diff --git a/compiler/rustc_const_eval/src/interpret/eval_context.rs b/compiler/rustc_const_eval/src/interpret/eval_context.rs index a484fbd892c..d98d2107102 100644 --- a/compiler/rustc_const_eval/src/interpret/eval_context.rs +++ b/compiler/rustc_const_eval/src/interpret/eval_context.rs @@ -1,4 +1,5 @@ use std::cell::Cell; +use std::ptr; use std::{fmt, mem}; use either::{Either, Left, Right}; @@ -279,6 +280,11 @@ impl<'mir, 'tcx, Prov: Provenance, Extra> Frame<'mir, 'tcx, Prov, Extra> { } }) } + + #[inline(always)] + pub(super) fn locals_addr(&self) -> usize { + ptr::addr_of!(self.locals).addr() + } } // FIXME: only used by miri, should be removed once translatable. @@ -1212,18 +1218,16 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> std::fmt::Debug { fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { match self.place { - Place::Local { frame, local, offset } => { + Place::Local { local, offset, locals_addr } => { + debug_assert_eq!(locals_addr, self.ecx.frame().locals_addr()); let mut allocs = Vec::new(); write!(fmt, "{local:?}")?; if let Some(offset) = offset { write!(fmt, "+{:#x}", offset.bytes())?; } - if frame != self.ecx.frame_idx() { - write!(fmt, " ({} frames up)", self.ecx.frame_idx() - frame)?; - } write!(fmt, ":")?; - match self.ecx.stack()[frame].locals[local].value { + match self.ecx.frame().locals[local].value { LocalValue::Dead => write!(fmt, " is dead")?, LocalValue::Live(Operand::Immediate(Immediate::Uninit)) => { write!(fmt, " is uninitialized")? diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs index 317e5673b51..48b0dad47ff 100644 --- a/compiler/rustc_const_eval/src/interpret/operand.rs +++ b/compiler/rustc_const_eval/src/interpret/operand.rs @@ -661,9 +661,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> { match place.as_mplace_or_local() { Left(mplace) => Ok(mplace.into()), - Right((frame, local, offset)) => { + Right((local, offset, locals_addr)) => { debug_assert!(place.layout.is_sized()); // only sized locals can ever be `Place::Local`. - let base = self.local_to_op(&self.stack()[frame], local, None)?; + debug_assert_eq!(locals_addr, self.frame().locals_addr()); + let base = self.local_to_op(&self.frame(), local, None)?; Ok(match offset { Some(offset) => base.offset(offset, place.layout, self)?, None => { diff --git a/compiler/rustc_const_eval/src/interpret/place.rs b/compiler/rustc_const_eval/src/interpret/place.rs index 60f7710c11d..52a74f43405 100644 --- a/compiler/rustc_const_eval/src/interpret/place.rs +++ b/compiler/rustc_const_eval/src/interpret/place.rs @@ -187,11 +187,13 @@ pub(super) enum Place { /// where in the local this place is located; if it is `None`, no projection has been applied. /// Such projections are meaningful even if the offset is 0, since they can change layouts. /// (Without that optimization, we'd just always be a `MemPlace`.) - /// Note that this only stores the frame index, not the thread this frame belongs to -- that is - /// implicit. This means a `Place` must never be moved across interpreter thread boundaries! + /// `Local` places always refer to the current stack frame, so they are unstable under + /// function calls/returns and switching betweens stacks of different threads! + /// We carry around the address of the `locals` buffer of the correct stack frame as a sanity + /// chec to be able to catch some cases of using a dangling `Place`. /// /// This variant shall not be used for unsized types -- those must always live in memory. - Local { frame: usize, local: mir::Local, offset: Option }, + Local { local: mir::Local, offset: Option, locals_addr: usize }, } /// An evaluated place, together with its type. @@ -233,10 +235,10 @@ impl<'tcx, Prov: Provenance> PlaceTy<'tcx, Prov> { #[inline(always)] pub fn as_mplace_or_local( &self, - ) -> Either, (usize, mir::Local, Option)> { + ) -> Either, (mir::Local, Option, usize)> { match self.place { Place::Ptr(mplace) => Left(MPlaceTy { mplace, layout: self.layout }), - Place::Local { frame, local, offset } => Right((frame, local, offset)), + Place::Local { local, offset, locals_addr } => Right((local, offset, locals_addr)), } } @@ -279,7 +281,7 @@ impl<'tcx, Prov: Provenance> Projectable<'tcx, Prov> for PlaceTy<'tcx, Prov> { ) -> InterpResult<'tcx, Self> { Ok(match self.as_mplace_or_local() { Left(mplace) => mplace.offset_with_meta(offset, mode, meta, layout, ecx)?.into(), - Right((frame, local, old_offset)) => { + Right((local, old_offset, locals_addr)) => { debug_assert!(layout.is_sized(), "unsized locals should live in memory"); assert_matches!(meta, MemPlaceMeta::None); // we couldn't store it anyway... // `Place::Local` are always in-bounds of their surrounding local, so we can just @@ -292,7 +294,10 @@ impl<'tcx, Prov: Provenance> Projectable<'tcx, Prov> for PlaceTy<'tcx, Prov> { .offset(old_offset.unwrap_or(Size::ZERO).bytes(), offset.bytes())?, ); - PlaceTy { place: Place::Local { frame, local, offset: Some(new_offset) }, layout } + PlaceTy { + place: Place::Local { local, offset: Some(new_offset), locals_addr }, + layout, + } } }) } @@ -331,7 +336,7 @@ impl<'tcx, Prov: Provenance> OpTy<'tcx, Prov> { pub trait Writeable<'tcx, Prov: Provenance>: Projectable<'tcx, Prov> { fn as_mplace_or_local( &self, - ) -> Either, (usize, mir::Local, Option, TyAndLayout<'tcx>)>; + ) -> Either, (mir::Local, Option, usize, TyAndLayout<'tcx>)>; fn force_mplace<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>( &self, @@ -343,9 +348,9 @@ impl<'tcx, Prov: Provenance> Writeable<'tcx, Prov> for PlaceTy<'tcx, Prov> { #[inline(always)] fn as_mplace_or_local( &self, - ) -> Either, (usize, mir::Local, Option, TyAndLayout<'tcx>)> { + ) -> Either, (mir::Local, Option, usize, TyAndLayout<'tcx>)> { self.as_mplace_or_local() - .map_right(|(frame, local, offset)| (frame, local, offset, self.layout)) + .map_right(|(local, offset, locals_addr)| (local, offset, locals_addr, self.layout)) } #[inline(always)] @@ -361,7 +366,7 @@ impl<'tcx, Prov: Provenance> Writeable<'tcx, Prov> for MPlaceTy<'tcx, Prov> { #[inline(always)] fn as_mplace_or_local( &self, - ) -> Either, (usize, mir::Local, Option, TyAndLayout<'tcx>)> { + ) -> Either, (mir::Local, Option, usize, TyAndLayout<'tcx>)> { Left(self.clone()) } @@ -512,7 +517,7 @@ where let layout = self.layout_of_local(frame_ref, local, None)?; let place = if layout.is_sized() { // We can just always use the `Local` for sized values. - Place::Local { frame, local, offset: None } + Place::Local { local, offset: None, locals_addr: frame_ref.locals_addr() } } else { // Unsized `Local` isn't okay (we cannot store the metadata). match frame_ref.locals[local].access()? { @@ -611,15 +616,16 @@ where // See if we can avoid an allocation. This is the counterpart to `read_immediate_raw`, // but not factored as a separate function. let mplace = match dest.as_mplace_or_local() { - Right((frame, local, offset, layout)) => { + Right((local, offset, locals_addr, layout)) => { if offset.is_some() { // This has been projected to a part of this local. We could have complicated // logic to still keep this local as an `Operand`... but it's much easier to // just fall back to the indirect path. dest.force_mplace(self)? } else { - M::before_access_local_mut(self, frame, local)?; - match self.stack_mut()[frame].locals[local].access_mut()? { + debug_assert_eq!