel::str::{CStrExt, CString}; + /// let penguin = c"🐧"; + /// let s = CString::try_from_fmt(fmt!("{}", penguin.display())).unwrap(); + /// assert_eq!(s.to_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_bytes()); + /// + /// let ascii = c"so \"cool\""; + /// let s = CString::try_from_fmt(fmt!("{}", ascii.display())).unwrap(); + /// assert_eq!(s.to_bytes_with_nul(), "so \"cool\"\0".as_bytes()); /// ``` - 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{:02x}", c)?, - } - } - f.write_str("\"") - } -} - -impl AsRef<BStr> for CStr { - #[inline] - fn as_ref(&self) -> &BStr { - BStr::from_bytes(self.as_bytes()) - } -} - -impl Deref for CStr { - type Target = BStr; - - #[inline] - fn deref(&self) -> &Self::Target { - self.as_ref() - } -} + fn display(&self) -> CStrDisplay<'_>; -impl Index<ops::RangeFrom<usize>> for CStr { - type Output = CStr; - - #[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..]) } - } + /// 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). + unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) -> &mut Self; } -impl Index<ops::RangeFull> for CStr { - type Output = CStr; - - #[inline] - fn index(&self, _index: ops::RangeFull) -> &Self::Output { - self +impl CStrExt for CStr { + fn display(&self) -> CStrDisplay<'_> { + CStrDisplay(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<usize> {} - impl CStrIndex for ops::RangeInclusive<usize> {} - impl CStrIndex for ops::RangeToInclusive<usize> {} -} - -impl<Idx> Index<Idx> for CStr -where - Idx: private::CStrIndex, - BStr: Index<Idx>, -{ - type Output = <BStr as Index<Idx>>::Output; - - #[inline] - fn index(&self, index: Idx) -> &Self::Output { - &self.as_ref()[index] + unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) -> &mut Self { + // SAFETY: Properties of `bytes` guaranteed by the safety precondition. + unsafe { &mut *(bytes as *mut [u8] as *mut CStr) } } } /// Creates a new [`CStr`] from a string literal. /// -/// The string literal should not contain any `NUL` bytes. +/// This macro is not needed when C-string literals (`c"hello"` syntax) can be +/// used directly, but can be used when a C-string version of a standard string +/// literal is required (often when working with macros). +/// +/// The string should not contain any `NUL` bytes. /// /// # Examples /// /// ``` +/// # use core::ffi::CStr; /// # use kernel::c_str; -/// # use kernel::str::CStr; -/// const MY_CSTR: &CStr = c_str!("My awesome CStr!"); +/// const MY_CSTR: &CStr = c_str!(stringify!(5)); /// ``` #[macro_export] macro_rules! c_str { ($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"), }; @@ -540,65 +253,6 @@ mod tests { \\xe0\\xe1\\xe2\\xe3\\xe4\\xe5\\xe6\\xe7\\xe8\\xe9\\xea\\xeb\\xec\\xed\\xee\\xef\ \\xf0\\xf1\\xf2\\xf3\\xf4\\xf5\\xf6\\xf7\\xf8\\xf9\\xfa\\xfb\\xfc\\xfd\\xfe\\xff"; - #[test] - fn test_cstr_to_str() { - let good_bytes = b"\xf0\x9f\xa6\x80\0"; - let checked_cstr = CStr::from_bytes_with_nul(good_bytes).unwrap(); - let checked_str = checked_cstr.to_str().unwrap(); - assert_eq!(checked_str, "🦀"); - } - - #[test] - #[should_panic] - fn test_cstr_to_str_panic() { - let bad_bytes = b"\xc3\x28\0"; - let checked_cstr = CStr::from_bytes_with_nul(bad_bytes).unwrap(); - checked_cstr.to_str().unwrap(); - } - - #[test] - fn test_cstr_as_str_unchecked() { - let good_bytes = b"\xf0\x9f\x90\xA7\0"; - let checked_cstr = CStr::from_bytes_with_nul(good_bytes).unwrap(); - let unchecked_str = unsafe { checked_cstr.as_str_unchecked() }; - assert_eq!(unchecked_str, "🐧"); - } - - #[test] - fn test_cstr_display() { - let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap(); - assert_eq!(format!("{}", hello_world), "hello, world!"); - let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap(); - assert_eq!(format!("{}", non_printables), "\\x01\\x09\\x0a"); - let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap(); - assert_eq!(format!("{}", non_ascii), "d\\xe9j\\xe0 vu"); - let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap(); - assert_eq!(format!("{}", good_bytes), "\\xf0\\x9f\\xa6\\x80"); - } - - #[test] - fn test_cstr_display_all_bytes() { - let mut bytes: [u8; 256] = [0; 256]; - // fill `bytes` with [1..=255] + [0] - for i in u8::MIN..=u8::MAX { - bytes[i as usize] = i.wrapping_add(1); - } - let cstr = CStr::from_bytes_with_nul(&bytes).unwrap(); - assert_eq!(format!("{}", cstr), ALL_ASCII_CHARS); - } - - #[test] - fn test_cstr_debug() { - let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap(); - assert_eq!(format!("{:?}", hello_world), "\"hello, world!\""); - let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap(); - assert_eq!(format!("{:?}", non_printables), "\"\\x01\\x09\\x0a\""); - let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap(); - assert_eq!(format!("{:?}", non_ascii), "\"d\\xe9j\\xe0 vu\""); - let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap(); - assert_eq!(format!("{:?}", good_bytes), "\"\\xf0\\x9f\\xa6\\x80\""); - } - #[test] fn test_bstr_display() { let hello_world = BStr::from_bytes(b"hello, world!"); @@ -626,6 +280,29 @@ fn test_bstr_debug() { let good_bytes = BStr::from_bytes(b"\xf0\x9f\xa6\x80"); assert_eq!(format!("{:?}", good_bytes), "\"\\xf0\\x9f\\xa6\\x80\""); } + + #[test] + fn test_cstr_display() { + let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap(); + assert_eq!(format!("{}", hello_world.display()), "hello, world!"); + let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap(); + assert_eq!(format!("{}", non_printables.display()), "\\x01\\x09\\x0a"); + let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap(); + assert_eq!(format!("{}", non_ascii.display()), "d\\xe9j\\xe0 vu"); + let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap(); + assert_eq!(format!("{}", good_bytes.display()), "\\xf0\\x9f\\xa6\\x80"); + } + + #[test] + fn test_cstr_display_all_bytes() { + let mut bytes: [u8; 256] = [0; 256]; + // fill `bytes` with [1..=255] + [0] + for i in u8::MIN..=u8::MAX { + bytes[i as usize] = i.wrapping_add(1); + } + let cstr = CStr::from_bytes_with_nul(&bytes).unwrap(); + assert_eq!(format!("{}", cstr.display()), ALL_ASCII_CHARS); + } } /// Allows formatting of [`fmt::Arguments`] into a raw buffer. @@ -779,11 +456,11 @@ fn write_str(&mut self, s: &str) -> fmt::Result { /// use kernel::{str::CString, fmt}; /// /// let s = CString::try_from_fmt(fmt!("{}{}{}", "abc", 10, 20)).unwrap(); -/// 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)).unwrap(); -/// 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)); @@ -838,21 +515,13 @@ fn deref(&self) -> &Self::Target { } } -impl DerefMut for CString { - fn deref_mut(&mut self) -> &mut Self::Target { - // SAFETY: A `CString` is always NUL-terminated and contains no other - // NUL bytes. - unsafe { CStr::from_bytes_with_nul_unchecked_mut(self.buf.as_mut_slice()) } - } -} - impl<'a> TryFrom<&'a CStr> for CString { type Error = AllocError; fn try_from(cstr: &'a CStr) -> Result<CString, AllocError> { let mut buf = Vec::new(); - <Vec<_> as VecExt<_>>::extend_from_slice(&mut buf, cstr.as_bytes_with_nul(), GFP_KERNEL) + <Vec<_> as VecExt<_>>::extend_from_slice(&mut buf, cstr.to_bytes_with_nul(), GFP_KERNEL) .map_err(|_| AllocError)?; // INVARIANT: The `CStr` and `CString` types have the same invariants for diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs index 2b306afbe56d..16d1a1cb8d00 100644 --- a/rust/kernel/sync/condvar.rs +++ b/rust/kernel/sync/condvar.rs @@ -9,12 +9,11 @@ use crate::{ init::PinInit, pin_init, - str::CStr, task::{MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE, TASK_NORMAL, TASK_UNINTERRUPTIBLE}, time::Jiffies, types::Opaque, }; -use core::ffi::{c_int, c_long}; +use core::ffi::{c_int, c_long, CStr}; use core::marker::PhantomPinned; use core::ptr; use macros::pin_data; @@ -108,7 +107,7 @@ pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self // SAFETY: `slot` is valid while the closure is called and both `name` and `key` have // static lifetimes so they live indefinitely. wait_queue_head <- Opaque::ffi_init(|slot| unsafe { - bindings::__init_waitqueue_head(slot, name.as_char_ptr(), key.as_ptr()) + bindings::__init_waitqueue_head(slot, name.as_ptr(), key.as_ptr()) }), }) } diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs index f6c34ca4d819..318ecb5a5916 100644 --- a/rust/kernel/sync/lock.rs +++ b/rust/kernel/sync/lock.rs @@ -6,8 +6,8 @@ //! spinlocks, raw spinlocks) to be provided with minimal effort. use super::LockClassKey; -use crate::{init::PinInit, pin_init, str::CStr, types::Opaque, types::ScopeGuard}; -use core::{cell::UnsafeCell, marker::PhantomData, marker::PhantomPinned}; +use crate::{init::PinInit, pin_init, types::Opaque, types::ScopeGuard}; +use core::{cell::UnsafeCell, ffi::CStr, marker::PhantomData, marker::PhantomPinned}; use macros::pin_data; pub mod mutex; @@ -113,7 +113,7 @@ pub fn new(t: T, name: &'static CStr, key: &'static LockClassKey) -> impl PinIni // SAFETY: `slot` is valid while the closure is called and both `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, name.as_ptr(), key.as_ptr()) }), }) } diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs index 553a5cba2adc..a6418873e82e 100644 --- a/rust/kernel/workqueue.rs +++ b/rust/kernel/workqueue.rs @@ -380,7 +380,7 @@ pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self slot, Some(T::Pointer::run), false, - name.as_char_ptr(), + name.as_ptr(), key.as_ptr(), ) } diff --git a/scripts/rustdoc_test_gen.rs b/scripts/rustdoc_test_gen.rs index 5ebd42ae4a3f..339991ee6885 100644 --- a/scripts/rustdoc_test_gen.rs +++ b/scripts/rustdoc_test_gen.rs @@ -172,7 +172,7 @@ pub extern "C" fn {kunit_name}(__kunit_test: *mut kernel::bindings::kunit) {{ #[allow(unused)] macro_rules! assert {{ ($cond:expr $(,)?) => {{{{ - kernel::kunit_assert!("{kunit_name}", "{real_path}", __DOCTEST_ANCHOR - {line}, $cond); + kernel::kunit_assert!(c"{kunit_name}", c"{real_path}", __DOCTEST_ANCHOR - {line}, $cond); }}}} }} @@ -180,7 +180,7 @@ macro_rules! assert {{ #[allow(unused)] macro_rules! assert_eq {{ ($left:expr, $right:expr $(,)?) => {{{{ - kernel::kunit_assert_eq!("{kunit_name}", "{real_path}", __DOCTEST_ANCHOR - {line}, $left, $right); + kernel::kunit_assert_eq!(c"{kunit_name}", c"{real_path}", __DOCTEST_ANCHOR - {line}, $left, $right); }}}} }} -- 2.45.2

