Auto merge of #113569 - RalfJung:miri, r=oli-obk

miri: protect Move() function arguments during the call

This gives `Move` operands a meaning specific to function calls:
- for the duration of the call, the place the operand comes from is protected, making all read and write accesses insta-UB.
- the contents of that place are reset to `Uninit`, so looking at them again after the function returns, we cannot observe their contents

Turns out we can replace the existing "retag return place" hack with the exact same sort of protection on the return place, which is nicely symmetric.

Fixes https://github.com/rust-lang/rust/issues/112564
Fixes https://github.com/rust-lang/miri/issues/2927

This starts with a Miri rustc-push, since we'd otherwise conflict with a PR that recently landed in Miri.
(The "miri tree borrows" commit is an unrelated cleanup I noticed while doing the PR. I can remove it if you prefer.)
r? `@oli-obk`
This commit is contained in:
bors 2023-07-12 10:19:42 +00:00
commit 136dab6614
37 changed files with 747 additions and 161 deletions

View File

@ -22,7 +22,7 @@ use rustc_target::spec::abi::Abi as CallAbi;
use crate::errors::{LongRunning, LongRunningWarn};
use crate::interpret::{
self, compile_time_machine, AllocId, ConstAllocation, FnVal, Frame, ImmTy, InterpCx,
self, compile_time_machine, AllocId, ConstAllocation, FnArg, FnVal, Frame, ImmTy, InterpCx,
InterpResult, OpTy, PlaceTy, Pointer, Scalar,
};
use crate::{errors, fluent_generated as fluent};
@ -201,7 +201,7 @@ impl<'mir, 'tcx: 'mir> CompileTimeEvalContext<'mir, 'tcx> {
fn hook_special_const_fn(
&mut self,
instance: ty::Instance<'tcx>,
args: &[OpTy<'tcx>],
args: &[FnArg<'tcx>],
dest: &PlaceTy<'tcx>,
ret: Option<mir::BasicBlock>,
) -> InterpResult<'tcx, Option<ty::Instance<'tcx>>> {
@ -210,6 +210,7 @@ impl<'mir, 'tcx: 'mir> CompileTimeEvalContext<'mir, 'tcx> {
if Some(def_id) == self.tcx.lang_items().panic_display()
|| Some(def_id) == self.tcx.lang_items().begin_panic_fn()
{
let args = self.copy_fn_args(args)?;
// &str or &&str
assert!(args.len() == 1);
@ -236,8 +237,9 @@ impl<'mir, 'tcx: 'mir> CompileTimeEvalContext<'mir, 'tcx> {
return Ok(Some(new_instance));
} else if Some(def_id) == self.tcx.lang_items().align_offset_fn() {
let args = self.copy_fn_args(args)?;
// For align_offset, we replace the function call if the pointer has no address.
match self.align_offset(instance, args, dest, ret)? {
match self.align_offset(instance, &args, dest, ret)? {
ControlFlow::Continue(()) => return Ok(Some(instance)),
ControlFlow::Break(()) => return Ok(None),
}
@ -293,7 +295,7 @@ impl<'mir, 'tcx: 'mir> CompileTimeEvalContext<'mir, 'tcx> {
self.eval_fn_call(
FnVal::Instance(instance),
(CallAbi::Rust, fn_abi),
&[addr, align],
&[FnArg::Copy(addr), FnArg::Copy(align)],
/* with_caller_location = */ false,
dest,
ret,
@ -427,7 +429,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
ecx: &mut InterpCx<'mir, 'tcx, Self>,
instance: ty::Instance<'tcx>,
_abi: CallAbi,
args: &[OpTy<'tcx>],
args: &[FnArg<'tcx>],
dest: &PlaceTy<'tcx>,
ret: Option<mir::BasicBlock>,
_unwind: mir::UnwindAction, // unwinding is not supported in consts

View File

@ -682,11 +682,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
return_to_block: StackPopCleanup,
) -> InterpResult<'tcx> {
trace!("body: {:#?}", body);
// Clobber previous return place contents, nobody is supposed to be able to see them any more
// This also checks dereferenceable, but not align. We rely on all constructed places being
// sufficiently aligned (in particular we rely on `deref_operand` checking alignment).
self.write_uninit(return_place)?;
// first push a stack frame so we have access to the local substs
// First push a stack frame so we have access to the local substs
let pre_frame = Frame {
body,
loc: Right(body.span), // Span used for errors caused during preamble.
@ -805,6 +801,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
throw_ub_custom!(fluent::const_eval_unwind_past_top);
}
M::before_stack_pop(self, self.frame())?;
// Copy return value. Must of course happen *before* we deallocate the locals.
let copy_ret_result = if !unwinding {
let op = self

View File

@ -30,7 +30,7 @@ use super::{
use crate::const_eval;
use crate::errors::{DanglingPtrInFinal, UnsupportedUntypedPointer};
pub trait CompileTimeMachine<'mir, 'tcx, T> = Machine<
pub trait CompileTimeMachine<'mir, 'tcx: 'mir, T> = Machine<
'mir,
'tcx,
MemoryKind = T,

View File

@ -17,7 +17,7 @@ use rustc_target::spec::abi::Abi as CallAbi;
use crate::const_eval::CheckAlignment;
use super::{
AllocBytes, AllocId, AllocRange, Allocation, ConstAllocation, Frame, ImmTy, InterpCx,
AllocBytes, AllocId, AllocRange, Allocation, ConstAllocation, FnArg, Frame, ImmTy, InterpCx,
InterpResult, MemoryKind, OpTy, Operand, PlaceTy, Pointer, Provenance, Scalar,
};
@ -84,7 +84,7 @@ pub trait AllocMap<K: Hash + Eq, V> {
/// Methods of this trait signifies a point where CTFE evaluation would fail
/// and some use case dependent behaviour can instead be applied.
pub trait Machine<'mir, 'tcx>: Sized {
pub trait Machine<'mir, 'tcx: 'mir>: Sized {
/// Additional memory kinds a machine wishes to distinguish from the builtin ones
type MemoryKind: Debug + std::fmt::Display + MayLeak + Eq + 'static;
@ -182,7 +182,7 @@ pub trait Machine<'mir, 'tcx>: Sized {
ecx: &mut InterpCx<'mir, 'tcx, Self>,
instance: ty::Instance<'tcx>,
abi: CallAbi,
args: &[OpTy<'tcx, Self::Provenance>],
args: &[FnArg<'tcx, Self::Provenance>],
destination: &PlaceTy<'tcx, Self::Provenance>,
target: Option<mir::BasicBlock>,
unwind: mir::UnwindAction,
@ -194,7 +194,7 @@ pub trait Machine<'mir, 'tcx>: Sized {
ecx: &mut InterpCx<'mir, 'tcx, Self>,
fn_val: Self::ExtraFnVal,
abi: CallAbi,
args: &[OpTy<'tcx, Self::Provenance>],
args: &[FnArg<'tcx, Self::Provenance>],
destination: &PlaceTy<'tcx, Self::Provenance>,
target: Option<mir::BasicBlock>,
unwind: mir::UnwindAction,
@ -418,6 +418,18 @@ pub trait Machine<'mir, 'tcx>: Sized {
Ok(())
}
/// Called on places used for in-place function argument and return value handling.
///
/// These places need to be protected to make sure the program cannot tell whether the
/// argument/return value was actually copied or passed in-place..
fn protect_in_place_function_argument(
ecx: &mut InterpCx<'mir, 'tcx, Self>,
place: &PlaceTy<'tcx, Self::Provenance>,
) -> InterpResult<'tcx> {
// Without an aliasing model, all we can do is put `Uninit` into the place.
ecx.write_uninit(place)
}
/// Called immediately before a new stack frame gets pushed.
fn init_frame_extra(
ecx: &mut InterpCx<'mir, 'tcx, Self>,
@ -439,6 +451,14 @@ pub trait Machine<'mir, 'tcx>: Sized {
Ok(())
}
/// Called just before the return value is copied to the caller-provided return place.
fn before_stack_pop(
_ecx: &InterpCx<'mir, 'tcx, Self>,
_frame: &Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>,
) -> InterpResult<'tcx> {
Ok(())
}
/// Called immediately after a stack frame got popped, but before jumping back to the caller.
/// The `locals` have already been destroyed!
fn after_stack_pop(
@ -484,7 +504,7 @@ pub macro compile_time_machine(<$mir: lifetime, $tcx: lifetime>) {
_ecx: &mut InterpCx<$mir, $tcx, Self>,
fn_val: !,
_abi: CallAbi,
_args: &[OpTy<$tcx>],
_args: &[FnArg<$tcx>],
_destination: &PlaceTy<$tcx, Self::Provenance>,
_target: Option<mir::BasicBlock>,
_unwind: mir::UnwindAction,

