All of lore.kernel.org
 help / color / mirror / Atom feed
From: ojeda@kernel.org
To: Linus Torvalds <torvalds@linux-foundation.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: rust-for-linux@vger.kernel.org, linux-kbuild@vger.kernel.org,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	Miguel Ojeda <ojeda@kernel.org>,
	Alex Gaynor <alex.gaynor@gmail.com>,
	Geoffrey Thomas <geofft@ldpreload.com>,
	Finn Behrens <me@kloenk.de>,
	Adam Bratschi-Kaye <ark.email@gmail.com>,
	Wedson Almeida Filho <wedsonaf@google.com>,
	Boqun Feng <boqun.feng@gmail.com>,
	Sumera Priyadarsini <sylphrenadin@gmail.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Sven Van Asbroeck <thesven73@gmail.com>,
	Gary Guo <gary@garyguo.net>,
	Boris-Chengbiao Zhou <bobo1239@web.de>,
	Fox Chen <foxhlchen@gmail.com>,
	Ayaan Zaidi <zaidi.ayaan@gmail.com>,
	Douglas Su <d0u9.su@outlook.com>, Yuki Okushi <jtitor@2k36.org>
Subject: [PATCH 09/17] rust: add `macros` crate
Date: Sun,  4 Jul 2021 22:27:48 +0200	[thread overview]
Message-ID: <20210704202756.29107-10-ojeda@kernel.org> (raw)
In-Reply-To: <20210704202756.29107-1-ojeda@kernel.org>

From: Miguel Ojeda <ojeda@kernel.org>

This crate contains all the procedural macros ("proc macros")
shared by all the kernel.

Procedural macros allow to create syntax extensions. They run at
compile-time and can consume as well as produce Rust syntax.

For instance, the `module!` macro that is used by Rust modules
is implemented here. It allows to easily declare the equivalent
information to the `MODULE_*` macros in C modules, e.g.:

    module! {
        type: RustMinimal,
        name: b"rust_minimal",
        author: b"Rust for Linux Contributors",
        description: b"Rust minimal sample",
        license: b"GPL v2",
    }

Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Geoffrey Thomas <geofft@ldpreload.com>
Signed-off-by: Geoffrey Thomas <geofft@ldpreload.com>
Co-developed-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Finn Behrens <me@kloenk.de>
Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Co-developed-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Co-developed-by: Fox Chen <foxhlchen@gmail.com>
Signed-off-by: Fox Chen <foxhlchen@gmail.com>
Co-developed-by: Ayaan Zaidi <zaidi.ayaan@gmail.com>
Signed-off-by: Ayaan Zaidi <zaidi.ayaan@gmail.com>
Co-developed-by: Douglas Su <d0u9.su@outlook.com>
Signed-off-by: Douglas Su <d0u9.su@outlook.com>
Co-developed-by: Yuki Okushi <jtitor@2k36.org>
Signed-off-by: Yuki Okushi <jtitor@2k36.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/macros/lib.rs    | 127 +++++++
 rust/macros/module.rs | 754 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 881 insertions(+)
 create mode 100644 rust/macros/lib.rs
 create mode 100644 rust/macros/module.rs

diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
new file mode 100644
index 00000000000..cb7a4f12f3b
--- /dev/null
+++ b/rust/macros/lib.rs
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Crate for all kernel procedural macros.
+
+mod module;
+
+use proc_macro::TokenStream;
+
+/// Declares a kernel module.
+///
+/// The `type` argument should be a type which implements the [`KernelModule`]
+/// trait. Also accepts various forms of kernel metadata.
+///
+/// C header: [`include/linux/moduleparam.h`](../../../include/linux/moduleparam.h)
+///
+/// [`KernelModule`]: ../kernel/trait.KernelModule.html
+///
+/// # Examples
+///
+/// ```ignore
+/// use kernel::prelude::*;
+///
+/// module!{
+///     type: MyKernelModule,
+///     name: b"my_kernel_module",
+///     author: b"Rust for Linux Contributors",
+///     description: b"My very own kernel module!",
+///     license: b"GPL v2",
+///     params: {
+///        my_i32: i32 {
+///            default: 42,
+///            permissions: 0o000,
+///            description: b"Example of i32",
+///        },
+///        writeable_i32: i32 {
+///            default: 42,
+///            permissions: 0o644,
+///            description: b"Example of i32",
+///        },
+///    },
+/// }
+///
+/// struct MyKernelModule;
+///
+/// impl KernelModule for MyKernelModule {
+///     fn init() -> Result<Self> {
+///         // If the parameter is writeable, then the kparam lock must be
+///         // taken to read the parameter:
+///         {
+///             let lock = THIS_MODULE.kernel_param_lock();
+///             pr_info!("i32 param is:  {}\n", writeable_i32.read(&lock));
+///         }
+///         // If the parameter is read only, it can be read without locking
+///         // the kernel parameters:
+///         pr_info!("i32 param is:  {}\n", my_i32.read());
+///         Ok(MyKernelModule)
+///     }
+/// }
+/// ```
+///
+/// # Supported argument types
+///   - `type`: type which implements the [`KernelModule`] trait (required).
