diff --git a/src/tools/miri/src/concurrency/sync.rs b/src/tools/miri/src/concurrency/sync.rs index b22684faec43..2901cb9ccb0e 100644 --- a/src/tools/miri/src/concurrency/sync.rs +++ b/src/tools/miri/src/concurrency/sync.rs @@ -1,4 +1,3 @@ -use std::any::Any; use std::collections::VecDeque; use std::collections::hash_map::Entry; use std::ops::Not; @@ -129,9 +128,6 @@ struct Condvar { /// Contains the clock of the last thread to /// perform a condvar-signal. clock: VClock, - - /// Additional data that can be set by shim implementations. - data: Option>, } /// The futex state. @@ -220,32 +216,6 @@ pub(super) trait EvalContextExtPriv<'tcx>: crate::MiriInterpCxExt<'tcx> { }) } - /// Eagerly creates a Miri sync structure. - /// - /// `create_id` will store the index of the sync_structure in the memory pointed to by - /// `lock_op`, so that future calls to `get_or_create_id` will see it as initialized. - /// - `lock_op` must hold a pointer to the sync structure. - /// - `lock_layout` must be the memory layout of the sync structure. - /// - `offset` must be the offset inside the sync structure where its miri id will be stored. - /// - `get_objs` is described in `get_or_create_id`. - /// - `obj` must be the new sync object. - fn create_id( - &mut self, - lock: &MPlaceTy<'tcx>, - offset: u64, - get_objs: impl for<'a> Fn(&'a mut MiriInterpCx<'tcx>) -> &'a mut IndexVec, - obj: T, - ) -> InterpResult<'tcx, Id> { - let this = self.eval_context_mut(); - let offset = Size::from_bytes(offset); - assert!(lock.layout.size >= offset + this.machine.layouts.u32.size); - let id_place = lock.offset(offset, this.machine.layouts.u32, this)?; - - let new_index = get_objs(this).push(obj); - this.write_scalar(Scalar::from_u32(new_index.to_u32()), &id_place)?; - interp_ok(new_index) - } - fn condvar_reacquire_mutex( &mut self, mutex: MutexId, @@ -303,45 +273,9 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { } /// Eagerly create and initialize a new condvar. - fn condvar_create( - &mut self, - condvar: &MPlaceTy<'tcx>, - offset: u64, - data: Option>, - ) -> InterpResult<'tcx, CondvarId> { + fn condvar_create(&mut self) -> CondvarId { let this = self.eval_context_mut(); - this.create_id(condvar, offset, |ecx| &mut ecx.machine.sync.condvars, Condvar { - data, - ..Default::default() - }) - } - - fn condvar_get_or_create_id( - &mut self, - lock: &MPlaceTy<'tcx>, - offset: u64, - initialize_data: impl for<'a> FnOnce( - &'a mut MiriInterpCx<'tcx>, - ) -> InterpResult<'tcx, Option>>, - ) -> InterpResult<'tcx, CondvarId> { - let this = self.eval_context_mut(); - this.get_or_create_id( - lock, - offset, - |ecx| &mut ecx.machine.sync.condvars, - |ecx| initialize_data(ecx).map(|data| Condvar { data, ..Default::default() }), - )? - .ok_or_else(|| err_ub_format!("condvar has invalid ID")) - .into() - } - - /// Retrieve the additional data stored for a condvar. - fn condvar_get_data<'a, T: 'static>(&'a mut self, id: CondvarId) -> Option<&'a T> - where - 'tcx: 'a, - { - let this = self.eval_context_ref(); - this.machine.sync.condvars[id].data.as_deref().and_then(|p| p.downcast_ref::()) + this.machine.sync.condvars.push(Default::default()) } #[inline] diff --git a/src/tools/miri/src/shims/unix/sync.rs b/src/tools/miri/src/shims/unix/sync.rs index 1a4c4094c5d2..1942f25996eb 100644 --- a/src/tools/miri/src/shims/unix/sync.rs +++ b/src/tools/miri/src/shims/unix/sync.rs @@ -37,7 +37,7 @@ fn bytewise_equal_atomic_relaxed<'tcx>( /// If `init` is set to this, we consider the primitive initialized. const INIT_COOKIE: u32 = 0xcafe_affe; -fn sync_create<'tcx, T: 'static + Copy>( +fn sync_init<'tcx, T: 'static + Copy>( ecx: &mut MiriInterpCx<'tcx>, primitive: &MPlaceTy<'tcx>, init_offset: Size, @@ -137,6 +137,28 @@ fn