View File

@ -26,6 +26,7 @@ pub use self::machine::{compile_time_machine, AllocMap, Machine, MayLeak, StackP
pub use self::memory::{AllocKind, AllocRef, AllocRefMut, FnVal, Memory, MemoryKind};
pub use self::operand::{ImmTy, Immediate, OpTy, Operand};
pub use self::place::{MPlaceTy, MemPlace, MemPlaceMeta, Place, PlaceTy};
pub use self::terminator::FnArg;
pub use self::validity::{CtfeValidationMode, RefTracking};
pub use self::visitor::{MutValueVisitor, Value, ValueVisitor};

View File

@ -575,14 +575,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
Ok(op)
}
/// Evaluate a bunch of operands at once
pub(super) fn eval_operands(
&self,
ops: &[mir::Operand<'tcx>],
) -> InterpResult<'tcx, Vec<OpTy<'tcx, M::Provenance>>> {
ops.iter().map(|op| self.eval_operand(op, None)).collect()
}
fn eval_ty_constant(
&self,
val: ty::Const<'tcx>,

View File

@ -328,7 +328,8 @@ where
};
let mplace = MemPlace { ptr: ptr.to_pointer(self)?, meta };
// When deref'ing a pointer, the *static* alignment given by the type is what matters.
// `ref_to_mplace` is called on raw pointers even if they don't actually get dereferenced;
// we hence can't call `size_and_align_of` since that asserts more validity than we want.
let align = layout.align.abi;
Ok(MPlaceTy { mplace, layout, align })
}
@ -354,34 +355,37 @@ where
#[inline]
pub(super) fn get_place_alloc(
&self,
place: &MPlaceTy<'tcx, M::Provenance>,
mplace: &MPlaceTy<'tcx, M::Provenance>,
) -> InterpResult<'tcx, Option<AllocRef<'_, 'tcx, M::Provenance, M::AllocExtra, M::Bytes>>>
{
assert!(place.layout.is_sized());
assert!(!place.meta.has_meta());
let size = place.layout.size;
self.get_ptr_alloc(place.ptr, size, place.align)
let (size, _align) = self
.size_and_align_of_mplace(&mplace)?
.unwrap_or((mplace.layout.size, mplace.layout.align.abi));
// Due to packed places, only `mplace.align` matters.
self.get_ptr_alloc(mplace.ptr, size, mplace.align)
}
#[inline]
pub(super) fn get_place_alloc_mut(
&mut self,
place: &MPlaceTy<'tcx, M::Provenance>,
mplace: &MPlaceTy<'tcx, M::Provenance>,
) -> InterpResult<'tcx, Option<AllocRefMut<'_, 'tcx, M::Provenance, M::AllocExtra, M::Bytes>>>
{
assert!(place.layout.is_sized());
assert!(!place.meta.has_meta());
let size = place.layout.size;
self.get_ptr_alloc_mut(place.ptr, size, place.align)
let (size, _align) = self
.size_and_align_of_mplace(&mplace)?
.unwrap_or((mplace.layout.size, mplace.layout.align.abi));
// Due to packed places, only `mplace.align` matters.
self.get_ptr_alloc_mut(mplace.ptr, size, mplace.align)
}
/// Check if this mplace is dereferenceable and sufficiently aligned.
pub fn check_mplace(&self, mplace: MPlaceTy<'tcx, M::Provenance>) -> InterpResult<'tcx> {
let (size, align) = self
let (size, _align) = self
.size_and_align_of_mplace(&mplace)?
.unwrap_or((mplace.layout.size, mplace.layout.align.abi));
assert!(mplace.align <= align, "dynamic alignment less strict than static one?");
let align = if M::enforce_alignment(self).should_check() { align } else { Align::ONE };
// Due to packed places, only `mplace.align` matters.
let align =
if M::enforce_alignment(self).should_check() { mplace.align } else { Align::ONE };
self.check_ptr_access_align(mplace.ptr, size, align, CheckInAllocMsg::DerefTest)?;
Ok(())
}