9 months, 2 weeks

2
1
0 0

[PATCH v4] rust: str: Use `core::CStr`, remove the custom `CStr` implementation

by Michal Rostecki

`CStr` became a part of `core` library in Rust 1.75. This change replaces the custom `CStr` implementation with the one from `core`. `core::CStr` behaves generally the same as the removed implementation, with the following differences: - It does not implement `Display`. - It does not provide `from_bytes_with_nul_unchecked_mut` method. - It has `as_ptr()` method instead of `as_char_ptr()`, which also returns `*const c_char`. The first two differences are handled by providing the `CStrExt` trait, with `display()` and `from_bytes_with_nul_unchecked_mut()` methods. `display()` returns a `CStrDisplay` wrapper, with a custom `Display` implementation. `DerefMut` implementation for `CString` is removed here, as it's not being used anywhere. Signed-off-by: Michal Rostecki <vadorovsky(a)gmail.com> --- v1 -> 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`. v2 -> v3: - Fix the commit message. - Remove redundant braces in `use`, when only one item is imported. v3 -> 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/). rust/kernel/error.rs | 7 +- rust/kernel/kunit.rs | 18 +- rust/kernel/net/phy.rs | 2 +- rust/kernel/prelude.rs | 4 +- rust/kernel/str.rs | 492 +++++------------------------------- rust/kernel/sync/condvar.rs | 5 +- rust/kernel/sync/lock.rs | 6 +- rust/kernel/workqueue.rs | 2 +- scripts/rustdoc_test_gen.rs | 4 +- 9 files changed, 88 insertions(+), 452 deletions(-) diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs index 55280ae9fe40..18808b29604d 100644 --- a/rust/kernel/error.rs +++ b/rust/kernel/error.rs @@ -4,10 +4,11 @@ //! //! C header: [`include/uapi/asm-generic/errno-base.h`](srctree/include/uapi/asm-generic/errno-base.h) -use crate::{alloc::AllocError, str::CStr}; +use crate::alloc::AllocError; use alloc::alloc::LayoutError; +use core::ffi::CStr; use core::fmt; use core::num::TryFromIntError; use core::str::Utf8Error; @@ -142,7 +143,7 @@ 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 { CStr::from_ptr(ptr) }) } } @@ -164,7 +165,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { None => f.debug_tuple("Error").field(&-self.0).finish(), // SAFETY: These strings are ASCII-only. Some(name) => f - .debug_tuple(unsafe { core::str::from_utf8_unchecked(name) }) + .debug_tuple(unsafe { core::str::from_utf8_unchecked(name.to_bytes()) }) .finish(), } } diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 0ba77276ae7e..79a50ab59af0 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -56,13 +56,15 @@ macro_rules! kunit_assert { break 'out; } - static FILE: &'static $crate::str::CStr = $crate::c_str!($file); + static FILE: &'static core::ffi::CStr = $file; static LINE: i32 = core::line!() as i32 - $diff; - static CONDITION: &'static $crate::str::CStr = $crate::c_str!(stringify!($condition)); + static CONDITION: &'static core::ffi::CStr = $crate::c_str!(stringify!($condition)); // SAFETY: FFI call without safety requirements. let kunit_test = unsafe { $crate::bindings::kunit_get_current_test() }; if kunit_test.is_null() { + use kernel::str::CStrExt; + // The assertion failed but this task is not running a KUnit test, so we cannot call // KUnit, but at least print an error to the kernel log. This may happen if this // macro is called from an spawned thread in a test (see @@ -71,11 +73,13 @@ macro_rules! kunit_assert { // // This mimics KUnit's failed assertion format. $crate::kunit::err(format_args!( - " # {}: ASSERTION FAILED at {FILE}:{LINE}\n", - $name + " # {}: ASSERTION FAILED at {}:{LINE}\n", + $name.display(), + FILE.display(), )); $crate::kunit::err(format_args!( - " Expected {CONDITION} to be true, but is false\n" + " Expected {} to be true, but is false\n", + CONDITION.display(), )); $crate::kunit::err(format_args!( " Failure not reported to KUnit since this is a non-KUnit task\n" @@ -98,12 +102,12 @@ unsafe impl Sync for Location {} unsafe impl Sync for UnaryAssert {} static LOCATION: Location = Location($crate::bindings::kunit_loc { - file: FILE.as_char_ptr(), + file: FILE.as_ptr(), line: LINE, }); static ASSERTION: UnaryAssert = UnaryAssert($crate::bindings::kunit_unary_assert { assert: $crate::bindings::kunit_assert {}, - condition: CONDITION.as_char_ptr(), + condition: CONDITION.as_ptr(), expected_true: true, }); diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs index fd40b703d224..19f45922ec42 100644 --- a/rust/kernel/net/phy.rs +++ b/rust/kernel/net/phy.rs @@ -502,7 +502,7 @@ 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: T::NAME.as_ptr().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/prelude.rs b/rust/kernel/prelude.rs index b37a0b3180fb..b0969ca78f10 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -12,7 +12,7 @@ //! ``` #[doc(no_inline)] -pub use core::pin::Pin; +pub use core::{ffi::CStr, pin::Pin}; pub use crate::alloc::{box_ext::BoxExt, flags::*, vec_ext::VecExt}; @@ -35,7 +35,7 @@ pub use super::error::{code::*, Error, Result}; -pub use super::{str::CStr, ThisModule}; +pub use super::ThisModule; pub use super::init::{InPlaceInit, Init, PinInit}; diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index bb8d4f41475b..ec220a760d89 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -4,8 +4,9 @@ use crate::alloc::{flags::*, vec_ext::VecExt, AllocError}; use alloc::vec::Vec; +use core::ffi::CStr; use core::fmt::{self, Write}; -use core::ops::{self, Deref, DerefMut, Index}; +use core::ops::Deref; use crate::error::{code::*, Error}; @@ -41,11 +42,11 @@ impl fmt::Display for BStr { /// # use kernel::{fmt, b_str, str::{BStr, CString}}; /// let ascii = b_str!("Hello, BStr!"); /// let s = CString::try_from_fmt(fmt!("{}", ascii)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes()); + /// assert_eq!(s.to_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes()); /// ``` fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { for &b in &self.0 { @@ -72,11 +73,11 @@ impl fmt::Debug for BStr { /// // Embedded double quotes are escaped. /// let ascii = b_str!("Hello, \"BStr\"!"); /// let s = CString::try_from_fmt(fmt!("{:?}", ascii)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes(), "\"\\xf0\\x9f\\x98\\xba\"".as_bytes()); + /// assert_eq!(s.to_bytes(), "\"\\xf0\\x9f\\x98\\xba\"".as_bytes()); /// ``` fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.write_char('"')?; @@ -128,271 +129,29 @@ 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, +/// Wrapper around [`CStr`] which implements [`Display`](core::fmt::Display). +pub struct CStrDisplay<'a>(&'a CStr); - /// Supplied bytes are not terminated by `NUL`. - NotNulTerminated, -} - -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 { - // 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. - if self.0.is_empty() { - 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 - } - - /// 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 `ptr` - /// must not be mutated. - #[inline] - pub unsafe fn from_char_ptr<'a>(ptr: *const core::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 as _) }; - // 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) } - } - - /// 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 precondition. - 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 core::ffi::c_char { - self.0.as_ptr() as _ - } - - /// 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").unwrap(); - /// assert_eq!(cstr.to_str(), Ok("foo")); - /// ``` - #[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. +impl fmt::Display for CStrDisplay<'_> { + /// Formats printable ASCII characters, escaping the rest. /// /// # Examples /// /// ``` - /// # use kernel::c_str; - /// # use kernel::str::CStr; - /// let bar = c_str!("ツ"); - /// // SAFETY: String literals are guaranteed to be valid UTF-8 - /// // by the Rust compiler. - /// assert_eq!(unsafe { bar.as_str_unchecked() }, "ツ"); - /// ``` - #[inline] - pub unsafe fn as_str_unchecked(&self) -> &str { - 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, AllocError> { - 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 one, 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 one, 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<CString, AllocError> { - let mut s = 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<CString, AllocError> { - let mut s = self.to_cstring()?; - - s.make_ascii_uppercase(); - - Ok(s) - } -} - -impl fmt::Display for CStr { - /// Formats printable ASCII characters, escaping the rest. - /// - /// ``` + /// # use core::ffi::CStr; /// # use kernel::c_str; /// # use kernel::fmt; - /// # use kernel::str::CStr; - /// # use kernel::str::CString; - /// let penguin = c_str!("🐧"); - /// let s = CString::try_from_fmt(fmt!("{}", penguin)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_bytes()); - /// - /// let ascii = c_str!("so \"cool\""); - /// let s = CString::try_from_fmt(fmt!("{}", ascii)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "so \"cool\"\0".as_bytes()); + /// # use kernel::str::{CStrExt, CString}; + /// let penguin = c"🐧"; + /// let s = CString::try_from_fmt(fmt!("{}", penguin.display())).unwrap(); + /// assert_eq!(s.to_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_bytes()); + /// + /// let ascii = c"so \"cool\""; + /// let s = CString::try_from_fmt(fmt!("{}", ascii.display())).unwrap(); + /// assert_eq!(s.to_bytes_with_nul(), "so \"cool\"\0".as_bytes()); /// ``` fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - for &c in self.as_bytes() { + for &c in self.0.to_bytes() { if (0x20..0x7f).contains(&c) { // Printable character. f.write_char(c as char)?; @@ -404,116 +163,70 @@ 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. +/// Extensions to [`CStr`]. +pub trait CStrExt { + /// Returns an object that implements [`Display`](core::fmt::Display) for + /// safely printing a [`CStr`] that may contain non-ASCII data, which are + /// escaped. + /// + /// # Examples /// /// ``` + /// # use core::ffi::CStr; /// # use kernel::c_str; /// # use kernel::fmt; - /// # use kernel::str::CStr; - /// # use kernel::str::CString; - /// let penguin = c_str!("🐧"); - /// let s = CString::try_from_fmt(fmt!("{:?