| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | |
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| 3 | //! Seq file bindings. |
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| 4 | //! |
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| 5 | //! C header: [`include/linux/seq_file.h`](srctree/include/linux/seq_file.h) |
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| 6 | |
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| 7 | use crate::{bindings, c_str, types::NotThreadSafe, types::Opaque}; |
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| 8 | |
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| 9 | /// A utility for generating the contents of a seq file. |
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| 10 | #[repr(transparent)] |
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| 11 | pub struct SeqFile { |
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| 12 | inner: Opaque<bindings::seq_file>, |
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| 13 | _not_send: NotThreadSafe, |
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| 14 | } |
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| 15 | |
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| 16 | impl SeqFile { |
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| 17 | /// Creates a new [`SeqFile`] from a raw pointer. |
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| 18 | /// |
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| 19 | /// # Safety |
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| 20 | /// |
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| 21 | /// The caller must ensure that for the duration of `'a` the following is satisfied: |
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| 22 | /// * The pointer points at a valid `struct seq_file`. |
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| 23 | /// * The `struct seq_file` is not accessed from any other thread. |
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| 24 | pub unsafe fn from_raw<'a>(ptr: *mut bindings::seq_file) -> &'a SeqFile { |
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| 25 | // SAFETY: The caller ensures that the reference is valid for 'a. There's no way to trigger |
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| 26 | // a data race by using the `&SeqFile` since this is the only thread accessing the seq_file. |
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| 27 | // |
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| 28 | // CAST: The layout of `struct seq_file` and `SeqFile` is compatible. |
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| 29 | unsafe { &*ptr.cast() } |
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| 30 | } |
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| 31 | |
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| 32 | /// Used by the [`seq_print`] macro. |
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| 33 | #[inline] |
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| 34 | pub fn call_printf(&self, args: core::fmt::Arguments<'_>) { |
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| 35 | // SAFETY: Passing a void pointer to `Arguments` is valid for `%pA`. |
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| 36 | unsafe { |
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| 37 | bindings::seq_printf( |
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| 38 | self.inner.get(), |
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| 39 | c_str!("%pA" ).as_char_ptr(), |
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| 40 | &args as *const _ as *const crate::ffi::c_void, |
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| 41 | ); |
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| 42 | } |
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| 43 | } |
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| 44 | } |
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| 45 | |
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| 46 | /// Write to a [`SeqFile`] with the ordinary Rust formatting syntax. |
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| 47 | #[macro_export] |
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| 48 | macro_rules! seq_print { |
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| 49 | ($m:expr, $($arg:tt)+) => ( |
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| 50 | $m.call_printf(format_args!($($arg)+)) |
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| 51 | ); |
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| 52 | } |
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| 53 | pub use seq_print; |
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| 54 | |
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