diff --git a/target/arm/cpregs.h b/target/arm/cpregs.h
index fb3b84baa1e..52377c6eb50 100644
--- a/target/arm/cpregs.h
+++ b/target/arm/cpregs.h
@@ -337,13 +337,14 @@ typedef enum CPAccessResult {
     CP_ACCESS_TRAP_EL3 = CP_ACCESS_TRAP_BIT | 3,
 
     /*
-     * Access fails and results in an exception syndrome 0x0 ("uncategorized").
+     * Access fails with UNDEFINED, i.e. an exception syndrome 0x0
+     * ("uncategorized"), which is what an undefined insn produces.
      * Note that this is not a catch-all case -- the set of cases which may
      * result in this failure is specifically defined by the architecture.
      * This trap is always to the usual target EL, never directly to a
      * specified target EL.
      */
-    CP_ACCESS_TRAP_UNCATEGORIZED = (2 << 2),
+    CP_ACCESS_UNDEFINED = (2 << 2),
 } CPAccessResult;
 
 /* Indexes into fgt_read[] */
diff --git a/target/arm/helper.c b/target/arm/helper.c
index aacb53d31a2..71dead7241b 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -285,7 +285,7 @@ static CPAccessResult access_el3_aa32ns(CPUARMState *env,
 {
     if (!is_a64(env) && arm_current_el(env) == 3 &&
         arm_is_secure_below_el3(env)) {
-        return CP_ACCESS_TRAP_UNCATEGORIZED;
+        return CP_ACCESS_UNDEFINED;
     }
     return CP_ACCESS_OK;
 }
@@ -310,7 +310,7 @@ static CPAccessResult access_trap_aa32s_el1(CPUARMState *env,
         return CP_ACCESS_TRAP_EL3;
     }
     /* This will be EL1 NS and EL2 NS, which just UNDEF */
-    return CP_ACCESS_TRAP_UNCATEGORIZED;
+    return CP_ACCESS_UNDEFINED;
 }
 
 /*
@@ -2246,7 +2246,7 @@ static CPAccessResult gt_cntfrq_access(CPUARMState *env, const ARMCPRegInfo *ri,
         if (!isread && ri->state == ARM_CP_STATE_AA32 &&
             arm_is_secure_below_el3(env)) {
             /* Accesses from 32-bit Secure EL1 UNDEF (*not* trap to EL3!) */
-            return CP_ACCESS_TRAP_UNCATEGORIZED;
+            return CP_ACCESS_UNDEFINED;
         }
         break;
     case 2:
@@ -2255,7 +2255,7 @@ static CPAccessResult gt_cntfrq_access(CPUARMState *env, const ARMCPRegInfo *ri,
     }
 
     if (!isread && el < arm_highest_el(env)) {
-        return CP_ACCESS_TRAP_UNCATEGORIZED;
+        return CP_ACCESS_UNDEFINED;
     }
 
     return CP_ACCESS_OK;
@@ -2385,7 +2385,7 @@ static CPAccessResult gt_stimer_access(CPUARMState *env,
     switch (arm_current_el(env)) {
     case 1:
         if (!arm_is_secure(env)) {
-            return CP_ACCESS_TRAP_UNCATEGORIZED;
+            return CP_ACCESS_UNDEFINED;
         }
         if (!(env->cp15.scr_el3 & SCR_ST)) {
             return CP_ACCESS_TRAP_EL3;
@@ -2393,7 +2393,7 @@ static CPAccessResult gt_stimer_access(CPUARMState *env,
         return CP_ACCESS_OK;
     case 0:
     case 2:
-        return CP_ACCESS_TRAP_UNCATEGORIZED;
+        return CP_ACCESS_UNDEFINED;
     case 3:
         return CP_ACCESS_OK;
     default:
@@ -3304,7 +3304,7 @@ static CPAccessResult ats_access(CPUARMState *env, const ARMCPRegInfo *ri,
                 }
                 return CP_ACCESS_TRAP_EL3;
             }
-            return CP_ACCESS_TRAP_UNCATEGORIZED;
+            return CP_ACCESS_UNDEFINED;
         }
     }
     return CP_ACCESS_OK;
@@ -3601,7 +3601,7 @@ static CPAccessResult at_e012_access(CPUARMState *env, const ARMCPRegInfo *ri,
      * scr_write() ensures that the NSE bit is not set otherwise.
      */
     if ((env->cp15.scr_el3 & (SCR_NSE | SCR_NS)) == SCR_NSE) {
-        return CP_ACCESS_TRAP_UNCATEGORIZED;
+        return CP_ACCESS_UNDEFINED;
     }
     return CP_ACCESS_OK;
 }
@@ -3611,7 +3611,7 @@ static CPAccessResult at_s1e2_access(CPUARMState *env, const ARMCPRegInfo *ri,
 {
     if (arm_current_el(env) == 3 &&
         !(env->cp15.scr_el3 & (SCR_NS | SCR_EEL2))) {
-        return CP_ACCESS_TRAP_UNCATEGORIZED;
+        return CP_ACCESS_UNDEFINED;
     }
     return at_e012_access(env, ri, isread);
 }
@@ -4684,7 +4684,7 @@ static CPAccessResult sp_el0_access(CPUARMState *env, const ARMCPRegInfo *ri,
          * Access to SP_EL0 is undefined if it's being used as
          * the stack pointer.
          */
-        return CP_ACCESS_TRAP_UNCATEGORIZED;
+        return CP_ACCESS_UNDEFINED;
     }
     return CP_ACCESS_OK;
 }
@@ -5674,7 +5674,7 @@ static CPAccessResult sel2_access(CPUARMState *env, const ARMCPRegInfo *ri,
     if (arm_current_el(env) == 3 || arm_is_secure_below_el3(env)) {
         return CP_ACCESS_OK;
     }
-    return CP_ACCESS_TRAP_UNCATEGORIZED;
+    return CP_ACCESS_UNDEFINED;
 }
 
