ssamoswap is treated as an invalid instruction when ss is not active

Author: mohanson

src/instructions/cfi.rs

@@ -41,7 +41,7 @@ pub fn factory<R: Register>(
             }
             insts::OP_SSAMOSWAP_W | insts::OP_SSAMOSWAP_D => {
                 if !cfi.ss {
-                    return Some(set_instruction_length_4(nop()));
+                    return None;
                 }
                 return Some(i);
             }

tests/programs/_build_cfi_native.sh

@@ -15,6 +15,7 @@ build() {
 
 build cfi_ss_success.S cfi_ss_success
 build cfi_ss_not_active.S cfi_ss_not_active
+build cfi_ss_not_active_amo.S cfi_ss_not_active_amo
 build cfi_ss_stack_downto_zero.S cfi_ss_stack_downto_zero
 build cfi_ss_stack_full.S cfi_ss_stack_full
 build cfi_lpad_unlabeled.S cfi_lpad_unlabeled
@@ -26,4 +27,3 @@ build cfi_lpad_func_sig_failed.S cfi_lpad_func_sig_failed
 build cfi_ss_only_pop.S cfi_ss_only_pop
 build cfi_ss_popchk_failed.S cfi_ss_popchk_failed
 build cfi_lpad_align_failed.S cfi_lpad_align_failed
-

tests/programs/cfi_ss_not_active

@@ -16,9 +16,6 @@ _start:
     ssrdp t0
     beqz t0, 1f
     exit_imm 1
-    
+
 1:
-    // ssamoswap works as May-Be-Operations? TODO
-    li t0, -1
-    ssamoswap.d ra, x0, (t0)
-    exit_imm 0 
+    exit_imm 0

tests/programs/cfi_ss_not_active.S

@@ -0,0 +1,10 @@
+.include "cfi_macro.h"
+
+gnu_property_cfi_ss 0
+
+.text
+.global _start
+_start:
+    li t0, -1
+    ssamoswap.d ra, x0, (t0)
+    exit_imm 0

tests/programs/cfi_ss_not_active_amo

@@ -36,6 +36,18 @@ pub fn test_cfi_ss_not_active() {
     assert_eq!(ret, Ok(0));
 }
 
+#[test]
+pub fn test_cfi_ss_not_active_amo() {
+    let ret = run("tests/programs/cfi_ss_not_active_amo");
+    assert!(matches!(
+        ret,
+        Err(Error::InvalidInstruction {
+            pc: 69922,
+            instruction: 1208135855
+        })
+    ));
+}
+
 #[test]
 pub fn test_cfi_ss_stack_downto_zero() {
     let ret = run("tests/programs/cfi_ss_stack_downto_zero");