mutexattr_set_kind<'tcx>( /// field *not* PTHREAD_MUTEX_DEFAULT but this special flag. const PTHREAD_MUTEX_KIND_UNCHANGED: i32 = 0x8000000; +/// Translates the mutex kind from what is stored in pthread_mutexattr_t to our enum. +fn mutexattr_translate_kind<'tcx>( + ecx: &MiriInterpCx<'tcx>, + kind: i32, +) -> InterpResult<'tcx, MutexKind> { + interp_ok(if kind == (ecx.eval_libc_i32("PTHREAD_MUTEX_NORMAL")) { + MutexKind::Normal + } else if kind == ecx.eval_libc_i32("PTHREAD_MUTEX_ERRORCHECK") { + MutexKind::ErrorCheck + } else if kind == ecx.eval_libc_i32("PTHREAD_MUTEX_RECURSIVE") { + MutexKind::Recursive + } else if kind == ecx.eval_libc_i32("PTHREAD_MUTEX_DEFAULT") + || kind == PTHREAD_MUTEX_KIND_UNCHANGED + { + // We check this *last* since PTHREAD_MUTEX_DEFAULT may be numerically equal to one of the + // others, and we want an explicit `mutexattr_settype` to work as expected. + MutexKind::Default + } else { + throw_unsup_format!("unsupported type of mutex: {kind}"); + }) +} + // # pthread_mutex_t // We store some data directly inside the type, ignoring the platform layout: // - init: u32 @@ -170,7 +192,7 @@ fn mutex_init_offset<'tcx>(ecx: &MiriInterpCx<'tcx>) -> InterpResult<'tcx, Size> let offset = Size::from_bytes(offset); // Sanity-check this against PTHREAD_MUTEX_INITIALIZER (but only once): - // the `init` field must start out not equal to MUTEX_INIT_COOKIE. + // the `init` field must start out not equal to INIT_COOKIE. static SANITY: AtomicBool = AtomicBool::new(false); if !SANITY.swap(true, Ordering::Relaxed) { let check_static_initializer = |name| { @@ -208,7 +230,7 @@ fn mutex_create<'tcx>( let mutex = ecx.deref_pointer(mutex_ptr)?; let id = ecx.mutex_create(); let data = MutexData { id, kind }; - sync_create(ecx, &mutex, mutex_init_offset(ecx)?, data)?; + sync_init(ecx, &mutex, mutex_init_offset(ecx)?, data)?; interp_ok(data) } @@ -259,38 +281,13 @@ fn mutex_kind_from_static_initializer<'tcx>( }, _ => {} } - throw_unsup_format!("unsupported static initializer used for `pthread_mutex_t"); -} - -/// Translates the mutex kind from what is stored in pthread_mutexattr_t to our enum. -fn mutex_translate_kind<'tcx>( - ecx: &MiriInterpCx<'tcx>, - kind: i32, -) -> InterpResult<'tcx, MutexKind> { - interp_ok(if kind == (ecx.eval_libc_i32("PTHREAD_MUTEX_NORMAL")) { - MutexKind::Normal - } else if kind == ecx.eval_libc_i32("PTHREAD_MUTEX_ERRORCHECK") { - MutexKind::ErrorCheck - } else if kind == ecx.eval_libc_i32("PTHREAD_MUTEX_RECURSIVE") { - MutexKind::Recursive - } else if kind == ecx.eval_libc_i32("PTHREAD_MUTEX_DEFAULT") - || kind == PTHREAD_MUTEX_KIND_UNCHANGED - { - // We check this *last* since PTHREAD_MUTEX_DEFAULT may be numerically equal to one of the - // others, and we want an explicit `mutexattr_settype` to work as expected. - MutexKind::Default - } else { - throw_unsup_format!("unsupported type of mutex: {kind}"); - }) + throw_unsup_format!("unsupported static initializer used for `pthread_mutex_t`"); } // # pthread_rwlock_t // We store some data directly inside the type, ignoring the platform layout: // - init: u32 -/// If `init` is set to this, we consider the rwlock initialized. -const RWLOCK_INIT_COOKIE: u32 = 0xcafe_affe; - #[derive(Debug, Copy, Clone)] /// Additional data that we attach with each rwlock instance. pub struct RwLockData { @@ -307,14 +304,14 @@ fn rwlock_init_offset<'tcx>(ecx: &MiriInterpCx<'tcx>) -> InterpResult<'tcx, Size let offset = Size::from_bytes(offset); // Sanity-check this against PTHREAD_RWLOCK_INITIALIZER (but only once): - // the `init` field must start out not equal to RWLOCK_INIT_COOKIE. + // the `init` field must start out not equal to INIT_COOKIE. static SANITY: AtomicBool = AtomicBool::new(false); if !SANITY.swap(true, Ordering::Relaxed) { let static_initializer = ecx.eval_path(&["libc", "PTHREAD_RWLOCK_INITIALIZER"]); let init_field = static_initializer.offset(offset, ecx.machine.layouts.u32, ecx).unwrap(); let init = ecx.read_scalar(&init_field).unwrap().to_u32().unwrap(); assert_ne!