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Auto merge of #2699 - RalfJung:schedule-refactor, r=RalfJung

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refactor scheduler

Refactors the scheduler to use something akin to a generator -- a callback that will be invoked when the stack of a thread is empty, which has the chance to push a new stack frame or do other things and then indicates whether this thread is done, or should be scheduled again. (Unfortunately I think we [cannot use actual generators](https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/Generators.20that.20borrow.20on.20each.20resume.3F) here.) The interpreter loop is now a proper infinite loop, the only way to leave it is for some kind of interrupt to be triggered (represented as `InterpError`) -- unifying how we handle 'exit when calling `process::exit`' and 'exit when main thread quits'.

The last commit implements an alternative approach to https://github.com/rust-lang/miri/pull/2660 using this new structure. Fixes https://github.com/rust-lang/miri/issues/2629.
This commit is contained in:
bors 2022-12-01 09:08:06 +00:00
commit 623b4aba6c
15 changed files with 412 additions and 327 deletions
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16
src/tools/miri/cargo-miri/src/setup.rs
View file

@ -99,12 +99,10 @@ pub fn setup(subcommand: &MiriCommand, target: &str, rustc_version: &VersionMeta
// `config.toml`.
command.env("RUSTC_WRAPPER", "");
if only_setup {
if print_sysroot {
// Be extra sure there is no noise on stdout.
command.stdout(process::Stdio::null());
}
if only_setup && !print_sysroot {
// Forward output.
} else {
// Supress output.
command.stdout(process::Stdio::null());
command.stderr(process::Stdio::null());
}
@ -120,7 +118,9 @@ pub fn setup(subcommand: &MiriCommand, target: &str, rustc_version: &VersionMeta
std::env::set_var("MIRI_SYSROOT", &sysroot_dir);
// Do the build.
if only_setup {
if print_sysroot {
// Be silent.
} else if only_setup {
// We want to be explicit.
eprintln!("Preparing a sysroot for Miri (target: {target})...");
} else {
@ -143,7 +143,9 @@ pub fn setup(subcommand: &MiriCommand, target: &str, rustc_version: &VersionMeta
)
}
});
if only_setup {
if print_sysroot {
// Be silent.
} else if only_setup {
eprintln!("A sysroot for Miri is now available in `{}`.", sysroot_dir.display());
} else {
eprintln!("done");

11
src/tools/miri/ci.sh
View file

@ -40,10 +40,15 @@ function run_tests {
./miri test
if [ -z "${MIRI_TEST_TARGET+exists}" ]; then
# Only for host architecture: tests with optimizations (`-O` is what cargo passes, but crank MIR
# optimizations up all the way).
# Optimizations change diagnostics (mostly backtraces), so we don't check them
#FIXME(#2155): we want to only run the pass and panic tests here, not the fail tests.
# optimizations up all the way, too).
# Optimizations change diagnostics (mostly backtraces), so we don't check
# them. Also error locations change so we don't run the failing tests.
MIRIFLAGS="${MIRIFLAGS:-} -O -Zmir-opt-level=4" MIRI_SKIP_UI_CHECKS=1 ./miri test -- tests/{pass,panic}
# Also run some many-seeds tests. 64 seeds means this takes around a minute per test.
for FILE in tests/many-seeds/*.rs; do
MIRI_SEEDS=64 CARGO_EXTRA_FLAGS="$CARGO_EXTRA_FLAGS -q" ./miri many-seeds ./miri run "$FILE"
done
fi
## test-cargo-miri

9
src/tools/miri/miri
View file

@ -36,7 +36,8 @@ Mainly meant to be invoked by rust-analyzer.
./miri many-seeds <command>:
Runs <command> over and over again with different seeds for Miri. The MIRIFLAGS
variable is set to its original value appended with ` -Zmiri-seed=$SEED` for
many different seeds.
many different seeds. The MIRI_SEEDS variable controls how many seeds are being
tried; MIRI_SEED_START controls the first seed to try.
./miri bench <benches>:
Runs the benchmarks from bench-cargo-miri in hyperfine. hyperfine needs to be installed.
@ -174,7 +175,9 @@ rustc-push)
fi
;;
many-seeds)
for SEED in $(seq 0 255); do
MIRI_SEED_START=${MIRI_SEED_START:-0} # default to 0
MIRI_SEEDS=${MIRI_SEEDS:-256} # default to 256
for SEED in $(seq $MIRI_SEED_START $(( $MIRI_SEED_START + $MIRI_SEEDS - 1 )) ); do
echo "Trying seed: $SEED"
MIRIFLAGS="$MIRIFLAGS -Zlayout-seed=$SEED -Zmiri-seed=$SEED" $@ || { echo "Failing seed: $SEED"; break; }
done
@ -249,6 +252,8 @@ export RUSTFLAGS="-C link-args=-Wl,-rpath,$LIBDIR $RUSTFLAGS"
# Build a sysroot and set MIRI_SYSROOT to use it. Arguments are passed to `cargo miri setup`.
build_sysroot() {
if ! MIRI_SYSROOT="$($CARGO run $CARGO_EXTRA_FLAGS --manifest-path "$MIRIDIR"/cargo-miri/Cargo.toml -- miri setup --print-sysroot "$@")"; then
# Run it again so the user can see the error.
$CARGO run $CARGO_EXTRA_FLAGS --manifest-path "$MIRIDIR"/cargo-miri/Cargo.toml -- miri setup "$@"
echo "'cargo miri setup' failed"
exit 1
fi

