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3b83f5d5e7
`kernel::ffi::CStr` was introduced in commitd126d23801("rust: str: add `CStr` type") in November 2022 as an upstreaming of earlier work that was done in May 2021[0]. That earlier work, having predated the inclusion of `CStr` in `core`, largely duplicated the implementation of `std::ffi::CStr`. `std::ffi::CStr` was moved to `core::ffi::CStr` in Rust 1.64 in September 2022. Hence replace `kernel::str::CStr` with `core::ffi::CStr` to reduce our custom code footprint, and retain needed custom functionality through an extension trait. Add `CStr` to `ffi` and the kernel prelude. Link:faa3cbcca0[0] Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Link: https://patch.msgid.link/20251018-cstr-core-v18-16-9378a54385f8@gmail.com [ Removed assert that would now depend on the Rust version. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
54 lines
1.7 KiB
Rust
54 lines
1.7 KiB
Rust
// SPDX-License-Identifier: GPL-2.0
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//! Seq file bindings.
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//!
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//! C header: [`include/linux/seq_file.h`](srctree/include/linux/seq_file.h)
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use crate::{bindings, c_str, fmt, str::CStrExt as _, types::NotThreadSafe, types::Opaque};
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/// A utility for generating the contents of a seq file.
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#[repr(transparent)]
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pub struct SeqFile {
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inner: Opaque<bindings::seq_file>,
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_not_send: NotThreadSafe,
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}
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impl SeqFile {
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/// Creates a new [`SeqFile`] from a raw pointer.
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///
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/// # Safety
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///
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/// The caller must ensure that for the duration of `'a` the following is satisfied:
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/// * The pointer points at a valid `struct seq_file`.
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/// * The `struct seq_file` is not accessed from any other thread.
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pub unsafe fn from_raw<'a>(ptr: *mut bindings::seq_file) -> &'a SeqFile {
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// SAFETY: The caller ensures that the reference is valid for 'a. There's no way to trigger
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// a data race by using the `&SeqFile` since this is the only thread accessing the seq_file.
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//
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// CAST: The layout of `struct seq_file` and `SeqFile` is compatible.
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unsafe { &*ptr.cast() }
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}
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/// Used by the [`seq_print`] macro.
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#[inline]
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pub fn call_printf(&self, args: fmt::Arguments<'_>) {
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// SAFETY: Passing a void pointer to `Arguments` is valid for `%pA`.
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unsafe {
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bindings::seq_printf(
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self.inner.get(),
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c_str!("%pA").as_char_ptr(),
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core::ptr::from_ref(&args).cast::<crate::ffi::c_void>(),
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);
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}
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}
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}
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/// Write to a [`SeqFile`] with the ordinary Rust formatting syntax.
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#[macro_export]
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macro_rules! seq_print {
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($m:expr, $($arg:tt)+) => (
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$m.call_printf($crate::prelude::fmt!($($arg)+))
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);
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}
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pub use seq_print;
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