View File

@ -1,7 +1,8 @@
use std::borrow::Cow;
use either::Either;
use rustc_ast::ast::InlineAsmOptions;
use rustc_middle::ty::layout::{FnAbiOf, LayoutOf};
use rustc_middle::ty::layout::{FnAbiOf, LayoutOf, TyAndLayout};
use rustc_middle::ty::Instance;
use rustc_middle::{
mir,
@ -12,12 +13,63 @@ use rustc_target::abi::call::{ArgAbi, ArgAttribute, ArgAttributes, FnAbi, PassMo
use rustc_target::spec::abi::Abi;
use super::{
FnVal, ImmTy, Immediate, InterpCx, InterpResult, MPlaceTy, Machine, MemoryKind, OpTy, Operand,
PlaceTy, Scalar, StackPopCleanup,
AllocId, FnVal, ImmTy, Immediate, InterpCx, InterpResult, MPlaceTy, Machine, MemoryKind, OpTy,
Operand, PlaceTy, Provenance, Scalar, StackPopCleanup,
};
use crate::fluent_generated as fluent;
/// An argment passed to a function.
#[derive(Clone, Debug)]
pub enum FnArg<'tcx, Prov: Provenance = AllocId> {
/// Pass a copy of the given operand.
Copy(OpTy<'tcx, Prov>),
/// Allow for the argument to be passed in-place: destroy the value originally stored at that place and
/// make the place inaccessible for the duration of the function call.
InPlace(PlaceTy<'tcx, Prov>),
}
impl<'tcx, Prov: Provenance> FnArg<'tcx, Prov> {
pub fn layout(&self) -> &TyAndLayout<'tcx> {
match self {
FnArg::Copy(op) => &op.layout,
FnArg::InPlace(place) => &place.layout,
}
}
}
impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
/// Make a copy of the given fn_arg. Any `InPlace` are degenerated to copies, no protection of the
/// original memory occurs.
pub fn copy_fn_arg(
&self,
arg: &FnArg<'tcx, M::Provenance>,
) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
match arg {
FnArg::Copy(op) => Ok(op.clone()),
FnArg::InPlace(place) => self.place_to_op(&place),
}
}
/// Make a copy of the given fn_args. Any `InPlace` are degenerated to copies, no protection of the
/// original memory occurs.
pub fn copy_fn_args(
&self,
args: &[FnArg<'tcx, M::Provenance>],
) -> InterpResult<'tcx, Vec<OpTy<'tcx, M::Provenance>>> {
args.iter().map(|fn_arg| self.copy_fn_arg(fn_arg)).collect()
}
pub fn fn_arg_field(
&mut self,
arg: &FnArg<'tcx, M::Provenance>,
field: usize,
) -> InterpResult<'tcx, FnArg<'tcx, M::Provenance>> {
Ok(match arg {
FnArg::Copy(op) => FnArg::Copy(self.operand_field(op, field)?),
FnArg::InPlace(place) => FnArg::InPlace(self.place_field(place, field)?),
})
}
pub(super) fn eval_terminator(
&mut self,
terminator: &mir::Terminator<'tcx>,
@ -68,14 +120,14 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
let old_stack = self.frame_idx();
let old_loc = self.frame().loc;
let func = self.eval_operand(func, None)?;
let args = self.eval_operands(args)?;
let args = self.eval_fn_call_arguments(args)?;
let fn_sig_binder = func.layout.ty.fn_sig(*self.tcx);
let fn_sig =
self.tcx.normalize_erasing_late_bound_regions(self.param_env, fn_sig_binder);
let extra_args = &args[fn_sig.inputs().len()..];
let extra_args =
self.tcx.mk_type_list_from_iter(extra_args.iter().map(|arg| arg.layout.ty));
self.tcx.mk_type_list_from_iter(extra_args.iter().map(|arg| arg.layout().ty));
let (fn_val, fn_abi, with_caller_location) = match *func.layout.ty.kind() {
ty::FnPtr(_sig) => {
@ -185,6 +237,21 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
Ok(())
}
/// Evaluate the arguments of a function call
pub(super) fn eval_fn_call_arguments(
&mut self,
ops: &[mir::Operand<'tcx>],
) -> InterpResult<'tcx, Vec<FnArg<'tcx, M::Provenance>>> {
ops.iter()
.map(|op| {
Ok(match op {
mir::Operand::Move(place) => FnArg::InPlace(self.eval_place(*place)?),
_ => FnArg::Copy(self.eval_operand(op, None)?),
})
})
.collect()
}
fn check_argument_compat(
caller_abi: &ArgAbi<'tcx, Ty<'tcx>>,
callee_abi: &ArgAbi<'tcx, Ty<'tcx>>,
@ -275,7 +342,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
fn pass_argument<'x, 'y>(
&mut self,
caller_args: &mut impl Iterator<
Item = (&'x OpTy<'tcx, M::Provenance>, &'y ArgAbi<'tcx, Ty<'tcx>>),
Item = (&'x FnArg<'tcx, M::Provenance>, &'y ArgAbi<'tcx, Ty<'tcx>>),
>,
callee_abi: &ArgAbi<'tcx, Ty<'tcx>>,
callee_arg: &PlaceTy<'tcx, M::Provenance>,
@ -295,21 +362,25 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// Now, check
if !Self::check_argument_compat(caller_abi, callee_abi) {
let callee_ty = format!("{}", callee_arg.layout.ty);
let caller_ty = format!("{}", caller_arg.layout.ty);
let caller_ty = format!("{}", caller_arg.layout().ty);
throw_ub_custom!(
fluent::const_eval_incompatible_types,
callee_ty = callee_ty,
caller_ty = caller_ty,
)
}
// We work with a copy of the argument for now; if this is in-place argument passing, we
// will later protect the source it comes from. This means the callee cannot observe if we
// did in-place of by-copy argument passing, except for pointer equality tests.
let caller_arg_copy = self.copy_fn_arg(&caller_arg)?;
// Special handling for unsized parameters.
if caller_arg.layout.is_unsized() {
if caller_arg_copy.layout.is_unsized() {
// `check_argument_compat` ensures that both have the same type, so we know they will use the metadata the same way.
assert_eq!(caller_arg.layout.ty, callee_arg.layout.ty);
assert_eq!(caller_arg_copy.layout.ty, callee_arg.layout.ty);
// We have to properly pre-allocate the memory for the callee.
// So let's tear down some wrappers.
// So let's tear down some abstractions.
// This all has to be in memory, there are no immediate unsized values.
let src = caller_arg.assert_mem_place();
let src = caller_arg_copy.assert_mem_place();
// The destination cannot be one of these "spread args".
let (dest_frame, dest_local) = callee_arg.assert_local();
// We are just initializing things, so there can't be anything here yet.
@ -331,7 +402,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// FIXME: Depending on the PassMode, this should reset some padding to uninitialized. (This
// is true for all `copy_op`, but there are a lot of special cases for argument passing
// specifically.)
self.copy_op(&caller_arg, callee_arg, /*allow_transmute*/ true)
self.copy_op(&caller_arg_copy, callee_arg, /*allow_transmute*/ true)?;
// If this was an in-place pass, protect the place it comes from for the duration of the call.
if let FnArg::InPlace(place) = caller_arg {
M::protect_in_place_function_argument(self, place)?;
}
Ok(())
}
/// Call this function -- pushing the stack frame and initializing the arguments.
@ -346,7 +422,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
&mut self,
fn_val: FnVal<'tcx, M::ExtraFnVal>,
(caller_abi, caller_fn_abi): (Abi, &FnAbi<'tcx, Ty<'tcx>>),
args: &[OpTy<'tcx, M::Provenance>],
args: &[FnArg<'tcx, M::Provenance>],
with_caller_location: bool,
destination: &PlaceTy<'tcx, M::Provenance>,
target: Option<mir::BasicBlock>,
@ -372,8 +448,15 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
match instance.def {
ty::InstanceDef::Intrinsic(def_id) => {
assert!(self.tcx.is_intrinsic(def_id));
// caller_fn_abi is not relevant here, we interpret the arguments directly for each intrinsic.
M::call_intrinsic(self, instance, args, destination, target, unwind)
// FIXME: Should `InPlace` arguments be reset to uninit?
M::call_intrinsic(
self,
instance,
&self.copy_fn_args(args)?,
destination,
target,
unwind,
)
}
ty::InstanceDef::VTableShim(..)
| ty::InstanceDef::ReifyShim(..)
@ -428,7 +511,13 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
"caller ABI: {:?}, args: {:#?}",
caller_abi,
args.iter()
.map(|arg| (arg.layout.ty, format!("{:?}", **arg)))
.map(|arg| (
arg.layout().ty,
match arg {
FnArg::Copy(op) => format!("copy({:?})", *op),
FnArg::InPlace(place) => format!("in-place({:?})", *place),
}
))
.collect::<Vec<_>>()
);
trace!(
@ -449,7 +538,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// last incoming argument. These two iterators do not have the same type,
// so to keep the code paths uniform we accept an allocation
// (for RustCall ABI only).
let caller_args: Cow<'_, [OpTy<'tcx, M::Provenance>]> =
let caller_args: Cow<'_, [FnArg<'tcx, M::Provenance>]> =
if caller_abi == Abi::RustCall && !args.is_empty() {
// Untuple
let (untuple_arg, args) = args.split_last().unwrap();
@ -458,11 +547,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
args.iter()
.map(|a| Ok(a.clone()))
.chain(
(0..untuple_arg.layout.fields.count())
.map(|i| self.operand_field(untuple_arg, i)),
(0..untuple_arg.layout().fields.count())
.map(|i| self.fn_arg_field(untuple_arg, i)),
)
.collect::<InterpResult<'_, Vec<OpTy<'tcx, M::Provenance>>>>(
)?,
.collect::<InterpResult<'_, Vec<_>>>()?,
)
} else {
// Plain arg passing
@ -523,6 +611,14 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
caller_ty = caller_ty,
)
}
// Ensure the return place is aligned and dereferenceable, and protect it for
// in-place return value passing.
if let Either::Left(mplace) = destination.as_mplace_or_local() {
self.check_mplace(mplace)?;
} else {
// Nothing to do for locals, they are always properly allocated and aligned.
}
M::protect_in_place_function_argument(self, destination)?;
};
match res {
Err(err) => {
@ -538,7 +634,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// We have to implement all "object safe receivers". So we have to go search for a
// pointer or `dyn Trait` type, but it could be wrapped in newtypes. So recursively
// unwrap those newtypes until we are there.
let mut receiver = args[0].clone();
// An `InPlace` does nothing here, we keep the original receiver intact. We can't
// really pass the argument in-place anyway, and we are constructing a new
// `Immediate` receiver.
let mut receiver = self.copy_fn_arg(&args[0])?;
let receiver_place = loop {
match receiver.layout.ty.kind() {
ty::Ref(..) | ty::RawPtr(..) => {
@ -648,11 +747,13 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
}
// Adjust receiver argument. Layout can be any (thin) ptr.
args[0] = ImmTy::from_immediate(
Scalar::from_maybe_pointer(adjusted_receiver, self).into(),
self.layout_of(Ty::new_mut_ptr(self.tcx.tcx, dyn_ty))?,
)
.into();
args[0] = FnArg::Copy(
ImmTy::from_immediate(
Scalar::from_maybe_pointer(adjusted_receiver, self).into(),
self.layout_of(Ty::new_mut_ptr(self.tcx.tcx, dyn_ty))?,
)
.into(),
);
trace!("Patched receiver operand to {:#?}", args[0]);
// recurse with concrete function
self.eval_fn_call(
@ -710,7 +811,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
self.eval_fn_call(
FnVal::Instance(instance),
(Abi::Rust, fn_abi),
&[arg.into()],
&[FnArg::Copy(arg.into())],
false,
&ret.into(),
Some(target),