269
src/tools/miri/src/concurrency/thread.rs
View file

@ -3,6 +3,7 @@
use std::cell::RefCell;
use std::collections::hash_map::Entry;
use std::num::TryFromIntError;
use std::task::Poll;
use std::time::{Duration, SystemTime};
use log::trace;
@ -16,18 +17,17 @@ use rustc_target::spec::abi::Abi;
use crate::concurrency::data_race;
use crate::concurrency::sync::SynchronizationState;
use crate::shims::tls;
use crate::*;
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum SchedulingAction {
enum SchedulingAction {
/// Execute step on the active thread.
ExecuteStep,
/// Execute a timeout callback.
ExecuteTimeoutCallback,
/// Execute destructors of the active thread.
ExecuteDtors,
/// Stop the program.
Stop,
/// Wait for a bit, until there is a timeout to be called.
Sleep(Duration),
}
/// Trait for callbacks that can be executed when some event happens, such as after a timeout.
@ -41,9 +41,6 @@ type TimeoutCallback<'mir, 'tcx> = Box<dyn MachineCallback<'mir, 'tcx> + 'tcx>;
#[derive(Clone, Copy, Debug, PartialOrd, Ord, PartialEq, Eq, Hash)]
pub struct ThreadId(u32);
/// The main thread. When it terminates, the whole application terminates.
const MAIN_THREAD: ThreadId = ThreadId(0);
impl ThreadId {
pub fn to_u32(self) -> u32 {
self.0
@ -118,6 +115,12 @@ pub struct Thread<'mir, 'tcx> {
/// The virtual call stack.
stack: Vec<Frame<'mir, 'tcx, Provenance, FrameData<'tcx>>>,
/// The function to call when the stack ran empty, to figure out what to do next.
/// Conceptually, this is the interpreter implementation of the things that happen 'after' the
/// Rust language entry point for this thread returns (usually implemented by the C or OS runtime).
/// (`None` is an error, it means the callback has not been set up yet or is actively running.)
pub(crate) on_stack_empty: Option<StackEmptyCallback<'mir, 'tcx>>,
/// The index of the topmost user-relevant frame in `stack`. This field must contain
/// the value produced by `get_top_user_relevant_frame`.
/// The `None` state here represents
@ -137,19 +140,10 @@ pub struct Thread<'mir, 'tcx> {
pub(crate) last_error: Option<MPlaceTy<'tcx, Provenance>>,
}
impl<'mir, 'tcx> Thread<'mir, 'tcx> {
/// Check if the thread is done executing (no more stack frames). If yes,
/// change the state to terminated and return `true`.
fn check_terminated(&mut self) -> bool {
if self.state == ThreadState::Enabled {
if self.stack.is_empty() {
self.state = ThreadState::Terminated;
return true;
}
}
false
}
pub type StackEmptyCallback<'mir, 'tcx> =
Box<dyn FnMut(&mut MiriInterpCx<'mir, 'tcx>) -> InterpResult<'tcx, Poll<()>>>;
impl<'mir, 'tcx> Thread<'mir, 'tcx> {
/// Get the name of the current thread, or `<unnamed>` if it was not set.
fn thread_name(&self) -> &[u8] {
if let Some(ref thread_name) = self.thread_name { thread_name } else { b"<unnamed>" }
@ -202,28 +196,21 @@ impl<'mir, 'tcx> std::fmt::Debug for Thread<'mir, 'tcx> {
}
}
impl<'mir, 'tcx> Default for Thread<'mir, 'tcx> {
fn default() -> Self {
impl<'mir, 'tcx> Thread<'mir, 'tcx> {
fn new(name: Option<&str>, on_stack_empty: Option<StackEmptyCallback<'mir, 'tcx>>) -> Self {
Self {
state: ThreadState::Enabled,
thread_name: None,
thread_name: name.map(|name| Vec::from(name.as_bytes())),
stack: Vec::new(),
top_user_relevant_frame: None,
join_status: ThreadJoinStatus::Joinable,
panic_payload: None,
last_error: None,
on_stack_empty,
}
}
}
impl<'mir, 'tcx> Thread<'mir, 'tcx> {
fn new(name: &str) -> Self {
let mut thread = Thread::default();
thread.thread_name = Some(Vec::from(name.as_bytes()));
thread
}
}
impl VisitTags for Thread<'_, '_> {
fn visit_tags(&self, visit: &mut dyn FnMut(SbTag)) {
let Thread {
@ -234,6 +221,7 @@ impl VisitTags for Thread<'_, '_> {
state: _,
thread_name: _,
join_status: _,
on_stack_empty: _, // we assume the closure captures no GC-relevant state
} = self;
panic_payload.visit_tags(visit);
@ -327,22 +315,6 @@ pub struct ThreadManager<'mir, 'tcx> {
timeout_callbacks: FxHashMap<ThreadId, TimeoutCallbackInfo<'mir, 'tcx>>,
}
impl<'mir, 'tcx> Default for ThreadManager<'mir, 'tcx> {
fn default() -> Self {
let mut threads = IndexVec::new();
// Create the main thread and add it to the list of threads.
threads.push(Thread::new("main"));
Self {
active_thread: ThreadId::new(0),
threads,
sync: SynchronizationState::default(),
thread_local_alloc_ids: Default::default(),
yield_active_thread: false,
timeout_callbacks: FxHashMap::default(),
}
}
}
impl VisitTags for ThreadManager<'_, '_> {
fn visit_tags(&self, visit: &mut dyn FnMut(SbTag)) {
let ThreadManager {
@ -367,8 +339,28 @@ impl VisitTags for ThreadManager<'_, '_> {
}
}
impl<'mir, 'tcx> Default for ThreadManager<'mir, 'tcx> {
fn default() -> Self {
let mut threads = IndexVec::new();
// Create the main thread and add it to the list of threads.
threads.push(Thread::new(Some("main"), None));
Self {
active_thread: ThreadId::new(0),
threads,
sync: SynchronizationState::default(),
thread_local_alloc_ids: Default::default(),
yield_active_thread: false,
timeout_callbacks: FxHashMap::default(),
}
}
}
impl<'mir, 'tcx: 'mir> ThreadManager<'mir, 'tcx> {
pub(crate) fn init(ecx: &mut MiriInterpCx<'mir, 'tcx>) {
pub(crate) fn init(
ecx: &mut MiriInterpCx<'mir, 'tcx>,
on_main_stack_empty: StackEmptyCallback<'mir, 'tcx>,
) {
ecx.machine.threads.threads[ThreadId::new(0)].on_stack_empty = Some(on_main_stack_empty);
if ecx.tcx.sess.target.os.as_ref() != "windows" {
// The main thread can *not* be joined on except on windows.
ecx.machine.threads.threads[ThreadId::new(0)].join_status = ThreadJoinStatus::Detached;
@ -411,9 +403,9 @@ impl<'mir, 'tcx: 'mir> ThreadManager<'mir, 'tcx> {
}
/// Create a new thread and returns its id.
fn create_thread(&mut self) -> ThreadId {
fn create_thread(&mut self, on_stack_empty: StackEmptyCallback<'mir, 'tcx>) -> ThreadId {
let new_thread_id = ThreadId::new(self.threads.len());
self.threads.push(Default::default());
self.threads.push(Thread::new(None, Some(on_stack_empty)));
new_thread_id
}
@ -458,7 +450,7 @@ impl<'mir, 'tcx: 'mir> ThreadManager<'mir, 'tcx> {
}
/// Get a mutable borrow of the currently active thread.
fn active_thread_mut(&mut self) -> &mut Thread<'mir, 'tcx> {
pub fn active_thread_mut(&mut self) -> &mut Thread<'mir, 'tcx> {
&mut self.threads[self.active_thread]
}
@ -669,18 +661,6 @@ impl<'mir, 'tcx: 'mir> ThreadManager<'mir, 'tcx> {
/// long as we can and switch only when we have to (the active thread was
/// blocked, terminated, or has explicitly asked to be preempted).
fn schedule(&mut self, clock: &Clock) -> InterpResult<'tcx, SchedulingAction> {
// Check whether the thread has **just** terminated (`check_terminated`
// checks whether the thread has popped all its stack and if yes, sets
// the thread state to terminated).
if self.threads[self.active_thread].check_terminated() {
return Ok(SchedulingAction::ExecuteDtors);
}
// If we get here again and the thread is *still* terminated, there are no more dtors to run.
if self.threads[MAIN_THREAD].state == ThreadState::Terminated {
// The main thread terminated; stop the program.
// We do *not* run TLS dtors of remaining threads, which seems to match rustc behavior.
return Ok(SchedulingAction::Stop);
}
// This thread and the program can keep going.
if self.threads[self.active_thread].state == ThreadState::Enabled
&& !self.yield_active_thread
@ -688,18 +668,18 @@ impl<'mir, 'tcx: 'mir> ThreadManager<'mir, 'tcx> {
// The currently active thread is still enabled, just continue with it.
return Ok(SchedulingAction::ExecuteStep);
}
// The active thread yielded. Let's see if there are any timeouts to take care of. We do
// this *before* running any other thread, to ensure that timeouts "in the past" fire before
// any other thread can take an action. This ensures that for `pthread_cond_timedwait`, "an
// error is returned if [...] the absolute time specified by abstime has already been passed
// at the time of the call".
// The active thread yielded or got terminated. Let's see if there are any timeouts to take
