fix: page fault access and set x32 regs

internal/polkavm/interpreter/instance.go

@@ -85,7 +85,7 @@ func (i *Instance) store(address uint32, v any) error {
 }
 
 func (i *Instance) setAndSkip32(dst polkavm.Reg, value uint32) {
-	i.regs[dst] = uint64(value)
+	i.regs[dst] = sext64(value)
 	i.skip()
 }
 

internal/polkavm/interpreter/step.go

@@ -247,7 +247,7 @@ func (i *Instance) step() (uint32, error) {
 		if err := jam.Unmarshal(i.code[i.instructionCounter+2+lenX:i.instructionCounter+2+lenX+lenY], &valueY); err != nil {
 			return 0, err
 		}
-		valueY = i.instructionCounter + sext(valueY, lenX)
+		valueY = i.instructionCounter + sext(valueY, lenY)
 
 		switch opcode {
 		case polkavm.LoadImmAndJump:
@@ -608,3 +608,8 @@ func sext(value uint32, length uint32) uint32 {
 		panic("unreachable")
 	}
 }
+
+// Xn∈{8}∶ N^28n → N_R
+func sext64(value uint32) uint64 {
+	return uint64(int64(int32(value)))
+}

tests/integration/pvm_integration_test.go

@@ -69,10 +69,16 @@ func Test_PVM_Vectors(t *testing.T) {
 			mem := getMemoryMap(tc.InitialPageMap)
 
 			for _, initialMem := range tc.InitialMemory {
+				pageIndex := initialMem.Address / polkavm.PageSize
+				access := mem.GetAccess(pageIndex)
+				err = mem.SetAccess(pageIndex, polkavm.ReadWrite)
+				assert.NoError(t, err)
 				err := mem.Write(initialMem.Address, initialMem.Contents)
 				if err != nil {
 					t.Fatal(err)
 				}
+				err = mem.SetAccess(pageIndex, access)
+				assert.NoError(t, err)
 			}
 			i, err := interpreter.Instantiate(tc.Program, tc.InitialPc, tc.InitialGas, tc.InitialRegs, mem)
 			require.NoError(t, err)