July 2024 - Linux-kselftest-mirror

[PATCH v2 0/2] kselftest/alsa: Diagnostic improvements

by Mark Brown

The first patch fixes unstable naming of tests due to probe ordering not being stable, the second just provides a bit more information. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- Changes in v2: - Switch to using ID rather than longame. - Log the PCM ID too. - Link to v1: https://lore.kernel.org/r/20240711-alsa-kselftest-board-name-v1-1-ab5cf2dbb… --- Mark Brown (2): kselftest/alsa: Use card name rather than number in test names kselftest/alsa: Log the PCM ID in pcm-test tools/testing/selftests/alsa/mixer-test.c | 98 +++++++++++++++++++------------ tools/testing/selftests/alsa/pcm-test.c | 68 +++++++++++++++------ 2 files changed, 108 insertions(+), 58 deletions(-) --- base-commit: f2661062f16b2de5d7b6a5c42a9a5c96326b8454 change-id: 20240711-alsa-kselftest-board-name-e4a1add4cfa0 Best regards, -- Mark Brown <broonie(a)kernel.org>

11 months

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KUnit file naming conventions (was Re: [GIT PULL] execve updates for v6.11-rc1)

by Kees Cook

On Tue, Jul 16, 2024 at 01:10:41PM -0700, Linus Torvalds wrote: > On Mon, 15 Jul 2024 at 09:21, Kees Cook <kees(a)kernel.org> wrote: > > > > fs/exec.c | 49 ++++++++-- > > fs/exec_test.c | 141 ++++++++++++++++++++++++++++ > > I've pulled this, but *PLEASE* don't do this. > > This screws up my workflow of just using tab-completion for filenames. > As a result, I absolutely abhor anybody who uses the same base-name > for different things. > > No, this is not the first time it happens, and it won't be the last. > And we had that same horrific pattern for fs/binfmt_elf_test.c from > before, and I didn't notice because it's not a core file to me, and I > seldom actually edit it. > > I would suggest that people use the patterns from lib/, which is > admittedly a bit schizophrenic in that you can either use > "lib/kunit/*.c" (probably preferred) or "lib/test_xyz.c". > > (Other subsystems use a "tests" subdirectory, so we do have a lot of > different ways to deal with this). > > Any of those models will keep the unit testing parts clearly separate, > and not mess up basic command line workflows. > > But do *not* use this "*_test.c" naming model. It's the worst of all > possible worlds. > > Please? Oh, sure, no problem! I have no attachment to this convention at all; I was trying to follow the Kunit docs: https://docs.kernel.org/dev-tools/kunit/style.html#test-file-and-module-nam… If I look at the existing naming, it's pretty scattered: $ git grep '^static struct kunit_suite\b' | cut -d: -f1 | sort -u /test/* 7 /tests/* 47 *-test.[ch] 27 *_test.[ch] 27 test-*.c 1 test_*.c 10 *-kunit.c 1 *_kunit.c 17 kunit-*.c 2 kunit_*.c 1 Should we go with "put it all under a 'tests' subdirectory" ? So for fs/exec_test.c and fs/binfmt_elf_test.c, perhaps fs/tests/exec.c and fs/tests/binfmt_elf.c respectively? And for the lib/*_kunit.c files, use lib/tests/*.c ? Then we can update the docs, etc. -- Kees Cook

11 months

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[PATCH] Documentation: KUnit: Update filename best practices