View File

@ -13,7 +13,7 @@ use super::{InterpCx, MPlaceTy, Machine, OpTy, PlaceTy};
/// A thing that we can project into, and that has a layout.
/// This wouldn't have to depend on `Machine` but with the current type inference,
/// that's just more convenient to work with (avoids repeating all the `Machine` bounds).
pub trait Value<'mir, 'tcx, M: Machine<'mir, 'tcx>>: Sized {
pub trait Value<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>>: Sized {
/// Gets this value's layout.
fn layout(&self) -> TyAndLayout<'tcx>;
@ -54,7 +54,7 @@ pub trait Value<'mir, 'tcx, M: Machine<'mir, 'tcx>>: Sized {
/// A thing that we can project into given *mutable* access to `ecx`, and that has a layout.
/// This wouldn't have to depend on `Machine` but with the current type inference,
/// that's just more convenient to work with (avoids repeating all the `Machine` bounds).
pub trait ValueMut<'mir, 'tcx, M: Machine<'mir, 'tcx>>: Sized {
pub trait ValueMut<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>>: Sized {
/// Gets this value's layout.
fn layout(&self) -> TyAndLayout<'tcx>;

View File

@ -1050,10 +1050,6 @@ pub type PlaceElem<'tcx> = ProjectionElem<Local, Ty<'tcx>>;
/// there may be other effects: if the type has a validity constraint loading the place might be UB
/// if the validity constraint is not met.
///
/// **Needs clarification:** Ralf proposes that loading a place not have side-effects.
/// This is what is implemented in miri today. Are these the semantics we want for MIR? Is this
/// something we can even decide without knowing more about Rust's memory model?
///
/// **Needs clarification:** Is loading a place that has its variant index set well-formed? Miri
/// currently implements it, but it seems like this may be something to check against in the
/// validator.
@ -1071,6 +1067,16 @@ pub enum Operand<'tcx> {
/// in [UCG#188]. You should not emit MIR that may attempt a subsequent second load of this
/// place without first re-initializing it.
///
/// **Needs clarification:** The operational impact of `Move` is unclear. Currently (both in
/// Miri and codegen) it has no effect at all unless it appears in an argument to `Call`; for
/// `Call` it allows the argument to be passed to the callee "in-place", i.e. the callee might
/// just get a reference to this place instead of a full copy. Miri implements this with a
/// combination of aliasing model "protectors" and putting `uninit` into the place. Ralf
/// proposes that we don't want these semantics for `Move` in regular assignments, because
/// loading a place should not have side-effects, and the aliasing model "protectors" are
/// inherently tied to a function call. Are these the semantics we want for MIR? Is this
/// something we can even decide without knowing more about Rust's memory model?
///
/// [UCG#188]: https://github.com/rust-lang/unsafe-code-guidelines/issues/188
Move(Place<'tcx>),

View File

@ -22,8 +22,8 @@ use rustc_target::spec::abi::Abi as CallAbi;
use crate::MirPass;
use rustc_const_eval::interpret::{
self, compile_time_machine, AllocId, ConstAllocation, ConstValue, Frame, ImmTy, Immediate,
InterpCx, InterpResult, LocalValue, MemoryKind, OpTy, PlaceTy, Pointer, Scalar,
self, compile_time_machine, AllocId, ConstAllocation, ConstValue, FnArg, Frame, ImmTy,
Immediate, InterpCx, InterpResult, LocalValue, MemoryKind, OpTy, PlaceTy, Pointer, Scalar,
StackPopCleanup,
};
@ -185,7 +185,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for ConstPropMachine<'mir, 'tcx>
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_instance: ty::Instance<'tcx>,
_abi: CallAbi,
_args: &[OpTy<'tcx>],
_args: &[FnArg<'tcx>],
_destination: &PlaceTy<'tcx>,
_target: Option<BasicBlock>,
_unwind: UnwindAction,

View File

@ -532,7 +532,7 @@ impl<'tcx, 'map, 'a> Visitor<'tcx> for OperandCollector<'tcx, 'map, 'a> {
struct DummyMachine;
impl<'mir, 'tcx> rustc_const_eval::interpret::Machine<'mir, 'tcx> for DummyMachine {
impl<'mir, 'tcx: 'mir> rustc_const_eval::interpret::Machine<'mir, 'tcx> for DummyMachine {
rustc_const_eval::interpret::compile_time_machine!(<'mir, 'tcx>);
type MemoryKind = !;
const PANIC_ON_ALLOC_FAIL: bool = true;
@ -557,7 +557,7 @@ impl<'mir, 'tcx> rustc_const_eval::interpret::Machine<'mir, 'tcx> for DummyMachi
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_instance: ty::Instance<'tcx>,
_abi: rustc_target::spec::abi::Abi,
_args: &[rustc_const_eval::interpret::OpTy<'tcx, Self::Provenance>],
_args: &[rustc_const_eval::interpret::FnArg<'tcx, Self::Provenance>],
_destination: &rustc_const_eval::interpret::PlaceTy<'tcx, Self::Provenance>,
_target: Option<BasicBlock>,
_unwind: UnwindAction,

View File

@ -1 +1 @@
d4096e0412ac5de785d739a0aa2b1c1c7b9d3b7d
743333f3dd90721461c09387ec73d09c080d5f5f

View File

@ -302,12 +302,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
}
}
fn retag_return_place(&mut self) -> InterpResult<'tcx> {
fn protect_place(&mut self, place: &MPlaceTy<'tcx, Provenance>) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
let method = this.machine.borrow_tracker.as_ref().unwrap().borrow().borrow_tracker_method;
match method {
BorrowTrackerMethod::StackedBorrows => this.sb_retag_return_place(),
BorrowTrackerMethod::TreeBorrows => this.tb_retag_return_place(),
BorrowTrackerMethod::StackedBorrows => this.sb_protect_place(place),
BorrowTrackerMethod::TreeBorrows => this.tb_protect_place(place),
}
}

View File

@ -189,7 +189,7 @@ struct RetagOp {
#[derive(Debug, Clone, Copy, PartialEq)]
pub enum RetagCause {
Normal,
FnReturnPlace,
InPlaceFnPassing,
FnEntry,
TwoPhase,
}
@ -501,7 +501,7 @@ impl RetagCause {
match self {
RetagCause::Normal => "retag",
RetagCause::FnEntry => "function-entry retag",
RetagCause::FnReturnPlace => "return-place retag",
RetagCause::InPlaceFnPassing => "in-place function argument/return passing protection",
RetagCause::TwoPhase => "two-phase retag",
}
.to_string()

