From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- rust/syn/mac.rs | 227 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 227 insertions(+) create mode 100644 rust/syn/mac.rs (limited to 'rust/syn/mac.rs') diff --git a/rust/syn/mac.rs b/rust/syn/mac.rs new file mode 100644 index 000000000..ce4b022b4 --- /dev/null +++ b/rust/syn/mac.rs @@ -0,0 +1,227 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +#[cfg(feature = "parsing")] +use crate::error::Result; +#[cfg(feature = "parsing")] +use crate::parse::{Parse, ParseStream, Parser}; +use crate::path::Path; +use crate::token::{Brace, Bracket, Paren}; +use proc_macro2::extra::DelimSpan; +#[cfg(feature = "parsing")] +use proc_macro2::Delimiter; +use proc_macro2::TokenStream; +#[cfg(feature = "parsing")] +use proc_macro2::TokenTree; + +ast_struct! { + /// A macro invocation: `println!("{}", mac)`. + #[cfg_attr(docsrs, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct Macro { + pub path: Path, + pub bang_token: Token![!], + pub delimiter: MacroDelimiter, + pub tokens: TokenStream, + } +} + +ast_enum! { + /// A grouping token that surrounds a macro body: `m!(...)` or `m!{...}` or `m![...]`. + #[cfg_attr(docsrs, doc(cfg(any(feature = "full", feature = "derive"))))] + pub enum MacroDelimiter { + Paren(Paren), + Brace(Brace), + Bracket(Bracket), + } +} + +impl MacroDelimiter { + pub fn span(&self) -> &DelimSpan { + match self { + MacroDelimiter::Paren(token) => &token.span, + MacroDelimiter::Brace(token) => &token.span, + MacroDelimiter::Bracket(token) => &token.span, + } + } + + #[cfg(all(feature = "full", any(feature = "parsing", feature = "printing")))] + pub(crate) fn is_brace(&self) -> bool { + match self { + MacroDelimiter::Brace(_) => true, + MacroDelimiter::Paren(_) | MacroDelimiter::Bracket(_) => false, + } + } +} + +impl Macro { + /// Parse the tokens within the macro invocation's delimiters into a syntax + /// tree. + /// + /// This is equivalent to `syn::parse2::(mac.tokens)` except that it + /// produces a more useful span when `tokens` is empty. + /// + /// # Example + /// + /// ``` + /// use syn::{parse_quote, Expr, ExprLit, Ident, Lit, LitStr, Macro, Token}; + /// use syn::ext::IdentExt; + /// use syn::parse::{Error, Parse, ParseStream, Result}; + /// use syn::punctuated::Punctuated; + /// + /// // The arguments expected by libcore's format_args macro, and as a + /// // result most other formatting and printing macros like println. + /// // + /// // println!("{} is {number:.prec$}", "x", prec=5, number=0.01) + /// struct FormatArgs { + /// format_string: Expr, + /// positional_args: Vec, + /// named_args: Vec<(Ident, Expr)>, + /// } + /// + /// impl Parse for FormatArgs { + /// fn parse(input: ParseStream) -> Result { + /// let format_string: Expr; + /// let mut positional_args = Vec::new(); + /// let mut named_args = Vec::new(); + /// + /// format_string = input.parse()?; + /// while !input.is_empty() { + /// input.parse::()?; + /// if input.is_empty() { + /// break; + /// } + /// if input.peek(Ident::peek_any) && input.peek2(Token![=]) { + /// while !input.is_empty() { + /// let name: Ident = input.call(Ident::parse_any)?; + /// input.parse::()?; + /// let value: Expr = input.parse()?; + /// named_args.push((name, value)); + /// if input.is_empty() { + /// break; + /// } + /// input.parse::()?; + /// } + /// break; + /// } + /// positional_args.push(input.parse()?); + /// } + /// + /// Ok(FormatArgs { + /// format_string, + /// positional_args, + /// named_args, + /// }) + /// } + /// } + /// + /// // Extract the first argument, the format string literal, from an + /// // invocation of a formatting or printing macro. + /// fn get_format_string(m: &Macro) -> Result { + /// let args: FormatArgs = m.parse_body()?; + /// match args.format_string { + /// Expr::Lit(ExprLit { lit: Lit::Str(lit), .. }) => Ok(lit), + /// other => { + /// // First argument was not a string literal expression. + /// // Maybe something like: println!