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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-10-02 12:17:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-10-02 12:17:24 -0700 |
| commit | 3f1fe48a36b0b6722dc3fd421d93512bac138e9a (patch) | |
| tree | b767d7f6e26bc64334d3f14f8422d187239dc45d /rust/syn/scan_expr.rs | |
| download | linux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.tar.gz linux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.zip | |
Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted
Pull io_uring fixes from Jens Axboe:
- Fix a task_work add use-after-free with SQPOLL.
The sqpoll thread could pop and complete the last request while
io_req_normal_work_add() was still looking at them after the mpscq
push.
Use the same approach as DEFER_TASKRUN to protect from that, holding
an RCU read lock across the add, and have exit wait for an RCU grace
period for SQPOLL rings as well.
- CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the
big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED
rings
- Mark the source filter table as COW when cloning bpf filters, so
registering another filter on the source doesn't modify the shared
table in place
- Initialize the task context before running the BPF loop
- Requeue zcrx multishot receives stopped by a local resource
- End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit)
* tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
io_uring: fix task_work add use-after-free with SQPOLL
io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full
io_uring/zcrx: requeue multishot receives stopped by a local resource
io_uring: initialize task context before running the BPF loop
io_uring: zero big_cqe for aux CQEs on CQE32 rings
io_uring: fix free entry check for 32b CQEs on CQE32 rings
io_uring: only post the dummy skip CQE on CQE_MIXED rings
io_uring/bpf_filter: mark source as COW when cloning filters
Diffstat (limited to 'rust/syn/scan_expr.rs')
| -rw-r--r-- | rust/syn/scan_expr.rs | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/rust/syn/scan_expr.rs b/rust/syn/scan_expr.rs new file mode 100644 index 000000000..a5fd1ddc1 --- /dev/null +++ b/rust/syn/scan_expr.rs @@ -0,0 +1,267 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +use self::{Action::*, Input::*}; +use proc_macro2::{Delimiter, Ident, Spacing, TokenTree}; +use syn::parse::{ParseStream, Result}; +use syn::{AngleBracketedGenericArguments, BinOp, Expr, ExprPath, Lifetime, Lit, Token, Type}; + +enum Input { + Keyword(&'static str), + Punct(&'static str), + ConsumeAny, + ConsumeBinOp, + ConsumeBrace, + ConsumeDelimiter, + ConsumeIdent, + ConsumeLifetime, + ConsumeLiteral, + ConsumeNestedBrace, + ExpectPath, + ExpectTurbofish, + ExpectType, + CanBeginExpr, + Otherwise, + Empty, +} + +enum Action { + SetState(&'static [(Input, Action)]), + IncDepth, + DecDepth, + Finish, +} + +static INIT: [(Input, Action); 28] = [ + (ConsumeDelimiter, SetState(&POSTFIX)), + (Keyword("async"), SetState(&ASYNC)), + (Keyword("break"), SetState(&BREAK_LABEL)), + (Keyword("const"), SetState(&CONST)), + (Keyword("continue"), SetState(&CONTINUE)), + (Keyword("for"), SetState(&FOR)), + (Keyword("if"), IncDepth), + (Keyword("let"), SetState(&PATTERN)), + (Keyword("loop"), SetState(&BLOCK)), + (Keyword("match"), IncDepth), + (Keyword("move"), SetState(&CLOSURE)), + (Keyword("return"), SetState(&RETURN)), + (Keyword("static"), SetState(&CLOSURE)), + (Keyword("unsafe"), SetState(&BLOCK)), + (Keyword("while"), IncDepth), + (Keyword("yield"), SetState(&RETURN)), + (Keyword("_"), SetState(&POSTFIX)), + (Punct("!"), SetState(&INIT)), + (Punct("#"), SetState(&[(ConsumeDelimiter, SetState(&INIT))])), + (Punct("&"), SetState(&REFERENCE)), + (Punct("*"), SetState(&INIT)), + (Punct("-"), SetState(&INIT)), + (Punct("..