}", penguin)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "\"so \\\"cool\\\"\"\0".as_bytes()); + /// # use kernel::str::{CStrExt, CString}; + /// let penguin = c"🐧"; + /// let s = CString::try_from_fmt(fmt!("{}", penguin.display())).unwrap(); + /// assert_eq!(s.to_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_bytes()); + /// + /// let ascii = c"so \"cool\""; + /// let s = CString::try_from_fmt(fmt!("{}", ascii.display())).unwrap(); + /// assert_eq!(s.to_bytes_with_nul(), "so \"cool\"\0".as_bytes()); /// ``` - 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{:02x}", c)?, - } - } - f.write_str("\"") - } -} - -impl AsRef<BStr> for CStr { - #[inline] - fn as_ref(&self) -> &BStr { - BStr::from_bytes(self.as_bytes()) - } -} - -impl Deref for CStr { - type Target = BStr; - - #[inline] - fn deref(&self) -> &Self::Target { - self.as_ref() - } -} - -impl Index<ops::RangeFrom<usize>> for CStr { - type Output = CStr; + fn display(&self) -> CStrDisplay<'_>; - #[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..]) } - } + /// 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). + unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) -> &mut Self; } -impl Index<ops::RangeFull> for CStr { - type Output = CStr; - - #[inline] - fn index(&self, _index: ops::RangeFull) -> &Self::Output { - self +impl CStrExt for CStr { + fn display(&self) -> CStrDisplay<'_> { + CStrDisplay(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<usize> {} - impl CStrIndex for ops::RangeInclusive<usize> {} - impl CStrIndex for ops::RangeToInclusive<usize> {} -} - -impl<Idx> Index<Idx> for CStr -where - Idx: private::CStrIndex, - BStr: Index<Idx>, -{ - type Output = <BStr as Index<Idx>>::Output; - #[inline] - fn index(&self, index: Idx) -> &Self::Output { - &self.as_ref()[index] + unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) -> &mut Self { + // SAFETY: Properties of `bytes` guaranteed by the safety precondition. + unsafe { &mut *(bytes as *mut [u8] as *mut CStr) } } } /// Creates a new [`CStr`] from a string literal. /// -/// The string literal should not contain any `NUL` bytes. +/// This macro is not needed when C-string literals (`c"hello"` syntax) can be +/// used directly, but can be used when a C-string version of a standard string +/// literal is required (often when working with macros). +/// +/// The string should not contain any `NUL` bytes. /// /// # Examples /// /// ``` +/// # use core::ffi::CStr; /// # use kernel::c_str; -/// # use kernel::str::CStr; -/// const MY_CSTR: &CStr = c_str!("My awesome CStr!"); +/// const MY_CSTR: &CStr = c_str!(stringify!(5)); /// ``` #[macro_export] macro_rules! c_str { ($str:expr) => {{ const S: &str = concat!($str, "\0"); - const C: &$crate::str::CStr = match $crate::str::CStr::from_bytes_with_nul(S.as_bytes()) { + const C: &core::ffi::CStr = match core::ffi::CStr::from_bytes_with_nul(S.as_bytes()) { Ok(v) => v, Err(_) => panic!("string contains interior NUL"), }; @@ -526,79 +239,6 @@ mod tests { use super::*; use alloc::format; - const ALL_ASCII_CHARS: &'static str = - "\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\x09\\x0a\\x0b\\x0c\\x0d\\x0e\\x0f\ - \\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f \ - !\"#$%&'()*+,-./0123456789:;<=>?@\ - ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\\x7f\ - \\x80\\x81\\x82\\x83\\x84\\x85\\x86\\x87\\x88\\x89\\x8a\\x8b\\x8c\\x8d\\x8e\\x8f\ - \\x90\\x91\\x92\\x93\\x94\\x95\\x96\\x97\\x98\\x99\\x9a\\x9b\\x9c\\x9d\\x9e\\x9f\ - \\xa0\\xa1\\xa2\\xa3\\xa4\\xa5\\xa6\\xa7\\xa8\\xa9\\xaa\\xab\\xac\\xad\\xae\\xaf\ - \\xb0\\xb1\\xb2\\xb3\\xb4\\xb5\\xb6\\xb7\\xb8\\xb9\\xba\\xbb\\xbc\\xbd\\xbe\\xbf\ - \\xc0\\xc1\\xc2\\xc3\\xc4\\xc5\\xc6\\xc7\\xc8\\xc9\\xca\\xcb\\xcc\\xcd\\xce\\xcf\ - \\xd0\\xd1\\xd2\\xd3\\xd4\\xd5\\xd6\\xd7\\xd8\\xd9\\xda\\xdb\\xdc\\xdd\\xde\\xdf\ - \\xe0\\xe1\\xe2\\xe3\\xe4\\xe5\\xe6\\xe7\\xe8\\xe9\\xea\\xeb\\xec\\xed\\xee\\xef\ - \\xf0\\xf1\\xf2\\xf3\\xf4\\xf5\\xf6\\xf7\\xf8\\xf9\\xfa\\xfb\\xfc\\xfd\\xfe\\xff"; - - #[test] - fn test_cstr_to_str() { - let good_bytes = b"\xf0\x9f\xa6\x80\0"; - let checked_cstr = CStr::from_bytes_with_nul(good_bytes).unwrap(); - let checked_str = checked_cstr.to_str().unwrap(); - assert_eq!(checked_str, "🦀"); - } - - #[test] - #[should_panic] - fn test_cstr_to_str_panic() { - let bad_bytes = b"\xc3\x28\0"; - let checked_cstr = CStr::from_bytes_with_nul(bad_bytes).unwrap(); - checked_cstr.to_str().unwrap(); - } - - #[test] - fn test_cstr_as_str_unchecked() { - let good_bytes = b"\xf0\x9f\x90\xA7\0"; - let checked_cstr = CStr::from_bytes_with_nul(good_bytes).unwrap(); - let unchecked_str = unsafe { checked_cstr.as_str_unchecked() }; - assert_eq!(unchecked_str, "🐧"); - } - - #[test] - fn test_cstr_display() { - let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap(); - assert_eq!(format!("{}", hello_world), "hello, world!"); - let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap(); - assert_eq!(format!("{}", non_printables), "\\x01\\x09\\x0a"); - let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap(); - assert_eq!(format!("{}", non_ascii), "d\\xe9j\\xe0 vu"); - let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap(); - assert_eq!(format!("{}", good_bytes), "\\xf0\\x9f\\xa6\\x80"); - } - - #[test] - fn test_cstr_display_all_bytes() { - let mut bytes: [u8; 256] = [0; 256]; - // fill `bytes` with [1..=255] + [0] - for i in u8::MIN..=u8::MAX { - bytes[i as usize] = i.wrapping_add(1); - } - let cstr = CStr::from_bytes_with_nul(&bytes).unwrap(); - assert_eq!(format!("{}", cstr), ALL_ASCII_CHARS); - } - - #[test] - fn test_cstr_debug() { - let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap(); - assert_eq!(format!("{:?}", hello_world), "\"hello, world!\""); - let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap(); - assert_eq!(format!("{:?}", non_printables), "\"\\x01\\x09\\x0a\""); - let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap(); - assert_eq!(format!("{:?}", non_ascii), "\"d\\xe9j\\xe0 vu\""); - let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap(); - assert_eq!(format!("{:?}", good_bytes), "\"\\xf0\\x9f\\xa6\\x80\""); - } - #[test] fn test_bstr_display() { let hello_world = BStr::from_bytes(b"hello, world!"); @@ -779,11 +419,11 @@ fn write_str(&mut self, s: &str) -> fmt::Result { /// use kernel::{str::CString, fmt}; /// /// let s = CString::try_from_fmt(fmt!("{}{}{}", "abc", 10, 20)).unwrap(); -/// 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)).unwrap(); -/// 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)); @@ -838,21 +478,13 @@ fn deref(&self) -> &Self::Target { } } -impl DerefMut for CString { - fn deref_mut(&mut self) -> &mut Self::Target { - // SAFETY: A `CString` is always NUL-terminated and contains no other - // NUL bytes. - unsafe { CStr::from_bytes_with_nul_unchecked_mut(self.buf.as_mut_slice()) } - } -} - impl<'a> TryFrom<&'a CStr> for CString { type Error = AllocError; fn try_from(cstr: &'a CStr) -> Result<CString, AllocError> { let mut buf = Vec::new(); - <Vec<_> as VecExt<_>>::extend_from_slice(&mut buf, cstr.as_bytes_with_nul(), GFP_KERNEL) + <Vec<_> as VecExt<_>>::extend_from_slice(&mut buf, cstr.to_bytes_with_nul(), GFP_KERNEL) .map_err(|_| AllocError)?; // INVARIANT: The `CStr` and `CString` types have the same invariants for diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs index 2b306afbe56d..16d1a1cb8d00 100644 --- a/rust/kernel/sync/condvar.rs +++ b/rust/kernel/sync/condvar.rs @@ -9,12 +9,11 @@ use crate::{ init::PinInit, pin_init, - str::CStr, task::{MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE, TASK_NORMAL, TASK_UNINTERRUPTIBLE}, time::Jiffies, types::Opaque, }; -use core::ffi::{c_int, c_long}; +use core::ffi::{c_int, c_long, CStr}; use core::marker::PhantomPinned; use core::ptr; use macros::pin_data; @@ -108,7 +107,7 @@ pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self // SAFETY: `slot` is valid while the closure is called and both `name` and `key` have // static lifetimes so they live indefinitely. wait_queue_head <- Opaque::ffi_init(|slot| unsafe { - bindings::__init_waitqueue_head(slot, name.as_char_ptr(), key.as_ptr()) + bindings::__init_waitqueue_head(slot, name.as_ptr(), key.as_ptr()) }), }) } diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs index f6c34ca4d819..318ecb5a5916 100644 --- a/rust/kernel/sync/lock.rs +++ b/rust/kernel/sync/lock.rs @@ -6,8 +6,8 @@ //! spinlocks, raw spinlocks) to be provided with minimal effort. use super::LockClassKey; -use crate::{init::PinInit, pin_init, str::CStr, types::Opaque, types::ScopeGuard}; -use core::{cell::UnsafeCell, marker::PhantomData, marker::PhantomPinned}; +use crate::{init::PinInit, pin_init, types::Opaque, types::ScopeGuard}; +use core::{cell::UnsafeCell, ffi::CStr, marker::PhantomData, marker::PhantomPinned}; use macros::pin_data; pub mod mutex; @@ -113,7 +113,7 @@ pub fn new(t: T, name: &'static CStr, key: &'static LockClassKey) -> impl PinIni // SAFETY: `slot` is valid while the closure is called and both `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, name.as_ptr(), key.as_ptr()) }), }) } diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs index 553a5cba2adc..a6418873e82e 100644 --- a/rust/kernel/workqueue.rs +++ b/rust/kernel/workqueue.rs @@ -380,7 +380,7 @@ pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self slot, Some(T::Pointer::run), false, - name.as_char_ptr(), + name.as_ptr(), key.as_ptr(), ) } diff --git a/scripts/rustdoc_test_gen.rs b/scripts/rustdoc_test_gen.rs index 5ebd42ae4a3f..339991ee6885 100644 --- a/scripts/rustdoc_test_gen.rs +++ b/scripts/rustdoc_test_gen.rs @@ -172,7 +172,7 @@ pub extern "C" fn {kunit_name}(__kunit_test: *mut kernel::bindings::kunit) {{ #[allow(unused)] macro_rules! assert {{ ($cond:expr $(,)?) => {{{{ - kernel::kunit_assert!("{kunit_name}", "{real_path}", __DOCTEST_ANCHOR - {line}, $cond); + kernel::kunit_assert!(c"{kunit_name}", c"{real_path}", __DOCTEST_ANCHOR - {line}, $cond); }}}} }} @@ -180,7 +180,7 @@ macro_rules! assert {{ #[allow(unused)] macro_rules! assert_eq {{ ($left:expr, $right:expr $(,)?) => {{{{ - kernel::kunit_assert_eq!("{kunit_name}", "{real_path}", __DOCTEST_ANCHOR - {line}, $left, $right); + kernel::kunit_assert_eq!(c"{kunit_name}", c"{real_path}", __DOCTEST_ANCHOR - {line}, $left, $right); }}}} }} -- 2.45.2