+///   - `name`: byte array of the name of the kernel module (required).
+///   - `author`: byte array of the author of the kernel module.
+///   - `description`: byte array of the description of the kernel module.
+///   - `license`: byte array of the license of the kernel module (required).
+///   - `alias`: byte array of alias name of the kernel module.
+///   - `alias_rtnl_link`: byte array of the `rtnl_link_alias` of the kernel module (mutually exclusive with `alias`).
+///   - `params`: parameters for the kernel module, as described below.
+///
+/// # Supported parameter types
+///
+///   - `bool`: Corresponds to C `bool` param type.
+///   - `i8`: No equivalent C param type.
+///   - `u8`: Corresponds to C `char` param type.
+///   - `i16`: Corresponds to C `short` param type.
+///   - `u16`: Corresponds to C `ushort` param type.
+///   - `i32`: Corresponds to C `int` param type.
+///   - `u32`: Corresponds to C `uint` param type.
+///   - `i64`: No equivalent C param type.
+///   - `u64`: Corresponds to C `ullong` param type.
+///   - `isize`: No equivalent C param type.
+///   - `usize`: No equivalent C param type.
+///   - `str`: Corresponds to C `charp` param type. Reading returns a byte slice.
+///   - `ArrayParam<T,N>`: Corresponds to C parameters created using `module_param_array`. An array
+///     of `T`'s of length at **most** `N`.
+///
+/// `invbool` is unsupported: it was only ever used in a few modules.
+/// Consider using a `bool` and inverting the logic instead.
+#[proc_macro]
+pub fn module(ts: TokenStream) -> TokenStream {
+    module::module(ts)
+}
+
+/// Declares a kernel module that exposes a single misc device.
+///
+/// The `type` argument should be a type which implements the [`FileOpener`] trait. Also accepts
+/// various forms of kernel metadata.
+///
+/// C header: [`include/linux/moduleparam.h`](../../../include/linux/moduleparam.h)
+///
+/// [`FileOpener`]: ../kernel/file_operations/trait.FileOpener.html
+///
+/// # Examples
+///
+/// ```ignore
+/// use kernel::prelude::*;
+///
+/// module_misc_device! {
+///     type: MyFile,
+///     name: b"my_miscdev_kernel_module",
+///     author: b"Rust for Linux Contributors",
+///     description: b"My very own misc device kernel module!",
+///     license: b"GPL v2",
+/// }
+///
+/// #[derive(Default)]
+/// struct MyFile;
+///
+/// impl kernel::file_operations::FileOperations for MyFile {
+///     kernel::declare_file_operations!();
+/// }
+/// ```
+#[proc_macro]
+pub fn module_misc_device(ts: TokenStream) -> TokenStream {
+    module::module_misc_device(ts)
+}
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
new file mode 100644
index 00000000000..1389c53aa22
--- /dev/null
+++ b/rust/macros/module.rs
@@ -0,0 +1,754 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use proc_macro::{token_stream, Delimiter, Group, Literal, TokenStream, TokenTree};
+
+fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> {
+    if let Some(TokenTree::Ident(ident)) = it.next() {
+        Some(ident.to_string())
+    } else {
+        None
+    }
+}
+
+fn try_literal(it: &mut token_stream::IntoIter) -> Option<String> {
+    if let Some(TokenTree::Literal(literal)) = it.next() {
+        Some(literal.to_string())
+    } else {
+        None
+    }
+}
+
+fn try_byte_string(it: &mut token_stream::IntoIter) -> Option<String> {
+    try_literal(it).and_then(|byte_string| {
+        if byte_string.starts_with("b\"") && byte_string.ends_with('\"') {
+            Some(byte_string[2..byte_string.len() - 1].to_string())
+        } else {
+            None
+        }
+    })
+}
+
+fn expect_ident(it: &mut token_stream::IntoIter) -> String {
+    try_ident(it).expect("Expected Ident")
+}
+
+fn expect_punct(it: &mut token_stream::IntoIter) -> char {
+    if let TokenTree::Punct(punct) = it.next().expect("Reached end of token stream for Punct") {
+        punct.as_char()
+    } else {
+        panic!("Expected Punct");
+    }
+}
+
+fn expect_literal(it: &mut token_stream::IntoIter) -> String {
+    try_literal(it).expect("Expected Literal")
+}
+
+fn expect_group(it: &mut token_stream::IntoIter) -> Group {
+    if let TokenTree::Group(group) = it.next().expect("Reached end of token stream for Group") {
+        group
+    } else {
+        panic!("Expected Group");
+    }
+}
+
+fn expect_byte_string(it: &mut token_stream::IntoIter) -> String {
+    try_byte_string(it).expect("Expected byte string")
+}
+
+#[derive(Clone, PartialEq)]
+enum ParamType {
+    Ident(String),
+    Array { vals: String, max_length: usize },
+}
+
+fn expect_array_fields(it: &mut token_stream::IntoIter) -> ParamType {
+    assert_eq!(expect_punct(it), '<');
+    let vals = expect_ident(it);
+    assert_eq!(expect_punct(it), ',');
+    let max_length_str = expect_literal(it);
+    let max_length = max_length_str
+        .parse::<usize>()
+        .expect("Expected usize length");
+    assert_eq!(expect_punct(it), '>');
+    ParamType::Array { vals, max_length }
+}
+
+fn expect_type(it: &mut token_stream::IntoIter) -> ParamType {
+    if let TokenTree::Ident(ident) = it
+        .next()
+        .expect("Reached end of token stream for param type")
+    {
+        match ident.to_string().as_ref() {