View File

@ -994,35 +994,25 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
}
}
/// After a stack frame got pushed, retag the return place so that we are sure
/// it does not alias with anything.
/// Protect a place so that it cannot be used any more for the duration of the current function
/// call.
///
/// This is a HACK because there is nothing in MIR that would make the retag
/// explicit. Also see <https://github.com/rust-lang/rust/issues/71117>.
fn sb_retag_return_place(&mut self) -> InterpResult<'tcx> {
/// This is used to ensure soundness of in-place function argument/return passing.
fn sb_protect_place(&mut self, place: &MPlaceTy<'tcx, Provenance>) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
let return_place = &this.frame().return_place;
if return_place.layout.is_zst() {
// There may not be any memory here, nothing to do.
return Ok(());
}
// We need this to be in-memory to use tagged pointers.
let return_place = this.force_allocation(&return_place.clone())?;
// We have to turn the place into a pointer to use the existing code.
// We have to turn the place into a pointer to use the usual retagging logic.
// (The pointer type does not matter, so we use a raw pointer.)
let ptr_layout = this.layout_of(Ty::new_mut_ptr(this.tcx.tcx, return_place.layout.ty))?;
let val = ImmTy::from_immediate(return_place.to_ref(this), ptr_layout);
// Reborrow it. With protection! That is part of the point.
let ptr_layout = this.layout_of(Ty::new_mut_ptr(this.tcx.tcx, place.layout.ty))?;
let ptr = ImmTy::from_immediate(place.to_ref(this), ptr_layout);
// Reborrow it. With protection! That is the entire point.
let new_perm = NewPermission::Uniform {
perm: Permission::Unique,
access: Some(AccessKind::Write),
protector: Some(ProtectorKind::StrongProtector),
};
let val = this.sb_retag_reference(&val, new_perm, RetagCause::FnReturnPlace)?;
// And use reborrowed pointer for return place.
let return_place = this.ref_to_mplace(&val)?;
this.frame_mut().return_place = return_place.into();
let _new_ptr = this.sb_retag_reference(&ptr, new_perm, RetagCause::InPlaceFnPassing)?;
// We just throw away `new_ptr`, so nobody can access this memory while it is protected.
Ok(())
}

View File

@ -178,7 +178,7 @@ trait EvalContextPrivExt<'mir: 'ecx, 'tcx: 'mir, 'ecx>: crate::MiriInterpCxExt<'
&mut self,
place: &MPlaceTy<'tcx, Provenance>, // parent tag extracted from here
ptr_size: Size,
new_perm: Option<NewPermission>,
new_perm: NewPermission,
new_tag: BorTag,
) -> InterpResult<'tcx, Option<(AllocId, BorTag)>> {
let this = self.eval_context_mut();
@ -256,10 +256,6 @@ trait EvalContextPrivExt<'mir: 'ecx, 'tcx: 'mir, 'ecx>: crate::MiriInterpCxExt<'
ptr_size.bytes()
);
let Some(new_perm) = new_perm else {
return Ok(Some((alloc_id, orig_tag)));
};
if let Some(protect) = new_perm.protector {
// We register the protection in two different places.
// This makes creating a protector slower, but checking whether a tag
@ -305,7 +301,7 @@ trait EvalContextPrivExt<'mir: 'ecx, 'tcx: 'mir, 'ecx>: crate::MiriInterpCxExt<'
fn tb_retag_reference(
&mut self,
val: &ImmTy<'tcx, Provenance>,
new_perm: Option<NewPermission>,
new_perm: NewPermission,
) -> InterpResult<'tcx, ImmTy<'tcx, Provenance>> {
let this = self.eval_context_mut();
// We want a place for where the ptr *points to*, so we get one.
@ -317,7 +313,7 @@ trait EvalContextPrivExt<'mir: 'ecx, 'tcx: 'mir, 'ecx>: crate::MiriInterpCxExt<'
// - if the pointer is not reborrowed (raw pointer) or if `zero_size` is set
// then we override the size to do a zero-length reborrow.
let reborrow_size = match new_perm {
Some(NewPermission { zero_size: false, .. }) =>
NewPermission { zero_size: false, .. } =>
this.size_and_align_of_mplace(&place)?
.map(|(size, _)| size)
.unwrap_or(place.layout.size),
@ -374,7 +370,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
NewPermission::from_ref_ty(pointee, mutability, kind, this),
_ => None,
};
this.tb_retag_reference(val, new_perm)
if let Some(new_perm) = new_perm {
this.tb_retag_reference(val, new_perm)
} else {
Ok(val.clone())
}
}
/// Retag all pointers that are stored in this place.
@ -405,9 +405,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
place: &PlaceTy<'tcx, Provenance>,
new_perm: Option<NewPermission>,
) -> InterpResult<'tcx> {
let val = self.ecx.read_immediate(&self.ecx.place_to_op(place)?)?;
let val = self.ecx.tb_retag_reference(&val, new_perm)?;
self.ecx.write_immediate(*val, place)?;
if let Some(new_perm) = new_perm {
let val = self.ecx.read_immediate(&self.ecx.place_to_op(place)?)?;
let val = self.ecx.tb_retag_reference(&val, new_perm)?;
self.ecx.write_immediate(*val, place)?;
}
Ok(())
}
}
@ -493,37 +495,25 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
}
}
/// After a stack frame got pushed, retag the return place so that we are sure
/// it does not alias with anything.
/// Protect a place so that it cannot be used any more for the duration of the current function
/// call.
///
/// This is a HACK because there is nothing in MIR that would make the retag
/// explicit. Also see <https://github.com/rust-lang/rust/issues/71117>.
fn tb_retag_return_place(&mut self) -> InterpResult<'tcx> {
/// This is used to ensure soundness of in-place function argument/return passing.
fn tb_protect_place(&mut self, place: &MPlaceTy<'tcx, Provenance>) -> InterpResult<'tcx> {
let this = self.eval_context_mut();
//this.debug_hint_location();
let return_place = &this.frame().return_place;
if return_place.layout.is_zst() {
// There may not be any memory here, nothing to do.
return Ok(());
}
// We need this to be in-memory to use tagged pointers.
let return_place = this.force_allocation(&return_place.clone())?;
// We have to turn the place into a pointer to use the existing code.
// We have to turn the place into a pointer to use the usual retagging logic.
// (The pointer type does not matter, so we use a raw pointer.)
let ptr_layout = this.layout_of(Ty::new_mut_ptr(this.tcx.tcx, return_place.layout.ty))?;
let val = ImmTy::from_immediate(return_place.to_ref(this), ptr_layout);
// Reborrow it. With protection! That is part of the point.
// FIXME: do we truly want a 2phase borrow here?
let new_perm = Some(NewPermission {
initial_state: Permission::new_unique_2phase(/*freeze*/ false),
let ptr_layout = this.layout_of(Ty::new_mut_ptr(this.tcx.tcx, place.layout.ty))?;
let ptr = ImmTy::from_immediate(place.to_ref(this), ptr_layout);
// Reborrow it. With protection! That is the entire point.
let new_perm = NewPermission {
initial_state: Permission::new_active(),
zero_size: false,
protector: Some(ProtectorKind::StrongProtector),
});
let val = this.tb_retag_reference(&val, new_perm)?;
// And use reborrowed pointer for return place.
let return_place = this.ref_to_mplace(&val)?;
this.frame_mut().return_place = return_place.into();
};
let _new_ptr = this.tb_retag_reference(&ptr, new_perm)?;
// We just throw away `new_ptr`, so nobody can access this memory while it is protected.
Ok(())
}

View File

@ -138,6 +138,11 @@ impl Permission {
Self { inner: Reserved { ty_is_freeze } }
}
/// Default initial permission for return place.
pub fn new_active() -> Self {
Self { inner: Active }
}
/// Default initial permission of a reborrowed shared reference
pub fn new_frozen() -> Self {
Self { inner: Frozen }

View File

@ -55,6 +55,7 @@ extern crate rustc_index;
extern crate rustc_session;
extern crate rustc_span;
extern crate rustc_target;
extern crate either; // the one from rustc
// Necessary to pull in object code as the rest of the rustc crates are shipped only as rmeta
// files.