( - init, RWLOCK_INIT_COOKIE, + init, INIT_COOKIE, "PTHREAD_RWLOCK_INITIALIZER is incompatible with our initialization cookie" ); } @@ -333,9 +330,16 @@ fn rwlock_get_data<'tcx>( { interp_ok(data) } else { + if !bytewise_equal_atomic_relaxed( + ecx, + &rwlock, + &ecx.eval_path(&["libc", "PTHREAD_RWLOCK_INITIALIZER"]), + )? { + throw_unsup_format!("unsupported static initializer used for `pthread_rwlock_t`"); + } let id = ecx.rwlock_create(); let data = RwLockData { id }; - sync_create(ecx, &rwlock, init_offset, data)?; + sync_init(ecx, &rwlock, init_offset, data)?; interp_ok(data) } } @@ -366,19 +370,6 @@ fn condattr_get_clock_id<'tcx>( .to_i32() } -fn cond_translate_clock_id<'tcx>( - ecx: &MiriInterpCx<'tcx>, - raw_id: i32, -) -> InterpResult<'tcx, ClockId> { - interp_ok(if raw_id == ecx.eval_libc_i32("CLOCK_REALTIME") { - ClockId::Realtime - } else if raw_id == ecx.eval_libc_i32("CLOCK_MONOTONIC") { - ClockId::Monotonic - } else { - throw_unsup_format!("unsupported clock id: {raw_id}"); - }) -} - fn condattr_set_clock_id<'tcx>( ecx: &mut MiriInterpCx<'tcx>, attr_ptr: &OpTy<'tcx>, @@ -393,30 +384,43 @@ fn condattr_set_clock_id<'tcx>( ) } +/// Translates the clock from what is stored in pthread_condattr_t to our enum. +fn condattr_translate_clock_id<'tcx>( + ecx: &MiriInterpCx<'tcx>, + raw_id: i32, +) -> InterpResult<'tcx, ClockId> { + interp_ok(if raw_id == ecx.eval_libc_i32("CLOCK_REALTIME") { + ClockId::Realtime + } else if raw_id == ecx.eval_libc_i32("CLOCK_MONOTONIC") { + ClockId::Monotonic + } else { + throw_unsup_format!("unsupported clock id: {raw_id}"); + }) +} + // # pthread_cond_t // We store some data directly inside the type, ignoring the platform layout: -// - id: u32 +// - init: u32 -fn cond_id_offset<'tcx>(ecx: &MiriInterpCx<'tcx>) -> InterpResult<'tcx, u64> { +fn cond_init_offset<'tcx>(ecx: &MiriInterpCx<'tcx>) -> InterpResult<'tcx, Size> { let offset = match &*ecx.tcx.sess.target.os { "linux" | "illumos" | "solaris" | "freebsd" | "android" => 0, - // macOS stores a signature in the first bytes, so we have to move to offset 4. + // macOS stores a signature in the first bytes, so we move to offset 4. "macos" => 4, os => throw_unsup_format!("`pthread_cond` is not supported on {os}"), }; + let offset = Size::from_bytes(offset); // Sanity-check this against PTHREAD_COND_INITIALIZER (but only once): - // the id must start out as 0. + // the `init` field must start out not equal to INIT_COOKIE. static SANITY: AtomicBool = AtomicBool::new(false); if !SANITY.swap(true, Ordering::Relaxed) { let static_initializer = ecx.eval_path(&["libc", "PTHREAD_COND_INITIALIZER"]); - let id_field = static_initializer - .offset(Size::from_bytes(offset), ecx.machine.layouts.u32, ecx) - .unwrap(); - let id = ecx.read_scalar(&id_field).unwrap().to_u32().unwrap(); - assert_eq!( - id, 0, - "PTHREAD_COND_INITIALIZER is incompatible with our pthread_cond layout: id is not 0" + let init_field = static_initializer.offset(offset, ecx.machine.layouts.u32, ecx).unwrap(); + let init = ecx.read_scalar(&init_field).unwrap().to_u32().unwrap(); + assert_ne!