+            "ArrayParam" => expect_array_fields(it),
+            _ => ParamType::Ident(ident.to_string()),
+        }
+    } else {
+        panic!("Expected Param Type")
+    }
+}
+
+fn expect_end(it: &mut token_stream::IntoIter) {
+    if it.next().is_some() {
+        panic!("Expected end");
+    }
+}
+
+fn get_literal(it: &mut token_stream::IntoIter, expected_name: &str) -> String {
+    assert_eq!(expect_ident(it), expected_name);
+    assert_eq!(expect_punct(it), ':');
+    let literal = expect_literal(it);
+    assert_eq!(expect_punct(it), ',');
+    literal
+}
+
+fn get_byte_string(it: &mut token_stream::IntoIter, expected_name: &str) -> String {
+    assert_eq!(expect_ident(it), expected_name);
+    assert_eq!(expect_punct(it), ':');
+    let byte_string = expect_byte_string(it);
+    assert_eq!(expect_punct(it), ',');
+    byte_string
+}
+
+struct ModInfoBuilder<'a> {
+    module: &'a str,
+    counter: usize,
+    buffer: String,
+}
+
+impl<'a> ModInfoBuilder<'a> {
+    fn new(module: &'a str) -> Self {
+        ModInfoBuilder {
+            module,
+            counter: 0,
+            buffer: String::new(),
+        }
+    }
+
+    fn emit_base(&mut self, field: &str, content: &str, builtin: bool) {
+        use std::fmt::Write;
+
+        let string = if builtin {
+            // Built-in modules prefix their modinfo strings by `module.`.
+            format!(
+                "{module}.{field}={content}\0",
+                module = self.module,
+                field = field,
+                content = content
+            )
+        } else {
+            // Loadable modules' modinfo strings go as-is.
+            format!("{field}={content}\0", field = field, content = content)
+        };
+
+        write!(
+            &mut self.buffer,
+            "
+                {cfg}
+                #[doc(hidden)]
+                #[link_section = \".modinfo\"]
+                #[used]
+                pub static __{module}_{counter}: [u8; {length}] = *{string};
+            ",
+            cfg = if builtin {
+                "#[cfg(not(MODULE))]"
+            } else {
+                "#[cfg(MODULE)]"
+            },
+            module = self.module,
+            counter = self.counter,
+            length = string.len(),
+            string = Literal::byte_string(string.as_bytes()),
+        )
+        .unwrap();
+
+        self.counter += 1;
+    }
+
+    fn emit_only_builtin(&mut self, field: &str, content: &str) {
+        self.emit_base(field, content, true)
+    }
+
+    fn emit_only_loadable(&mut self, field: &str, content: &str) {
+        self.emit_base(field, content, false)
+    }
+
+    fn emit(&mut self, field: &str, content: &str) {
+        self.emit_only_builtin(field, content);
+        self.emit_only_loadable(field, content);
+    }
+
+    fn emit_param(&mut self, field: &str, param: &str, content: &str) {
+        let content = format!("{param}:{content}", param = param, content = content);
+        self.emit(field, &content);
+    }
+}
+
+fn permissions_are_readonly(perms: &str) -> bool {
+    let (radix, digits) = if let Some(n) = perms.strip_prefix("0x") {
+        (16, n)
+    } else if let Some(n) = perms.strip_prefix("0o") {
+        (8, n)
+    } else if let Some(n) = perms.strip_prefix("0b") {
+        (2, n)
+    } else {
+        (10, perms)
+    };
+    match u32::from_str_radix(digits, radix) {
+        Ok(perms) => perms & 0o222 == 0,
+        Err(_) => false,
+    }
+}
+
+fn param_ops_path(param_type: &str) -> &'static str {
+    match param_type {
+        "bool" => "kernel::module_param::PARAM_OPS_BOOL",
+        "i8" => "kernel::module_param::PARAM_OPS_I8",
+        "u8" => "kernel::module_param::PARAM_OPS_U8",
+        "i16" => "kernel::module_param::PARAM_OPS_I16",
+        "u16" => "kernel::module_param::PARAM_OPS_U16",
+        "i32" => "kernel::module_param::PARAM_OPS_I32",
+        "u32" => "kernel::module_param::PARAM_OPS_U32",
+        "i64" => "kernel::module_param::PARAM_OPS_I64",
+        "u64" => "kernel::module_param::PARAM_OPS_U64",
+        "isize" => "kernel::module_param::PARAM_OPS_ISIZE",
+        "usize" => "kernel::module_param::PARAM_OPS_USIZE",
+        "str" => "kernel::module_param::PARAM_OPS_STR",
+        t => panic!("Unrecognized type {}", t),
+    }
+}
+
+fn try_simple_param_val(
+    param_type: &str,
+) -> Box<dyn Fn(&mut token_stream::IntoIter) -> Option<String>> {
+    match param_type {
+        "bool" => Box::new(|param_it| try_ident(param_it)),
+        "str" => Box::new(|param_it| {
+            try_byte_string(param_it)
+                .map(|s| format!("kernel::module_param::StringParam::Ref(b\"{}\")", s))
+        }),
+        _ => Box::new(|param_it| try_literal(param_it)),
+    }
+}
+
+fn get_default(param_type: &ParamType, param_it: &mut token_stream::IntoIter) -> String {
+    let try_param_val = match param_type {
+        ParamType::Ident(ref param_type)
+        | ParamType::Array {
+            vals: ref param_type,
+            max_length: _,
+        } => try_simple_param_val(param_type),
+    };
+    assert_eq!(expect_ident(param_it), "default");
+    assert_eq!(expect_punct(param_it), ':');
+    let default = match param_type {
