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cranelift: Correctly calculate heap addresses in interpreter (#5155)

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We were accidentally including the size as part of the offset when
computing heap addresses.
This commit is contained in:
Afonso Bordado
2022-10-31 22:07:14 +00:00
committed by GitHub
parent 6d289723bd
commit faeeed4fb9
2 changed files with 27 additions and 3 deletions
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17
cranelift/filetests/filetests/runtests/heap.clif
View File

@@ -204,3 +204,20 @@ block0(v0: i64, v1: i32):
; heap: static, size=0x1000, ptr=vmctx+0, bound=vmctx+8
; run: %iadd_imm(1) == 1
; run: %iadd_imm(-1) == -1
function %heap_limit_i64(i64 vmctx, i64, i32) -> i32 {
gv0 = vmctx
gv1 = load.i64 notrap aligned gv0+0
heap0 = static gv1, min 0, bound 0x8, offset_guard 0, index_type i64
block0(v0: i64, v1: i64, v2: i32):
v3 = heap_addr.i64 heap0, v1, 4
store.i32 v2, v3
v4 = load.i32 v3
return v4
}
; heap: static, size=0x8, ptr=vmctx+0, bound=vmctx+8
; run: %heap_limit_i64(0, 1) == 1
; run: %heap_limit_i64(0, -1) == -1
; run: %heap_limit_i64(4, 1) == 1
; run: %heap_limit_i64(4, -1) == -1

13
cranelift/interpreter/src/step.rs
View File

@@ -498,10 +498,17 @@ where
Opcode::TlsValue => unimplemented!("TlsValue"),
Opcode::HeapAddr => {
if let InstructionData::HeapAddr { heap, .. } = inst {
let load_ty = inst_context.controlling_type().unwrap();
let offset = calculate_addr(ctrl_ty, imm(), args()?)? as u64;
let addr_ty = inst_context.controlling_type().unwrap();
let offset = arg(0)?.into_int()? as u64;
let load_size = imm().into_int()? as u64;
assign_or_memtrap({
AddressSize::try_from(load_ty).and_then(|addr_size| {
AddressSize::try_from(addr_ty).and_then(|addr_size| {
// Attempt to build an address at the maximum possible offset
// for this load. If address generation fails we know it's out of bounds.
let bound_offset = (offset + load_size).saturating_sub(1);
state.heap_address(addr_size, heap, bound_offset)?;
// Build the actual address
let addr = state.heap_address(addr_size, heap, offset)?;
let dv = DataValue::try_from(addr)?;
Ok(dv.into())