( + init, INIT_COOKIE, + "PTHREAD_COND_INITIALIZER is incompatible with our initialization cookie" ); } @@ -429,36 +433,45 @@ enum ClockId { Monotonic, } -#[derive(Debug)] +#[derive(Debug, Copy, Clone)] /// Additional data that we attach with each cond instance. -struct AdditionalCondData { - /// The address of the cond. - address: u64, - - /// The clock id of the cond. - clock_id: ClockId, +struct CondData { + id: CondvarId, + clock: ClockId, } -fn cond_get_id<'tcx>( +fn cond_create<'tcx>( ecx: &mut MiriInterpCx<'tcx>, cond_ptr: &OpTy<'tcx>, -) -> InterpResult<'tcx, CondvarId> { + clock: ClockId, +) -> InterpResult<'tcx, CondData> { let cond = ecx.deref_pointer(cond_ptr)?; - let address = cond.ptr().addr().bytes(); - let id = ecx.condvar_get_or_create_id(&cond, cond_id_offset(ecx)?, |_ecx| { + let id = ecx.condvar_create(); + let data = CondData { id, clock }; + sync_init(ecx, &cond, cond_init_offset(ecx)?, data)?; + interp_ok(data) +} + +fn cond_get_data<'tcx>( + ecx: &mut MiriInterpCx<'tcx>, + cond_ptr: &OpTy<'tcx>, +) -> InterpResult<'tcx, CondData> { + let cond = ecx.deref_pointer(cond_ptr)?; + let init_offset = cond_init_offset(ecx)?; + + if let Some(data) = sync_get_data::(ecx, &cond, init_offset, "pthread_cond_t")? { + interp_ok(data) + } else { // This used the static initializer. The clock there is always CLOCK_REALTIME. - interp_ok(Some(Box::new(AdditionalCondData { address, clock_id: ClockId::Realtime }))) - })?; - - // Check that the mutex has not been moved since last use. - let data = ecx - .condvar_get_data::(id) - .expect("data should always exist for pthreads"); - if data.address != address { - throw_ub_format!("pthread_cond_t can't be moved after first use") + if !bytewise_equal_atomic_relaxed( + ecx, + &cond, + &ecx.eval_path(&["libc", "PTHREAD_COND_INITIALIZER"]), + )? { + throw_unsup_format!("unsupported static initializer used for `pthread_cond_t`"); + } + cond_create(ecx, cond_ptr, ClockId::Realtime) } - - interp_ok(id) } impl<'tcx> EvalContextExt<'tcx> for crate::MiriInterpCx<'tcx> {} @@ -531,7 +544,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { let kind = if this.ptr_is_null(attr)? { MutexKind::Default } else { - mutex_translate_kind(this, mutexattr_get_kind(this, attr_op)?)? + mutexattr_translate_kind(this, mutexattr_get_kind(this, attr_op)?)? }; mutex_create(this, mutex_op, kind)?; @@ -839,29 +852,23 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { } else { condattr_get_clock_id(this, attr_op)? }; - let clock_id = cond_translate_clock_id(this, clock_id)?; + let clock_id = condattr_translate_clock_id(this, clock_id)?; - let cond = this.deref_pointer(cond_op)?; - let address = cond.ptr().addr().bytes(); - this.condvar_create( - &cond, - cond_id_offset(this)?, - Some(Box::new(AdditionalCondData { address, clock_id })), - )?; + cond_create(this, cond_op, clock_id)?; interp_ok(()) } fn pthread_cond_signal(&mut self, cond_op: &OpTy<'tcx>) -> InterpResult<'tcx, ()> { let this = self.eval_context_mut(); - let id = cond_get_id(this, cond_op)?; + let id = cond_get_data(this, cond_op)?.id; this.condvar_signal(id)?; interp_ok(()) } fn pthread_cond_broadcast(&mut self, cond_op: &OpTy<'tcx>) -> InterpResult<'tcx, ()> { let this = self.eval_context_mut(); - let id = cond_get_id(this, cond_op)?; + let id = cond_get_data(this, cond_op)?.id; while this.condvar_signal(id)? {} interp_ok(()) } @@ -874,11 +881,11 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { ) -> InterpResult<'tcx> { let this = self.eval_context_mut(); - let id = cond_get_id(this, cond_op)?; + let data = cond_get_data(this, cond_op)?; let mutex_id = mutex_get_data(this, mutex_op)?.id; this.condvar_wait( - id, + data.id, mutex_id, None, // no timeout Scalar::from_i32(0), @@ -898,14 +905,10 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { ) -> InterpResult<'tcx> { let this = self.eval_context_mut(); - let id = cond_get_id(this, cond_op)?; + let data = cond_get_data(this, cond_op)?; let mutex_id = mutex_get_data(this, mutex_op)?.id; // Extract the timeout. - let clock_id = this - .condvar_get_data::(id) - .expect("additional data should always be present for pthreads") - .clock_id; let duration = match this .read_timespec(&this.deref_pointer_as(abstime_op, this.libc_ty_layout("timespec"))?)