9 months, 2 weeks

1
0
0 0

[PATCH] rust: str: Use `core::CStr`, remove the custom `CStr` implementation

by Michal Rostecki

`CStr` became a part of `core` library in Rust 1.75, therefore there is no need to keep the custom implementation. `core::CStr` behaves generally the same as the removed implementation, with the following differences: - It does not implement `Display` (but implements `Debug`). - It does not provide `from_bytes_with_nul_unchecked_mut` method. - It was used only in `DerefMut` implementation for `CString`. This change replaces it with a manual cast to `&mut CStr`. - Otherwise, having such a method is not really desirable. `CStr` is a reference type or `str` are usually not supposed to be modified. - It has `as_ptr()` method instead of `as_char_ptr()`, which also returns `*const c_char`. Rust also introduces C literals (`c""`), so the `c_str` macro is removed here as well. Signed-off-by: Michal Rostecki <vadorovsky(a)gmail.com> --- rust/kernel/error.rs | 7 +- rust/kernel/init.rs | 8 +- rust/kernel/kunit.rs | 16 +- rust/kernel/net/phy.rs | 2 +- rust/kernel/prelude.rs | 4 +- rust/kernel/str.rs | 490 +----------------------------------- rust/kernel/sync.rs | 13 +- rust/kernel/sync/condvar.rs | 5 +- rust/kernel/sync/lock.rs | 6 +- rust/kernel/workqueue.rs | 10 +- scripts/rustdoc_test_gen.rs | 4 +- 11 files changed, 57 insertions(+), 508 deletions(-) diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs index 55280ae9fe40..18808b29604d 100644 --- a/rust/kernel/error.rs +++ b/rust/kernel/error.rs @@ -4,10 +4,11 @@ //! //! C header: [`include/uapi/asm-generic/errno-base.h`](srctree/include/uapi/asm-generic/errno-base.h) -use crate::{alloc::AllocError, str::CStr}; +use crate::alloc::AllocError; use alloc::alloc::LayoutError; +use core::ffi::CStr; use core::fmt; use core::num::TryFromIntError; use core::str::Utf8Error; @@ -142,7 +143,7 @@ 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 { CStr::from_ptr(ptr) }) } } @@ -164,7 +165,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { None => f.debug_tuple("Error").field(&-self.0).finish(), // SAFETY: These strings are ASCII-only. Some(name) => f - .debug_tuple(unsafe { core::str::from_utf8_unchecked(name) }) + .debug_tuple(unsafe { core::str::from_utf8_unchecked(name.to_bytes()) }) .finish(), } } diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs index 68605b633e73..af0017e56c0e 100644 --- a/rust/kernel/init.rs +++ b/rust/kernel/init.rs @@ -46,7 +46,7 @@ //! } //! //! let foo = pin_init!(Foo { -//! a <- new_mutex!(42, "Foo::a"), +//! a <- new_mutex!(42, c"Foo::a"), //! b: 24, //! }); //! ``` @@ -65,7 +65,7 @@ //! # b: u32, //! # } //! # let foo = pin_init!(Foo { -//! # a <- new_mutex!(42, "Foo::a"), +//! # a <- new_mutex!(42, c"Foo::a"), //! # b: 24, //! # }); //! let foo: Result<Pin<Box<Foo>>> = Box::pin_init(foo, GFP_KERNEL); @@ -81,7 +81,7 @@ //! ```rust //! # use kernel::sync::{new_mutex, Arc, Mutex}; //! let mtx: Result<Arc<Mutex<usize>>> = -//! Arc::pin_init(new_mutex!(42, "example::mtx"), GFP_KERNEL); +//! Arc::pin_init(new_mutex!(42, c"example::mtx"), GFP_KERNEL); //! ``` //! //! To declare an init macro/function you just return an [`impl PinInit<T, E>`]: @@ -99,7 +99,7 @@ //! impl DriverData { //! fn new() -> impl PinInit<Self, Error> { //! try_pin_init!(Self { -//! status <- new_mutex!(0, "DriverData::status"), +//! status <- new_mutex!(0, c"DriverData::status"), //! buffer: Box::init(kernel::init::zeroed(), GFP_KERNEL)?, //! }) //! } diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 0ba77276ae7e..6da0d5e237b6 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -56,9 +56,13 @@ macro_rules! kunit_assert { break 'out; } - static FILE: &'static $crate::str::CStr = $crate::c_str!($file); + static FILE: &'static core::ffi::CStr = $file; static LINE: i32 = core::line!() as i32 - $diff; - static CONDITION: &'static $crate::str::CStr = $crate::c_str!(stringify!($condition)); + static CONDITION: &'static core::ffi::CStr = unsafe { + core::ffi::CStr::from_bytes_with_nul_unchecked( + core::concat!(stringify!($condition), "\0").as_bytes() + ) + }; // SAFETY: FFI call without safety requirements. let kunit_test = unsafe { $crate::bindings::kunit_get_current_test() }; @@ -71,11 +75,11 @@ macro_rules! kunit_assert { // // This mimics KUnit's failed assertion format. $crate::kunit::err(format_args!( - " # {}: ASSERTION FAILED at {FILE}:{LINE}\n", + " # {:?}: ASSERTION FAILED at {FILE:?}:{LINE:?}\n", $name )); $crate::kunit::err(format_args!( - " Expected {CONDITION} to be true, but is false\n" + " Expected {CONDITION:?} to be true, but is false\n" )); $crate::kunit::err(format_args!( " Failure not reported to KUnit since this is a non-KUnit task\n" @@ -98,12 +102,12 @@ unsafe impl Sync for Location {} unsafe impl Sync for UnaryAssert {} static LOCATION: Location = Location($crate::bindings::kunit_loc { - file: FILE.as_char_ptr(), + file: FILE.as_ptr(), line: LINE, }); static ASSERTION: UnaryAssert = UnaryAssert($crate::bindings::kunit_unary_assert { assert: $crate::bindings::kunit_assert {}, - condition: CONDITION.as_char_ptr(), + condition: CONDITION.as_ptr(), expected_true: true, }); diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs index fd40b703d224..19f45922ec42 100644 --- a/rust/kernel/net/phy.rs +++ b/rust/kernel/net/phy.rs @@ -502,7 +502,7 @@ 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: T::NAME.as_ptr().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/prelude.rs b/rust/kernel/prelude.rs index b37a0b3180fb..5efabfaa5804 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -12,7 +12,7 @@ //! ``` #[doc(no_inline)] -pub use core::pin::Pin; +pub use core::{ffi::CStr, pin::Pin}; pub use crate::alloc::{box_ext::BoxExt, flags::*, vec_ext::VecExt}; @@ -35,7 +35,7 @@ pub use super::error::{code::*, Error, Result}; -pub use super::{str::CStr, ThisModule}; +pub use super::{ThisModule}; pub use super::init::{InPlaceInit, Init, PinInit}; diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index bb8d4f41475b..d1e6335a02a3 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -4,8 +4,9 @@ use crate::alloc::{flags::*, vec_ext::VecExt, AllocError}; use alloc::vec::Vec; +use core::ffi::CStr; use core::fmt::{self, Write}; -use core::ops::{self, Deref, DerefMut, Index}; +use core::ops::{Deref, DerefMut}; use crate::error::{code::*, Error}; @@ -41,11 +42,11 @@ impl fmt::Display for BStr { /// # use kernel::{fmt, b_str, str::{BStr, CString}}; /// let ascii = b_str!("Hello, BStr!"); /// let s = CString::try_from_fmt(fmt!("{}", ascii)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes()); + /// assert_eq!(s.to_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes()); /// ``` fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { for &b in &self.0 { @@ -72,11 +73,11 @@ impl fmt::Debug for BStr { /// // Embedded double quotes are escaped. /// let ascii = b_str!("Hello, \"BStr\"!"); /// let s = CString::try_from_fmt(fmt!("{:?}", ascii)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes(), "\"\\xf0\\x9f\\x98\\xba\"".as_bytes()); + /// assert_eq!(s.to_bytes(), "\"\\xf0\\x9f\\x98\\xba\"".as_bytes()); /// ``` fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.write_char('"')?; @@ -128,477 +129,11 @@ 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, - - /// Supplied bytes are not terminated by `NUL`. - NotNulTerminated, -} - -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 { - // 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. - if self.0.is_empty() { - 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 - } - - /// 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 `ptr` - /// must not be mutated. - #[inline] - pub unsafe fn from_char_ptr<'a>(ptr: *const core::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 as _) }; - // 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) } - } - - /// 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 precondition. - 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 core::ffi::c_char { - self.0.as_ptr() as _ - } - - /// 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").unwrap(); - /// assert_eq!(cstr.to_str(), Ok("foo")); - /// ``` - #[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!("ツ"); - /// // SAFETY: String literals are guaranteed to be valid UTF-8 - /// // by the Rust compiler. - /// assert_eq!(unsafe { bar.as_str_unchecked() }, "ツ"); - /// ``` - #[inline] - pub unsafe fn as_str_unchecked(&self) -> &str { - 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, AllocError> { - 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 one, 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 one, 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<CString, AllocError> { - let mut s = 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<CString, AllocError> { - let mut s = self.to_cstring()?; - - s.make_ascii_uppercase(); - - Ok(s) - } -} - -impl fmt::Display for CStr { - /// Formats printable ASCII characters, escaping the rest. - /// - /// ``` - /// # use kernel::c_str; - /// # use kernel::fmt; - /// # use kernel::str::CStr; - /// # use kernel::str::CString; - /// let penguin = c_str!("🐧"); - /// let s = CString::try_from_fmt(fmt!("{}", penguin)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_bytes()); - /// - /// let ascii = c_str!("so \"cool\""); - /// let s = CString::try_from_fmt(fmt!("{}", ascii)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "so \"cool\"\0".as_bytes()); - /// ``` - 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)?; - } - } - Ok(()) - } -} - -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::fmt; - /// # use kernel::str::CStr; - /// # use kernel::str::CString; - /// let penguin = c_str!("🐧"); - /// let s = CString::try_from_fmt(fmt!("{:?