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ptr_get_alloc_id: don't return an actual Pointer

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This commit is contained in:
Ralf Jung 2022-04-17 22:27:14 -04:00
parent ad4e98ed7d
commit 54ab357a5b
2 changed files with 29 additions and 30 deletions
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57
compiler/rustc_const_eval/src/interpret/memory.rs
View file

@ -238,7 +238,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
new_align: Align, new_align: Align,
kind: MemoryKind<M::MemoryKind>, kind: MemoryKind<M::MemoryKind>,
) -> InterpResult<'tcx, Pointer<M::PointerTag>> { ) -> InterpResult<'tcx, Pointer<M::PointerTag>> {
let (alloc_id, offset, ptr) = self.ptr_get_alloc_id(ptr)?; let (alloc_id, offset, _tag) = self.ptr_get_alloc_id(ptr)?;
if offset.bytes() != 0 { if offset.bytes() != 0 {
throw_ub_format!( throw_ub_format!(
"reallocating {:?} which does not point to the beginning of an object", "reallocating {:?} which does not point to the beginning of an object",
@ -255,14 +255,14 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
}; };
// This will also call the access hooks. // This will also call the access hooks.
self.mem_copy( self.mem_copy(
ptr.into(), ptr,
Align::ONE, Align::ONE,
new_ptr.into(), new_ptr.into(),
Align::ONE, Align::ONE,
old_size.min(new_size), old_size.min(new_size),
/*nonoverlapping*/ true, /*nonoverlapping*/ true,
)?; )?;
self.deallocate_ptr(ptr.into(), old_size_and_align, kind)?; self.deallocate_ptr(ptr, old_size_and_align, kind)?;
Ok(new_ptr) Ok(new_ptr)
} }
@ -274,7 +274,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
old_size_and_align: Option<(Size, Align)>, old_size_and_align: Option<(Size, Align)>,
kind: MemoryKind<M::MemoryKind>, kind: MemoryKind<M::MemoryKind>,
) -> InterpResult<'tcx> { ) -> InterpResult<'tcx> {
let (alloc_id, offset, ptr) = self.ptr_get_alloc_id(ptr)?; let (alloc_id, offset, tag) = self.ptr_get_alloc_id(ptr)?;
trace!("deallocating: {}", alloc_id); trace!("deallocating: {}", alloc_id);
if offset.bytes() != 0 { if offset.bytes() != 0 {
@ -330,7 +330,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
*self.tcx, *self.tcx,
&mut self.machine, &mut self.machine,
&mut alloc.extra, &mut alloc.extra,
ptr.provenance, tag,
alloc_range(Size::ZERO, size), alloc_range(Size::ZERO, size),
)?; )?;
@ -350,17 +350,17 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
ptr: Pointer<Option<M::PointerTag>>, ptr: Pointer<Option<M::PointerTag>>,
size: Size, size: Size,
align: Align, align: Align,
) -> InterpResult<'tcx, Option<(AllocId, Size, Pointer<M::PointerTag>)>> { ) -> InterpResult<'tcx, Option<(AllocId, Size, M::PointerTag)>> {
let align = M::enforce_alignment(&self).then_some(align); let align = M::enforce_alignment(&self).then_some(align);
self.check_and_deref_ptr( self.check_and_deref_ptr(
ptr, ptr,
size, size,
align, align,
CheckInAllocMsg::MemoryAccessTest, CheckInAllocMsg::MemoryAccessTest,
|alloc_id, offset, ptr| { |alloc_id, offset, tag| {
let (size, align) = let (size, align) =
self.get_alloc_size_and_align(alloc_id, AllocCheck::Dereferenceable)?; self.get_alloc_size_and_align(alloc_id, AllocCheck::Dereferenceable)?;
Ok((size, align, (alloc_id, offset, ptr))) Ok((size, align, (alloc_id, offset, tag)))
}, },
) )
} }
@ -404,7 +404,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
alloc_size: impl FnOnce( alloc_size: impl FnOnce(
AllocId, AllocId,
Size, Size,
Pointer<M::PointerTag>, M::PointerTag,
) -> InterpResult<'tcx, (Size, Align, T)>, ) -> InterpResult<'tcx, (Size, Align, T)>,
) -> InterpResult<'tcx, Option<T>> { ) -> InterpResult<'tcx, Option<T>> {
fn check_offset_align(offset: u64, align: Align) -> InterpResult<'static> { fn check_offset_align(offset: u64, align: Align) -> InterpResult<'static> {
@ -433,8 +433,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
} }
None None
} }
Ok((alloc_id, offset, ptr)) => { Ok((alloc_id, offset, tag)) => {
let (alloc_size, alloc_align, ret_val) = alloc_size(alloc_id, offset, ptr)?; let (alloc_size, alloc_align, ret_val) = alloc_size(alloc_id, offset, tag)?;
// Test bounds. This also ensures non-null. // Test bounds. This also ensures non-null.