View File

@ -7,6 +7,7 @@ use std::fmt;
use std::path::Path;
use std::process;
use either::Either;
use rand::rngs::StdRng;
use rand::SeedableRng;
@ -533,7 +534,7 @@ impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
let target = &tcx.sess.target;
match target.arch.as_ref() {
"wasm32" | "wasm64" => 64 * 1024, // https://webassembly.github.io/spec/core/exec/runtime.html#memory-instances
"aarch64" =>
"aarch64" => {
if target.options.vendor.as_ref() == "apple" {
// No "definitive" source, but see:
// https://www.wwdcnotes.com/notes/wwdc20/10214/
@ -541,7 +542,8 @@ impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
16 * 1024
} else {
4 * 1024
},
}
}
_ => 4 * 1024,
}
};
@ -892,7 +894,7 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
ecx: &mut MiriInterpCx<'mir, 'tcx>,
instance: ty::Instance<'tcx>,
abi: Abi,
args: &[OpTy<'tcx, Provenance>],
args: &[FnArg<'tcx, Provenance>],
dest: &PlaceTy<'tcx, Provenance>,
ret: Option<mir::BasicBlock>,
unwind: mir::UnwindAction,
@ -905,12 +907,13 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
ecx: &mut MiriInterpCx<'mir, 'tcx>,
fn_val: Dlsym,
abi: Abi,
args: &[OpTy<'tcx, Provenance>],
args: &[FnArg<'tcx, Provenance>],
dest: &PlaceTy<'tcx, Provenance>,
ret: Option<mir::BasicBlock>,
_unwind: mir::UnwindAction,
) -> InterpResult<'tcx> {
ecx.call_dlsym(fn_val, abi, args, dest, ret)
let args = ecx.copy_fn_args(args)?; // FIXME: Should `InPlace` arguments be reset to uninit?
ecx.call_dlsym(fn_val, abi, &args, dest, ret)
}
#[inline(always)]
@ -1094,8 +1097,9 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
ptr: Pointer<Self::Provenance>,
) -> InterpResult<'tcx> {
match ptr.provenance {
Provenance::Concrete { alloc_id, tag } =>
intptrcast::GlobalStateInner::expose_ptr(ecx, alloc_id, tag),
Provenance::Concrete { alloc_id, tag } => {
intptrcast::GlobalStateInner::expose_ptr(ecx, alloc_id, tag)
}
Provenance::Wildcard => {
// No need to do anything for wildcard pointers as
// their provenances have already been previously exposed.
@ -1206,6 +1210,25 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
Ok(())
}
fn protect_in_place_function_argument(
ecx: &mut InterpCx<'mir, 'tcx, Self>,
place: &PlaceTy<'tcx, Provenance>,
) -> InterpResult<'tcx> {
// We do need to write `uninit` so that even after the call ends, the former contents of
// this place cannot be observed any more.
ecx.write_uninit(place)?;
// If we have a borrow tracker, we also have it set up protection so that all reads *and
// writes* during this call are insta-UB.
if ecx.machine.borrow_tracker.is_some() {
if let Either::Left(place) = place.as_mplace_or_local() {
ecx.protect_place(&place)?;
} else {
// Locals that don't have their address taken are as protected as they can ever be.
}
}
Ok(())
}
#[inline(always)]
fn init_frame_extra(
ecx: &mut InterpCx<'mir, 'tcx, Self>,
@ -1288,8 +1311,17 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
let stack_len = ecx.active_thread_stack().len();
ecx.active_thread_mut().set_top_user_relevant_frame(stack_len - 1);
}
if ecx.machine.borrow_tracker.is_some() {
ecx.retag_return_place()?;
Ok(())
}
fn before_stack_pop(
ecx: &InterpCx<'mir, 'tcx, Self>,
frame: &Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>,
) -> InterpResult<'tcx> {
// We want this *before* the return value copy, because the return place itself is protected
// until we do `end_call` here.
if let Some(borrow_tracker) = &ecx.machine.borrow_tracker {
borrow_tracker.borrow_mut().end_call(&frame.extra);
}
Ok(())
}
@ -1308,9 +1340,6 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
ecx.active_thread_mut().recompute_top_user_relevant_frame();
}
let timing = frame.extra.timing.take();
if let Some(borrow_tracker) = &ecx.machine.borrow_tracker {
borrow_tracker.borrow_mut().end_call(&frame.extra);
}
let res = ecx.handle_stack_pop_unwind(frame.extra, unwinding);
if let Some(profiler) = ecx.machine.profiler.as_ref() {
profiler.finish_recording_interval_event(timing.unwrap());

View File

@ -31,7 +31,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
&mut self,
instance: ty::Instance<'tcx>,
abi: Abi,
args: &[OpTy<'tcx, Provenance>],
args: &[FnArg<'tcx, Provenance>],
dest: &PlaceTy<'tcx, Provenance>,
ret: Option<mir::BasicBlock>,
unwind: mir::UnwindAction,
@ -41,7 +41,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
// There are some more lang items we want to hook that CTFE does not hook (yet).
if this.tcx.lang_items().align_offset_fn() == Some(instance.def.def_id()) {
let [ptr, align] = check_arg_count(args)?;
let args = this.copy_fn_args(args)?;
let [ptr, align] = check_arg_count(&args)?;
if this.align_offset(ptr, align, dest, ret, unwind)? {
return Ok(None);
}
@ -55,7 +56,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
// to run extra MIR), and Ok(Some(body)) if we found MIR to run for the
// foreign function
// Any needed call to `goto_block` will be performed by `emulate_foreign_item`.
return this.emulate_foreign_item(instance.def_id(), abi, args, dest, ret, unwind);
let args = this.copy_fn_args(args)?; // FIXME: Should `InPlace` arguments be reset to uninit?
return this.emulate_foreign_item(instance.def_id(), abi, &args, dest, ret, unwind);
}
// Otherwise, load the MIR.

View File

@ -0,0 +1,34 @@
//@revisions: stack tree
//@[tree]compile-flags: -Zmiri-tree-borrows
#![feature(custom_mir, core_intrinsics)]
use std::intrinsics::mir::*;
pub struct S(i32);
#[custom_mir(dialect = "runtime", phase = "optimized")]
fn main() {
mir! {
let unit: ();
{
let non_copy = S(42);
let ptr = std::ptr::addr_of_mut!(non_copy);
// Inside `callee`, the first argument and `*ptr` are basically
// aliasing places!
Call(unit, after_call, callee(Move(*ptr), ptr))
}
after_call = {
Return()
}
}
}
pub fn callee(x: S, ptr: *mut S) {
// With the setup above, if `x` is indeed moved in
// (i.e. we actually just get a pointer to the underlying storage),
// then writing to `ptr` will change the value stored in `x`!
unsafe { ptr.write(S(0)) };
//~[stack]^ ERROR: not granting access
//~[tree]| ERROR: /write access .* forbidden/
assert_eq!(x.0, 42);
}

View File

@ -0,0 +1,37 @@
error: Undefined Behavior: not granting access to tag <TAG> because that would remove [Unique for <TAG>] which is strongly protected because it is an argument of call ID
--> $DIR/arg_inplace_mutate.rs:LL:CC
|
LL | unsafe { ptr.write(S(0)) };
| ^^^^^^^^^^^^^^^ not granting access to tag <TAG> because that would remove [Unique for <TAG>] which is strongly protected because it is an argument of call ID
|
= help: this indicates a potential bug in the program: it performed an invalid operation, but the Stacked Borrows rules it violated are still experimental
= help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md for further information
help: <TAG> was created by a SharedReadWrite retag at offsets [0x0..0x4]
--> $DIR/arg_inplace_mutate.rs:LL:CC
|
LL | / mir! {
LL | | let unit: ();
LL | | {
LL | | let non_copy = S(42);
... |
LL | |
LL | | }
| |_____^
help: <TAG> is this argument
--> $DIR/arg_inplace_mutate.rs:LL:CC
|
LL | unsafe { ptr.write(S(0)) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: BACKTRACE (of the first span):
= note: inside `callee` at $DIR/arg_inplace_mutate.rs:LL:CC
note: inside `main`
--> $DIR/arg_inplace_mutate.rs:LL:CC
|
LL | Call(unit, after_call, callee(Move(*ptr), ptr))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: this error originates in the macro `::core::intrinsics::mir::__internal_remove_let` which comes from the expansion of the macro `mir` (in Nightly builds, run with -Z macro-backtrace for more info)
note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
error: aborting due to previous error