}", penguin)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "\"so \\\"cool\\\"\"\0".as_bytes()); - /// ``` - 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{:02x}", c)?, - } - } - f.write_str("\"") - } -} - -impl AsRef<BStr> for CStr { - #[inline] - fn as_ref(&self) -> &BStr { - BStr::from_bytes(self.as_bytes()) - } -} - -impl Deref for CStr { - type Target = BStr; - - #[inline] - fn deref(&self) -> &Self::Target { - self.as_ref() - } -} - -impl Index<ops::RangeFrom<usize>> for CStr { - type Output = CStr; - - #[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..]) } - } -} - -impl Index<ops::RangeFull> for CStr { - type Output = 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<usize> {} - impl CStrIndex for ops::RangeInclusive<usize> {} - impl CStrIndex for ops::RangeToInclusive<usize> {} -} - -impl<Idx> Index<Idx> for CStr -where - Idx: private::CStrIndex, - BStr: Index<Idx>, -{ - type Output = <BStr as Index<Idx>>::Output; - - #[inline] - fn index(&self, index: Idx) -> &Self::Output { - &self.as_ref()[index] - } -} - -/// Creates a new [`CStr`] from a string literal. -/// -/// The string literal should not contain any `NUL` bytes. -/// -/// # Examples -/// -/// ``` -/// # use kernel::c_str; -/// # use kernel::str::CStr; -/// const MY_CSTR: &CStr = c_str!("My awesome CStr!"); -/// ``` -#[macro_export] -macro_rules! c_str { - ($str:expr) => {{ - const S: &str = concat!($str, "\0"); - const C: &$crate::str::CStr = match $crate::str::CStr::from_bytes_with_nul(S.as_bytes()) { - Ok(v) => v, - Err(_) => panic!("string contains interior NUL"), - }; - C - }}; -} - #[cfg(test)] mod tests { use super::*; use alloc::format; - const ALL_ASCII_CHARS: &'static str = - "\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\x09\\x0a\\x0b\\x0c\\x0d\\x0e\\x0f\ - \\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f \ - !\"#$%&'()*+,-./0123456789:;<=>?@\ - ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\\x7f\ - \\x80\\x81\\x82\\x83\\x84\\x85\\x86\\x87\\x88\\x89\\x8a\\x8b\\x8c\\x8d\\x8e\\x8f\ - \\x90\\x91\\x92\\x93\\x94\\x95\\x96\\x97\\x98\\x99\\x9a\\x9b\\x9c\\x9d\\x9e\\x9f\ - \\xa0\\xa1\\xa2\\xa3\\xa4\\xa5\\xa6\\xa7\\xa8\\xa9\\xaa\\xab\\xac\\xad\\xae\\xaf\ - \\xb0\\xb1\\xb2\\xb3\\xb4\\xb5\\xb6\\xb7\\xb8\\xb9\\xba\\xbb\\xbc\\xbd\\xbe\\xbf\ - \\xc0\\xc1\\xc2\\xc3\\xc4\\xc5\\xc6\\xc7\\xc8\\xc9\\xca\\xcb\\xcc\\xcd\\xce\\xcf\ - \\xd0\\xd1\\xd2\\xd3\\xd4\\xd5\\xd6\\xd7\\xd8\\xd9\\xda\\xdb\\xdc\\xdd\\xde\\xdf\ - \\xe0\\xe1\\xe2\\xe3\\xe4\\xe5\\xe6\\xe7\\xe8\\xe9\\xea\\xeb\\xec\\xed\\xee\\xef\ - \\xf0\\xf1\\xf2\\xf3\\xf4\\xf5\\xf6\\xf7\\xf8\\xf9\\xfa\\xfb\\xfc\\xfd\\xfe\\xff"; - - #[test] - fn test_cstr_to_str() { - let good_bytes = b"\xf0\x9f\xa6\x80\0"; - let checked_cstr = CStr::from_bytes_with_nul(good_bytes).unwrap(); - let checked_str = checked_cstr.to_str().unwrap(); - assert_eq!(checked_str, "🦀"); - } - - #[test] - #[should_panic] - fn test_cstr_to_str_panic() { - let bad_bytes = b"\xc3\x28\0"; - let checked_cstr = CStr::from_bytes_with_nul(bad_bytes).unwrap(); - checked_cstr.to_str().unwrap(); - } - - #[test] - fn test_cstr_as_str_unchecked() { - let good_bytes = b"\xf0\x9f\x90\xA7\0"; - let checked_cstr = CStr::from_bytes_with_nul(good_bytes).unwrap(); - let unchecked_str = unsafe { checked_cstr.as_str_unchecked() }; - assert_eq!(unchecked_str, "🐧"); - } - - #[test] - fn test_cstr_display() { - let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap(); - assert_eq!(format!("{}", hello_world), "hello, world!"); - let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap(); - assert_eq!(format!("{}", non_printables), "\\x01\\x09\\x0a"); - let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap(); - assert_eq!(format!("{}", non_ascii), "d\\xe9j\\xe0 vu"); - let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap(); - assert_eq!(format!("{}", good_bytes), "\\xf0\\x9f\\xa6\\x80"); - } - - #[test] - fn test_cstr_display_all_bytes() { - let mut bytes: [u8; 256] = [0; 256]; - // fill `bytes` with [1..=255] + [0] - for i in u8::MIN..=u8::MAX { - bytes[i as usize] = i.wrapping_add(1); - } - let cstr = CStr::from_bytes_with_nul(&bytes).unwrap(); - assert_eq!(format!("{}", cstr), ALL_ASCII_CHARS); - } - - #[test] - fn test_cstr_debug() { - let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap(); - assert_eq!(format!("{:?}", hello_world), "\"hello, world!\""); - let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap(); - assert_eq!(format!("{:?}", non_printables), "\"\\x01\\x09\\x0a\""); - let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap(); - assert_eq!(format!("{:?}", non_ascii), "\"d\\xe9j\\xe0 vu\""); - let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap(); - assert_eq!(format!("{:?}", good_bytes), "\"\\xf0\\x9f\\xa6\\x80\""); - } - #[test] fn test_bstr_display() { let hello_world = BStr::from_bytes(b"hello, world!"); @@ -779,11 +314,11 @@ fn write_str(&mut self, s: &str) -> fmt::Result { /// use kernel::{str::CString, fmt}; /// /// let s = CString::try_from_fmt(fmt!("{}{}{}", "abc", 10, 20)).unwrap(); -/// 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)).unwrap(); -/// 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)); @@ -840,9 +375,10 @@ fn deref(&self) -> &Self::Target { impl DerefMut for CString { fn deref_mut(&mut self) -> &mut Self::Target { - // SAFETY: A `CString` is always NUL-terminated and contains no other - // NUL bytes. - unsafe { CStr::from_bytes_with_nul_unchecked_mut(self.buf.as_mut_slice()) } + debug_assert!(!self.buf.is_empty() && self.buf[self.buf.len() - 1] == 0); + // SAFETY: Casting to CStr is safe because its internal representation + // is a [u8] too. + unsafe { &mut *(self.buf.as_mut_slice() as *mut [u8] as *mut CStr) } } } @@ -852,7 +388,7 @@ impl<'a> TryFrom<&'a CStr> for CString { fn try_from(cstr: &'a CStr) -> Result<CString, AllocError> { let mut buf = Vec::new(); - <Vec<_> as VecExt<_>>::extend_from_slice(&mut buf, cstr.as_bytes_with_nul(), GFP_KERNEL) + <Vec<_> as VecExt<_>>::extend_from_slice(&mut buf, cstr.to_bytes_with_nul(), GFP_KERNEL) .map_err(|_| AllocError)?; // INVARIANT: The `CStr` and `CString` types have the same invariants for diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs index 0ab20975a3b5..f909e7bb2070 100644 --- a/rust/kernel/sync.rs +++ b/rust/kernel/sync.rs @@ -59,9 +59,18 @@ macro_rules! static_lock_class { #[macro_export] macro_rules! optional_name { () => { - $crate::c_str!(::core::concat!(::core::file!(), ":", ::core::line!())) + unsafe { + CStr::from_bytes_with_nul_unchecked( + ::core::concat!( + ::core::file!(), + ":", + ::core::line!(), + "\0" + ).as_bytes() + ) + } }; ($name:literal) => { - $crate::c_str!($name) + $name }; } diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs index 2b306afbe56d..16d1a1cb8d00 100644 --- a/rust/kernel/sync/condvar.rs +++ b/rust/kernel/sync/condvar.rs @@ -9,12 +9,11 @@ use crate::{ init::PinInit, pin_init, - str::CStr, task::{MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE, TASK_NORMAL, TASK_UNINTERRUPTIBLE}, time::Jiffies, types::Opaque, }; -use core::ffi::{c_int, c_long}; +use core::ffi::{c_int, c_long, CStr}; use core::marker::PhantomPinned; use core::ptr; use macros::pin_data; @@ -108,7 +107,7 @@ pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self // SAFETY: `slot` is valid while the closure is called and both `name` and `key` have // static lifetimes so they live indefinitely. wait_queue_head <- Opaque::ffi_init(|slot| unsafe { - bindings::__init_waitqueue_head(slot, name.as_char_ptr(), key.as_ptr()) + bindings::__init_waitqueue_head(slot, name.as_ptr(), key.as_ptr()) }), }) } diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs index f6c34ca4d819..318ecb5a5916 100644 --- a/rust/kernel/sync/lock.rs +++ b/rust/kernel/sync/lock.rs @@ -6,8 +6,8 @@ //! spinlocks, raw spinlocks) to be provided with minimal effort. use super::LockClassKey; -use crate::{init::PinInit, pin_init, str::CStr, types::Opaque, types::ScopeGuard}; -use core::{cell::UnsafeCell, marker::PhantomData, marker::PhantomPinned}; +use crate::{init::PinInit, pin_init, types::Opaque, types::ScopeGuard}; +use core::{cell::UnsafeCell, ffi::CStr, marker::PhantomData, marker::PhantomPinned}; use macros::pin_data; pub mod mutex; @@ -113,7 +113,7 @@ pub fn new(t: T, name: &'static CStr, key: &'static LockClassKey) -> impl PinIni // SAFETY: `slot` is valid while the closure is called and both `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, name.as_ptr(), key.as_ptr()) }), }) } diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs index 553a5cba2adc..b1f5c4b5840c 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) //! } //! } @@ -97,8 +97,8 @@ //! 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) //! } //! } @@ -212,7 +212,7 @@ 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), }); @@ -380,7 +380,7 @@ pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self slot, Some(T::Pointer::run), false, - name.as_char_ptr(), + name.as_ptr(), key.as_ptr(), ) } diff --git a/scripts/rustdoc_test_gen.rs b/scripts/rustdoc_test_gen.rs index 5ebd42ae4a3f..339991ee6885 100644 --- a/scripts/rustdoc_test_gen.rs +++ b/scripts/rustdoc_test_gen.rs @@ -172,7 +172,7 @@ pub extern "C" fn {kunit_name}(__kunit_test: *mut kernel::bindings::kunit) {{ #[allow(unused)] macro_rules! assert {{ ($cond:expr $(,)?) => {{{{ - kernel::kunit_assert!("{kunit_name}", "{real_path}", __DOCTEST_ANCHOR - {line}, $cond); + kernel::kunit_assert!(c"{kunit_name}", c"{real_path}", __DOCTEST_ANCHOR - {line}, $cond); }}}} }} @@ -180,7 +180,7 @@ macro_rules! assert {{ #[allow(unused)] macro_rules! assert_eq {{ ($left:expr, $right:expr $(,)?) => {{{{ - kernel::kunit_assert_eq!("{kunit_name}", "{real_path}", __DOCTEST_ANCHOR - {line}, $left, $right); + kernel::kunit_assert_eq!(c"{kunit_name}", c"{real_path}", __DOCTEST_ANCHOR - {line}, $left, $right); }}}} }} -- 2.45.2