(concat!(...), ...) + /// Err(Error::new_spanned(other, "format string must be a string literal")) + /// } + /// } + /// } + /// + /// fn main() { + /// let invocation = parse_quote! { + /// println!("{:?}", Instant::now()) + /// }; + /// let lit = get_format_string(&invocation).unwrap(); + /// assert_eq!(lit.value(), "{:?}"); + /// } + /// ``` + #[cfg(feature = "parsing")] + #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))] + pub fn parse_body(&self) -> Result { + self.parse_body_with(T::parse) + } + + /// Parse the tokens within the macro invocation's delimiters using the + /// given parser. + #[cfg(feature = "parsing")] + #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))] + pub fn parse_body_with(&self, parser: F) -> Result { + let scope = self.delimiter.span().close(); + crate::parse::parse_scoped(parser, scope, self.tokens.clone()) + } +} + +#[cfg(feature = "parsing")] +pub(crate) fn parse_delimiter(input: ParseStream) -> Result<(MacroDelimiter, TokenStream)> { + input.step(|cursor| { + if let Some((TokenTree::Group(g), rest)) = cursor.token_tree() { + let span = g.delim_span(); + let delimiter = match g.delimiter() { + Delimiter::Parenthesis => MacroDelimiter::Paren(Paren(span)), + Delimiter::Brace => MacroDelimiter::Brace(Brace(span)), + Delimiter::Bracket => MacroDelimiter::Bracket(Bracket(span)), + Delimiter::None => { + return Err(cursor.error("expected delimiter")); + } + }; + Ok(((delimiter, g.stream()), rest)) + } else { + Err(cursor.error("expected delimiter")) + } + }) +} + +#[cfg(feature = "parsing")] +pub(crate) mod parsing { + use crate::error::Result; + use crate::mac::{parse_delimiter, Macro}; + use crate::parse::{Parse, ParseStream}; + use crate::path::Path; + + #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))] + impl Parse for Macro { + fn parse(input: ParseStream) -> Result { + let tokens; + Ok(Macro { + path: input.call(Path::parse_mod_style)?, + bang_token: input.parse()?, + delimiter: { + let (delimiter, content) = parse_delimiter(input)?; + tokens = content; + delimiter + }, + tokens, + }) + } + } +} + +#[cfg(feature = "printing")] +mod printing { + use crate::mac::{Macro, MacroDelimiter}; + use crate::path; + use crate::path::printing::PathStyle; + use crate::token; + use proc_macro2::{Delimiter, TokenStream}; + use quote::ToTokens; + + impl MacroDelimiter { + pub(crate) fn surround(&self, tokens: &mut TokenStream, inner: TokenStream) { + let (delim, span) = match self { + MacroDelimiter::Paren(paren) => (Delimiter::Parenthesis, paren.span), + MacroDelimiter::Brace(brace) => (Delimiter::Brace, brace.span), + MacroDelimiter::Bracket(bracket) => (Delimiter::Bracket, bracket.span), + }; + token::printing::delim(delim, span.join(), tokens, inner); + } + } + + #[cfg_attr(docsrs, doc(cfg(feature = "printing")))] + impl ToTokens for Macro { + fn to_tokens(&self, tokens: &mut TokenStream) { + path::printing::print_path(tokens, &self.path, PathStyle::Mod); + self.bang_token.to_tokens(tokens); + self.delimiter.surround(tokens, self.tokens.clone()); + } + } +} -- cgit v1.3.1