(locals_addr, self.frame().locals_addr()); + M::before_access_local_mut(self, self.frame_idx(), local)?; + match self.frame_mut().locals[local].access_mut()? { Operand::Immediate(local_val) => { // Local can be updated in-place. *local_val = src; @@ -627,7 +633,7 @@ where // (*After* doing the update for borrow checker reasons.) if cfg!(debug_assertions) { let local_layout = - self.layout_of_local(&self.stack()[frame], local, None)?; + self.layout_of_local(&self.frame(), local, None)?; match (src, local_layout.abi) { (Immediate::Scalar(scalar), Abi::Scalar(s)) => { assert_eq!(scalar.size(), s.size(self)) @@ -725,7 +731,7 @@ where ) -> InterpResult<'tcx> { let mplace = match dest.as_mplace_or_local() { Left(mplace) => mplace, - Right((frame, local, offset, layout)) => { + Right((local, offset, locals_addr, layout)) => { if offset.is_some() { // This has been projected to a part of this local. We could have complicated // logic to still keep this local as an `Operand`... but it's much easier to @@ -733,8 +739,9 @@ where // FIXME: share the logic with `write_immediate_no_validate`. dest.force_mplace(self)? } else { - M::before_access_local_mut(self, frame, local)?; - match self.stack_mut()[frame].locals[local].access_mut()? { + debug_assert_eq!(locals_addr, self.frame().locals_addr()); + M::before_access_local_mut(self, self.frame_idx(), local)?; + match self.frame_mut().locals[local].access_mut()? { Operand::Immediate(local) => { *local = Immediate::Uninit; return Ok(()); @@ -912,17 +919,17 @@ where place: &PlaceTy<'tcx, M::Provenance>, ) -> InterpResult<'tcx, MPlaceTy<'tcx, M::Provenance>> { let mplace = match place.place { - Place::Local { frame, local, offset } => { - M::before_access_local_mut(self, frame, local)?; - let whole_local = match self.stack_mut()[frame].locals[local].access_mut()? { + Place::Local { local, offset, locals_addr } => { + debug_assert_eq!(locals_addr, self.frame().locals_addr()); + M::before_access_local_mut(self, self.frame_idx(), local)?; + let whole_local = match self.frame_mut().locals[local].access_mut()? { &mut Operand::Immediate(local_val) => { // We need to make an allocation. // We need the layout of the local. We can NOT use the layout we got, // that might e.g., be an inner field of a struct with `Scalar` layout, // that has different alignment than the outer field. - let local_layout = - self.layout_of_local(&self.stack()[frame], local, None)?; + let local_layout = self.layout_of_local(&self.frame(), local, None)?; assert!(local_layout.is_sized(), "unsized locals cannot be immediate"); let mplace = self.allocate(local_layout, MemoryKind::Stack)?; // Preserve old value. (As an optimization, we can skip this if it was uninit.) @@ -936,11 +943,11 @@ where mplace.mplace, )?; } - M::after_local_allocated(self, frame, local, &mplace)?; + M::after_local_allocated(self, self.frame_idx(), local, &mplace)?; // Now we can call `access_mut` again, asserting it goes well, and actually // overwrite things. This points to the entire allocation, not just the part // the place refers to, i.e. we do this before we apply `offset`. - *self.stack_mut()[frame].locals[local].access_mut().unwrap() = + *self.frame_mut().locals[local].access_mut().unwrap() = Operand::Indirect(mplace.mplace); mplace.mplace } diff --git a/compiler/rustc_const_eval/src/lib.rs b/compiler/rustc_const_eval/src/lib.rs index 51836063945..1e7ee208af1 100644 --- a/compiler/rustc_const_eval/src/lib.rs +++ b/compiler/rustc_const_eval/src/lib.rs @@ -14,6 +14,7 @@ Rust MIR: a lowered representation of Rust. #![feature(generic_nonzero)] #![feature(let_chains)] #![feature(slice_ptr_get)] +#![feature(strict_provenance)] #![feature(never_type)] #![feature(trait_alias)] #![feature(try_blocks)]