+        ParamType::Ident(_) => try_param_val(param_it).expect("Expected default param value"),
+        ParamType::Array {
+            vals: _,
+            max_length: _,
+        } => {
+            let group = expect_group(param_it);
+            assert_eq!(group.delimiter(), Delimiter::Bracket);
+            let mut default_vals = Vec::new();
+            let mut it = group.stream().into_iter();
+
+            while let Some(default_val) = try_param_val(&mut it) {
+                default_vals.push(default_val);
+                match it.next() {
+                    Some(TokenTree::Punct(punct)) => assert_eq!(punct.as_char(), ','),
+                    None => break,
+                    _ => panic!("Expected ',' or end of array default values"),
+                }
+            }
+
+            let mut default_array = "kernel::module_param::ArrayParam::create(&[".to_string();
+            default_array.push_str(
+                &default_vals
+                    .iter()
+                    .map(|val| val.to_string())
+                    .collect::<Vec<String>>()
+                    .join(","),
+            );
+            default_array.push_str("])");
+            default_array
+        }
+    };
+    assert_eq!(expect_punct(param_it), ',');
+    default
+}
+
+fn generated_array_ops_name(vals: &str, max_length: usize) -> String {
+    format!(
+        "__generated_array_ops_{vals}_{max_length}",
+        vals = vals,
+        max_length = max_length
+    )
+}
+
+#[derive(Debug, Default)]
+struct ModuleInfo {
+    type_: String,
+    license: String,
+    name: String,
+    author: Option<String>,
+    description: Option<String>,
+    alias: Option<String>,
+    params: Option<Group>,
+}
+
+impl ModuleInfo {
+    fn parse(it: &mut token_stream::IntoIter) -> Self {
+        let mut info = ModuleInfo::default();
+
+        const EXPECTED_KEYS: &[&str] = &[
+            "type",
+            "name",
+            "author",
+            "description",
+            "license",
+            "alias",
+            "alias_rtnl_link",
+            "params",
+        ];
+        const REQUIRED_KEYS: &[&str] = &["type", "name", "license"];
+        let mut seen_keys = Vec::new();
+
+        loop {
+            let key = match it.next() {
+                Some(TokenTree::Ident(ident)) => ident.to_string(),
+                Some(_) => panic!("Expected Ident or end"),
+                None => break,
+            };
+
+            if seen_keys.contains(&key) {
+                panic!(
+                    "Duplicated key \"{}\". Keys can only be specified once.",
+                    key
+                );
+            }
+
+            assert_eq!(expect_punct(it), ':');
+
+            match key.as_str() {
+                "type" => info.type_ = expect_ident(it),
+                "name" => info.name = expect_byte_string(it),
+                "author" => info.author = Some(expect_byte_string(it)),
+                "description" => info.description = Some(expect_byte_string(it)),
+                "license" => info.license = expect_byte_string(it),
+                "alias" => info.alias = Some(expect_byte_string(it)),
+                "alias_rtnl_link" => {
+                    info.alias = Some(format!("rtnl-link-{}", expect_byte_string(it)))
+                }
+                "params" => info.params = Some(expect_group(it)),
+                _ => panic!(
+                    "Unknown key \"{}\". Valid keys are: {:?}.",
+                    key, EXPECTED_KEYS
+                ),
+            }
+
+            assert_eq!(expect_punct(it), ',');
+
+            seen_keys.push(key);
+        }
+
+        expect_end(it);
+
+        for key in REQUIRED_KEYS {
+            if !seen_keys.iter().any(|e| e == key) {
+                panic!("Missing required key \"{}\".", key);
+            }
+        }
+
+        let mut ordered_keys: Vec<&str> = Vec::new();
+        for key in EXPECTED_KEYS {
+            if seen_keys.iter().any(|e| e == key) {
+                ordered_keys.push(key);
+            }
+        }
+
+        if seen_keys != ordered_keys {
+            panic!(
+                "Keys are not ordered as expected. Order them like: {:?}.",
+                ordered_keys
+            );
+        }
+
+        info
+    }
+}
+
+pub fn module(ts: TokenStream) -> TokenStream {
+    let mut it = ts.into_iter();
+
+    let info = ModuleInfo::parse(&mut it);
+
+    let name = info.name.clone();
+
+    let mut modinfo = ModInfoBuilder::new(&name);
+    if let Some(author) = info.author {
+        modinfo.emit("author", &author);
+    }
+    if let Some(description) = info.description {
+        modinfo.emit("description", &description);
+    }
+    modinfo.emit("license", &info.license);
+    if let Some(alias) = info.alias {
+        modinfo.emit("alias", &alias);
+    }
+
+    // Built-in modules also export the `file` modinfo string
+    let file =
+        std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable");
+    modinfo.emit_only_builtin("file", &file);
+
+    let mut array_types_to_generate = Vec::new();
+    if let Some(params) = info.params {
+        assert_eq!(params.delimiter(), Delimiter::Brace);
+
