arm: Panics in miscreg read functions can be tripped by O3 model

Unimplemented miscregs for the generic timer were guarded by panics
in arm/isa.cc which can be tripped by the O3 model if it speculatively
executes a wrong path containing a mrs instruction with a bad miscreg
index. These registers were flagged as implemented and accessible.
This patch changes the miscreg info bit vector to flag them as
unimplemented and inaccessible. In this case, and UndefinedInst
fault will be generated if the register access is not trapped
by a hypervisor.

3 files changed, 34 insertions, 35 deletions

diff --git a/src/arch/arm/isa.cc b/src/arch/arm/isa.cc
index 4f1ef91ec..5f8378e09 100644
--- a/src/arch/arm/isa.cc
+++ b/src/arch/arm/isa.cc
@@ -729,30 +729,30 @@ ISA::readMiscReg(int misc_reg, ThreadContext *tc)
         return getArchTimer(tc, tc->cpuId())->control();
       // PL1 phys. timer, secure
       //   AArch64
-      case MISCREG_CNTPS_CVAL_EL1:
-      case MISCREG_CNTPS_TVAL_EL1:
-      case MISCREG_CNTPS_CTL_EL1:
+      // case MISCREG_CNTPS_CVAL_EL1:
+      // case MISCREG_CNTPS_TVAL_EL1:
+      // case MISCREG_CNTPS_CTL_EL1:
       // PL2 phys. timer, non-secure
       //   AArch32
-      case MISCREG_CNTHCTL:
-      case MISCREG_CNTHP_CVAL:
-      case MISCREG_CNTHP_TVAL:
-      case MISCREG_CNTHP_CTL:
+      // case MISCREG_CNTHCTL:
+      // case MISCREG_CNTHP_CVAL:
+      // case MISCREG_CNTHP_TVAL:
+      // case MISCREG_CNTHP_CTL:
       //   AArch64
-      case MISCREG_CNTHCTL_EL2:
-      case MISCREG_CNTHP_CVAL_EL2:
-      case MISCREG_CNTHP_TVAL_EL2:
-      case MISCREG_CNTHP_CTL_EL2:
+      // case MISCREG_CNTHCTL_EL2:
+      // case MISCREG_CNTHP_CVAL_EL2:
+      // case MISCREG_CNTHP_TVAL_EL2:
+      // case MISCREG_CNTHP_CTL_EL2:
       // Virtual timer
       //   AArch32
-      case MISCREG_CNTV_CVAL:
-      case MISCREG_CNTV_TVAL:
-      case MISCREG_CNTV_CTL:
+      // case MISCREG_CNTV_CVAL:
+      // case MISCREG_CNTV_TVAL:
+      // case MISCREG_CNTV_CTL:
       //   AArch64
       // case MISCREG_CNTV_CVAL_EL2:
       // case MISCREG_CNTV_TVAL_EL2:
       // case MISCREG_CNTV_CTL_EL2:
-        panic("Generic Timer register not implemented\n");
+      default:
         break;
 
