bjoernager/rust
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make use of symbolic vtables in interpreter

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This commit is contained in:
Ralf Jung 2022-07-17 16:02:49 -04:00
parent a10d8e4581
commit fe00573324
23 changed files with 282 additions and 376 deletions
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51
compiler/rustc_const_eval/src/interpret/validity.rs
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@ -313,50 +313,15 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
match tail.kind() {
ty::Dynamic(..) => {
let vtable = self.ecx.scalar_to_ptr(meta.unwrap_meta())?;
// Direct call to `check_ptr_access_align` checks alignment even on CTFE machines.
try_validation!(
self.ecx.check_ptr_access_align(
vtable,
3 * self.ecx.tcx.data_layout.pointer_size, // drop, size, align
self.ecx.tcx.data_layout.pointer_align.abi,
CheckInAllocMsg::InboundsTest, // will anyway be replaced by validity message
),
// Make sure it is a genuine vtable pointer.
let (_ty, _trait) = try_validation!(
self.ecx.get_ptr_vtable(vtable),
self.path,
err_ub!(DanglingIntPointer(..)) |
err_ub!(PointerUseAfterFree(..)) =>
{ "dangling vtable pointer in wide pointer" },
err_ub!(AlignmentCheckFailed { .. }) =>
{ "unaligned vtable pointer in wide pointer" },
err_ub!(PointerOutOfBounds { .. }) =>
{ "too small vtable" },
err_ub!(InvalidVtablePointer(..)) =>
{ "{vtable}" } expected { "a vtable pointer" },
);
try_validation!(
self.ecx.read_drop_type_from_vtable(vtable),
self.path,
err_ub!(DanglingIntPointer(..)) |
err_ub!(InvalidFunctionPointer(..)) =>
{ "invalid drop function pointer in vtable (not pointing to a function)" },
err_ub!(InvalidVtableDropFn(..)) =>
{ "invalid drop function pointer in vtable (function has incompatible signature)" },
// Stacked Borrows errors can happen here, see https://github.com/rust-lang/miri/issues/2123.
// (We assume there are no other MachineStop errors possible here.)
InterpError::MachineStop(_) =>
{ "vtable pointer does not have permission to read drop function pointer" },
);
try_validation!(
self.ecx.read_size_and_align_from_vtable(vtable),
self.path,
err_ub!(InvalidVtableSize) =>
{ "invalid vtable: size is bigger than largest supported object" },
err_ub!(InvalidVtableAlignment(msg)) =>
{ "invalid vtable: alignment {}", msg },
err_unsup!(ReadPointerAsBytes) => { "invalid size or align in vtable" },
// Stacked Borrows errors can happen here, see https://github.com/rust-lang/miri/issues/2123.
// (We assume there are no other MachineStop errors possible here.)
InterpError::MachineStop(_) =>
{ "vtable pointer does not have permission to read size and alignment" },
);
// FIXME: More checks for the vtable.
// FIXME: check if the type/trait match what ty::Dynamic says?
}
ty::Slice(..) | ty::Str => {
let _len = try_validation!(
@ -607,11 +572,9 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
let _fn = try_validation!(
self.ecx.get_ptr_fn(ptr),
self.path,
err_ub!(DanglingIntPointer(0, _)) =>
{ "a null function pointer" },
err_ub!(DanglingIntPointer(..)) |
err_ub!(InvalidFunctionPointer(..)) =>
{ "{:x}", value } expected { "a function pointer" },
{ "{ptr}" } expected { "a function pointer" },
);
// FIXME: Check if the signature matches
} else {