+        let mut it = params.stream().into_iter();
+
+        loop {
+            let param_name = match it.next() {
+                Some(TokenTree::Ident(ident)) => ident.to_string(),
+                Some(_) => panic!("Expected Ident or end"),
+                None => break,
+            };
+
+            assert_eq!(expect_punct(&mut it), ':');
+            let param_type = expect_type(&mut it);
+            let group = expect_group(&mut it);
+            assert_eq!(expect_punct(&mut it), ',');
+
+            assert_eq!(group.delimiter(), Delimiter::Brace);
+
+            let mut param_it = group.stream().into_iter();
+            let param_default = get_default(&param_type, &mut param_it);
+            let param_permissions = get_literal(&mut param_it, "permissions");
+            let param_description = get_byte_string(&mut param_it, "description");
+            expect_end(&mut param_it);
+
+            // TODO: more primitive types
+            // TODO: other kinds: unsafes, etc.
+            let (param_kernel_type, ops): (String, _) = match param_type {
+                ParamType::Ident(ref param_type) => (
+                    param_type.to_string(),
+                    param_ops_path(param_type).to_string(),
+                ),
+                ParamType::Array {
+                    ref vals,
+                    max_length,
+                } => {
+                    array_types_to_generate.push((vals.clone(), max_length));
+                    (
+                        format!("__rust_array_param_{}_{}", vals, max_length),
+                        generated_array_ops_name(vals, max_length),
+                    )
+                }
+            };
+
+            modinfo.emit_param("parmtype", &param_name, &param_kernel_type);
+            modinfo.emit_param("parm", &param_name, &param_description);
+            let param_type_internal = match param_type {
+                ParamType::Ident(ref param_type) => match param_type.as_ref() {
+                    "str" => "kernel::module_param::StringParam".to_string(),
+                    other => other.to_string(),
+                },
+                ParamType::Array {
+                    ref vals,
+                    max_length,
+                } => format!(
+                    "kernel::module_param::ArrayParam<{vals}, {max_length}>",
+                    vals = vals,
+                    max_length = max_length
+                ),
+            };
+            let read_func = if permissions_are_readonly(&param_permissions) {
+                format!(
+                    "
+                        fn read(&self) -> &<{param_type_internal} as kernel::module_param::ModuleParam>::Value {{
+                            // SAFETY: Parameters do not need to be locked because they are read only or sysfs is not enabled.
+                            unsafe {{ <{param_type_internal} as kernel::module_param::ModuleParam>::value(&__{name}_{param_name}_value) }}
+                        }}
+                    ",
+                    name = name,
+                    param_name = param_name,
+                    param_type_internal = param_type_internal,
+                )
+            } else {
+                format!(
+                    "
+                        fn read<'lck>(&self, lock: &'lck kernel::KParamGuard) -> &'lck <{param_type_internal} as kernel::module_param::ModuleParam>::Value {{
+                            // SAFETY: Parameters are locked by `KParamGuard`.
+                            unsafe {{ <{param_type_internal} as kernel::module_param::ModuleParam>::value(&__{name}_{param_name}_value) }}
+                        }}
+                    ",
+                    name = name,
+                    param_name = param_name,
+                    param_type_internal = param_type_internal,
+                )
+            };
+            let kparam = format!(
+                "
+                    kernel::bindings::kernel_param__bindgen_ty_1 {{
+                        arg: unsafe {{ &__{name}_{param_name}_value }} as *const _ as *mut kernel::c_types::c_void,
+                    }},
+                ",
+                name = name,
+                param_name = param_name,
+            );
+            modinfo.buffer.push_str(
+                &format!(
+                    "
+                    static mut __{name}_{param_name}_value: {param_type_internal} = {param_default};
+
+                    struct __{name}_{param_name};
+
+                    impl __{name}_{param_name} {{ {read_func} }}
+
+                    const {param_name}: __{name}_{param_name} = __{name}_{param_name};
+
+                    // Note: the C macro that generates the static structs for the `__param` section
+                    // asks for them to be `aligned(sizeof(void *))`. However, that was put in place
+                    // in 2003 in commit 38d5b085d2 (\"[PATCH] Fix over-alignment problem on x86-64\")
+                    // to undo GCC over-alignment of static structs of >32 bytes. It seems that is
+                    // not the case anymore, so we simplify to a transparent representation here
+                    // in the expectation that it is not needed anymore.