// care of. We do this *before* running any other thread, to ensure that timeouts "in the
// past" fire before any other thread can take an action. This ensures that for
// `pthread_cond_timedwait`, "an error is returned if [...] the absolute time specified by
// abstime has already been passed at the time of the call".
// <https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html>
let potential_sleep_time =
self.timeout_callbacks.values().map(|info| info.call_time.get_wait_time(clock)).min();
if potential_sleep_time == Some(Duration::new(0, 0)) {
return Ok(SchedulingAction::ExecuteTimeoutCallback);
}
// No callbacks scheduled, pick a regular thread to execute.
// No callbacks immediately scheduled, pick a regular thread to execute.
// The active thread blocked or yielded. So we go search for another enabled thread.
// Crucially, we start searching at the current active thread ID, rather than at 0, since we
// want to avoid always scheduling threads 0 and 1 without ever making progress in thread 2.
@ -730,15 +710,58 @@ impl<'mir, 'tcx: 'mir> ThreadManager<'mir, 'tcx> {
// All threads are currently blocked, but we have unexecuted
// timeout_callbacks, which may unblock some of the threads. Hence,
// sleep until the first callback.
clock.sleep(sleep_time);
Ok(SchedulingAction::ExecuteTimeoutCallback)
Ok(SchedulingAction::Sleep(sleep_time))
} else {
throw_machine_stop!(TerminationInfo::Deadlock);
}
}
}
impl<'mir, 'tcx: 'mir> EvalContextPrivExt<'mir, 'tcx> for MiriInterpCx<'mir, 'tcx> {}
trait EvalContextPrivExt<'mir, 'tcx: 'mir>: MiriInterpCxExt<'mir, 'tcx> {
/// Execute a timeout callback on the callback's thread.
#[inline]
fn run_timeout_callback(&mut self) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
let (thread, callback) = if let Some((thread, callback)) =
this.machine.threads.get_ready_callback(&this.machine.clock)
{
(thread, callback)
} else {
// get_ready_callback can return None if the computer's clock
// was shifted after calling the scheduler and before the call
// to get_ready_callback (see issue
// https://github.com/rust-lang/miri/issues/1763). In this case,
// just do nothing, which effectively just returns to the
// scheduler.
return Ok(());
};
// This back-and-forth with `set_active_thread` is here because of two
// design decisions:
// 1. Make the caller and not the callback responsible for changing
// thread.
// 2. Make the scheduler the only place that can change the active
// thread.
let old_thread = this.set_active_thread(thread);
callback.call(this)?;
this.set_active_thread(old_thread);
Ok(())
}
#[inline]
fn run_on_stack_empty(&mut self) -> InterpResult<'tcx, Poll<()>> {
let this = self.eval_context_mut();
let mut callback = this
.active_thread_mut()
.on_stack_empty
.take()
.expect("`on_stack_empty` not set up, or already running");
let res = callback(this)?;
this.active_thread_mut().on_stack_empty = Some(callback);
Ok(res)
}
}
// Public interface to thread management.
impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
@ -773,18 +796,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
}
}
/// Start a regular (non-main) thread.
#[inline]
fn create_thread(&mut self) -> ThreadId {
let this = self.eval_context_mut();
let id = this.machine.threads.create_thread();
if let Some(data_race) = &mut this.machine.data_race {
data_race.thread_created(&this.machine.threads, id);
}
id
}
#[inline]
fn start_thread(
fn start_regular_thread(
&mut self,
thread: Option<MPlaceTy<'tcx, Provenance>>,
start_routine: Pointer<Option<Provenance>>,
@ -795,7 +809,13 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
let this = self.eval_context_mut();
// Create the new thread
let new_thread_id = this.create_thread();
let new_thread_id = this.machine.threads.create_thread({
let mut state = tls::TlsDtorsState::default();
Box::new(move |m| state.on_stack_empty(m))
});
if let Some(data_race) = &mut this.machine.data_race {
data_race.thread_created(&this.machine.threads, new_thread_id);
}
// Write the current thread-id, switch to the next thread later
// to treat this write operation as occuring on the current thread.
@ -888,12 +908,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
this.machine.threads.get_total_thread_count()
}
#[inline]
fn has_terminated(&self, thread_id: ThreadId) -> bool {
let this = self.eval_context_ref();
this.machine.threads.has_terminated(thread_id)
}
#[inline]
fn have_all_terminated(&self) -> bool {
let this = self.eval_context_ref();
@ -943,26 +957,22 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
where
'mir: 'c,
{
let this = self.eval_context_ref();
this.machine.threads.get_thread_name(thread)
self.eval_context_ref().machine.threads.get_thread_name(thread)
}
#[inline]
fn block_thread(&mut self, thread: ThreadId) {
let this = self.eval_context_mut();
this.machine.threads.block_thread(thread);
self.eval_context_mut().machine.threads.block_thread(thread);
}
#[inline]
fn unblock_thread(&mut self, thread: ThreadId) {
let this = self.eval_context_mut();
this.machine.threads.unblock_thread(thread);
self.eval_context_mut().machine.threads.unblock_thread(thread);
}
#[inline]
fn yield_active_thread(&mut self) {
let this = self.eval_context_mut();
this.machine.threads.yield_active_thread();
self.eval_context_mut().machine.threads.yield_active_thread();
}
#[inline]
@ -995,49 +1005,42 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
this.machine.threads.unregister_timeout_callback_if_exists(thread);
}
/// Execute a timeout callback on the callback's thread.
#[inline]
fn run_timeout_callback(&mut self) -> InterpResult<'tcx> {
/// Run the core interpreter loop. Returns only when an interrupt occurs (an error or program
/// termination).
fn run_threads(&mut self) -> InterpResult<'tcx, !> {
let this = self.eval_context_mut();
let (thread, callback) = if let Some((thread, callback)) =
this.machine.threads.get_ready_callback(&this.machine.clock)
{
(thread, callback)
} else {
// get_ready_callback can return None if the computer's clock
// was shifted after calling the scheduler and before the call
// to get_ready_callback (see issue
// https://github.com/rust-lang/miri/issues/1763). In this case,
// just do nothing, which effectively just returns to the
// scheduler.
return Ok(());
};
// This back-and-forth with `set_active_thread` is here because of two
// design decisions:
// 1. Make the caller and not the callback responsible for changing
// thread.
// 2. Make the scheduler the only place that can change the active
// thread.
let old_thread = this.set_active_thread(thread);
callback.call(this)?;
this.set_active_thread(old_thread);
Ok(())
}
/// Decide which action to take next and on which thread.
#[inline]
fn schedule(&mut self) -> InterpResult<'tcx, SchedulingAction> {
let this = self.eval_context_mut();
this.machine.threads.schedule(&this.machine.clock)
loop {
match this.machine.threads.schedule(&this.machine.clock)? {
SchedulingAction::ExecuteStep => {
if !this.step()? {
// See if this thread can do something else.
match this.run_on_stack_empty()? {
Poll::Pending => {} // keep going
Poll::Ready(()) => this.terminate_active_thread()?,
}
}
}
SchedulingAction::ExecuteTimeoutCallback => {
this.run_timeout_callback()?;
}
SchedulingAction::Sleep(duration) => {
this.machine.clock.sleep(duration);
}
}
}
}
/// Handles thread termination of the active thread: wakes up threads joining on this one,
/// and deallocated thread-local statics.
///
/// This is called from `tls.rs` after handling the TLS dtors.
/// This is called by the eval loop when a thread's on_stack_empty returns `Ready`.
#[inline]
fn thread_terminated(&mut self) -> InterpResult<'tcx> {
fn terminate_active_thread(&mut self) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
let thread = this.active_thread_mut();
assert!(thread.stack.is_empty(), "only threads with an empty stack can be terminated");
thread.state = ThreadState::Terminated;
for ptr in this.machine.threads.thread_terminated(this.machine.data_race.as_mut()) {
this.deallocate_ptr(ptr.into(), None, MiriMemoryKind::Tls.into())?;
}