     }
@@ -1902,7 +1902,6 @@ ISA::setMiscReg(int misc_reg, const MiscReg &val, ThreadContext *tc)
           // case MISCREG_CNTV_CVAL_EL2:
           // case MISCREG_CNTV_TVAL_EL2:
           // case MISCREG_CNTV_CTL_EL2:
-            panic("Generic Timer register not implemented\n");
             break;
         }
     }
diff --git a/src/arch/arm/isa/insts/misc.isa b/src/arch/arm/isa/insts/misc.isa
index 678a125fb..76fc1fbed 100644
--- a/src/arch/arm/isa/insts/misc.isa
+++ b/src/arch/arm/isa/insts/misc.isa
@@ -851,7 +851,7 @@ let {{
     // if we're in non secure PL1 mode then we can trap regargless of whether
     // the register is accessable, in other modes we trap if only if the register
     // IS accessable.
-    if (!canRead & !(hypTrap & !inUserMode(Cpsr) & !inSecureState(Scr, Cpsr))) {
+    if (!canRead && !(hypTrap && !inUserMode(Cpsr) && !inSecureState(Scr, Cpsr))) {
         return new UndefinedInstruction(machInst, false, mnemonic);
     }
     if (hypTrap) {
@@ -906,7 +906,7 @@ let {{
     // if we're in non secure PL1 mode then we can trap regargless of whether
     // the register is accessable, in other modes we trap if only if the register
     // IS accessable.
-    if (!canRead & !(hypTrap & !inUserMode(Cpsr) & !inSecureState(Scr, Cpsr))) {
+    if (!canRead && !(hypTrap && !inUserMode(Cpsr) && !inSecureState(Scr, Cpsr))) {
         return new UndefinedInstruction(machInst, false, mnemonic);
     }
     if (hypTrap) {
diff --git a/src/arch/arm/miscregs.cc b/src/arch/arm/miscregs.cc
index 6fa304938..313ac18f9 100644
--- a/src/arch/arm/miscregs.cc
+++ b/src/arch/arm/miscregs.cc
@@ -714,15 +714,15 @@ bitset<NUM_MISCREG_INFOS> miscRegInfo[NUM_MISCREGS] = {
     // MISCREG_CNTP_CTL_S
     bitset<NUM_MISCREG_INFOS>(string("0011001100111110000")),
     // MISCREG_CNTV_TVAL
-    bitset<NUM_MISCREG_INFOS>(string("1111111111111100001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_CNTV_CTL
-    bitset<NUM_MISCREG_INFOS>(string("1111111111111100001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_CNTHCTL
-    bitset<NUM_MISCREG_INFOS>(string("1100110000000000001")),
+    bitset<NUM_MISCREG_INFOS>(string("0100100000000000000")),
     // MISCREG_CNTHP_TVAL
-    bitset<NUM_MISCREG_INFOS>(string("1100110000000000001")),
+    bitset<NUM_MISCREG_INFOS>(string("0100100000000000000")),
     // MISCREG_CNTHP_CTL
-    bitset<NUM_MISCREG_INFOS>(string("1100110000000000001")),
+    bitset<NUM_MISCREG_INFOS>(string("0100100000000000000")),
     // MISCREG_IL1DATA0
     bitset<NUM_MISCREG_INFOS>(string("1111111111000000000")),
     // MISCREG_IL1DATA1
@@ -762,11 +762,11 @@ bitset<NUM_MISCREG_INFOS> miscRegInfo[NUM_MISCREGS] = {
     // MISCREG_CNTP_CVAL_S
     bitset<NUM_MISCREG_INFOS>(string("0011001100111110000")),
     // MISCREG_CNTV_CVAL
-    bitset<NUM_MISCREG_INFOS>(string("1111111111111100001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_CNTVOFF
     bitset<NUM_MISCREG_INFOS>(string("1100110000000000001")),
     // MISCREG_CNTHP_CVAL
-    bitset<NUM_MISCREG_INFOS>(string("1100110000000000001")),
+    bitset<NUM_MISCREG_INFOS>(string("0100100000000000000")),
     // MISCREG_CPUMERRSR
     bitset<NUM_MISCREG_INFOS>(string("1111111111000000000")),
     // MISCREG_L2MERRSR
@@ -1258,11 +1258,11 @@ bitset<NUM_MISCREG_INFOS> miscRegInfo[NUM_MISCREGS] = {
     // MISCREG_CNTP_CVAL_EL0
     bitset<NUM_MISCREG_INFOS>(string("1111111111111100001")),
     // MISCREG_CNTV_TVAL_EL0
-    bitset<NUM_MISCREG_INFOS>(string("1111111111111100001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_CNTV_CTL_EL0
-    bitset<NUM_MISCREG_INFOS>(string("1111111111111100001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_CNTV_CVAL_EL0
-    bitset<NUM_MISCREG_INFOS>(string("1111111111111100001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_PMEVCNTR0_EL0
     bitset<NUM_MISCREG_INFOS>(string("1111111111111100001")),
     // MISCREG_PMEVCNTR1_EL0
@@ -1290,19 +1290,19 @@ bitset<NUM_MISCREG_INFOS> miscRegInfo[NUM_MISCREGS] = {
     // MISCREG_CNTVOFF_EL2
     bitset<NUM_MISCREG_INFOS>(string("1111110000000000001")),
     // MISCREG_CNTHCTL_EL2
-    bitset<NUM_MISCREG_INFOS>(string("1111110000000000001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_CNTHP_TVAL_EL2
-    bitset<NUM_MISCREG_INFOS>(string("1111110000000000001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_CNTHP_CTL_EL2
-    bitset<NUM_MISCREG_INFOS>(string("1111110000000000001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_CNTHP_CVAL_EL2
-    bitset<NUM_MISCREG_INFOS>(string("1111110000000000001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_CNTPS_TVAL_EL1
-    bitset<NUM_MISCREG_INFOS>(string("1111111111111100001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_CNTPS_CTL_EL1
-    bitset<NUM_MISCREG_INFOS>(string("1111111111111100001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_CNTPS_CVAL_EL1
-    bitset<NUM_MISCREG_INFOS>(string("1111111111111100001")),
+    bitset<NUM_MISCREG_INFOS>(string("0111100000000000000")),
     // MISCREG_IL1DATA0_EL1
     bitset<NUM_MISCREG_INFOS>(string("1111111111000000001")),
     // MISCREG_IL1DATA1_EL1