Implement intptrcast methods

src/fn_call.rs

@@ -979,7 +979,7 @@ fn gen_random<'mir, 'tcx>(
     }
     let ptr = dest.to_ptr()?;
 
-    let data = match &mut this.machine.rng {
+    let data = match &mut this.memory_mut().extra.rng {
         Some(rng) => {
             let mut data = vec![0; len];
             rng.fill_bytes(&mut data);

src/intptrcast.rs

@@ -0,0 +1,22 @@
+use std::cell::RefCell;
+
+use rustc::mir::interpret::AllocId;
+
+pub type MemoryState = RefCell<GlobalState>;
+
+#[derive(Clone, Debug)]
+pub struct GlobalState {
+    /// This field is used as a map between the address of each allocation and its `AllocId`
+    pub int_to_ptr_map: Vec<(u64, AllocId)>,
+    pub next_base_addr: u64,
+}
+
+impl Default for GlobalState {
+    // FIXME: Query the page size in the future
+    fn default() -> Self {
+        GlobalState {
+            int_to_ptr_map: Vec::default(),
+            next_base_addr: 2u64.pow(16)
+        }
+    }
+}

src/lib.rs

@@ -20,9 +20,12 @@ mod tls;
 mod range_map;
 mod mono_hash_map;
 mod stacked_borrows;
+mod intptrcast;
+mod memory;
 
 use std::collections::HashMap;
 use std::borrow::Cow;
+use std::cell::Cell;
 use std::rc::Rc;
 
 use rand::rngs::StdRng;
@@ -48,6 +51,7 @@ use crate::range_map::RangeMap;
 pub use crate::helpers::{EvalContextExt as HelpersEvalContextExt};
 use crate::mono_hash_map::MonoHashMap;
 pub use crate::stacked_borrows::{EvalContextExt as StackedBorEvalContextExt};
+use crate::memory::AllocExtra;
 
 // Used by priroda.
 pub use crate::stacked_borrows::{Tag, Permission, Stack, Stacks, Item};
@@ -79,9 +83,11 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
     let mut ecx = InterpretCx::new(
         tcx.at(syntax::source_map::DUMMY_SP),
         ty::ParamEnv::reveal_all(),
-        Evaluator::new(config.validate, config.seed),
+        Evaluator::new(config.validate),
     );
 
+    ecx.memory_mut().extra.rng = config.seed.map(StdRng::seed_from_u64);
+
     let main_instance = ty::Instance::mono(ecx.tcx.tcx, main_id);
     let main_mir = ecx.load_mir(main_instance.def)?;
 
@@ -205,7 +211,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
             cur_ptr = cur_ptr.offset(char_size, tcx)?;
         }
     }
-
+ 
     assert!(args.next().is_none(), "start lang item has more arguments than expected");
 
     Ok(ecx)
@@ -341,14 +347,10 @@ pub struct Evaluator<'tcx> {
 
     /// Whether to enforce the validity invariant.
     pub(crate) validate: bool,
-
-    /// The random number generator to use if Miri
-    /// is running in non-deterministic mode
-    pub(crate) rng: Option<StdRng>
 }
 
 impl<'tcx> Evaluator<'tcx> {
-    fn new(validate: bool, seed: Option<u64>) -> Self {
+    fn new(validate: bool) -> Self {
         Evaluator {
             env_vars: HashMap::default(),
             argc: None,
@@ -357,7 +359,6 @@ impl<'tcx> Evaluator<'tcx> {
             last_error: 0,
             tls: TlsData::default(),
             validate,
-            rng: seed.map(|s| StdRng::seed_from_u64(s))
         }
     }
 }
@@ -386,8 +387,8 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'tcx> {
     type MemoryKinds = MiriMemoryKind;
 
     type FrameExtra = stacked_borrows::CallId;
-    type MemoryExtra = stacked_borrows::MemoryState;
-    type AllocExtra = stacked_borrows::Stacks;
+    type MemoryExtra = memory::MemoryState;
+    type AllocExtra = memory::AllocExtra;
     type PointerTag = Tag;
 