13
src/tools/miri/src/diagnostics.rs
View file

@ -11,7 +11,10 @@ use crate::*;
/// Details of premature program termination.
pub enum TerminationInfo {
Exit(i64),
Exit {
code: i64,
leak_check: bool,
},
Abort(String),
UnsupportedInIsolation(String),
StackedBorrowsUb {
@ -38,7 +41,7 @@ impl fmt::Display for TerminationInfo {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
use TerminationInfo::*;
match self {
Exit(code) => write!(f, "the evaluated program completed with exit code {code}"),
Exit { code, .. } => write!(f, "the evaluated program completed with exit code {code}"),
Abort(msg) => write!(f, "{msg}"),
UnsupportedInIsolation(msg) => write!(f, "{msg}"),
Int2PtrWithStrictProvenance =>
@ -148,11 +151,11 @@ fn prune_stacktrace<'tcx>(
/// Emit a custom diagnostic without going through the miri-engine machinery.
///
/// Returns `Some` if this was regular program termination with a given exit code, `None` otherwise.
/// Returns `Some` if this was regular program termination with a given exit code and a `bool` indicating whether a leak check should happen; `None` otherwise.
pub fn report_error<'tcx, 'mir>(
ecx: &InterpCx<'mir, 'tcx, MiriMachine<'mir, 'tcx>>,
e: InterpErrorInfo<'tcx>,
) -> Option<i64> {
) -> Option<(i64, bool)> {
use InterpError::*;
let mut msg = vec![];
@ -161,7 +164,7 @@ pub fn report_error<'tcx, 'mir>(
let info = info.downcast_ref::<TerminationInfo>().expect("invalid MachineStop payload");
use TerminationInfo::*;
let title = match info {
Exit(code) => return Some(*code),
Exit { code, leak_check } => return Some((*code, *leak_check)),
Abort(_) => Some("abnormal termination"),
UnsupportedInIsolation(_) | Int2PtrWithStrictProvenance =>
Some("unsupported operation"),