// It is sufficient to check this for the end pointer. Also check for overflow! // It is sufficient to check this for the end pointer. Also check for overflow!
if offset.checked_add(size, &self.tcx).map_or(true, |end| end > alloc_size) { if offset.checked_add(size, &self.tcx).map_or(true, |end| end > alloc_size) {
@ -450,10 +450,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// we want the error to be about the bounds. // we want the error to be about the bounds.
if let Some(align) = align { if let Some(align) = align {
if M::force_int_for_alignment_check(self) { if M::force_int_for_alignment_check(self) {
let addr = Scalar::from_pointer(ptr, &self.tcx) assert!(M::PointerTag::OFFSET_IS_ADDR, "ptr-to-int cast for align check should never fail");
.to_machine_usize(&self.tcx) let (_, addr) = ptr.into_parts(); // we checked that offset is absolute
.expect("ptr-to-int cast for align check should never fail"); check_offset_align(addr.bytes(), align)?;
check_offset_align(addr, align)?;
} else { } else {
// Check allocation alignment and offset alignment. // Check allocation alignment and offset alignment.
if alloc_align.bytes() < align.bytes() { if alloc_align.bytes() < align.bytes() {
@ -569,14 +568,14 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
size, size,
align, align,
CheckInAllocMsg::MemoryAccessTest, CheckInAllocMsg::MemoryAccessTest,
|alloc_id, offset, ptr| { |alloc_id, offset, tag| {
let alloc = self.get_alloc_raw(alloc_id)?; let alloc = self.get_alloc_raw(alloc_id)?;
Ok((alloc.size(), alloc.align, (alloc_id, offset, ptr, alloc))) Ok((alloc.size(), alloc.align, (alloc_id, offset, tag, alloc)))
}, },
)?; )?;
if let Some((alloc_id, offset, ptr, alloc)) = ptr_and_alloc { if let Some((alloc_id, offset, tag, alloc)) = ptr_and_alloc {
let range = alloc_range(offset, size); let range = alloc_range(offset, size);
M::memory_read(*self.tcx, &self.machine, &alloc.extra, ptr.provenance, range)?; M::memory_read(*self.tcx, &self.machine, &alloc.extra, tag, range)?;
Ok(Some(AllocRef { alloc, range, tcx: *self.tcx, alloc_id })) Ok(Some(AllocRef { alloc, range, tcx: *self.tcx, alloc_id }))
} else { } else {
// Even in this branch we have to be sure that we actually access the allocation, in // Even in this branch we have to be sure that we actually access the allocation, in
@ -631,13 +630,13 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
align: Align, align: Align,
) -> InterpResult<'tcx, Option<AllocRefMut<'a, 'tcx, M::PointerTag, M::AllocExtra>>> { ) -> InterpResult<'tcx, Option<AllocRefMut<'a, 'tcx, M::PointerTag, M::AllocExtra>>> {
let parts = self.get_ptr_access(ptr, size, align)?; let parts = self.get_ptr_access(ptr, size, align)?;
if let Some((alloc_id, offset, ptr)) = parts { if let Some((alloc_id, offset, tag)) = parts {
let tcx = *self.tcx; let tcx = *self.tcx;
// FIXME: can we somehow avoid looking up the allocation twice here? // FIXME: can we somehow avoid looking up the allocation twice here?
// We cannot call `get_raw_mut` inside `check_and_deref_ptr` as that would duplicate `&mut self`. // We cannot call `get_raw_mut` inside `check_and_deref_ptr` as that would duplicate `&mut self`.
let (alloc, machine) = self.get_alloc_raw_mut(alloc_id)?; let (alloc, machine) = self.get_alloc_raw_mut(alloc_id)?;
let range = alloc_range(offset, size); let range = alloc_range(offset, size);
M::memory_written(tcx, machine, &mut alloc.extra, ptr.provenance, range)?; M::memory_written(tcx, machine, &mut alloc.extra, tag, range)?;
Ok(Some(AllocRefMut { alloc, range, tcx, alloc_id })) Ok(Some(AllocRefMut { alloc, range, tcx, alloc_id }))
} else { } else {
Ok(None) Ok(None)
@ -732,7 +731,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
ptr: Pointer<Option<M::PointerTag>>, ptr: Pointer<Option<M::PointerTag>>,
) -> InterpResult<'tcx, FnVal<'tcx, M::ExtraFnVal>> { ) -> InterpResult<'tcx, FnVal<'tcx, M::ExtraFnVal>> {
trace!("get_fn({:?})", ptr); trace!("get_fn({:?})", ptr);
let (alloc_id, offset, _ptr) = self.ptr_get_alloc_id(ptr)?; let (alloc_id, offset, _tag) = self.ptr_get_alloc_id(ptr)?;
if offset.bytes() != 0 { if offset.bytes() != 0 {
throw_ub!(InvalidFunctionPointer(Pointer::new(alloc_id, offset))) throw_ub!(InvalidFunctionPointer(Pointer::new(alloc_id, offset)))
} }
@ -1009,16 +1008,16 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// and once below to get the underlying `&[mut] Allocation`. // and once below to get the underlying `&[mut] Allocation`.