+                    // TODO: revisit this to confirm the above comment and remove it if it happened
+                    #[repr(transparent)]
+                    struct __{name}_{param_name}_RacyKernelParam(kernel::bindings::kernel_param);
+
+                    unsafe impl Sync for __{name}_{param_name}_RacyKernelParam {{
+                    }}
+
+                    #[cfg(not(MODULE))]
+                    const __{name}_{param_name}_name: *const kernel::c_types::c_char = b\"{name}.{param_name}\\0\" as *const _ as *const kernel::c_types::c_char;
+
+                    #[cfg(MODULE)]
+                    const __{name}_{param_name}_name: *const kernel::c_types::c_char = b\"{param_name}\\0\" as *const _ as *const kernel::c_types::c_char;
+
+                    #[link_section = \"__param\"]
+                    #[used]
+                    static __{name}_{param_name}_struct: __{name}_{param_name}_RacyKernelParam = __{name}_{param_name}_RacyKernelParam(kernel::bindings::kernel_param {{
+                        name: __{name}_{param_name}_name,
+                        // SAFETY: `__this_module` is constructed by the kernel at load time and will not be freed until the module is unloaded.
+                        #[cfg(MODULE)]
+                        mod_: unsafe {{ &kernel::bindings::__this_module as *const _ as *mut _ }},
+                        #[cfg(not(MODULE))]
+                        mod_: core::ptr::null_mut(),
+                        ops: unsafe {{ &{ops} }} as *const kernel::bindings::kernel_param_ops,
+                        perm: {permissions},
+                        level: -1,
+                        flags: 0,
+                        __bindgen_anon_1: {kparam}
+                    }});
+                    ",
+                    name = name,
+                    param_type_internal = param_type_internal,
+                    read_func = read_func,
+                    param_default = param_default,
+                    param_name = param_name,
+                    ops = ops,
+                    permissions = param_permissions,
+                    kparam = kparam,
+                )
+            );
+        }
+    }
+
+    let mut generated_array_types = String::new();
+
+    for (vals, max_length) in array_types_to_generate {
+        let ops_name = generated_array_ops_name(&vals, max_length);
+        generated_array_types.push_str(&format!(
+            "
+                kernel::make_param_ops!(
+                    {ops_name},
+                    kernel::module_param::ArrayParam<{vals}, {{ {max_length} }}>
+                );
+            ",
+            ops_name = ops_name,
+            vals = vals,
+            max_length = max_length,
+        ));
+    }
+
+    format!(
+        "
+            /// The module name.
+            ///
+            /// Used by the printing macros, e.g. [`info!`].
+            const __LOG_PREFIX: &[u8] = b\"{name}\\0\";
+
+            static mut __MOD: Option<{type_}> = None;
+
+            // SAFETY: `__this_module` is constructed by the kernel at load time and will not be freed until the module is unloaded.
+            #[cfg(MODULE)]
+            static THIS_MODULE: kernel::ThisModule = unsafe {{ kernel::ThisModule::from_ptr(&kernel::bindings::__this_module as *const _ as *mut _) }};
+            #[cfg(not(MODULE))]
+            static THIS_MODULE: kernel::ThisModule = unsafe {{ kernel::ThisModule::from_ptr(core::ptr::null_mut()) }};
+
+            // Loadable modules need to export the `{{init,cleanup}}_module` identifiers
+            #[cfg(MODULE)]
+            #[doc(hidden)]
+            #[no_mangle]
+            pub extern \"C\" fn init_module() -> kernel::c_types::c_int {{
+                __init()
+            }}
+
+            #[cfg(MODULE)]
+            #[doc(hidden)]
+            #[no_mangle]
+            pub extern \"C\" fn cleanup_module() {{
+                __exit()
+            }}
+
+            // Built-in modules are initialized through an initcall pointer
+            // and the identifiers need to be unique
+            #[cfg(not(MODULE))]
+            #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
+            #[doc(hidden)]
+            #[link_section = \"{initcall_section}\"]
+            #[used]
+            pub static __{name}_initcall: extern \"C\" fn() -> kernel::c_types::c_int = __{name}_init;
+
+            #[cfg(not(MODULE))]
+            #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]
+            global_asm!(
+                r#\".section \"{initcall_section}\", \"a\"
+                __{name}_initcall:
+                    .long   __{name}_init - .