View File

@ -0,0 +1,39 @@
error: Undefined Behavior: write access through <TAG> (root of the allocation) is forbidden
--> $DIR/arg_inplace_mutate.rs:LL:CC
|
LL | unsafe { ptr.write(S(0)) };
| ^^^^^^^^^^^^^^^ write access through <TAG> (root of the allocation) is forbidden
|
= help: this indicates a potential bug in the program: it performed an invalid operation, but the Tree Borrows rules it violated are still experimental
= help: the accessed tag <TAG> (root of the allocation) is foreign to the protected tag <TAG> (i.e., it is not a child)
= help: this foreign write access would cause the protected tag <TAG> to transition from Active to Disabled
= help: this transition would be a loss of read and write permissions, which is not allowed for protected tags
help: the accessed tag <TAG> was created here
--> $DIR/arg_inplace_mutate.rs:LL:CC
|
LL | / mir! {
LL | | let unit: ();
LL | | {
LL | | let non_copy = S(42);
... |
LL | |
LL | | }
| |_____^
help: the protected tag <TAG> was created here, in the initial state Active
--> $DIR/arg_inplace_mutate.rs:LL:CC
|
LL | unsafe { ptr.write(S(0)) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: BACKTRACE (of the first span):
= note: inside `callee` at $DIR/arg_inplace_mutate.rs:LL:CC
note: inside `main`
--> $DIR/arg_inplace_mutate.rs:LL:CC
|
LL | Call(unit, after_call, callee(Move(*ptr), ptr))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: this error originates in the macro `::core::intrinsics::mir::__internal_remove_let` which comes from the expansion of the macro `mir` (in Nightly builds, run with -Z macro-backtrace for more info)
note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
error: aborting due to previous error

View File

@ -0,0 +1,27 @@
#![feature(custom_mir, core_intrinsics)]
use std::intrinsics::mir::*;
pub struct S(i32);
#[custom_mir(dialect = "runtime", phase = "optimized")]
fn main() {
// FIXME: the span is not great (probably caused by custom MIR)
mir! { //~ERROR: uninitialized
let unit: ();
{
let non_copy = S(42);
// This could change `non_copy` in-place
Call(unit, after_call, change_arg(Move(non_copy)))
}
after_call = {
// So now we must not be allowed to observe non-copy again.
let _observe = non_copy.0;
Return()
}
}
}
pub fn change_arg(mut x: S) {
x.0 = 0;
}

View File

@ -0,0 +1,22 @@
error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
--> $DIR/arg_inplace_observe_after.rs:LL:CC
|
LL | / mir! {
LL | | let unit: ();
LL | | {
LL | | let non_copy = S(42);
... |
LL | |
LL | | }
| |_____^ using uninitialized data, but this operation requires initialized memory
|
= 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
= note: BACKTRACE:
= note: inside `main` at RUSTLIB/core/src/intrinsics/mir.rs:LL:CC
= note: this error originates in the macro `::core::intrinsics::mir::__internal_remove_let` which comes from the expansion of the macro `mir` (in Nightly builds, run with -Z macro-backtrace for more info)
note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
error: aborting due to previous error

View File

@ -0,0 +1,20 @@
error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
--> $DIR/arg_inplace_observe_during.rs:LL:CC
|
LL | unsafe { ptr.read() };
| ^^^^^^^^^^ using uninitialized data, but this operation requires initialized memory
|
= 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
= note: BACKTRACE:
= note: inside `change_arg` at $DIR/arg_inplace_observe_during.rs:LL:CC
note: inside `main`
--> $DIR/arg_inplace_observe_during.rs:LL:CC
|
LL | Call(unit, after_call, change_arg(Move(*ptr), ptr))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
error: aborting due to previous error

View File

@ -0,0 +1,34 @@
//@revisions: stack tree none
//@[tree]compile-flags: -Zmiri-tree-borrows
//@[none]compile-flags: -Zmiri-disable-stacked-borrows
#![feature(custom_mir, core_intrinsics)]
use std::intrinsics::mir::*;
pub struct S(i32);
#[custom_mir(dialect = "runtime", phase = "optimized")]
fn main() {
mir! {
let unit: ();
{
let non_copy = S(42);
let ptr = std::ptr::addr_of_mut!(non_copy);
// This could change `non_copy` in-place
Call(unit, after_call, change_arg(Move(*ptr), ptr))
}
after_call = {
Return()
}
}
}
pub fn change_arg(mut x: S, ptr: *mut S) {
x.0 = 0;
// If `x` got passed in-place, we'd see the write through `ptr`!
// Make sure we are not allowed to do that read.
unsafe { ptr.read() };
//~[stack]^ ERROR: not granting access
//~[tree]| ERROR: /read access .* forbidden/
//~[none]| ERROR: uninitialized
}

View File

@ -0,0 +1,37 @@
error: Undefined Behavior: not granting access to tag <TAG> because that would remove [Unique for <TAG>] which is strongly protected because it is an argument of call ID
--> $DIR/arg_inplace_observe_during.rs:LL:CC
|
LL | unsafe { ptr.read() };
| ^^^^^^^^^^ not granting access to tag <TAG> because that would remove [Unique for <TAG>] which is strongly protected because it is an argument of call ID
|
= help: this indicates a potential bug in the program: it performed an invalid operation, but the Stacked Borrows rules it violated are still experimental
= help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md for further information
help: <TAG> was created by a SharedReadWrite retag at offsets [0x0..0x4]
--> $DIR/arg_inplace_observe_during.rs:LL:CC
|
LL | / mir! {
LL | | let unit: ();
LL | | {
LL | | let non_copy = S(42);
... |
LL | |
LL | | }
| |_____^
help: <TAG> is this argument
--> $DIR/arg_inplace_observe_during.rs:LL:CC
|
LL | x.0 = 0;
| ^^^^^^^
= note: BACKTRACE (of the first span):
= note: inside `change_arg` at $DIR/arg_inplace_observe_during.rs:LL:CC
note: inside `main`
--> $DIR/arg_inplace_observe_during.rs:LL:CC
|
LL | Call(unit, after_call, change_arg(Move(*ptr), ptr))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: this error originates in the macro `::core::intrinsics::mir::__internal_remove_let` which comes from the expansion of the macro `mir` (in Nightly builds, run with -Z macro-backtrace for more info)
note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
error: aborting due to previous error