163
src/tools/miri/src/eval.rs
View file

@ -4,6 +4,7 @@ use std::ffi::{OsStr, OsString};
use std::iter;
use std::panic::{self, AssertUnwindSafe};
use std::path::PathBuf;
use std::task::Poll;
use std::thread;
use log::info;
@ -20,8 +21,14 @@ use rustc_target::spec::abi::Abi;
use rustc_session::config::EntryFnType;
use crate::shims::tls;
use crate::*;
/// When the main thread would exit, we will yield to any other thread that is ready to execute.
/// But we must only do that a finite number of times, or a background thread running `loop {}`
/// will hang the program.
const MAIN_THREAD_YIELDS_AT_SHUTDOWN: u32 = 256;
#[derive(Copy, Clone, Debug, PartialEq)]
pub enum AlignmentCheck {
/// Do not check alignment.
@ -172,17 +179,79 @@ impl Default for MiriConfig {
}
}
/// Returns a freshly created `InterpCx`, along with an `MPlaceTy` representing
/// the location where the return value of the `start` function will be
/// written to.
/// The state of the main thread. Implementation detail of `on_main_stack_empty`.
#[derive(Default, Debug)]
enum MainThreadState {
#[default]
Running,
TlsDtors(tls::TlsDtorsState),
Yield {
remaining: u32,
},
Done,
}
impl MainThreadState {
fn on_main_stack_empty<'tcx>(
&mut self,
this: &mut MiriInterpCx<'_, 'tcx>,
) -> InterpResult<'tcx, Poll<()>> {
use MainThreadState::*;
match self {
Running => {
*self = TlsDtors(Default::default());
}
TlsDtors(state) =>
match state.on_stack_empty(this)? {
Poll::Pending => {} // just keep going
Poll::Ready(()) => {
// Give background threads a chance to finish by yielding the main thread a
// couple of times -- but only if we would also preempt threads randomly.
if this.machine.preemption_rate > 0.0 {
// There is a non-zero chance they will yield back to us often enough to
// make Miri terminate eventually.
*self = Yield { remaining: MAIN_THREAD_YIELDS_AT_SHUTDOWN };
} else {
// The other threads did not get preempted, so no need to yield back to
// them.
*self = Done;
}
}
},
Yield { remaining } =>
match remaining.checked_sub(1) {
None => *self = Done,
Some(new_remaining) => {
*remaining = new_remaining;
this.yield_active_thread();
}
},
Done => {
// Figure out exit code.
let ret_place = MPlaceTy::from_aligned_ptr(
this.machine.main_fn_ret_place.unwrap().ptr,
this.machine.layouts.isize,
);
let exit_code = this.read_scalar(&ret_place.into())?.to_machine_isize(this)?;
// Need to call this ourselves since we are not going to return to the scheduler
// loop, and we want the main thread TLS to not show up as memory leaks.
this.terminate_active_thread()?;
// Stop interpreter loop.
throw_machine_stop!(TerminationInfo::Exit { code: exit_code, leak_check: true });
}
}
Ok(Poll::Pending)
}
}
/// Returns a freshly created `InterpCx`.
/// Public because this is also used by `priroda`.
pub fn create_ecx<'mir, 'tcx: 'mir>(
tcx: TyCtxt<'tcx>,
entry_id: DefId,
entry_type: EntryFnType,
config: &MiriConfig,
) -> InterpResult<'tcx, (InterpCx<'mir, 'tcx, MiriMachine<'mir, 'tcx>>, MPlaceTy<'tcx, Provenance>)>
{
) -> InterpResult<'tcx, InterpCx<'mir, 'tcx, MiriMachine<'mir, 'tcx>>> {
let param_env = ty::ParamEnv::reveal_all();
let layout_cx = LayoutCx { tcx, param_env };
let mut ecx = InterpCx::new(
@ -193,7 +262,11 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
);
// Some parts of initialization require a full `InterpCx`.
MiriMachine::late_init(&mut ecx, config)?;
MiriMachine::late_init(&mut ecx, config, {
let mut state = MainThreadState::default();
// Cannot capture anything GC-relevant here.
Box::new(move |m| state.on_main_stack_empty(m))
})?;
// Make sure we have MIR. We check MIR for some stable monomorphic function in libcore.
let sentinel = ecx.try_resolve_path(&["core", "ascii", "escape_default"], Namespace::ValueNS);
@ -274,6 +347,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
// Return place (in static memory so that it does not count as leak).
let ret_place = ecx.allocate(ecx.machine.layouts.isize, MiriMemoryKind::Machine.into())?;
ecx.machine.main_fn_ret_place = Some(*ret_place);
// Call start function.
match entry_type {
@ -321,7 +395,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
}
}
Ok((ecx, ret_place))
Ok(ecx)
}
/// Evaluates the entry function specified by `entry_id`.
@ -337,7 +411,7 @@ pub fn eval_entry<'tcx>(
// Copy setting before we move `config`.
let ignore_leaks = config.ignore_leaks;
let (mut ecx, ret_place) = match create_ecx(tcx, entry_id, entry_type, &config) {
let mut ecx = match create_ecx(tcx, entry_id, entry_type, &config) {
Ok(v) => v,
Err(err) => {
err.print_backtrace();
@ -346,34 +420,17 @@ pub fn eval_entry<'tcx>(
};
// Perform the main execution.
let res: thread::Result<InterpResult<'_, i64>> = panic::catch_unwind(AssertUnwindSafe(|| {
// Main loop.
loop {
match ecx.schedule()? {
SchedulingAction::ExecuteStep => {
assert!(ecx.step()?, "a terminated thread was scheduled for execution");
}
SchedulingAction::ExecuteTimeoutCallback => {
ecx.run_timeout_callback()?;
}
SchedulingAction::ExecuteDtors => {
// This will either enable the thread again (so we go back
// to `ExecuteStep`), or determine that this thread is done
// for good.
ecx.schedule_next_tls_dtor_for_active_thread()?;
}
SchedulingAction::Stop => {
break;
}
}
}
let return_code = ecx.read_scalar(&ret_place.into())?.to_machine_isize(&ecx)?;
Ok(return_code)
}));
let res: thread::Result<InterpResult<'_, !>> =
panic::catch_unwind(AssertUnwindSafe(|| ecx.run_threads()));
let res = res.unwrap_or_else(|panic_payload| {
ecx.handle_ice();
panic::resume_unwind(panic_payload)
});
let res = match res {
Err(res) => res,
// `Ok` can never happen
Ok(never) => match never {},
};
// Machine cleanup. Only do this if all threads have terminated; threads that are still running
// might cause Stacked Borrows errors (https://github.com/rust-lang/miri/issues/2396).
@ -386,32 +443,26 @@ pub fn eval_entry<'tcx>(
}
// Process the result.
match res {
Ok(return_code) => {
if !ignore_leaks {
// Check for thread leaks.
if !ecx.have_all_terminated() {
tcx.sess.err(
"the main thread terminated without waiting for all remaining threads",
);
tcx.sess.note_without_error("pass `-Zmiri-ignore-leaks` to disable this check");
return None;
}
// Check for memory leaks.
info!("Additonal static roots: {:?}", ecx.machine.static_roots);
let leaks = ecx.leak_report(&ecx.machine.static_roots);
if leaks != 0 {
tcx.sess.err("the evaluated program leaked memory");
tcx.sess.note_without_error("pass `-Zmiri-ignore-leaks` to disable this check");
// Ignore the provided return code - let the reported error
// determine the return code.
return None;
}
}
Some(return_code)
let (return_code, leak_check) = report_error(&ecx, res)?;
if leak_check && !ignore_leaks {
// Check for thread leaks.
if !ecx.have_all_terminated() {
tcx.sess.err("the main thread terminated without waiting for all remaining threads");
tcx.sess.note_without_error("pass `-Zmiri-ignore-leaks` to disable this check");
return None;
}
// Check for memory leaks.
info!("Additonal static roots: {:?}", ecx.machine.static_roots);
let leaks = ecx.leak_report(&ecx.machine.static_roots);
if leaks != 0 {
tcx.sess.err("the evaluated program leaked memory");
tcx.sess.note_without_error("pass `-Zmiri-ignore-leaks` to disable this check");
// Ignore the provided return code - let the reported error
// determine the return code.
return None;
}
Err(e) => report_error(&ecx, e),
}
Some(return_code)
}
/// Turns an array of arguments into a Windows command line string.