     type MemoryMap = MonoHashMap<AllocId, (MemoryKind<MiriMemoryKind>, Allocation<Tag, Self::AllocExtra>)>;
@@ -515,14 +516,14 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'tcx> {
         let (extra, base_tag) = Stacks::new_allocation(
             id,
             Size::from_bytes(alloc.bytes.len() as u64),
-            Rc::clone(&memory.extra),
+            Rc::clone(&memory.extra.stacked),
             kind,
         );
         if kind != MiriMemoryKind::Static.into() {
             assert!(alloc.relocations.is_empty(), "Only statics can come initialized with inner pointers");
             // Now we can rely on the inner pointers being static, too.
         }
-        let mut memory_extra = memory.extra.borrow_mut();
+        let mut memory_extra = memory.extra.stacked.borrow_mut();
         let alloc: Allocation<Tag, Self::AllocExtra> = Allocation {
             bytes: alloc.bytes,
             relocations: Relocations::from_presorted(
@@ -535,7 +536,10 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'tcx> {
             undef_mask: alloc.undef_mask,
             align: alloc.align,
             mutability: alloc.mutability,
-            extra,
+            extra: AllocExtra {
+                stacks: extra,
+                base_addr: Cell::new(None),
+            },
         };
         (Cow::Owned(alloc), base_tag)
     }
@@ -545,7 +549,7 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'tcx> {
         id: AllocId,
         memory: &Memory<'mir, 'tcx, Self>,
     ) -> Self::PointerTag {
-        memory.extra.borrow_mut().static_base_ptr(id)
+        memory.extra.stacked.borrow_mut().static_base_ptr(id)
     }
 
     #[inline(always)]
@@ -570,14 +574,82 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'tcx> {
     fn stack_push(
         ecx: &mut InterpretCx<'mir, 'tcx, Self>,
     ) -> InterpResult<'tcx, stacked_borrows::CallId> {
-        Ok(ecx.memory().extra.borrow_mut().new_call())
+        Ok(ecx.memory().extra.stacked.borrow_mut().new_call())
     }
 
     #[inline(always)]
     fn stack_pop(
         ecx: &mut InterpretCx<'mir, 'tcx, Self>,
         extra: stacked_borrows::CallId,
     ) -> InterpResult<'tcx> {
-        Ok(ecx.memory().extra.borrow_mut().end_call(extra))
+        Ok(ecx.memory().extra.stacked.borrow_mut().end_call(extra))
+    }
+
+    fn int_to_ptr(
+        int: u64,
+        memory: &Memory<'mir, 'tcx, Self>,
+    ) -> InterpResult<'tcx, Pointer<Self::PointerTag>> {
+        if int == 0 {
+            return err!(InvalidNullPointerUsage);
+        }
+
+        if memory.extra.rng.is_none() {
+            return err!(ReadBytesAsPointer);
+        }
+
+        let extra = memory.extra.intptrcast.borrow();
+
+        match extra.int_to_ptr_map.binary_search_by_key(&int, |(int, _)| *int) {
+            Ok(pos) => {
+                let (_, alloc_id) = extra.int_to_ptr_map[pos];
+                Ok(Pointer::new_with_tag(alloc_id, Size::from_bytes(0), Tag::Untagged))
+            }
+            Err(pos) => {
+                if pos > 0 {
+                    let (glb, alloc_id) = extra.int_to_ptr_map[pos - 1];
+                    let offset = int - glb;
+                    if offset <= memory.get(alloc_id)?.bytes.len() as u64 {
+                        Ok(Pointer::new_with_tag(alloc_id, Size::from_bytes(offset), Tag::Untagged))
+                    } else {
+                        return err!(DanglingPointerDeref);
+                    }
+                } else {
+                    return err!(DanglingPointerDeref);
+                }
+            }
+        }
+    }
+
+    fn ptr_to_int(
+        ptr: Pointer<Self::PointerTag>,
+        memory: &Memory<'mir, 'tcx, Self>,
+    ) -> InterpResult<'tcx, u64> {
+        if memory.extra.rng.is_none() {
+            return err!(ReadPointerAsBytes);
+        }
+
+        let mut extra = memory.extra.intptrcast.borrow_mut();
+
+        let alloc = memory.get(ptr.alloc_id)?;
+
+        let base_addr = match alloc.extra.base_addr.get() { 
+            Some(base_addr) => base_addr,
+            None => {
+                let base_addr = extra.next_base_addr;
+                extra.next_base_addr += alloc.bytes.len() as u64;
+
+                alloc.extra.base_addr.set(Some(base_addr));
+
+                let elem = (base_addr, ptr.alloc_id);
+
+                // Given that `next_base_addr` increases in each allocation, pushing the
+                // corresponding tuple keeps `int_to_ptr_map` sorted
+                extra.int_to_ptr_map.push(elem); 
+
+                base_addr
+            }
+        };
+
+        Ok(base_addr + ptr.offset.bytes())
     }
 }