9 months, 2 weeks

3
8
0 0

[PATCH v3] rust: str: Use `core::CStr`, remove the custom `CStr` implementation

by Michal Rostecki

`CStr` became a part of `core` library in Rust 1.75. This change replaces the custom `CStr` implementation with the one from `core`. `core::CStr` behaves generally the same as the removed implementation, with the following differences: - It does not implement `Display` (but implements `Debug`). Therefore, by switching to `core::CStr`, we lose the `Display` implementation. - Lack of `Display` implementation impacted only rust/kernel/kunit.rs. In this change, we use `Debug` format there. The only difference between the removed `Display` output and `Debug` output are quotation marks present in the latter (`foo` vs `"foo"`). - It does not provide `from_bytes_with_nul_unchecked_mut` method. - It was used only in `DerefMut` implementation for `CString`. This change removes that implementation. - Otherwise, having such a method is not desirable. The rule in Rust std is that `str` is used only as an immutable reference (`&str`), while mutating strings is done with the owned `String` type. Similarly, we can introduce the rule that `CStr` should be used only as an immutable reference (`&CStr`), while mutating is done only with the owned `CString` type. - It has `as_ptr()` method instead of `as_char_ptr()`, which also returns `*const c_char`. Signed-off-by: Michal Rostecki <vadorovsky(a)gmail.com> --- v1 -> 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`. v2 -> v3: - Fix the commit message. - Remove redundant braces in `use`, when only one item is imported. rust/kernel/error.rs | 7 +- rust/kernel/kunit.rs | 12 +- rust/kernel/net/phy.rs | 2 +- rust/kernel/prelude.rs | 4 +- rust/kernel/str.rs | 486 ++---------------------------------- rust/kernel/sync/condvar.rs | 5 +- rust/kernel/sync/lock.rs | 6 +- rust/kernel/workqueue.rs | 2 +- scripts/rustdoc_test_gen.rs | 4 +- 9 files changed, 44 insertions(+), 484 deletions(-) diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs index 55280ae9fe40..18808b29604d 100644 --- a/rust/kernel/error.rs +++ b/rust/kernel/error.rs @@ -4,10 +4,11 @@ //! //! C header: [`include/uapi/asm-generic/errno-base.h`](srctree/include/uapi/asm-generic/errno-base.h) -use crate::{alloc::AllocError, str::CStr}; +use crate::alloc::AllocError; use alloc::alloc::LayoutError; +use core::ffi::CStr; use core::fmt; use core::num::TryFromIntError; use core::str::Utf8Error; @@ -142,7 +143,7 @@ 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 { CStr::from_ptr(ptr) }) } } @@ -164,7 +165,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { None => f.debug_tuple("Error").field(&-self.0).finish(), // SAFETY: These strings are ASCII-only. Some(name) => f - .debug_tuple(unsafe { core::str::from_utf8_unchecked(name) }) + .debug_tuple(unsafe { core::str::from_utf8_unchecked(name.to_bytes()) }) .finish(), } } diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 0ba77276ae7e..c08f9dddaa6f 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -56,9 +56,9 @@ macro_rules! kunit_assert { break 'out; } - static FILE: &'static $crate::str::CStr = $crate::c_str!($file); + static FILE: &'static core::ffi::CStr = $file; static LINE: i32 = core::line!() as i32 - $diff; - static CONDITION: &'static $crate::str::CStr = $crate::c_str!(stringify!($condition)); + static CONDITION: &'static core::ffi::CStr = $crate::c_str!(stringify!($condition)); // SAFETY: FFI call without safety requirements. let kunit_test = unsafe { $crate::bindings::kunit_get_current_test() }; @@ -71,11 +71,11 @@ macro_rules! kunit_assert { // // This mimics KUnit's failed assertion format. $crate::kunit::err(format_args!( - " # {}: ASSERTION FAILED at {FILE}:{LINE}\n", + " # {:?}: ASSERTION FAILED at {FILE:?}:{LINE:?}\n", $name )); $crate::kunit::err(format_args!( - " Expected {CONDITION} to be true, but is false\n" + " Expected {CONDITION:?} to be true, but is false\n" )); $crate::kunit::err(format_args!( " Failure not reported to KUnit since this is a non-KUnit task\n" @@ -98,12 +98,12 @@ unsafe impl Sync for Location {} unsafe impl Sync for UnaryAssert {} static LOCATION: Location = Location($crate::bindings::kunit_loc { - file: FILE.as_char_ptr(), + file: FILE.as_ptr(), line: LINE, }); static ASSERTION: UnaryAssert = UnaryAssert($crate::bindings::kunit_unary_assert { assert: $crate::bindings::kunit_assert {}, - condition: CONDITION.as_char_ptr(), + condition: CONDITION.as_ptr(), expected_true: true, }); diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs index fd40b703d224..19f45922ec42 100644 --- a/rust/kernel/net/phy.rs +++ b/rust/kernel/net/phy.rs @@ -502,7 +502,7 @@ 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: T::NAME.as_ptr().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/prelude.rs b/rust/kernel/prelude.rs index b37a0b3180fb..b0969ca78f10 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -12,7 +12,7 @@ //! ``` #[doc(no_inline)] -pub use core::pin::Pin; +pub use core::{ffi::CStr, pin::Pin}; pub use crate::alloc::{box_ext::BoxExt, flags::*, vec_ext::VecExt}; @@ -35,7 +35,7 @@ pub use super::error::{code::*, Error, Result}; -pub use super::{str::CStr, ThisModule}; +pub use super::ThisModule; pub use super::init::{InPlaceInit, Init, PinInit}; diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index bb8d4f41475b..e491a9803187 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -4,8 +4,9 @@ use crate::alloc::{flags::*, vec_ext::VecExt, AllocError}; use alloc::vec::Vec; +use core::ffi::CStr; use core::fmt::{self, Write}; -use core::ops::{self, Deref, DerefMut, Index}; +use core::ops::Deref; use crate::error::{code::*, Error}; @@ -41,11 +42,11 @@ impl fmt::Display for BStr { /// # use kernel::{fmt, b_str, str::{BStr, CString}}; /// let ascii = b_str!("Hello, BStr!"); /// let s = CString::try_from_fmt(fmt!("{}", ascii)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes()); + /// assert_eq!(s.to_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes()); /// ``` fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { for &b in &self.0 { @@ -72,11 +73,11 @@ impl fmt::Debug for BStr { /// // Embedded double quotes are escaped. /// let ascii = b_str!("Hello, \"BStr\"!"); /// let s = CString::try_from_fmt(fmt!("{:?}", ascii)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes(), "\"\\xf0\\x9f\\x98\\xba\"".as_bytes()); + /// assert_eq!(s.to_bytes(), "\"\\xf0\\x9f\\x98\\xba\"".as_bytes()); /// ``` fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.write_char('"')?; @@ -128,392 +129,32 @@ 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, - - /// Supplied bytes are not terminated by `NUL`. - NotNulTerminated, -} - -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 { - // 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. - if self.0.is_empty() { - 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 - } - - /// 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 `ptr` - /// must not be mutated. - #[inline] - pub unsafe fn from_char_ptr<'a>(ptr: *const core::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 as _) }; - // 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) } - } - - /// 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 precondition. - 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 core::ffi::c_char { - self.0.as_ptr() as _ - } - - /// 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").unwrap(); - /// assert_eq!(cstr.to_str(), Ok("foo")); - /// ``` - #[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!("ツ"); - /// // SAFETY: String literals are guaranteed to be valid UTF-8 - /// // by the Rust compiler. - /// assert_eq!(unsafe { bar.as_str_unchecked() }, "ツ"); - /// ``` - #[inline] - pub unsafe fn as_str_unchecked(&self) -> &str { - 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, AllocError> { - 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 one, 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 one, 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<CString, AllocError> { - let mut s = 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<CString, AllocError> { - let mut s = self.to_cstring()?; - - s.make_ascii_uppercase(); - - Ok(s) - } -} - -impl fmt::Display for CStr { - /// Formats printable ASCII characters, escaping the rest. - /// - /// ``` - /// # use kernel::c_str; - /// # use kernel::fmt; - /// # use kernel::str::CStr; - /// # use kernel::str::CString; - /// let penguin = c_str!("🐧"); - /// let s = CString::try_from_fmt(fmt!("{}", penguin)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "\\xf0\\x9f\\x90\\xa7\0".as_bytes()); - /// - /// let ascii = c_str!("so \"cool\""); - /// let s = CString::try_from_fmt(fmt!("{}", ascii)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "so \"cool\"\0".as_bytes()); - /// ``` - 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)?; - } - } - Ok(()) - } -} - -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::fmt; - /// # use kernel::str::CStr; - /// # use kernel::str::CString; - /// let penguin = c_str!("🐧"); - /// let s = CString::try_from_fmt(fmt!("{:?}", penguin)).unwrap(); - /// 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)).unwrap(); - /// assert_eq!(s.as_bytes_with_nul(), "\"so \\\"cool\\\"\"\0".as_bytes()); - /// ``` - 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{:02x}", c)?, - } - } - f.write_str("\"") - } -} - -impl AsRef<BStr> for CStr { - #[inline] - fn as_ref(&self) -> &BStr { - BStr::from_bytes(self.as_bytes()) - } -} - -impl Deref for CStr { - type Target = BStr; - - #[inline] - fn deref(&self) -> &Self::Target { - self.as_ref() - } -} - -impl Index<ops::RangeFrom<usize>> for CStr { - type Output = CStr; - - #[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..]) } - } -} - -impl Index<ops::RangeFull> for CStr { - type Output = 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<usize> {} - impl CStrIndex for ops::RangeInclusive<usize> {} - impl CStrIndex for ops::RangeToInclusive<usize> {} -} - -impl<Idx> Index<Idx> for CStr -where - Idx: private::CStrIndex, - BStr: Index<Idx>, -{ - type Output = <BStr as Index<Idx>>::Output; - - #[inline] - fn index(&self, index: Idx) -> &Self::Output { - &self.as_ref()[index] - } -} - /// Creates a new [`CStr`] from a string literal. /// -/// The string literal should not contain any `NUL` bytes. +/// Usually, defining C-string literals directly should be preffered, but this +/// macro is helpful in situations when C-string literals are hard or +/// impossible to use, for example: +/// +/// - 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. +/// +/// The string should not contain any `NUL` bytes. /// /// # Examples /// /// ``` +/// # use core::ffi::CStr; /// # use kernel::c_str; -/// # use kernel::str::CStr; -/// const MY_CSTR: &CStr = c_str!("My awesome CStr!"); +/// const MY_CSTR: &CStr = c_str!(stringify!(5)); /// ``` #[macro_export] macro_rules! c_str { ($str:expr) => {{ const S: &str = concat!($str, "\0"); - const C: &$crate::str::CStr = match $crate::str::CStr::from_bytes_with_nul(S.as_bytes()) { + const C: &core::ffi::CStr = match core::ffi::CStr::from_bytes_with_nul(S.as_bytes()) { Ok(v) => v, Err(_) => panic!("string contains interior NUL"), }; @@ -526,79 +167,6 @@ mod tests { use super::*; use alloc::format; - const ALL_ASCII_CHARS: &'static str = - "\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\x09\\x0a\\x0b\\x0c\\x0d\\x0e\\x0f\ - \\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f \ - !\"#$%&'()*+,-./0123456789:;<=>?@\ - ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\\x7f\ - \\x80\\x81\\x82\\x83\\x84\\x85\\x86\\x87\\x88\\x89\\x8a\\x8b\\x8c\\x8d\\x8e\\x8f\ - \\x90\\x91\\x92\\x93\\x94\\x95\\x96\\x97\\x98\\x99\\x9a\\x9b\\x9c\\x9d\\x9e\\x9f\ - \\xa0\\xa1\\xa2\\xa3\\xa4\\xa5\\xa6\\xa7\\xa8\\xa9\\xaa\\xab\\xac\\xad\\xae\\xaf\ - \\xb0\\xb1\\xb2\\xb3\\xb4\\xb5\\xb6\\xb7\\xb8\\xb9\\xba\\xbb\\xbc\\xbd\\xbe\\xbf\ - \\xc0\\xc1\\xc2\\xc3\\xc4\\xc5\\xc6\\xc7\\xc8\\xc9\\xca\\xcb\\xcc\\xcd\\xce\\xcf\ - \\xd0\\xd1\\xd2\\xd3\\xd4\\xd5\\xd6\\xd7\\xd8\\xd9\\xda\\xdb\\xdc\\xdd\\xde\\xdf\ - \\xe0\\xe1\\xe2\\xe3\\xe4\\xe5\\xe6\\xe7\\xe8\\xe9\\xea\\xeb\\xec\\xed\\xee\\xef\ - \\xf0\\xf1\\xf2\\xf3\\xf4\\xf5\\xf6\\xf7\\xf8\\xf9\\xfa\\xfb\\xfc\\xfd\\xfe\\xff"; - - #[test] - fn test_cstr_to_str() { - let good_bytes = b"\xf0\x9f\xa6\x80\0"; - let checked_cstr = CStr::from_bytes_with_nul(good_bytes).unwrap(); - let checked_str = checked_cstr.to_str().unwrap(); - assert_eq!(checked_str, "🦀"); - } - - #[test] - #[should_panic] - fn test_cstr_to_str_panic() { - let bad_bytes = b"\xc3\x28\0"; - let checked_cstr = CStr::from_bytes_with_nul(bad_bytes).unwrap(); - checked_cstr.to_str().unwrap(); - } - - #[test] - fn test_cstr_as_str_unchecked() { - let good_bytes = b"\xf0\x9f\x90\xA7\0"; - let checked_cstr = CStr::from_bytes_with_nul(good_bytes).unwrap(); - let unchecked_str = unsafe { checked_cstr.as_str_unchecked() }; - assert_eq!(unchecked_str, "🐧"); - } - - #[test] - fn test_cstr_display() { - let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap(); - assert_eq!(format!("{}", hello_world), "hello, world!"); - let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap(); - assert_eq!(format!("{}", non_printables), "\\x01\\x09\\x0a"); - let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap(); - assert_eq!(format!("{}", non_ascii), "d\\xe9j\\xe0 vu"); - let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap(); - assert_eq!(format!("{}", good_bytes), "\\xf0\\x9f\\xa6\\x80"); - } - - #[test] - fn test_cstr_display_all_bytes() { - let mut bytes: [u8; 256] = [0; 256]; - // fill `bytes` with [1..=255] + [0] - for i in u8::MIN..=u8::MAX { - bytes[i as usize] = i.wrapping_add(1); - } - let cstr = CStr::from_bytes_with_nul(&bytes).unwrap(); - assert_eq!(format!("{}", cstr), ALL_ASCII_CHARS); - } - - #[test] - fn test_cstr_debug() { - let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap(); - assert_eq!(format!("{:?}", hello_world), "\"hello, world!\""); - let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap(); - assert_eq!(format!("{:?}", non_printables), "\"\\x01\\x09\\x0a\""); - let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap(); - assert_eq!(format!("{:?}", non_ascii), "\"d\\xe9j\\xe0 vu\""); - let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap(); - assert_eq!(format!("{:?}", good_bytes), "\"\\xf0\\x9f\\xa6\\x80\""); - } - #[test] fn test_bstr_display() { let hello_world = BStr::from_bytes(b"hello, world!"); @@ -779,11 +347,11 @@ fn write_str(&mut self, s: &str) -> fmt::Result { /// use kernel::{str::CString, fmt}; /// /// let s = CString::try_from_fmt(fmt!("{}{}{}", "abc", 10, 20)).unwrap(); -/// 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)).unwrap(); -/// 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)); @@ -838,21 +406,13 @@ fn deref(&self) -> &Self::Target { } } -impl DerefMut for CString { - fn deref_mut(&mut self) -> &mut Self::Target { - // SAFETY: A `CString` is always NUL-terminated and contains no other - // NUL bytes. - unsafe { CStr::from_bytes_with_nul_unchecked_mut(self.buf.as_mut_slice()) } - } -} - impl<'a> TryFrom<&'a CStr> for CString { type Error = AllocError; fn try_from(cstr: &'a CStr) -> Result<CString, AllocError> { let mut buf = Vec::new(); - <Vec<_> as VecExt<_>>::extend_from_slice(&mut buf, cstr.as_bytes_with_nul(), GFP_KERNEL) + <Vec<_> as VecExt<_>>::extend_from_slice(&mut buf, cstr.to_bytes_with_nul(), GFP_KERNEL) .map_err(|_| AllocError)?; // INVARIANT: The `CStr` and `CString` types have the same invariants for diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs index 2b306afbe56d..16d1a1cb8d00 100644 --- a/rust/kernel/sync/condvar.rs +++ b/rust/kernel/sync/condvar.rs @@ -9,12 +9,11 @@ use crate::{ init::PinInit, pin_init, - str::CStr, task::{MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE, TASK_NORMAL, TASK_UNINTERRUPTIBLE}, time::Jiffies, types::Opaque, }; -use core::ffi::{c_int, c_long}; +use core::ffi::{c_int, c_long, CStr}; use core::marker::PhantomPinned; use core::ptr; use macros::pin_data; @@ -108,7 +107,7 @@ pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self // SAFETY: `slot` is valid while the closure is called and both `name` and `key` have // static lifetimes so they live indefinitely. wait_queue_head <- Opaque::ffi_init(|slot| unsafe { - bindings::__init_waitqueue_head(slot, name.as_char_ptr(), key.as_ptr()) + bindings::__init_waitqueue_head(slot, name.as_ptr(), key.as_ptr()) }), }) } diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs index f6c34ca4d819..318ecb5a5916 100644 --- a/rust/kernel/sync/lock.rs +++ b/rust/kernel/sync/lock.rs @@ -6,8 +6,8 @@ //! spinlocks, raw spinlocks) to be provided with minimal effort. use super::LockClassKey; -use crate::{init::PinInit, pin_init, str::CStr, types::Opaque, types::ScopeGuard}; -use core::{cell::UnsafeCell, marker::PhantomData, marker::PhantomPinned}; +use crate::{init::PinInit, pin_init, types::Opaque, types::ScopeGuard}; +use core::{cell::UnsafeCell, ffi::CStr, marker::PhantomData, marker::PhantomPinned}; use macros::pin_data; pub mod mutex; @@ -113,7 +113,7 @@ pub fn new(t: T, name: &'static CStr, key: &'static LockClassKey) -> impl PinIni // SAFETY: `slot` is valid while the closure is called and both `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, name.as_ptr(), key.as_ptr()) }), }) } diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs index 553a5cba2adc..a6418873e82e 100644 --- a/rust/kernel/workqueue.rs +++ b/rust/kernel/workqueue.rs @@ -380,7 +380,7 @@ pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self slot, Some(T::Pointer::run), false, - name.as_char_ptr(), + name.as_ptr(), key.as_ptr(), ) } diff --git a/scripts/rustdoc_test_gen.rs b/scripts/rustdoc_test_gen.rs index 5ebd42ae4a3f..339991ee6885 100644 --- a/scripts/rustdoc_test_gen.rs +++ b/scripts/rustdoc_test_gen.rs @@ -172,7 +172,7 @@ pub extern "C" fn {kunit_name}(__kunit_test: *mut kernel::bindings::kunit) {{ #[allow(unused)] macro_rules! assert {{ ($cond:expr $(,)?) => {{{{ - kernel::kunit_assert!("{kunit_name}", "{real_path}", __DOCTEST_ANCHOR - {line}, $cond); + kernel::kunit_assert!(c"{kunit_name}", c"{real_path}", __DOCTEST_ANCHOR - {line}, $cond); }}}} }} @@ -180,7 +180,7 @@ macro_rules! assert {{ #[allow(unused)] macro_rules! assert_eq {{ ($left:expr, $right:expr $(,)?) => {{{{ - kernel::kunit_assert_eq!("{kunit_name}", "{real_path}", __DOCTEST_ANCHOR - {line}, $left, $right); + kernel::kunit_assert_eq!(c"{kunit_name}", c"{real_path}", __DOCTEST_ANCHOR - {line}, $left, $right); }}}} }} -- 2.45.2