by Kees Cook

Based on feedback from Linus[1], change the suggested file naming for KUnit tests. Link: https://lore.kernel.org/lkml/CAHk-=wgim6pNiGTBMhP8Kd3tsB7_JTAuvNJ=XYd3wPvvk… [1] Signed-off-by: Kees Cook <kees(a)kernel.org> --- Cc: David Gow <davidgow(a)google.com> Cc: Brendan Higgins <brendan.higgins(a)linux.dev> Cc: Rae Moar <rmoar(a)google.com> Cc: Jonathan Corbet <corbet(a)lwn.net> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: linux-kselftest(a)vger.kernel.org Cc: kunit-dev(a)googlegroups.com Cc: linux-doc(a)vger.kernel.org --- Documentation/dev-tools/kunit/style.rst | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/Documentation/dev-tools/kunit/style.rst b/Documentation/dev-tools/kunit/style.rst index b6d0d7359f00..761dee3f89ca 100644 --- a/Documentation/dev-tools/kunit/style.rst +++ b/Documentation/dev-tools/kunit/style.rst @@ -188,15 +188,20 @@ For example, a Kconfig entry might look like: Test File and Module Names ========================== -KUnit tests can often be compiled as a module. These modules should be named -after the test suite, followed by ``_test``. If this is likely to conflict with -non-KUnit tests, the suffix ``_kunit`` can also be used. - -The easiest way of achieving this is to name the file containing the test suite -``<suite>_test.c`` (or, as above, ``<suite>_kunit.c``). This file should be -placed next to the code under test. +Whether a KUnit test is compiled as a separate module or via an +``#include`` in a core kernel source file, the files should be named +after the test suite, followed by ``_test``, and live in a ``tests`` +subdirectory to avoid conflicting with regular modules or the core kernel +source file names (e.g. for tab-completion). If this would conflict with +non-KUnit tests, the suffix ``_kunit`` can be used instead. + +So for the common case, name the file containing the test suite +``tests/<suite>_test.c`` (or, if needed, ``tests/<suite>_kunit.c``). The +``tests`` directory should be placed at the same level as the +code under test. For example, tests for ``lib/string.c`` live in +``lib/tests/string_test.c``. If the suite name contains some or all of the name of the test's parent directory, it may make sense to modify the source filename to reduce redundancy. -For example, a ``foo_firmware`` suite could be in the ``foo/firmware_test.c`` +For example, a ``foo_firmware`` suite could be in the ``tests/foo/firmware_test.c`` file. -- 2.34.1

11 months

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[PATCH v2] 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. v1->v2: - Guard with ifdeffery to prevent compiler warning on other arches Signed-off-by: Dev Jain <dev.jain(a)arm.com> Reviewed-by: Ryan Roberts <ryan.roberts(a)arm.com> --- The patch applies on linux-next. tools/testing/selftests/mm/va_high_addr_switch.c | 16 +++++++++++++++- 1 file changed, 15 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..896b3f73fc53 100644 --- a/tools/testing/selftests/mm/va_high_addr_switch.c +++ b/tools/testing/selftests/mm/va_high_addr_switch.c @@ -293,6 +293,20 @@ static int run_test(struct testcase *test, int count) return ret; } +#ifdef __aarch64__ +/* 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; +} +#endif + static int supported_arch(void) { #if defined(__powerpc64__) @@ -300,7 +314,7 @@ 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

11 months

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[PATCH v4 0/3] Allow userspace to change ID_AA64PFR1_EL1