src/memory.rs

@@ -0,0 +1,63 @@
+use std::cell::Cell;
+use rand::rngs::StdRng;
+
+use rustc_mir::interpret::{Pointer, Allocation, AllocationExtra, InterpResult};
+use rustc_target::abi::Size;
+
+use crate::{stacked_borrows, intptrcast};
+use crate::stacked_borrows::{Tag, AccessKind};
+
+#[derive(Default, Clone, Debug)]
+pub struct MemoryState {
+    pub stacked: stacked_borrows::MemoryState,
+    pub intptrcast: intptrcast::MemoryState,
+    /// The random number generator to use if Miri
+    /// is running in non-deterministic mode
+    pub(crate) rng: Option<StdRng>
+}
+
+#[derive(Debug, Clone,)]
+pub struct AllocExtra {
+    pub stacks: stacked_borrows::Stacks,
+    pub base_addr: Cell<Option<u64>>,
+}
+
+impl AllocationExtra<Tag> for AllocExtra {
+    #[inline(always)]
+    fn memory_read<'tcx>(
+        alloc: &Allocation<Tag, AllocExtra>,
+        ptr: Pointer<Tag>,
+        size: Size,
+    ) -> InterpResult<'tcx> {
+        trace!("read access with tag {:?}: {:?}, size {}", ptr.tag, ptr.erase_tag(), size.bytes());
+        alloc.extra.stacks.for_each(ptr, size, |stack, global| {
+            stack.access(AccessKind::Read, ptr.tag, global)?;
+            Ok(())
+        })
+    }
+
+    #[inline(always)]
+    fn memory_written<'tcx>(
+        alloc: &mut Allocation<Tag, AllocExtra>,
+        ptr: Pointer<Tag>,
+        size: Size,
+    ) -> InterpResult<'tcx> {
+        trace!("write access with tag {:?}: {:?}, size {}", ptr.tag, ptr.erase_tag(), size.bytes());
+        alloc.extra.stacks.for_each(ptr, size, |stack, global| {
+            stack.access(AccessKind::Write, ptr.tag, global)?;
+            Ok(())
+        })
+    }
+
+    #[inline(always)]
+    fn memory_deallocated<'tcx>(
+        alloc: &mut Allocation<Tag, AllocExtra>,
+        ptr: Pointer<Tag>,
+        size: Size,
+    ) -> InterpResult<'tcx> {
+        trace!("deallocation with tag {:?}: {:?}, size {}", ptr.tag, ptr.erase_tag(), size.bytes());
+        alloc.extra.stacks.for_each(ptr, size, |stack, global| {
+            stack.dealloc(ptr.tag, global)
+        })
+    }
+}

src/operator.rs

@@ -44,6 +44,16 @@ impl<'mir, 'tcx> EvalContextExt<'tcx> for super::MiriEvalContext<'mir, 'tcx> {
 
         trace!("ptr_op: {:?} {:?} {:?}", *left, bin_op, *right);
 
+        if self.memory().extra.rng.is_some() && bin_op != Offset {
+            let l_bits = self.force_bits(left.imm.to_scalar()?, left.layout.size)?;
+            let r_bits = self.force_bits(right.imm.to_scalar()?, right.layout.size)?;
+
+            let left = ImmTy::from_scalar(Scalar::from_uint(l_bits, left.layout.size), left.layout);
+            let right = ImmTy::from_scalar(Scalar::from_uint(r_bits, left.layout.size), right.layout);
+
+            return self.binary_op(bin_op, left, right);
+        } 
+
         // Operations that support fat pointers
         match bin_op {
             Eq | Ne => {