9 months, 2 weeks

2
2
0 0

[PATCH] selftests/mm: Skip test for non-LPA2 and non-LVA systems

by Dev Jain

Post my improvement of the test: https://lore.kernel.org/all/20240522070435.773918-3-dev.jain@arm.com/ The test begins to fail on 4k and 16k pages, on non-LPA2 systems. To reduce noise in the CI systems, let us skip the test when higher address space is not implemented. Signed-off-by: Dev Jain <dev.jain(a)arm.com> --- The patch applies on linux-next. tools/testing/selftests/mm/va_high_addr_switch.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/va_high_addr_switch.c b/tools/testing/selftests/mm/va_high_addr_switch.c index fa7eabfaf841..c6040e1d6e53 100644 --- a/tools/testing/selftests/mm/va_high_addr_switch.c +++ b/tools/testing/selftests/mm/va_high_addr_switch.c @@ -293,6 +293,18 @@ static int run_test(struct testcase *test, int count) return ret; } +/* Check if userspace VA > 48 bits */ +static int high_address_present(void) +{ + void *ptr = mmap((void *)(1UL << 50), 1, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); + if (ptr == MAP_FAILED) + return 0; + + munmap(ptr, 1); + return 1; +} + static int supported_arch(void) { #if defined(__powerpc64__) @@ -300,7 +312,7 @@ static int supported_arch(void) #elif defined(__x86_64__) return 1; #elif defined(__aarch64__) - return 1; + return high_address_present(); #else return 0; #endif -- 2.34.1

9 months, 2 weeks

2
3
0 0

[GIT PULL] Kselftest update for Linux 6.11-rc1

by Shuah Khan

Hi Linus, Please pull the kselftest update for Linux 6.11-rc1. This kselftest next update for Linux 6.11-rc1 consists of: -- changes to resctrl test to cleanup resctrl_val() and generalize it by removing test name specific handling from the function. -- several clang build failure fixes to framework and tests -- adds tests to verify IFS (In Field Scan) driver functionality -- cleanups to remove unused variables and document changes Testing notes: Passed on linux-next and linux-kselftest next branch: - Build - make kselftest-all - Run - make kselftest diff is attached. thanks, -- Shuah ---------------------------------------------------------------- The following changes since commit 256abd8e550ce977b728be79a74e1729438b4948: Linux 6.10-rc7 (2024-07-07 14:23:46 -0700) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest tags/linux_kselftest-next-6.11-rc1 for you to fetch changes up to bb408dae9e73803eab8a648115d6c4a1bca4dba3: selftests: ifs: verify IFS ARRAY BIST functionality (2024-07-11 11:31:11 -0600) ---------------------------------------------------------------- linux_kselftest-next-6.11-rc1 This kselftest next update for Linux 6.11-rc1 consists of: -- changes to resctrl test to cleanup resctrl_val() and generalize it by removing test name specific handling from the function. -- several clang build failure fixes to framework and tests -- adds tests to verify IFS (In Field Scan) driver functionality -- cleanups to remove unused variables and document changes ---------------------------------------------------------------- Ilpo Järvinen (16): selftests/resctrl: Fix closing IMC fds on error and open-code R+W instead of loops selftests/resctrl: Calculate resctrl FS derived mem bw over sleep(1) only selftests/resctrl: Make "bandwidth" consistent in comments & prints selftests/resctrl: Consolidate get_domain_id() into resctrl_val() selftests/resctrl: Use correct type for pids selftests/resctrl: Cleanup bm_pid and ppid usage & limit scope selftests/resctrl: Rename measure_vals() to measure_mem_bw_vals() & document selftests/resctrl: Simplify mem bandwidth file code for MBA & MBM tests selftests/resctrl: Add ->measure() callback to resctrl_val_param selftests/resctrl: Add ->init() callback into resctrl_val_param selftests/resctrl: Simplify bandwidth report type handling selftests/resctrl: Make some strings passed to resctrlfs functions const selftests/resctrl: Convert ctrlgrp & mongrp to pointers selftests/resctrl: Remove mongrp from MBA test selftests/resctrl: Remove mongrp from CMT test selftests/resctrl: Remove test name comparing from write_bm_pid_to_resctrl() John Hubbard (8): selftests/lib.mk: silence some clang warnings that gcc already ignores selftests/timers: remove unused irqcount variable selftests/x86: fix Makefile dependencies to work with clang selftests/x86: build fsgsbase_restore.c with clang selftests/x86: build sysret_rip.c with clang selftests/x86: avoid -no-pie warnings from clang during compilation selftests/x86: remove (or use) unused variables and functions selftests/x86: fix printk warnings reported by clang Muhammad Usama Anjum (2): selftests: Add information about TAP conformance in tests selftests: x86: test_FISTTP: use fisttps instead of ambiguous fisttp Pengfei Xu (4): selftests: ifs: verify test interfaces are created by the driver selftests: ifs: verify test image loading functionality selftests: ifs: verify IFS scan test functionality selftests: ifs: verify IFS ARRAY BIST functionality Zhu Jun (2): selftests/breakpoints:Remove unused variable selftests/dma:remove unused variable aigourensheng (1): selftests/sched: fix code format issues Documentation/dev-tools/kselftest.rst | 7 + MAINTAINERS | 1 + tools/testing/selftests/Makefile | 1 + .../breakpoints/step_after_suspend_test.c | 1 - tools/testing/selftests/dma/dma_map_benchmark.c | 1 - .../drivers/platform/x86/intel/ifs/Makefile | 6 + .../drivers/platform/x86/intel/ifs/test_ifs.sh | 494 +++++++++++++++++++++ tools/testing/selftests/lib.mk | 8 + tools/testing/selftests/resctrl/cache.c | 10 +- tools/testing/selftests/resctrl/cat_test.c | 5 +- tools/testing/selftests/resctrl/cmt_test.c | 22 +- tools/testing/selftests/resctrl/mba_test.c | 26 +- tools/testing/selftests/resctrl/mbm_test.c | 26 +- tools/testing/selftests/resctrl/resctrl.h | 49 +- tools/testing/selftests/resctrl/resctrl_val.c | 371 +++++++--------- tools/testing/selftests/resctrl/resctrlfs.c | 67 ++- tools/testing/selftests/sched/cs_prctl_test.c | 10 +- tools/testing/selftests/timers/rtcpie.c | 3 +- tools/testing/selftests/x86/Makefile | 31 +- tools/testing/selftests/x86/amx.c | 16 - tools/testing/selftests/x86/clang_helpers_32.S | 11 + tools/testing/selftests/x86/clang_helpers_64.S | 28 ++ tools/testing/selftests/x86/fsgsbase.c | 6 - tools/testing/selftests/x86/fsgsbase_restore.c | 11 +- tools/testing/selftests/x86/sigreturn.c | 2 +- tools/testing/selftests/x86/syscall_arg_fault.c | 1 - tools/testing/selftests/x86/sysret_rip.c | 20 +- tools/testing/selftests/x86/test_FISTTP.c | 8 +- tools/testing/selftests/x86/test_vsyscall.c | 15 +- tools/testing/selftests/x86/vdso_restorer.c | 2 + 30 files changed, 901 insertions(+), 358 deletions(-) create mode 100644 tools/testing/selftests/drivers/platform/x86/intel/ifs/Makefile create mode 100755 tools/testing/selftests/drivers/platform/x86/intel/ifs/test_ifs.sh create mode 100644 tools/testing/selftests/x86/clang_helpers_32.S create mode 100644 tools/testing/selftests/x86/clang_helpers_64.S ----------------------------------------------------------------

9 months, 2 weeks

2
1
0 0

[GIT PULL] KUnit update for Linux 6.11-rc1

by Shuah Khan

Hi Linus, Please pull the following KUnit next update for Linux 6.11-rc1. This KUnit next update for Linux 6.11-rc1 consists of: -- adds vm_mmap() allocation resource manager -- converts usercopy kselftest to KUnit -- disables usercopy testing on !CONFIG_MMU -- adds MODULE_DESCRIPTION() to core, list, and usercopy tests -- adds tests for assertion formatting functions - assert.c -- introduces KUNIT_ASSERT_MEMEQ and KUNIT_ASSERT_MEMNEQ macros -- fixes KUNIT_ASSERT_STRNEQ comments to make it clear that it is an assertion -- renames KUNIT_ASSERT_FAILURE to KUNIT_FAIL_AND_ABORT Testing notes: Trees: linux-next and linux-kselftest kunit branch Passed: - make allmodconfig build - Default um ./tools/testing/kunit/kunit.py run ./tools/testing/kunit/kunit.py run --alltests - x86_64 ./tools/testing/kunit/kunit.py run --arch x86_64 ./tools/testing/kunit/kunit.py run --alltests --arch x86_64 diff is attached. thanks, -- Shuah ---------------------------------------------------------------- The following changes since commit 1613e604df0cd359cf2a7fbd9be7a0bcfacfabd0: Linux 6.10-rc1 (2024-05-26 15:20:12 -0700) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest tags/linux_kselftest-kunit-6.11-rc1 for you to fetch changes up to ebf51e460e488511d9ee60b07d00dac68883facf: kunit: Introduce KUNIT_ASSERT_MEMEQ and KUNIT_ASSERT_MEMNEQ macros (2024-07-12 10:12:11 -0600) ---------------------------------------------------------------- linux_kselftest-kunit-6.11-rc1 This KUnit next update for Linux 6.11-rc1 consists of: -- adds vm_mmap() allocation resource manager -- converts usercopy kselftest to KUnit -- disables usercopy testing on !CONFIG_MMU -- adds MODULE_DESCRIPTION() to core, list, and usercopy tests -- adds tests for assertion formatting functions - assert.c -- introduces KUNIT_ASSERT_MEMEQ and KUNIT_ASSERT_MEMNEQ macros -- fixes KUNIT_ASSERT_STRNEQ comments to make it clear that it is an assertion -- renames KUNIT_ASSERT_FAILURE to KUNIT_FAIL_AND_ABORT ---------------------------------------------------------------- Dr. David Alan Gilbert (1): list: test: remove unused struct 'klist_test_struct' Eric Chan (3): kunit: Fix the comment of KUNIT_ASSERT_STRNEQ as assertion kunit: Rename KUNIT_ASSERT_FAILURE to KUNIT_FAIL_AND_ABORT for readability kunit: Introduce KUNIT_ASSERT_MEMEQ and KUNIT_ASSERT_MEMNEQ macros Ivan Orlov (1): kunit: Cover 'assert.c' with tests Jeff Johnson (3): kunit: add missing MODULE_DESCRIPTION() macros to core modules list: test: add the missing MODULE_DESCRIPTION() macro kunit/usercopy: Add missing MODULE_DESCRIPTION() Kees Cook (4): kunit: test: Add vm_mmap() allocation resource manager usercopy: Convert test_user_copy to KUnit test kunit/usercopy: Disable testing on !CONFIG_MMU kunit: executor: Simplify string allocation handling MAINTAINERS | 1 + drivers/input/tests/input_test.c | 2 +- include/kunit/assert.h | 13 +- include/kunit/test.h | 88 ++++++++- kernel/fork.c | 3 + lib/Kconfig.debug | 21 +-- lib/Makefile | 2 +- lib/kunit/Makefile | 2 + lib/kunit/assert.c | 19 +- lib/kunit/assert_test.c | 388 +++++++++++++++++++++++++++++++++++++++ lib/kunit/executor.c | 12 +- lib/kunit/executor_test.c | 2 +- lib/kunit/kunit-example-test.c | 1 + lib/kunit/kunit-test.c | 1 + lib/kunit/test.c | 1 + lib/kunit/user_alloc.c | 117 ++++++++++++ lib/list-test.c | 7 +- lib/test_user_copy.c | 331 --------------------------------- lib/usercopy_kunit.c | 335 +++++++++++++++++++++++++++++++++ mm/util.c | 5 + 20 files changed, 978 insertions(+), 373 deletions(-) create mode 100644 lib/kunit/assert_test.c create mode 100644 lib/kunit/user_alloc.c delete mode 100644 lib/test_user_copy.c create mode 100644 lib/usercopy_kunit.c ----------------------------------------------------------------

9 months, 2 weeks

2
1
0 0

[PATCH v2 0/4] selftest: x86: conform tests to TAP format output

by Muhammad Usama Anjum

In this series, 4 tests are being conformed to TAP. Changes since v1: - Correct the description of patches with what improvements they are bringing and why they are required Muhammad Usama Anjum (4): selftests: x86: check_initial_reg_state: remove manual counting and increase maintainability selftests: x86: corrupt_xstate_header: remove manual counting and increase maintainability selftests: x86: fsgsbase_restore: remove manual counting and increase maintainability selftests: x86: entry_from_vm86: remove manual counting and increase maintainability .../selftests/x86/check_initial_reg_state.c | 24 ++-- .../selftests/x86/corrupt_xstate_header.c | 30 +++-- tools/testing/selftests/x86/entry_from_vm86.c | 109 ++++++++-------- .../testing/selftests/x86/fsgsbase_restore.c | 117 +++++++++--------- 4 files changed, 139 insertions(+), 141 deletions(-) -- 2.39.2