 static const ARMCPRegInfo el2_sec_cp_reginfo[] = {
@@ -5710,7 +5710,7 @@ static CPAccessResult nsacr_access(CPUARMState *env, const ARMCPRegInfo *ri,
     if (isread) {
         return CP_ACCESS_OK;
     }
-    return CP_ACCESS_TRAP_UNCATEGORIZED;
+    return CP_ACCESS_UNDEFINED;
 }
 
 static const ARMCPRegInfo el3_cp_reginfo[] = {
@@ -5798,7 +5798,7 @@ static CPAccessResult e2h_access(CPUARMState *env, const ARMCPRegInfo *ri,
         return CP_ACCESS_OK;
     }
     if (!(arm_hcr_el2_eff(env) & HCR_E2H)) {
-        return CP_ACCESS_TRAP_UNCATEGORIZED;
+        return CP_ACCESS_UNDEFINED;
     }
     return CP_ACCESS_OK;
 }
@@ -5896,7 +5896,7 @@ static CPAccessResult el2_e2h_e12_access(CPUARMState *env,
     }
     /* FOO_EL12 aliases only exist when E2H is 1; otherwise they UNDEF */
     if (!(arm_hcr_el2_eff(env) & HCR_E2H)) {
-        return CP_ACCESS_TRAP_UNCATEGORIZED;
+        return CP_ACCESS_UNDEFINED;
     }
     if (ri->orig_accessfn) {
         return ri->orig_accessfn(env, ri->opaque, isread);
@@ -6751,7 +6751,7 @@ static CPAccessResult access_lor_other(CPUARMState *env,
 {
     if (arm_is_secure_below_el3(env)) {
         /* UNDEF if SCR_EL3.NS == 0 */
-        return CP_ACCESS_TRAP_UNCATEGORIZED;
+        return CP_ACCESS_UNDEFINED;
     }
     return access_lor_ns(env, ri, isread);
 }
diff --git a/target/arm/tcg/op_helper.c b/target/arm/tcg/op_helper.c
index fcee11e29ad..2230351a8f4 100644
--- a/target/arm/tcg/op_helper.c
+++ b/target/arm/tcg/op_helper.c
@@ -764,7 +764,7 @@ const void *HELPER(access_check_cp_reg)(CPUARMState *env, uint32_t key,
 
     if (arm_feature(env, ARM_FEATURE_XSCALE) && ri->cp < 14
         && extract32(env->cp15.c15_cpar, ri->cp, 1) == 0) {
-        res = CP_ACCESS_TRAP_UNCATEGORIZED;
+        res = CP_ACCESS_UNDEFINED;
         goto fail;
     }
 
@@ -869,8 +869,8 @@ const void *HELPER(access_check_cp_reg)(CPUARMState *env, uint32_t key,
     case CP_ACCESS_TRAP_EL2:
     case CP_ACCESS_TRAP_EL1:
         break;
-    case CP_ACCESS_TRAP_UNCATEGORIZED:
-        /* CP_ACCESS_TRAP_UNCATEGORIZED is never direct to a specified EL */
+    case CP_ACCESS_UNDEFINED:
+        /* CP_ACCESS_UNDEFINED is never direct to a specified EL */
         if (cpu_isar_feature(aa64_ids, cpu) && isread &&
             arm_cpreg_in_idspace(ri)) {
             /*
