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/classify.rs | 313 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 313 insertions(+) create mode 100644 rust/syn/classify.rs (limited to 'rust/syn/classify.rs') diff --git a/rust/syn/classify.rs b/rust/syn/classify.rs new file mode 100644 index 000000000..92a975bfe --- /dev/null +++ b/rust/syn/classify.rs @@ -0,0 +1,313 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +#[cfg(feature = "full")] +use crate::expr::Expr; +#[cfg(any(feature = "printing", feature = "full"))] +use crate::generics::TypeParamBound; +#[cfg(any(feature = "printing", feature = "full"))] +use crate::path::{Path, PathArguments}; +#[cfg(any(feature = "printing", feature = "full"))] +use crate::punctuated::Punctuated; +#[cfg(any(feature = "printing", feature = "full"))] +use crate::ty::{ReturnType, Type}; +#[cfg(feature = "full")] +use proc_macro2::{Delimiter, TokenStream, TokenTree}; +#[cfg(any(feature = "printing", feature = "full"))] +use std::ops::ControlFlow; + +#[cfg(feature = "full")] +pub(crate) fn requires_semi_to_be_stmt(expr: &Expr) -> bool { + match expr { + Expr::Macro(expr) => !expr.mac.delimiter.is_brace(), + _ => requires_comma_to_be_match_arm(expr), + } +} + +#[cfg(feature = "full")] +pub(crate) fn requires_comma_to_be_match_arm(expr: &Expr) -> bool { + match expr { + Expr::If(_) + | Expr::Match(_) + | Expr::Block(_) | Expr::Unsafe(_) // both under ExprKind::Block in rustc + | Expr::While(_) + | Expr::Loop(_) + | Expr::ForLoop(_) + | Expr::TryBlock(_) + | Expr::Const(_) => false, + + Expr::Array(_) + | Expr::Assign(_) + | Expr::Async(_) + | Expr::Await(_) + | Expr::Binary(_) + | Expr::Break(_) + | Expr::Call(_) + | Expr::Cast(_) + | Expr::Closure(_) + | Expr::Continue(_) + | Expr::Field(_) + | Expr::Group(_) + | Expr::Index(_) + | Expr::Infer(_) + | Expr::Let(_) + | Expr::Lit(_) + | Expr::Macro(_) + | Expr::MethodCall(_) + | Expr::Paren(_) + | Expr::Path(_) + | Expr::Range(_) + | Expr::RawAddr(_) + | Expr::Reference(_) + | Expr::Repeat(_) + | Expr::Return(_) + | Expr::Struct(_) + | Expr::Try(_) + | Expr::Tuple(_) + | Expr::Unary(_) + | Expr::Yield(_) + | Expr::Verbatim(_) => true, + } +} + +#[cfg(feature = "printing")] +pub(crate) fn trailing_unparameterized_path(mut ty: &Type) -> bool { + loop { + match ty { + Type::BareFn(t) => match &t.output { + ReturnType::Default => return false, + ReturnType::Type(_, ret) => ty = ret, + }, + Type::ImplTrait(t) => match last_type_in_bounds(&t.bounds) { + ControlFlow::Break(trailing_path) => return trailing_path, + ControlFlow::Continue(t) => ty = t, + }, + Type::Path(t) => match last_type_in_path(&t.path) { + ControlFlow::Break(trailing_path) => return trailing_path, + ControlFlow::Continue(t) => ty = t, + }, + Type::Ptr(t) => ty = &t.elem, + Type::Reference(t) => ty = &t.elem, + Type::TraitObject(t) => match last_type_in_bounds(&t.bounds) { + ControlFlow::Break(trailing_path) => return trailing_path, + ControlFlow::Continue(t) => ty = t, + }, + + Type::Array(_) + | Type::Group(_) + | Type::Infer(_) + | Type::Macro(_) + | Type::Never(_) + | Type::Paren(_) + | Type::Slice(_) + | Type::Tuple(_) + | Type::Verbatim(_) => return false, + } + } + + fn last_type_in_path(path: &Path) -> ControlFlow { + match &path.segments.last().unwrap().arguments { + PathArguments::None => ControlFlow::Break(true), + PathArguments::AngleBracketed(_) => ControlFlow::Break(false), + PathArguments::Parenthesized(arg) => match &arg.output { + ReturnType::Default => ControlFlow::Break(false), + ReturnType::Type(_, ret) => ControlFlow::Continue(ret), + }, + } + } + + fn last_type_in_bounds( + bounds: &Punctuated, + ) -> ControlFlow { + match bounds.last().unwrap() { + TypeParamBound::Trait(t) => last_type_in_path(&t.path), + TypeParamBound::Lifetime(_) + | TypeParamBound::PreciseCapture(_) + | TypeParamBound::Verbatim(_) => ControlFlow::Break(false), + } + } +} + +/// Whether the expression's first token is the label of a loop/block. +#[cfg(all(feature = "printing", feature = "full"))] +pub(crate) fn expr_leading_label(mut expr: &Expr) -> bool { + loop { + match expr { + Expr::Block(e) => return e.label.is_some(), + Expr::ForLoop(e) => return e.label.is_some(), + Expr::Loop(e) => return e.label.is_some(), + Expr::While(e) => return e.label.is_some(), + + Expr::Assign(e) => expr = &e.left, + Expr::Await(e) => expr = &e.base, + Expr::Binary(e) => expr = &e.left, + Expr::Call(e) => expr = &e.func, + Expr::Cast(e) => expr = &e.expr, + Expr::Field(e) => expr = &e.base, + Expr::Index(e) => expr = &e.expr, + Expr::MethodCall(e) => expr = &e.receiver, + Expr::Range(e) => match &e.start { + Some(start) => expr = start, + None => return false, + }, + Expr::Try(e) => expr = &e.expr, + + Expr::Array(_) + | Expr::Async(_) + | Expr::Break(_) + | Expr::Closure(_) + | Expr::Const(_) + | Expr::Continue(_) + | Expr::Group(_) + | Expr::If(_) + | Expr::Infer(_) + | Expr::Let(_) + | Expr::Lit(_) + | Expr::Macro(_) + | Expr::Match(_) + | Expr::Paren(_) + | Expr::Path(_) + | Expr::RawAddr(_) + | Expr::Reference(_) + | Expr::Repeat(_) + | Expr::Return(_) + | Expr::Struct(_) + | Expr::TryBlock(_) + | Expr::Tuple(_) + | Expr::Unary(_) + | Expr::Unsafe(_) + | Expr::Verbatim(_) + | Expr::Yield(_) => return false, + } + } +} + +/// Whether the expression's last token is `}`. +#[cfg(feature = "full")] +pub(crate) fn expr_trailing_brace(mut expr: &Expr) -> bool { + loop { + match expr { + Expr::Async(_) + | Expr::Block(_) + | Expr::Const(_) + | Expr::ForLoop(_) + | Expr::If(_) + | Expr::Loop(_) + | Expr::Match(_) + | Expr::Struct(_) + | Expr::TryBlock(_) + | Expr::Unsafe(_) + | Expr::While(_) => return true, + + Expr::Assign(e) => expr = &e.right, + Expr::Binary(e) => expr = &e.right, + Expr::Break(e) => match &e.expr { + Some(e) => expr = e, + None => return false, + }, + Expr::Cast(e) => return type_trailing_brace(&e.ty), + Expr::Closure(e) => expr = &e.body, + Expr::Let(e) => expr = &e.expr, + Expr::Macro(e) => return e.mac.delimiter.is_brace(), + Expr::Range(e) => match &e.end { + Some(end) => expr = end, + None => return false, + }, + Expr::RawAddr(e) => expr = &e.expr, + Expr::Reference(e) => expr = &e.expr, + Expr::Return(e) => match &e.expr { + Some(e) => expr = e, + None => return false, + }, + Expr::Unary(e) => expr = &e.expr, + Expr::Verbatim(e) => return tokens_trailing_brace(e), + Expr::Yield(e) => match &e.expr { + Some(e) => expr = e, + None => return false, + }, + + Expr::Array(_) + | Expr::Await(_) + | Expr::Call(_) + | Expr::Continue(_) + | Expr::Field(_) + | Expr::Group(_) + | Expr::Index(_) + | Expr::Infer(_) + | Expr::Lit(_) + | Expr::MethodCall(_) + | Expr::Paren(_) + | Expr::Path(_) + | Expr::Repeat(_) + | Expr::Try(_) + | Expr::Tuple(_) => return false, + } + } + + fn type_trailing_brace(mut ty: &Type) -> bool { + loop { + match ty { + Type::BareFn(t) => match &t.output { + ReturnType::Default => return false, + ReturnType::Type(_, ret) => ty = ret, + }, + Type::ImplTrait(t) => match last_type_in_bounds(&t.bounds) { + ControlFlow::Break(trailing_brace) => return trailing_brace, + ControlFlow::Continue(t) => ty = t, + }, + Type::Macro(t) => return t.mac.delimiter.is_brace(), + Type::Path(t) => match last_type_in_path(&t.path) { + Some(t) => ty = t, + None => return false, + }, + Type::Ptr(t) => ty = &t.elem, + Type::Reference(t) => ty = &t.elem, + Type::TraitObject(t) => match last_type_in_bounds(&t.bounds) { + ControlFlow::Break(trailing_brace) => return trailing_brace, + ControlFlow::Continue(t) => ty = t, + }, + Type::Verbatim(t) => return tokens_trailing_brace(t), + + Type::Array(_) + | Type::Group(_) + | Type::Infer(_) + | Type::Never(_) + | Type::Paren(_) + | Type::Slice(_) + | Type::Tuple(_) => return false, + } + } + } + + fn last_type_in_path(path: &Path) -> Option<&Type> { + match &path.segments.last().unwrap().arguments { + PathArguments::None | PathArguments::AngleBracketed(_) => None, + PathArguments::Parenthesized(arg) => match &arg.output { + ReturnType::Default => None, + ReturnType::Type(_, ret) => Some(ret), + }, + } + } + + fn last_type_in_bounds( + bounds: &Punctuated, + ) -> ControlFlow { + match bounds.last().unwrap() { + TypeParamBound::Trait(t) => match last_type_in_path(&t.path) { + Some(t) => ControlFlow::Continue(t), + None => ControlFlow::Break(false), + }, + TypeParamBound::Lifetime(_) | TypeParamBound::PreciseCapture(_) => { + ControlFlow::Break(false) + } + TypeParamBound::Verbatim(t) => ControlFlow::Break(tokens_trailing_brace(t)), + } + } + + fn tokens_trailing_brace(tokens: &TokenStream) -> bool { + if let Some(TokenTree::Group(last)) = tokens.clone().into_iter().last() { + last.delimiter() == Delimiter::Brace + } else { + false + } + } +} -- cgit v1.3.1