6
src/tools/miri/src/lib.rs
View file

@ -81,7 +81,7 @@ pub use crate::shims::intrinsics::EvalContextExt as _;
pub use crate::shims::os_str::EvalContextExt as _;
pub use crate::shims::panic::{CatchUnwindData, EvalContextExt as _};
pub use crate::shims::time::EvalContextExt as _;
pub use crate::shims::tls::{EvalContextExt as _, TlsData};
pub use crate::shims::tls::TlsData;
pub use crate::shims::EvalContextExt as _;
pub use crate::clock::{Clock, Instant};
@ -89,7 +89,7 @@ pub use crate::concurrency::{
data_race::{AtomicFenceOrd, AtomicReadOrd, AtomicRwOrd, AtomicWriteOrd, EvalContextExt as _},
init_once::{EvalContextExt as _, InitOnceId},
sync::{CondvarId, EvalContextExt as _, MutexId, RwLockId, SyncId},
thread::{EvalContextExt as _, SchedulingAction, ThreadId, ThreadManager, ThreadState, Time},
thread::{EvalContextExt as _, StackEmptyCallback, ThreadId, ThreadManager, Time},
};
pub use crate::diagnostics::{
report_error, EvalContextExt as _, NonHaltingDiagnostic, TerminationInfo,
@ -107,7 +107,7 @@ pub use crate::mono_hash_map::MonoHashMap;
pub use crate::operator::EvalContextExt as _;
pub use crate::range_map::RangeMap;
pub use crate::stacked_borrows::{
CallId, EvalContextExt as _, Item, Permission, RetagFields, SbTag, Stack, Stacks,
CallId, EvalContextExt as _, Item, Permission, RetagFields, SbTag,
};
pub use crate::tag_gc::{EvalContextExt as _, VisitTags};

17
src/tools/miri/src/machine.rs
View file

@ -363,6 +363,9 @@ pub struct MiriMachine<'mir, 'tcx> {
/// Miri does not expose env vars from the host to the emulated program.
pub(crate) env_vars: EnvVars<'tcx>,
/// Return place of the main function.
pub(crate) main_fn_ret_place: Option<MemPlace<Provenance>>,
/// Program arguments (`Option` because we can only initialize them after creating the ecx).
/// These are *pointers* to argc/argv because macOS.
/// We also need the full command line as one string because of Windows.
@ -492,6 +495,7 @@ impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
intptrcast: RefCell::new(intptrcast::GlobalStateInner::new(config)),
// `env_vars` depends on a full interpreter so we cannot properly initialize it yet.
env_vars: EnvVars::default(),
main_fn_ret_place: None,
argc: None,
argv: None,
cmd_line: None,
@ -556,10 +560,11 @@ impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
pub(crate) fn late_init(
this: &mut MiriInterpCx<'mir, 'tcx>,
config: &MiriConfig,
on_main_stack_empty: StackEmptyCallback<'mir, 'tcx>,
) -> InterpResult<'tcx> {
EnvVars::init(this, config)?;
MiriMachine::init_extern_statics(this)?;
ThreadManager::init(this);
ThreadManager::init(this, on_main_stack_empty);
Ok(())
}
@ -657,6 +662,7 @@ impl VisitTags for MiriMachine<'_, '_> {
threads,
tls,
env_vars,
main_fn_ret_place,
argc,
argv,
cmd_line,
@ -702,6 +708,7 @@ impl VisitTags for MiriMachine<'_, '_> {
data_race.visit_tags(visit);
stacked_borrows.visit_tags(visit);
intptrcast.visit_tags(visit);
main_fn_ret_place.visit_tags(visit);
argc.visit_tags(visit);
argv.visit_tags(visit);
cmd_line.visit_tags(visit);
@ -901,7 +908,13 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
let alloc = alloc.into_owned();
let stacks = ecx.machine.stacked_borrows.as_ref().map(|stacked_borrows| {
Stacks::new_allocation(id, alloc.size(), stacked_borrows, kind, &ecx.machine)
stacked_borrows::Stacks::new_allocation(
id,
alloc.size(),
stacked_borrows,
kind,
&ecx.machine,
)
});
let race_alloc = ecx.machine.data_race.as_ref().map(|data_race| {
data_race::AllocExtra::new_allocation(

2
src/tools/miri/src/shims/foreign_items.rs
View file

@ -286,7 +286,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
let [code] = this.check_shim(abi, exp_abi, link_name, args)?;
// it's really u32 for ExitProcess, but we have to put it into the `Exit` variant anyway
let code = this.read_scalar(code)?.to_i32()?;
throw_machine_stop!(TerminationInfo::Exit(code.into()));
throw_machine_stop!(TerminationInfo::Exit { code: code.into(), leak_check: false });
}
"abort" => {
let [] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;