by Shaoqin Huang

Hi guys, This is another try to allow userspace to change ID_AA64PFR1_EL1, and we want to give userspace the ability to control the visible feature set for a VM, which could be used by userspace in such a way to transparently migrate VMs. The patch series have three part: The first patch disable those fields which KVM doesn't know how to handle, so KVM will only expose value 0 of those fields to the guest. The second patch allow userspace to change ID_AA64PFR1_EL1, it allow as much as possible fields to be writable, except some special fields which is still not writable. The third patch adds the kselftest to test if userspace can change the ID_AA64PFR1_EL1. Besides, I also noticed there is another patch [1] which try to make the ID_AA64PFR1_EL1 writable. This patch [1] is try to enable GCS on baremental, and add GCS support for the guest. What I understand is if we have GCS support on baremental, it will be clear to how to handle them in KVM. And same for other fields like NMI, THE, DF2, MTEX.. I'm still not confident about the correctness of this patch series, but I've try my best to understand each of the fields. And follow Marc's comments to tweak this patch series. The question confuse me a lot is that should we allow those fields (NMI, GCS, THE, DF2, MTEX..) which KVM doesn't know how to handle writable? Baremental doesn't know about them, and the ftr_id_aa64pfr1[] doesn't know about them. I follow the comment "I should handle all 15 fields", so I allow them writable because they're disabled in the register read accessor, and their value will alwyas be 0, the userspace can write to it but only value 0. If I did anything wrong, please point me out. Thanks a lot. [1] [PATCH v9 13/39] KVM: arm64: Manage GCS registers for guests https://lore.kernel.org/all/20240625-arm64-gcs-v9-13-0f634469b8f0@kernel.or… Changelog: ---------- v3 -> v4: * Add a new patch to disable some feature which KVM doesn't know how to handle in the register accessor. * Handle all the fields in the register. * Fixes a small cnt issue in kselftest. v2 -> v3: * Give more description about why only part of the fields can be writable. * Updated the writable mask by referring the latest ARM spec. v1 -> v2: * Tackling the full register instead of single field. * Changing the patch title and commit message. RFCv1 -> v1: * Fix the compilation error. * Delete the machine specific information and make the description more generable. RFCv1: https://lore.kernel.org/all/20240612023553.127813-1-shahuang@redhat.com/ v1: https://lore.kernel.org/all/20240617075131.1006173-1-shahuang@redhat.com/ v2: https://lore.kernel.org/all/20240618063808.1040085-1-shahuang@redhat.com/ v3: https://lore.kernel.org/all/20240628060454.1936886-2-shahuang@redhat.com/ Shaoqin Huang (3): KVM: arm64: Disable fields that KVM doesn't know how to handle in ID_AA64PFR1_EL1 KVM: arm64: Allow userspace to change ID_AA64PFR1_EL1 KVM: selftests: aarch64: Add writable test for ID_AA64PFR1_EL1 arch/arm64/kvm/sys_regs.c | 13 ++++++++++- .../selftests/kvm/aarch64/set_id_regs.c | 23 ++++++++++++++++--- 2 files changed, 32 insertions(+), 4 deletions(-) -- 2.40.1

11 months

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[PATCH -next] selftests/mm: mseal, self_elf: Fix warning comparing pointer to 0

by Jiapeng Chong

Avoid pointer type value compared with 0 to make code clear. ./tools/testing/selftests/mm/mseal_test.c:486:27-28: WARNING comparing pointer to 0. ./tools/testing/selftests/mm/mseal_test.c:1399:29-30: WARNING comparing pointer to 0. Reported-by: Abaci Robot <abaci(a)linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9552 Signed-off-by: Jiapeng Chong <jiapeng.chong(a)linux.alibaba.com> --- tools/testing/selftests/mm/mseal_test.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/mm/mseal_test.c b/tools/testing/selftests/mm/mseal_test.c index a818f010de47..50a5b9b9399e 100644 --- a/tools/testing/selftests/mm/mseal_test.c +++ b/tools/testing/selftests/mm/mseal_test.c @@ -481,9 +481,8 @@ static void test_seal_zero_address(void) int prot; /* use mmap to change protection. */ - ptr = sys_mmap(0, size, PROT_NONE, - MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0); - FAIL_TEST_IF_FALSE(ptr == 0); + ptr = sys_mmap(0, size, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0); + FAIL_TEST_IF_FALSE(!ptr); size = get_vma_size(ptr, &prot); FAIL_TEST_IF_FALSE(size == 4 * page_size); @@ -1390,13 +1389,12 @@ static void test_seal_mremap_move_fixed_zero(bool seal) /* * MREMAP_FIXED can move the mapping to zero address */ - ret2 = mremap(ptr, size, 2 * page_size, MREMAP_MAYMOVE | MREMAP_FIXED, - 0); + ret2 = mremap(ptr, size, 2 * page_size, MREMAP_MAYMOVE | MREMAP_FIXED, 0); if (seal) { FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED); FAIL_TEST_IF_FALSE(errno == EPERM); } else { - FAIL_TEST_IF_FALSE(ret2 == 0); + FAIL_TEST_IF_FALSE(!ret2); } -- 2.32.0.3.g01195cf9f

11 months

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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

11 months

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

11 months

1
0
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[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

11 months

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

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