9 months, 2 weeks

2
5
0 0

[PATCH] kunit: add test duration attribute

by Rae Moar

Add a new test duration attribute to print the duration of a test run. Example: KTAP version 1 # Subtest: memcpy # module: memcpy_kunit 1..4 # memcpy_large_test.speed: slow # memcpy_large_test.duration: 1.134787584s ok 1 memcpy_large_test ... This attribute is printed for each test (excluding parameterized tests). Add documentation for this new attribute to KUnit docs. In order to save the timespec64 object, add the ability to save a memory allocated object to the attributes framework. Signed-off-by: Rae Moar <rmoar(a)google.com> --- .../dev-tools/kunit/running_tips.rst | 7 +++ include/kunit/attributes.h | 5 ++ include/kunit/test.h | 1 + lib/kunit/attributes.c | 61 ++++++++++++++++++- lib/kunit/test.c | 25 ++++++-- 5 files changed, 93 insertions(+), 6 deletions(-) diff --git a/Documentation/dev-tools/kunit/running_tips.rst b/Documentation/dev-tools/kunit/running_tips.rst index bd689db6fdd2..a528d92e5d8f 100644 --- a/Documentation/dev-tools/kunit/running_tips.rst +++ b/Documentation/dev-tools/kunit/running_tips.rst @@ -446,3 +446,10 @@ This attribute indicates whether the test uses init data or functions. This attribute is automatically saved as a boolean and tests can also be filtered using this attribute. + +``duration`` + +This attribute indicates the length of time in seconds of the test execution. + +This attribute is automatically saved as a timespec64 and printed for each test +(excluding parameterized tests). diff --git a/include/kunit/attributes.h b/include/kunit/attributes.h index bc76a0b786d2..89ca54ef380d 100644 --- a/include/kunit/attributes.h +++ b/include/kunit/attributes.h @@ -18,6 +18,11 @@ struct kunit_attr_filter { char *input; }; +/* + * Frees all of a test's allocated attributes. + */ +void kunit_free_attr(void *test_or_suite, bool is_test); + /* * Returns the name of the filter's attribute. */ diff --git a/include/kunit/test.h b/include/kunit/test.h index ec61cad6b71d..dca78d9bd3f6 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -82,6 +82,7 @@ enum kunit_speed { /* Holds attributes for each test case and suite */ struct kunit_attributes { enum kunit_speed speed; + struct timespec64 *duration; }; /** diff --git a/lib/kunit/attributes.c b/lib/kunit/attributes.c index 2cf04cc09372..b9fd6c686d65 100644 --- a/lib/kunit/attributes.c +++ b/lib/kunit/attributes.c @@ -40,6 +40,7 @@ struct kunit_attr { int (*filter)(void *attr, const char *input, int *err); void *attr_default; enum print_ops print; + bool to_free; }; /* String Lists for enum Attributes */ @@ -79,8 +80,29 @@ static const char *attr_string_to_string(void *attr, bool *to_free) return (char *) attr; } +static const char *attr_duration_to_string(void *attr, bool *to_free) +{ + int string_max_len = 20; + char *str = kmalloc(string_max_len, GFP_KERNEL); + struct timespec64 *val = (struct timespec64 *)attr; + + *to_free = true; + + /* Check if duration will overflow string */ + if (val->tv_sec >= 1000000) + str = "Greater than or equal to 1000000s"; + else + sprintf(str, "%lld.%09lds", val->tv_sec, val->tv_nsec); + return str; +} + /* Filter Methods */ +static int attr_default_filter(void *attr, const char *input, int *err) +{ + return false; +} + static const char op_list[] = "<>!="; /* @@ -246,8 +268,20 @@ static void *attr_is_init_get(void *test_or_suite, bool is_test) return ((void *) suite->is_init); } +static void *attr_duration_get(void *test_or_suite, bool is_test) +{ + struct kunit_case *test = is_test ? test_or_suite : NULL; + + if (test && !test->generate_params) + return ((void *) test->attr.duration); + else + return ((void *) NULL); +} + /* List of all Test Attributes */ +static struct timespec64 duration_default = {0, 0}; + static struct kunit_attr kunit_attr_list[] = { { .name = "speed", @@ -256,6 +290,7 @@ static struct kunit_attr kunit_attr_list[] = { .filter = attr_speed_filter, .attr_default = (void *)KUNIT_SPEED_NORMAL, .print = PRINT_ALWAYS, + .to_free = false, }, { .name = "module", @@ -264,6 +299,7 @@ static struct kunit_attr kunit_attr_list[] = { .filter = attr_string_filter, .attr_default = (void *)"", .print = PRINT_SUITE, + .to_free = false, }, { .name = "is_init", @@ -272,10 +308,33 @@ static struct kunit_attr kunit_attr_list[] = { .filter = attr_bool_filter, .attr_default = (void *)false, .print = PRINT_SUITE, + .to_free = false, + }, + { + .name = "duration", + .get_attr = attr_duration_get, + .to_string = attr_duration_to_string, + .filter = attr_default_filter, + .attr_default = (void *)(&duration_default), + .print = PRINT_ALWAYS, + .to_free = true, } }; -/* Helper Functions to Access Attributes */ +/* Helper Functions to Access/Free Attributes */ + +void kunit_free_attr(void *test_or_suite, bool is_test) +{ + int i; + void *attr; + + for (i = 0; i < ARRAY_SIZE(kunit_attr_list); i++) { + if (kunit_attr_list[i].to_free) { + attr = kunit_attr_list[i].get_attr(test_or_suite, is_test); + kfree(attr); + } + } +} const char *kunit_attr_filter_name(struct kunit_attr_filter filter) { diff --git a/lib/kunit/test.c b/lib/kunit/test.c index e8b1b52a19ab..0d18e4969015 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -376,11 +376,11 @@ static void kunit_run_case_check_speed(struct kunit *test, /* * Initializes and runs test case. Does not clean up or do post validations. */ -static void kunit_run_case_internal(struct kunit *test, +static struct timespec64 kunit_run_case_internal(struct kunit *test, struct kunit_suite *suite, struct kunit_case *test_case) { - struct timespec64 start, end; + struct timespec64 start, end, duration; if (suite->init) { int ret; @@ -389,7 +389,9 @@ static void kunit_run_case_internal(struct kunit *test, if (ret) { kunit_err(test, "failed to initialize: %d\n", ret); kunit_set_failure(test); - return; + duration.tv_sec = 0; + duration.tv_nsec = 0; + return duration; } } @@ -399,7 +401,11 @@ static void kunit_run_case_internal(struct kunit *test, ktime_get_ts64(&end); - kunit_run_case_check_speed(test, test_case, timespec64_sub(end, start)); + duration = timespec64_sub(end, start); + + kunit_run_case_check_speed(test, test_case, duration); + + return duration; } static void kunit_case_internal_cleanup(struct kunit *test) @@ -424,6 +430,7 @@ struct kunit_try_catch_context { struct kunit *test; struct kunit_suite *suite; struct kunit_case *test_case; + struct timespec64 duration; }; static void kunit_try_run_case(void *data) @@ -440,7 +447,7 @@ static void kunit_try_run_case(void *data) * abort will be called, this thread will exit, and finally the parent * thread will resume control and handle any necessary clean up. */ - kunit_run_case_internal(test, suite, test_case); + ctx->duration = kunit_run_case_internal(test, suite, test_case); } static void kunit_try_run_case_cleanup(void *data) @@ -521,6 +528,7 @@ static void kunit_run_case_catch_errors(struct kunit_suite *suite, { struct kunit_try_catch_context context; struct kunit_try_catch *try_catch; + struct timespec64 *duration = kmalloc(sizeof(struct timespec64), GFP_KERNEL); try_catch = &test->try_catch; @@ -533,6 +541,10 @@ static void kunit_run_case_catch_errors(struct kunit_suite *suite, context.test_case = test_case; kunit_try_catch_run(try_catch, &context); + duration->tv_sec = context.duration.tv_sec; + duration->tv_nsec = context.duration.tv_nsec; + test_case->attr.duration = duration; + /* Now run the cleanup */ kunit_try_catch_init(try_catch, test, @@ -670,6 +682,7 @@ int kunit_run_tests(struct kunit_suite *suite) } kunit_print_attr((void *)test_case, true, KUNIT_LEVEL_CASE); + kunit_free_attr((void *)test_case, true); kunit_print_test_stats(&test, param_stats); @@ -680,6 +693,7 @@ int kunit_run_tests(struct kunit_suite *suite) kunit_update_stats(&suite_stats, test_case->status); kunit_accumulate_stats(&total_stats, param_stats); + } if (suite->suite_exit) @@ -688,6 +702,7 @@ int kunit_run_tests(struct kunit_suite *suite) kunit_print_suite_stats(suite, suite_stats, total_stats); suite_end: kunit_print_suite_end(suite); + kunit_free_attr((void *)suite, false); return 0; } base-commit: 67c9971cd6d309ecbcb87b942e22ffc194d7a376 -- 2.45.2.993.g49e7a77208-goog

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[PATCH AUTOSEL 4.19 2/3] selftests/vDSO: fix clang build errors and warnings

by Sasha Levin

From: John Hubbard <jhubbard(a)nvidia.com> [ Upstream commit 73810cd45b99c6c418e1c6a487b52c1e74edb20d ] When building with clang, via: make LLVM=1 -C tools/testing/selftests ...there are several warnings, and an error. This fixes all of those and allows these tests to run and pass. 1. Fix linker error (undefined reference to memcpy) by providing a local version of memcpy. 2. clang complains about using this form: if (g = h & 0xf0000000) ...so factor out the assignment into a separate step. 3. The code is passing a signed const char* to elf_hash(), which expects a const unsigned char *. There are several callers, so fix this at the source by allowing the function to accept a signed argument, and then converting to unsigned operations, once inside the function. 4. clang doesn't have __attribute__((externally_visible)) and generates a warning to that effect. Fortunately, gcc 12 and gcc 13 do not seem to require that attribute in order to build, run and pass tests here, so remove it. Reviewed-by: Carlos Llamas <cmllamas(a)google.com> Reviewed-by: Edward Liaw <edliaw(a)google.com> Reviewed-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com> Tested-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com> Signed-off-by: John Hubbard <jhubbard(a)nvidia.com> Signed-off-by: Shuah Khan <skhan(a)linuxfoundation.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/testing/selftests/vDSO/parse_vdso.c | 16 +++++++++++----- .../selftests/vDSO/vdso_standalone_test_x86.c | 18 ++++++++++++++++-- 2 files changed, 27 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c index 1dbb4b87268fa..9ef3ad3789c17 100644 --- a/tools/testing/selftests/vDSO/parse_vdso.c +++ b/tools/testing/selftests/vDSO/parse_vdso.c @@ -77,14 +77,20 @@ static struct vdso_info ELF(Verdef) *verdef; } vdso_info; -/* Straight from the ELF specification. */ -static unsigned long elf_hash(const unsigned char *name) +/* + * Straight from the ELF specification...and then tweaked slightly, in order to + * avoid a few clang warnings. + */ +static unsigned long elf_hash(const char *name) { unsigned long h = 0, g; - while (*name) + const unsigned char *uch_name = (const unsigned char *)name; + + while (*uch_name) { - h = (h << 4) + *name++; - if (g = h & 0xf0000000) + h = (h << 4) + *uch_name++; + g = h & 0xf0000000; + if (g) h ^= g >> 24; h &= ~g; } diff --git a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c index 93b0ebf8cc38d..805e8c1892764 100644 --- a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c +++ b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c @@ -20,7 +20,7 @@ extern void *vdso_sym(const char *version, const char *name); extern void vdso_init_from_sysinfo_ehdr(uintptr_t base); extern void vdso_init_from_auxv(void *auxv); -/* We need a libc functions... */ +/* We need some libc functions... */ int strcmp(const char *a, const char *b) { /* This implementation is buggy: it never returns -1. */ @@ -36,6 +36,20 @@ int strcmp(const char *a, const char *b) return 0; } +/* + * The clang build needs this, although gcc does not. + * Stolen from lib/string.c. + */ +void *memcpy(void *dest, const void *src, size_t count) +{ + char *tmp = dest; + const char *s = src; + + while (count--) + *tmp++ = *s++; + return dest; +} + /* ...and two syscalls. This is x86-specific. */ static inline long x86_syscall3(long nr, long a0, long a1, long a2) { @@ -72,7 +86,7 @@ void to_base10(char *lastdig, time_t n) } } -__attribute__((externally_visible)) void c_main(void **stack) +void c_main(void **stack) { /* Parse the stack */ long argc = (long)*stack; -- 2.43.0

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