193
src/tools/miri/src/shims/tls.rs
View file

@ -1,12 +1,11 @@
//! Implement thread-local storage.
use std::collections::btree_map::Entry as BTreeEntry;
use std::collections::hash_map::Entry as HashMapEntry;
use std::collections::BTreeMap;
use std::task::Poll;
use log::trace;
use rustc_data_structures::fx::FxHashMap;
use rustc_middle::ty;
use rustc_target::abi::{HasDataLayout, Size};
use rustc_target::spec::abi::Abi;
@ -23,12 +22,12 @@ pub struct TlsEntry<'tcx> {
dtor: Option<ty::Instance<'tcx>>,
}
#[derive(Clone, Debug)]
struct RunningDtorsState {
#[derive(Default, Debug)]
struct RunningDtorState {
/// The last TlsKey used to retrieve a TLS destructor. `None` means that we
/// have not tried to retrieve a TLS destructor yet or that we already tried
/// all keys.
last_dtor_key: Option<TlsKey>,
last_key: Option<TlsKey>,
}
#[derive(Debug)]
@ -42,11 +41,6 @@ pub struct TlsData<'tcx> {
/// A single per thread destructor of the thread local storage (that's how
/// things work on macOS) with a data argument.
macos_thread_dtors: BTreeMap<ThreadId, (ty::Instance<'tcx>, Scalar<Provenance>)>,
/// State for currently running TLS dtors. If this map contains a key for a
/// specific thread, it means that we are in the "destruct" phase, during
/// which some operations are UB.
dtors_running: FxHashMap<ThreadId, RunningDtorsState>,
}
impl<'tcx> Default for TlsData<'tcx> {
@ -55,7 +49,6 @@ impl<'tcx> Default for TlsData<'tcx> {
next_key: 1, // start with 1 as we must not use 0 on Windows
keys: Default::default(),
macos_thread_dtors: Default::default(),
dtors_running: Default::default(),
}
}
}
@ -143,12 +136,6 @@ impl<'tcx> TlsData<'tcx> {
dtor: ty::Instance<'tcx>,
data: Scalar<Provenance>,
) -> InterpResult<'tcx> {
if self.dtors_running.contains_key(&thread) {
// UB, according to libstd docs.
throw_ub_format!(
"setting thread's local storage destructor while destructors are already running"
);
}
if self.macos_thread_dtors.insert(thread, (dtor, data)).is_some() {
throw_unsup_format!(
"setting more than one thread local storage destructor for the same thread is not supported"
@ -211,21 +198,6 @@ impl<'tcx> TlsData<'tcx> {
None
}
/// Set that dtors are running for `thread`. It is guaranteed not to change
/// the existing values stored in `dtors_running` for this thread. Returns
/// `true` if dtors for `thread` are already running.
fn set_dtors_running_for_thread(&mut self, thread: ThreadId) -> bool {
match self.dtors_running.entry(thread) {
HashMapEntry::Occupied(_) => true,
HashMapEntry::Vacant(entry) => {
// We cannot just do `self.dtors_running.insert` because that
// would overwrite `last_dtor_key` with `None`.
entry.insert(RunningDtorsState { last_dtor_key: None });
false
}
}
}
/// Delete all TLS entries for the given thread. This function should be
/// called after all TLS destructors have already finished.
fn delete_all_thread_tls(&mut self, thread_id: ThreadId) {
@ -237,7 +209,7 @@ impl<'tcx> TlsData<'tcx> {
impl VisitTags for TlsData<'_> {
fn visit_tags(&self, visit: &mut dyn FnMut(SbTag)) {
let TlsData { keys, macos_thread_dtors, next_key: _, dtors_running: _ } = self;
let TlsData { keys, macos_thread_dtors, next_key: _ } = self;
for scalar in keys.values().flat_map(|v| v.data.values()) {
scalar.visit_tags(visit);
@ -248,13 +220,77 @@ impl VisitTags for TlsData<'_> {
}
}
#[derive(Debug, Default)]
pub struct TlsDtorsState(TlsDtorsStatePriv);
#[derive(Debug, Default)]
enum TlsDtorsStatePriv {
#[default]
Init,
PthreadDtors(RunningDtorState),
Done,
}
impl TlsDtorsState {
pub fn on_stack_empty<'tcx>(
&mut self,
this: &mut MiriInterpCx<'_, 'tcx>,
) -> InterpResult<'tcx, Poll<()>> {
use TlsDtorsStatePriv::*;
match &mut self.0 {
Init => {
match this.tcx.sess.target.os.as_ref() {
"linux" | "freebsd" | "android" => {
// Run the pthread dtors.
self.0 = PthreadDtors(Default::default());
}
"macos" => {
// The macOS thread wide destructor runs "before any TLS slots get
// freed", so do that first.
this.schedule_macos_tls_dtor()?;
// When the stack is empty again, go on with the pthread dtors.
self.0 = PthreadDtors(Default::default());
}
"windows" => {
// Run the special magic hook.
this.schedule_windows_tls_dtors()?;
// And move to the final state.
self.0 = Done;
}
"wasi" | "none" => {
// No OS, no TLS dtors.
// FIXME: should we do something on wasi?
self.0 = Done;
}
os => {
throw_unsup_format!(
"the TLS machinery does not know how to handle OS `{os}`"
);
}
}
}
PthreadDtors(state) => {
match this.schedule_next_pthread_tls_dtor(state)? {
Poll::Pending => {} // just keep going
Poll::Ready(()) => self.0 = Done,
}
}
Done => {
this.machine.tls.delete_all_thread_tls(this.get_active_thread());
return Ok(Poll::Ready(()));
}
}
Ok(Poll::Pending)
}
}
impl<'mir, 'tcx: 'mir> EvalContextPrivExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
trait EvalContextPrivExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
/// Schedule TLS destructors for Windows.
/// On windows, TLS destructors are managed by std.
fn schedule_windows_tls_dtors(&mut self) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
let active_thread = this.get_active_thread();
// Windows has a special magic linker section that is run on certain events.
// Instead of searching for that section and supporting arbitrary hooks in there
@ -284,16 +320,12 @@ trait EvalContextPrivExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
None,
StackPopCleanup::Root { cleanup: true },
)?;
this.enable_thread(active_thread);
Ok(())
}
/// Schedule the MacOS thread destructor of the thread local storage to be
/// executed. Returns `true` if scheduled.
///
/// Note: It is safe to call this function also on other Unixes.
fn schedule_macos_tls_dtor(&mut self) -> InterpResult<'tcx, bool> {
/// executed.
fn schedule_macos_tls_dtor(&mut self) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
let thread_id = this.get_active_thread();
if let Some((instance, data)) = this.machine.tls.macos_thread_dtors.remove(&thread_id) {
@ -306,35 +338,27 @@ trait EvalContextPrivExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
None,
StackPopCleanup::Root { cleanup: true },
)?;
// Enable the thread so that it steps through the destructor which
// we just scheduled. Since we deleted the destructor, it is
// guaranteed that we will schedule it again. The `dtors_running`
// flag will prevent the code from adding the destructor again.
this.enable_thread(thread_id);
Ok(true)
} else {
Ok(false)
}
Ok(())
}
/// Schedule a pthread TLS destructor. Returns `true` if found
/// a destructor to schedule, and `false` otherwise.
fn schedule_next_pthread_tls_dtor(&mut self) -> InterpResult<'tcx, bool> {
fn schedule_next_pthread_tls_dtor(
&mut self,
state: &mut RunningDtorState,
) -> InterpResult<'tcx, Poll<()>> {
let this = self.eval_context_mut();
let active_thread = this.get_active_thread();
assert!(this.has_terminated(active_thread), "running TLS dtors for non-terminated thread");
// Fetch next dtor after `key`.
let last_key = this.machine.tls.dtors_running[&active_thread].last_dtor_key;
let dtor = match this.machine.tls.fetch_tls_dtor(last_key, active_thread) {
let dtor = match this.machine.tls.fetch_tls_dtor(state.last_key, active_thread) {
dtor @ Some(_) => dtor,
// We ran each dtor once, start over from the beginning.
None => this.machine.tls.fetch_tls_dtor(None, active_thread),
};
if let Some((instance, ptr, key)) = dtor {
this.machine.tls.dtors_running.get_mut(&active_thread).unwrap().last_dtor_key =
Some(key);
state.last_key = Some(key);
trace!("Running TLS dtor {:?} on {:?} at {:?}", instance, ptr, active_thread);
assert!(
!ptr.to_machine_usize(this).unwrap() != 0,
@ -349,64 +373,9 @@ trait EvalContextPrivExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
StackPopCleanup::Root { cleanup: true },
)?;
this.enable_thread(active_thread);
return Ok(true);
return Ok(Poll::Pending);
}
this.machine.tls.dtors_running.get_mut(&active_thread).unwrap().last_dtor_key = None;
Ok(false)
}
}
impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
/// Schedule an active thread's TLS destructor to run on the active thread.
/// Note that this function does not run the destructors itself, it just
/// schedules them one by one each time it is called and reenables the
/// thread so that it can be executed normally by the main execution loop.
///
/// Note: we consistently run TLS destructors for all threads, including the
/// main thread. However, it is not clear that we should run the TLS
/// destructors for the main thread. See issue:
/// <https://github.com/rust-lang/rust/issues/28129>.
fn schedule_next_tls_dtor_for_active_thread(&mut self) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
let active_thread = this.get_active_thread();
trace!("schedule_next_tls_dtor_for_active_thread on thread {:?}", active_thread);
if !this.machine.tls.set_dtors_running_for_thread(active_thread) {
// This is the first time we got asked to schedule a destructor. The
// Windows schedule destructor function must be called exactly once,
// this is why it is in this block.
if this.tcx.sess.target.os == "windows" {
// On Windows, we signal that the thread quit by starting the
// relevant function, reenabling the thread, and going back to
// the scheduler.
this.schedule_windows_tls_dtors()?;
return Ok(());
}
}
// The remaining dtors make some progress each time around the scheduler loop,
// until they return `false` to indicate that they are done.
// The macOS thread wide destructor runs "before any TLS slots get
// freed", so do that first.
if this.schedule_macos_tls_dtor()? {
// We have scheduled a MacOS dtor to run on the thread. Execute it
// to completion and come back here. Scheduling a destructor
// destroys it, so we will not enter this branch again.
return Ok(());
}
if this.schedule_next_pthread_tls_dtor()? {
// We have scheduled a pthread destructor and removed it from the
// destructors list. Run it to completion and come back here.
return Ok(());
}
// All dtors done!
this.machine.tls.delete_all_thread_tls(active_thread);
this.thread_terminated()?;
Ok(())
Ok(Poll::Ready(()))
}
}