="), SetState(&INIT)), + (Punct(".."), SetState(&RANGE)), + (Punct("|"), SetState(&CLOSURE_ARGS)), + (ConsumeLifetime, SetState(&[(Punct(":"), SetState(&INIT))])), + (ConsumeLiteral, SetState(&POSTFIX)), + (ExpectPath, SetState(&PATH)), +]; + +static POSTFIX: [(Input, Action); 10] = [ + (Keyword("as"), SetState(&[(ExpectType, SetState(&POSTFIX))])), + (Punct("..="), SetState(&INIT)), + (Punct(".."), SetState(&RANGE)), + (Punct("."), SetState(&DOT)), + (Punct("?"), SetState(&POSTFIX)), + (ConsumeBinOp, SetState(&INIT)), + (Punct("="), SetState(&INIT)), + (ConsumeNestedBrace, SetState(&IF_THEN)), + (ConsumeDelimiter, SetState(&POSTFIX)), + (Empty, Finish), +]; + +static ASYNC: [(Input, Action); 3] = [ + (Keyword("move"), SetState(&ASYNC)), + (Punct("|"), SetState(&CLOSURE_ARGS)), + (ConsumeBrace, SetState(&POSTFIX)), +]; + +static BLOCK: [(Input, Action); 1] = [(ConsumeBrace, SetState(&POSTFIX))]; + +static BREAK_LABEL: [(Input, Action); 2] = [ + (ConsumeLifetime, SetState(&BREAK_VALUE)), + (Otherwise, SetState(&BREAK_VALUE)), +]; + +static BREAK_VALUE: [(Input, Action); 3] = [ + (ConsumeNestedBrace, SetState(&IF_THEN)), + (CanBeginExpr, SetState(&INIT)), + (Otherwise, SetState(&POSTFIX)), +]; + +static CLOSURE: [(Input, Action); 7] = [ + (Keyword("async"), SetState(&CLOSURE)), + (Keyword("move"), SetState(&CLOSURE)), + (Punct(","), SetState(&CLOSURE)), + (Punct(">"), SetState(&CLOSURE)), + (Punct("|"), SetState(&CLOSURE_ARGS)), + (ConsumeLifetime, SetState(&CLOSURE)), + (ConsumeIdent, SetState(&CLOSURE)), +]; + +static CLOSURE_ARGS: [(Input, Action); 2] = [ + (Punct("|"), SetState(&CLOSURE_RET)), + (ConsumeAny, SetState(&CLOSURE_ARGS)), +]; + +static CLOSURE_RET: [(Input, Action); 2] = [ + (Punct("->"), SetState(&[(ExpectType, SetState(&BLOCK))])), + (Otherwise, SetState(&INIT)), +]; + +static CONST: [(Input, Action); 2] = [ + (Punct("|"), SetState(&CLOSURE_ARGS)), + (ConsumeBrace, SetState(&POSTFIX)), +]; + +static CONTINUE: [(Input, Action); 2] = [ + (ConsumeLifetime, SetState(&POSTFIX)), + (Otherwise, SetState(&POSTFIX)), +]; + +static DOT: [(Input, Action); 3] = [ + (Keyword("await"), SetState(&POSTFIX)), + (ConsumeIdent, SetState(&METHOD)), + (ConsumeLiteral, SetState(&POSTFIX)), +]; + +static FOR: [(Input, Action); 2] = [ + (Punct("<"), SetState(&CLOSURE)), + (Otherwise, SetState(&PATTERN)), +]; + +static IF_ELSE: [(Input, Action); 2] = [(Keyword("if"), SetState(&INIT)), (ConsumeBrace, DecDepth)]; +static IF_THEN: [(Input, Action); 2] = + [(Keyword("else"), SetState(&IF_ELSE)), (Otherwise, DecDepth)]; + +static METHOD: [(Input, Action); 1] = [(ExpectTurbofish, SetState(&POSTFIX))]; + +static PATH: [(Input, Action); 4] = [ + (Punct("!="), SetState(&INIT)), + (Punct("!"), SetState(&INIT)), + (ConsumeNestedBrace, SetState(&IF_THEN)), + (Otherwise, SetState(&POSTFIX)), +]; + +static PATTERN: [(Input, Action); 15] = [ + (ConsumeDelimiter, SetState(&PATTERN)), + (Keyword("box"), SetState(&PATTERN)), + (Keyword("in"), IncDepth), + (Keyword("mut"), SetState(&PATTERN)), + (Keyword("ref"), SetState(&PATTERN)), + (Keyword("_"), SetState(&PATTERN)), + (Punct("!"), SetState(&PATTERN)), + (Punct("&"), SetState(&PATTERN)), + (Punct("..