+                    .previous
+                \"#
+            );
+
+            #[cfg(not(MODULE))]
+            #[doc(hidden)]
+            #[no_mangle]
+            pub extern \"C\" fn __{name}_init() -> kernel::c_types::c_int {{
+                __init()
+            }}
+
+            #[cfg(not(MODULE))]
+            #[doc(hidden)]
+            #[no_mangle]
+            pub extern \"C\" fn __{name}_exit() {{
+                __exit()
+            }}
+
+            fn __init() -> kernel::c_types::c_int {{
+                match <{type_} as kernel::KernelModule>::init() {{
+                    Ok(m) => {{
+                        unsafe {{
+                            __MOD = Some(m);
+                        }}
+                        return 0;
+                    }}
+                    Err(e) => {{
+                        return e.to_kernel_errno();
+                    }}
+                }}
+            }}
+
+            fn __exit() {{
+                unsafe {{
+                    // Invokes `drop()` on `__MOD`, which should be used for cleanup.
+                    __MOD = None;
+                }}
+            }}
+
+            {modinfo}
+
+            {generated_array_types}
+        ",
+        type_ = info.type_,
+        name = info.name,
+        modinfo = modinfo.buffer,
+        generated_array_types = generated_array_types,
+        initcall_section = ".initcall6.init"
+    ).parse().expect("Error parsing formatted string into token stream.")
+}
+
+pub fn module_misc_device(ts: TokenStream) -> TokenStream {
+    let mut it = ts.into_iter();
+
+    let info = ModuleInfo::parse(&mut it);
+
+    let module = format!("__internal_ModuleFor{}", info.type_);
+
+    format!(
+        "
+            #[doc(hidden)]
+            struct {module} {{
+                _dev: core::pin::Pin<alloc::boxed::Box<kernel::miscdev::Registration>>,
+            }}
+
+            impl kernel::KernelModule for {module} {{
+                fn init() -> kernel::Result<Self> {{
+                    Ok(Self {{
+                        _dev: kernel::miscdev::Registration::new_pinned::<{type_}>(
+                            kernel::c_str!(\"{name}\"),
+                            None,
+                            (),
+                        )?,
+                    }})
+                }}
+            }}
+
+            kernel::prelude::module! {{
+                type: {module},
+                name: b\"{name}\",
+                {author}
+                {description}
+                license: b\"{license}\",
+                {alias}
+            }}
+        ",
+        module = module,
+        type_ = info.type_,
+        name = info.name,
+        author = info
+            .author
+            .map(|v| format!("author: b\"{}\",", v))
+            .unwrap_or_else(|| "".to_string()),
+        description = info
+            .description
+            .map(|v| format!("description: b\"{}\",", v))
+            .unwrap_or_else(|| "".to_string()),
+        alias = info
+            .alias
+            .map(|v| format!("alias: b\"{}\",", v))
+            .unwrap_or_else(|| "".to_string()),
+        license = info.license
+    )
+    .parse()
+    .expect("Error parsing formatted string into token stream.")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_permissions_are_readonly() {
+        assert!(permissions_are_readonly("0b000000000"));
+        assert!(permissions_are_readonly("0o000"));
+        assert!(permissions_are_readonly("000"));
+        assert!(permissions_are_readonly("0x000"));
+
+        assert!(!permissions_are_readonly("0b111111111"));
+        assert!(!permissions_are_readonly("0o777"));
+        assert!(!permissions_are_readonly("511"));
+        assert!(!permissions_are_readonly("0x1ff"));
+
+        assert!(permissions_are_readonly("0o014"));
+        assert!(permissions_are_readonly("0o015"));
+
+        assert!(!permissions_are_readonly("0o214"));
+        assert!(!permissions_are_readonly("0o024"));
+        assert!(!permissions_are_readonly("0o012"));
+
+        assert!(!permissions_are_readonly("0o315"));
+        assert!(!permissions_are_readonly("0o065"));
+        assert!(!permissions_are_readonly("0o017"));
+    }
+}
-- 
2.32.0


  parent reply	other threads:[~2021-07-04 20:29 UTC|newest]

Thread overview: 73+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-04 20:27 [PATCH 00/17] Rust support ojeda