2
src/tools/miri/src/shims/unix/thread.rs
View file

@ -19,7 +19,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
let func_arg = this.read_immediate(arg)?;
this.start_thread(
this.start_regular_thread(
Some(thread_info_place),
start_routine,
Abi::C { unwind: false },

2
src/tools/miri/src/shims/windows/thread.rs
View file

@ -46,7 +46,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
throw_unsup_format!("non-null `lpThreadAttributes` in `CreateThread`")
}
this.start_thread(
this.start_regular_thread(
thread,
start_routine,
Abi::System { unwind: false },

4
src/tools/miri/src/stacked_borrows/diagnostics.rs
View file

@ -5,7 +5,9 @@ use rustc_middle::mir::interpret::{alloc_range, AllocId, AllocRange};
use rustc_span::{Span, SpanData};
use rustc_target::abi::Size;
use crate::stacked_borrows::{err_sb_ub, AccessKind, GlobalStateInner, Permission, ProtectorKind};
use crate::stacked_borrows::{
err_sb_ub, AccessKind, GlobalStateInner, Permission, ProtectorKind, Stack,
};
use crate::*;
use rustc_middle::mir::interpret::InterpError;

8
src/tools/miri/tests/many-seeds/scoped-thread-leak.rs Normal file
View file

@ -0,0 +1,8 @@
//! Regression test for https://github.com/rust-lang/miri/issues/2629
use std::thread;
fn main() {
thread::scope(|s| {
s.spawn(|| {});
});
}

24
src/tools/miri/tests/pass/concurrency/scope.rs Normal file
View file

@ -0,0 +1,24 @@
use std::thread;
fn main() {
let mut a = vec![1, 2, 3];
let mut x = 0;
thread::scope(|s| {
s.spawn(|| {
// We can borrow `a` here.
let _s = format!("hello from the first scoped thread: {a:?}");
});
s.spawn(|| {
let _s = format!("hello from the second scoped thread");
// We can even mutably borrow `x` here,
// because no other threads are using it.
x += a[0] + a[2];
});
let _s = format!("hello from the main thread");
});
// After the scope, we can modify and access our variables again:
a.push(4);
assert_eq!(x, a.len());
}