// Source alloc preparations and access hooks. // Source alloc preparations and access hooks.
let Some((src_alloc_id, src_offset, src)) = src_parts else { let Some((src_alloc_id, src_offset, src_tag)) = src_parts else {
// Zero-sized *source*, that means dst is also zero-sized and we have nothing to do. // Zero-sized *source*, that means dst is also zero-sized and we have nothing to do.
return Ok(()); return Ok(());
}; };
let src_alloc = self.get_alloc_raw(src_alloc_id)?; let src_alloc = self.get_alloc_raw(src_alloc_id)?;
let src_range = alloc_range(src_offset, size); let src_range = alloc_range(src_offset, size);
M::memory_read(*tcx, &self.machine, &src_alloc.extra, src.provenance, src_range)?; M::memory_read(*tcx, &self.machine, &src_alloc.extra, src_tag, src_range)?;
// We need the `dest` ptr for the next operation, so we get it now. // We need the `dest` ptr for the next operation, so we get it now.
// We already did the source checks and called the hooks so we are good to return early. // We already did the source checks and called the hooks so we are good to return early.
let Some((dest_alloc_id, dest_offset, dest)) = dest_parts else { let Some((dest_alloc_id, dest_offset, dest_tag)) = dest_parts else {
// Zero-sized *destination*. // Zero-sized *destination*.
return Ok(()); return Ok(());
}; };
@ -1040,7 +1039,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// Destination alloc preparations and access hooks. // Destination alloc preparations and access hooks.
let (dest_alloc, extra) = self.get_alloc_raw_mut(dest_alloc_id)?; let (dest_alloc, extra) = self.get_alloc_raw_mut(dest_alloc_id)?;
let dest_range = alloc_range(dest_offset, size * num_copies); let dest_range = alloc_range(dest_offset, size * num_copies);
M::memory_written(*tcx, extra, &mut dest_alloc.extra, dest.provenance, dest_range)?; M::memory_written(*tcx, extra, &mut dest_alloc.extra, dest_tag, dest_range)?;
let dest_bytes = dest_alloc let dest_bytes = dest_alloc
.get_bytes_mut_ptr(&tcx, dest_range) .get_bytes_mut_ptr(&tcx, dest_range)
.map_err(|e| e.to_interp_error(dest_alloc_id))? .map_err(|e| e.to_interp_error(dest_alloc_id))?
@ -1159,11 +1158,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
pub fn ptr_try_get_alloc_id( pub fn ptr_try_get_alloc_id(
&self, &self,
ptr: Pointer<Option<M::PointerTag>>, ptr: Pointer<Option<M::PointerTag>>,
) -> Result<(AllocId, Size, Pointer<M::PointerTag>), u64> { ) -> Result<(AllocId, Size, M::PointerTag), u64> {
match ptr.into_pointer_or_addr() { match ptr.into_pointer_or_addr() {
Ok(ptr) => { Ok(ptr) => {
let (alloc_id, offset) = M::ptr_get_alloc(self, ptr); let (alloc_id, offset) = M::ptr_get_alloc(self, ptr);
Ok((alloc_id, offset, ptr)) Ok((alloc_id, offset, ptr.provenance))
} }
Err(addr) => Err(addr.bytes()), Err(addr) => Err(addr.bytes()),
} }
@ -1174,7 +1173,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
pub fn ptr_get_alloc_id( pub fn ptr_get_alloc_id(
&self, &self,
ptr: Pointer<Option<M::PointerTag>>, ptr: Pointer<Option<M::PointerTag>>,
) -> InterpResult<'tcx, (AllocId, Size, Pointer<M::PointerTag>)> { ) -> InterpResult<'tcx, (AllocId, Size, M::PointerTag)> {
self.ptr_try_get_alloc_id(ptr).map_err(|offset| { self.ptr_try_get_alloc_id(ptr).map_err(|offset| {
err_ub!(DanglingIntPointer(offset, CheckInAllocMsg::InboundsTest)).into() err_ub!(DanglingIntPointer(offset, CheckInAllocMsg::InboundsTest)).into()
}) })

2
compiler/rustc_const_eval/src/interpret/validity.rs
View file

@ -432,7 +432,7 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
if let Some(ref mut ref_tracking) = self.ref_tracking { if let Some(ref mut ref_tracking) = self.ref_tracking {
// Proceed recursively even for ZST, no reason to skip them! // Proceed recursively even for ZST, no reason to skip them!
// `!` is a ZST and we want to validate it. // `!` is a ZST and we want to validate it.
if let Ok((alloc_id, _offset, _ptr)) = self.ecx.ptr_try_get_alloc_id(place.ptr) { if let Ok((alloc_id, _offset, _tag)) = self.ecx.ptr_try_get_alloc_id(place.ptr) {
// Special handling for pointers to statics (irrespective of their type). // Special handling for pointers to statics (irrespective of their type).
let alloc_kind = self.ecx.tcx.get_global_alloc(alloc_id); let alloc_kind = self.ecx.tcx.get_global_alloc(alloc_id);
if let Some(GlobalAlloc::Static(did)) = alloc_kind { if let Some(GlobalAlloc::Static(did)) = alloc_kind {