? { @@ -916,7 +919,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { return interp_ok(()); } }; - let timeout_clock = match clock_id { + let timeout_clock = match data.clock { ClockId::Realtime => { this.check_no_isolation("`pthread_cond_timedwait` with `CLOCK_REALTIME`")?; TimeoutClock::RealTime @@ -925,7 +928,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { }; this.condvar_wait( - id, + data.id, mutex_id, Some((timeout_clock, TimeoutAnchor::Absolute, duration)), Scalar::from_i32(0), @@ -941,7 +944,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { // Reading the field also has the side-effect that we detect double-`destroy` // since we make the field unint below. - let id = cond_get_id(this, cond_op)?; + let id = cond_get_data(this, cond_op)?.id; if this.condvar_is_awaited(id) { throw_ub_format!("destroying an awaited conditional variable"); } diff --git a/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.init.stderr b/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.init.stderr index 6e90c490a231..9a8ddc0b5234 100644 --- a/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.init.stderr +++ b/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.init.stderr @@ -1,8 +1,8 @@ -error: Undefined Behavior: pthread_cond_t can't be moved after first use +error: Undefined Behavior: `pthread_cond_t` can't be moved after first use --> tests/fail-dep/concurrency/libc_pthread_cond_move.rs:LL:CC | LL | libc::pthread_cond_destroy(cond2.as_mut_ptr()); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pthread_cond_t can't be moved after first use + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `pthread_cond_t` can't be moved after first use | = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information diff --git a/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.rs b/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.rs index 8fd0caac7518..4db904ab5e22 100644 --- a/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.rs +++ b/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.rs @@ -18,7 +18,7 @@ fn check() { // move pthread_cond_t let mut cond2 = cond; - libc::pthread_cond_destroy(cond2.as_mut_ptr()); //~[init] ERROR: pthread_cond_t can't be moved after first use + libc::pthread_cond_destroy(cond2.as_mut_ptr()); //~[init] ERROR: can't be moved after first use } } @@ -32,6 +32,6 @@ fn check() { // move pthread_cond_t let mut cond2 = cond; - libc::pthread_cond_destroy(&mut cond2 as *mut _); //~[static_initializer] ERROR: pthread_cond_t can't be moved after first use + libc::pthread_cond_destroy(&mut cond2 as *mut _); //~[static_initializer] ERROR: can't be moved after first use } } diff --git a/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.static_initializer.stderr b/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.static_initializer.stderr index ba726ac7f386..8a7c0dee127d 100644 --- a/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.static_initializer.stderr +++ b/src/tools/miri/tests/fail-dep/concurrency/libc_pthread_cond_move.static_initializer.stderr @@ -1,8 +1,8 @@ -error: Undefined Behavior: pthread_cond_t can't be moved after first use +error: Undefined Behavior: `pthread_cond_t` can't be moved after first use --> tests/fail-dep/concurrency/libc_pthread_cond_move.rs:LL:CC | LL | libc::pthread_cond_destroy(&mut cond2 as *mut _); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pthread_cond_t can't be moved after first use + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `pthread_cond_t` can't be moved after first use | = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information