2021-07-04 20:27 ` [PATCH 01/17] kallsyms: support big kernel symbols (2-byte lengths) ojeda
2021-07-04 20:52   ` Linus Torvalds
2021-07-04 21:15     ` Miguel Ojeda
2021-07-04 21:28       ` Linus Torvalds
2021-07-04 21:04   ` Matthew Wilcox
2021-07-04 21:17     ` Miguel Ojeda
2021-07-04 21:33       ` Matthew Wilcox
2021-07-04 21:49         ` Matthew Wilcox
2021-07-04 22:07           ` Miguel Ojeda
2021-07-04 22:20         ` Gary Guo
2021-07-04 22:42           ` Matthew Wilcox
2021-07-04 23:14             ` Gary Guo
2021-07-13 18:02             ` Kent Overstreet
2021-07-04 21:20     ` Gary Guo
2021-07-05  4:35       ` Willy Tarreau
2021-07-04 20:27 ` [PATCH 02/17] kallsyms: increase maximum kernel symbol length to 512 ojeda
2021-07-14 18:20   ` Nick Desaulniers
2021-07-14 19:04     ` Linus Torvalds
2021-07-14 20:09       ` Eric W. Biederman
2021-07-14 20:21         ` Linus Torvalds
2021-07-14 20:48           ` Eric W. Biederman
2021-07-14 22:40             ` Linus Torvalds
2021-07-14 20:19     ` Miguel Ojeda
2021-07-04 20:27 ` [PATCH 03/17] Makefile: generate `CLANG_FLAGS` even in GCC builds ojeda
2021-07-14 18:13   ` Nick Desaulniers
2021-07-14 18:16     ` Nick Desaulniers
2021-07-14 20:31     ` Miguel Ojeda
2021-07-04 20:27 ` [PATCH 04/17] vsprintf: add new `%pA` format specifier ojeda
2021-07-07 20:31   ` Nick Desaulniers
2021-07-07 22:33     ` Miguel Ojeda
2021-07-04 20:27 ` [PATCH 05/17] rust: add C helpers ojeda
2021-07-07 10:19   ` Marco Elver
2021-07-09 10:31     ` Marco Elver
2021-07-09 14:32     ` Miguel Ojeda
2021-07-04 20:27 ` [PATCH 06/17] rust: add `compiler_builtins` crate ojeda
2021-07-04 20:27 ` [PATCH 07/17] rust: add `alloc` crate ojeda
2021-07-04 20:27 ` [PATCH 08/17] rust: add `build_error` crate ojeda
2021-07-04 20:27 ` ojeda [this message]
2021-07-04 20:27 ` [PATCH 10/17] rust: add `kernel` crate ojeda
2021-07-04 20:27 ` [PATCH 11/17] rust: export generated symbols ojeda
2021-07-04 20:27 ` [PATCH 12/17] Kbuild: add Rust support ojeda
2021-07-04 20:27 ` [PATCH 13/17] docs: add Rust documentation ojeda
2021-07-05  5:02   ` Willy Tarreau
2021-07-06  0:06     ` Miguel Ojeda
2021-07-06  2:09       ` Willy Tarreau
2021-07-14 18:37   ` Nick Desaulniers
2021-07-14 19:55     ` Miguel Ojeda
2021-07-04 20:27 ` [PATCH 14/17] samples: add Rust examples ojeda
2021-07-04 20:27 ` [PATCH 15/17] scripts: add `generate_rust_analyzer.py` ojeda
2021-07-05  5:05   ` Willy Tarreau
2021-07-05 23:41     ` Miguel Ojeda
2021-07-04 20:27 ` [PATCH 16/17] MAINTAINERS: Rust ojeda
2021-07-06  0:26   ` Pedro Tammela
2021-07-06 22:14     ` Miguel Ojeda
2021-07-04 20:27 ` [RFC PATCH 17/17] Android: Binder IPC in Rust (WIP) ojeda
2021-07-04 23:11 ` [PATCH 00/17] Rust support Miguel Ojeda
2021-07-07  6:43 ` Christoph Hellwig
2021-07-07 12:33   ` Miguel Ojeda
2021-07-07 12:50     ` Greg Kroah-Hartman
2021-07-07 14:07       ` Wedson Almeida Filho
2021-07-07 14:12         ` Christoph Hellwig
2021-07-07 15:02         ` Greg Kroah-Hartman
2021-07-07 20:56           ` Finn Behrens
2021-07-08  0:58             ` Matthew Wilcox
2021-07-08  6:39               ` [PATCH 00/17] Rust support, NVMe Geert Stappers
2021-07-08  8:29                 ` Finn Behrens
2021-07-22 22:55               ` [PATCH 00/17] Rust support Wedson Almeida Filho
2021-07-23  1:17                 ` Matthew Wilcox
2021-07-23 11:33                   ` [PATCH 00/17] Rust support, GPIO driver Geert Stappers
2021-07-23 15:08                 ` [PATCH 00/17] Rust support Keith Busch
2021-07-07 10:51 ` Marco Elver
2021-07-07 11:28   ` Miguel Ojeda

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210704202756.29107-10-ojeda@kernel.org \
    --to=ojeda@kernel.org \
    --cc=alex.gaynor@gmail.com \
    --cc=ark.email@gmail.com \
    --cc=bobo1239@web.de \
    --cc=boqun.feng@gmail.com \
    --cc=d0u9.su@outlook.com \
    --cc=foxhlchen@gmail.com \
    --cc=gary@garyguo.net \
    --cc=geofft@ldpreload.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jtitor@2k36.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=me@kloenk.de \
    --cc=mpe@ellerman.id.au \
    --cc=rust-for-linux@vger.kernel.org \
    --cc=sylphrenadin@gmail.com \
    --cc=thesven73@gmail.com \
    --cc=torvalds@linux-foundation.org \
    --cc=wedsonaf@google.com \
    --cc=zaidi.ayaan@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.