View File

@ -0,0 +1,39 @@
error: Undefined Behavior: read access through <TAG> (root of the allocation) is forbidden
--> $DIR/arg_inplace_observe_during.rs:LL:CC
|
LL | unsafe { ptr.read() };
| ^^^^^^^^^^ read access through <TAG> (root of the allocation) is forbidden
|
= help: this indicates a potential bug in the program: it performed an invalid operation, but the Tree Borrows rules it violated are still experimental
= help: the accessed tag <TAG> (root of the allocation) is foreign to the protected tag <TAG> (i.e., it is not a child)
= help: this foreign read access would cause the protected tag <TAG> to transition from Active to Frozen
= help: this transition would be a loss of write permissions, which is not allowed for protected tags
help: the accessed tag <TAG> was created here
--> $DIR/arg_inplace_observe_during.rs:LL:CC
|
LL | / mir! {
LL | | let unit: ();
LL | | {
LL | | let non_copy = S(42);
... |
LL | |
LL | | }
| |_____^
help: the protected tag <TAG> was created here, in the initial state Active
--> $DIR/arg_inplace_observe_during.rs:LL:CC
|
LL | x.0 = 0;
| ^^^^^^^
= note: BACKTRACE (of the first span):
= note: inside `change_arg` at $DIR/arg_inplace_observe_during.rs:LL:CC
note: inside `main`
--> $DIR/arg_inplace_observe_during.rs:LL:CC
|
LL | Call(unit, after_call, change_arg(Move(*ptr), ptr))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: this error originates in the macro `::core::intrinsics::mir::__internal_remove_let` which comes from the expansion of the macro `mir` (in Nightly builds, run with -Z macro-backtrace for more info)
note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
error: aborting due to previous error

View File

@ -0,0 +1,20 @@
error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
--> $DIR/return_pointer_aliasing.rs:LL:CC
|
LL | unsafe { ptr.read() };
| ^^^^^^^^^^ using uninitialized data, but this operation requires initialized memory
|
= 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
= note: BACKTRACE:
= note: inside `myfun` at $DIR/return_pointer_aliasing.rs:LL:CC
note: inside `main`
--> $DIR/return_pointer_aliasing.rs:LL:CC
|
LL | Call(*ptr, after_call, myfun(ptr))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
error: aborting due to previous error

View File

@ -0,0 +1,34 @@
//@revisions: stack tree none
//@[tree]compile-flags: -Zmiri-tree-borrows
//@[none]compile-flags: -Zmiri-disable-stacked-borrows
#![feature(raw_ref_op)]
#![feature(core_intrinsics)]
#![feature(custom_mir)]
use std::intrinsics::mir::*;
#[custom_mir(dialect = "runtime", phase = "optimized")]
pub fn main() {
mir! {
{
let x = 0;
let ptr = &raw mut x;
// We arrange for `myfun` to have a pointer that aliases
// its return place. Even just reading from that pointer is UB.
Call(*ptr, after_call, myfun(ptr))
}
after_call = {
Return()
}
}
}
fn myfun(ptr: *mut i32) -> i32 {
unsafe { ptr.read() };
//~[stack]^ ERROR: not granting access
//~[tree]| ERROR: /read access .* forbidden/
//~[none]| ERROR: uninitialized
// Without an aliasing model, reads are "fine" but at least they return uninit data.
13
}

View File

@ -0,0 +1,37 @@
error: Undefined Behavior: not granting access to tag <TAG> because that would remove [Unique for <TAG>] which is strongly protected because it is an argument of call ID
--> $DIR/return_pointer_aliasing.rs:LL:CC
|
LL | unsafe { ptr.read() };
| ^^^^^^^^^^ not granting access to tag <TAG> because that would remove [Unique for <TAG>] which is strongly protected because it is an argument of call ID
|
= help: this indicates a potential bug in the program: it performed an invalid operation, but the Stacked Borrows rules it violated are still experimental
= help: see https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md for further information
help: <TAG> was created by a SharedReadWrite retag at offsets [0x0..0x4]
--> $DIR/return_pointer_aliasing.rs:LL:CC
|
LL | / mir! {
LL | | {
LL | | let x = 0;
LL | | let ptr = &raw mut x;
... |
LL | | }
LL | | }
| |_____^
help: <TAG> is this argument
--> $DIR/return_pointer_aliasing.rs:LL:CC
|
LL | unsafe { ptr.read() };
| ^^^^^^^^^^^^^^^^^^^^^
= note: BACKTRACE (of the first span):
= note: inside `myfun` at $DIR/return_pointer_aliasing.rs:LL:CC
note: inside `main`
--> $DIR/return_pointer_aliasing.rs:LL:CC
|
LL | Call(*ptr, after_call, myfun(ptr))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: this error originates in the macro `::core::intrinsics::mir::__internal_remove_let` which comes from the expansion of the macro `mir` (in Nightly builds, run with -Z macro-backtrace for more info)
note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
error: aborting due to previous error

View File

@ -0,0 +1,39 @@
error: Undefined Behavior: read access through <TAG> (root of the allocation) is forbidden
--> $DIR/return_pointer_aliasing.rs:LL:CC
|
LL | unsafe { ptr.read() };
| ^^^^^^^^^^ read access through <TAG> (root of the allocation) is forbidden
|
= help: this indicates a potential bug in the program: it performed an invalid operation, but the Tree Borrows rules it violated are still experimental
= help: the accessed tag <TAG> (root of the allocation) is foreign to the protected tag <TAG> (i.e., it is not a child)
= help: this foreign read access would cause the protected tag <TAG> to transition from Active to Frozen
= help: this transition would be a loss of write permissions, which is not allowed for protected tags
help: the accessed tag <TAG> was created here
--> $DIR/return_pointer_aliasing.rs:LL:CC
|
LL | / mir! {
LL | | {
LL | | let x = 0;
LL | | let ptr = &raw mut x;
... |
LL | | }
LL | | }
| |_____^
help: the protected tag <TAG> was created here, in the initial state Active
--> $DIR/return_pointer_aliasing.rs:LL:CC
|
LL | unsafe { ptr.read() };
| ^^^^^^^^^^^^^^^^^^^^^
= note: BACKTRACE (of the first span):
= note: inside `myfun` at $DIR/return_pointer_aliasing.rs:LL:CC
note: inside `main`
--> $DIR/return_pointer_aliasing.rs:LL:CC
|
LL | Call(*ptr, after_call, myfun(ptr))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: this error originates in the macro `::core::intrinsics::mir::__internal_remove_let` which comes from the expansion of the macro `mir` (in Nightly builds, run with -Z macro-backtrace for more info)
note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
error: aborting due to previous error

View File

@ -1,5 +1,6 @@
// should find the bug even without validation and stacked borrows, but gets masked by optimizations
//@compile-flags: -Zmiri-disable-validation -Zmiri-disable-stacked-borrows -Zmir-opt-level=0 -Cdebug-assertions=no
// should find the bug even without, but gets masked by optimizations
//@compile-flags: -Zmiri-disable-stacked-borrows -Zmir-opt-level=0 -Cdebug-assertions=no
//@normalize-stderr-test: "but found [0-9]+" -> "but found $$ALIGN"
#[repr(align(256))]
#[derive(Debug)]
@ -19,6 +20,6 @@ fn main() {
(&mut ptr as *mut _ as *mut *const u8).write(&buf as *const _ as *const u8);
}
// Re-borrow that. This should be UB.
let _ptr = &*ptr; //~ERROR: alignment 256 is required
let _ptr = &*ptr; //~ERROR: required 256 byte alignment
}
}

View File

@ -1,8 +1,8 @@
error: Undefined Behavior: accessing memory with alignment ALIGN, but alignment ALIGN is required
error: Undefined Behavior: constructing invalid value: encountered an unaligned reference (required 256 byte alignment but found $ALIGN)
--> $DIR/dyn_alignment.rs:LL:CC
|
LL | let _ptr = &*ptr;
| ^^^^^ accessing memory with alignment ALIGN, but alignment ALIGN is required
| ^^^^^ constructing invalid value: encountered an unaligned reference (required 256 byte alignment but found $ALIGN)
|
= 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

View File

@ -0,0 +1,25 @@
#![feature(raw_ref_op)]
#![feature(core_intrinsics)]
#![feature(custom_mir)]
use std::intrinsics::mir::*;
// Make sure calls with the return place "on the heap" work.
#[custom_mir(dialect = "runtime", phase = "optimized")]
pub fn main() {
mir! {
{
let x = 0;
let ptr = &raw mut x;
Call(*ptr, after_call, myfun())
}
after_call = {
Return()
}
}
}
fn myfun() -> i32 {
13
}