="), SetState(&PATTERN)), + (Punct(".."), SetState(&PATTERN)), + (Punct("="), SetState(&INIT)), + (Punct("@"), SetState(&PATTERN)), + (Punct("|"), SetState(&PATTERN)), + (ConsumeLiteral, SetState(&PATTERN)), + (ExpectPath, SetState(&PATTERN)), +]; + +static RANGE: [(Input, Action); 6] = [ + (Punct("..="), SetState(&INIT)), + (Punct(".."), SetState(&RANGE)), + (Punct("."), SetState(&DOT)), + (ConsumeNestedBrace, SetState(&IF_THEN)), + (Empty, Finish), + (Otherwise, SetState(&INIT)), +]; + +static RAW: [(Input, Action); 3] = [ + (Keyword("const"), SetState(&INIT)), + (Keyword("mut"), SetState(&INIT)), + (Otherwise, SetState(&POSTFIX)), +]; + +static REFERENCE: [(Input, Action); 3] = [ + (Keyword("mut"), SetState(&INIT)), + (Keyword("raw"), SetState(&RAW)), + (Otherwise, SetState(&INIT)), +]; + +static RETURN: [(Input, Action); 2] = [ + (CanBeginExpr, SetState(&INIT)), + (Otherwise, SetState(&POSTFIX)), +]; + +pub(crate) fn scan_expr(input: ParseStream) -> Result<()> { + let mut state = INIT.as_slice(); + let mut depth = 0usize; + 'table: loop { + for rule in state { + if match rule.0 { + Input::Keyword(expected) => input.step(|cursor| match cursor.ident() { + Some((ident, rest)) if ident == expected => Ok((true, rest)), + _ => Ok((false, *cursor)), + })?, + Input::Punct(expected) => input.step(|cursor| { + let begin = *cursor; + let mut cursor = begin; + for (i, ch) in expected.chars().enumerate() { + match cursor.punct() { + Some((punct, _)) if punct.as_char() != ch => break, + Some((_, rest)) if i == expected.len() - 1 => { + return Ok((true, rest)); + } + Some((punct, rest)) if punct.spacing() == Spacing::Joint => { + cursor = rest; + } + _ => break, + } + } + Ok((false, begin)) + })?, + Input::ConsumeAny => input.parse::<Option<TokenTree>>()?.is_some(), + Input::ConsumeBinOp => input.parse::<BinOp>().is_ok(), + Input::ConsumeBrace | Input::ConsumeNestedBrace => { + (matches!(rule.0, Input::ConsumeBrace) || depth > 0) + && input.step(|cursor| match cursor.group(Delimiter::Brace) { + Some((_inside, _span, rest)) => Ok((true, rest)), + None => Ok((false, *cursor)), + })? + } + Input::ConsumeDelimiter => input.step(|cursor| match cursor.any_group() { + Some((_inside, _delimiter, _span, rest)) => Ok((true, rest)), + None => Ok((false, *cursor)), + })?, + Input::ConsumeIdent => input.parse::<Option<Ident>>()?.is_some(), + Input::ConsumeLifetime => input.parse::<Option<Lifetime>>()?.is_some(), + Input::ConsumeLiteral => input.parse::<Option<Lit>>()?.is_some(), + Input::ExpectPath => { + input.parse::<ExprPath>()?; + true + } + Input::ExpectTurbofish => { + if input.peek(Token![::]) { + input.parse::<AngleBracketedGenericArguments>()?; + } + true + } + Input::ExpectType => { + Type::without_plus(input)?; + true + } + Input::CanBeginExpr => Expr::peek(input), + Input::Otherwise => true, + Input::Empty => input.is_empty() || input.peek(Token![,]), + } { + state = match rule.1 { + Action::SetState(next) => next, + Action::IncDepth => (depth += 1, &INIT).1, + Action::DecDepth => (depth -= 1, &POSTFIX).1, + Action::Finish => return if depth == 0 { Ok(()) } else { break }, + }; + continue 'table; + } + } + return Err(input.error("unsupported expression")); + } +} |
