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Implement intptrcast methods #779

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Jun 26, 2019
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20 changes: 20 additions & 0 deletions src/intptrcast.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,20 @@
use std::cell::RefCell;

use rustc::mir::interpret::AllocId;

pub type MemoryState = RefCell<GlobalState>;

#[derive(Clone, Debug)]
pub struct GlobalState {
pub vec: Vec<(u64, AllocId)>,
pub addr: u64,
}

impl Default for GlobalState {
fn default() -> Self {
GlobalState {
vec: Vec::default(),
addr: 2u64.pow(16)
}
}
}
97 changes: 89 additions & 8 deletions src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -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::RefCell;
use std::rc::Rc;

use rand::rngs::StdRng;
Expand All @@ -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};
Expand Down Expand Up @@ -206,6 +210,8 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
}
}

ecx.memory_mut().extra.seed = config.seed.clone();

assert!(args.next().is_none(), "start lang item has more arguments than expected");

Ok(ecx)
Expand Down Expand Up @@ -386,8 +392,8 @@ 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>)>;
Expand Down Expand Up @@ -515,14 +521,14 @@ 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(
Expand All @@ -535,7 +541,10 @@ 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: RefCell::new(None),
},
};
(Cow::Owned(alloc), base_tag)
}
Expand All @@ -545,7 +554,7 @@ 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)]
Expand All @@ -570,14 +579,86 @@ 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.seed.is_none() {
return err!(ReadBytesAsPointer);
}

let extra = memory.extra.intptrcast.borrow();

match extra.vec.binary_search_by_key(&int, |(int, _)| *int) {
Ok(pos) => {
let (_, alloc_id) = extra.vec[pos];
Ok(Pointer::new_with_tag(alloc_id, Size::from_bytes(0), Tag::Untagged))
}
Err(pos) => {
if pos > 0 {
let (glb, alloc_id) = extra.vec[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.seed.is_none() {
return err!(ReadPointerAsBytes);
}

let mut extra = memory.extra.intptrcast.borrow_mut();

let alloc = memory.get(ptr.alloc_id)?;

let mut base_addr = alloc.extra.base_addr.borrow_mut();

let addr = match *base_addr {
Some(addr) => addr,
None => {
let addr = extra.addr;
extra.addr += alloc.bytes.len() as u64;

*base_addr = Some(addr);

let elem = (addr, ptr.alloc_id);

if let Err(pos) = extra.vec.binary_search(&elem) {
extra.vec.insert(pos, elem);
} else {
return err!(Unreachable);
}

addr
}
};

Ok(addr + ptr.offset.bytes())
}
}
60 changes: 60 additions & 0 deletions src/memory.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,60 @@
use std::cell::RefCell;

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,
pub seed: Option<u64>,
}

#[derive(Debug, Clone,)]
pub struct AllocExtra {
pub stacks: stacked_borrows::Stacks,
pub base_addr: RefCell<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)
})
}
}
10 changes: 10 additions & 0 deletions src/operator.rs
Original file line number Diff line number Diff line change
Expand Up @@ -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.seed.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 => {
Expand Down
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