commit 73b1160bd808cc523f49db37df597e4b2f3b9877
author Chuan Zhu <chuan.zhu@arm.com> Fri Jan 05 10:26:37 2018 +0000
committer Giacomo Travaglini <giacomo.travaglini@arm.com> Thu Feb 08 10:24:56 2018 +0000
tree 8a5494ac4611e67ff2efda4b008a3cbba5415916
parent ad36e61ce400deaddfb07e71b13aea8a74b52550

arch-arm: Fixed error in choosing vector offset

The old code chose vector offset associated with exceptions taken
to EL3 by incorrectly using "from64", which is associated with the
exception level where the exception was taken from. However, the
offset should depends on the ISA of the lower EL and not of the
starting EL itself, as specified in ARM ARM. This patch corrects
this by implementing the method in AArch64.TakeException in ARM ARM.

Change-Id: I8f7c9aa777c5f2eef9e2d89c36e9daee23f3a822
Reviewed-by: Jack Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/8001
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

src/arch/arm/faults.cc

diff --git a/src/arch/arm/faults.cc b/src/arch/arm/faults.cc
index 27894e0..e3488f4 100644
--- a/src/arch/arm/faults.cc
+++ b/src/arch/arm/faults.cc
@@ -350,7 +350,7 @@
         panic("Invalid target exception level");
         break;
     }
-    return vbar + offset64();
+    return vbar + offset64(tc);
 }
 
 MiscRegIndex
@@ -654,6 +654,8 @@
         ret_addr += spsr.t ? thumbPcElrOffset() : armPcElrOffset();
     tc->setMiscReg(elr_idx, ret_addr);
 
+    Addr vec_address = getVector64(tc);
+
     // Update process state
     OperatingMode64 mode = 0;
     mode.spX = 1;
@@ -666,7 +668,7 @@
     tc->setMiscReg(MISCREG_CPSR, cpsr);
 
     // Set PC to start of exception handler
-    Addr new_pc = purifyTaggedAddr(getVector64(tc), tc, toEL);
+    Addr new_pc = purifyTaggedAddr(vec_address, tc, toEL);
     DPRINTF(Faults, "Invoking Fault (AArch64 target EL):%s cpsr:%#x PC:%#x "
             "elr:%#x newVec: %#x\n", name(), cpsr, curr_pc, ret_addr, new_pc);
     PCState pc(new_pc);
@@ -893,6 +895,31 @@
     return isHypTrap ? 0x14 : vals.offset;
 }
 
+template<class T>
+FaultOffset
+ArmFaultVals<T>::offset64(ThreadContext *tc)
+{
+    if (toEL == fromEL) {
+        if (opModeIsT(fromMode))
+            return vals.currELTOffset;
+        return vals.currELHOffset;
+    } else {
+        bool lower_32 = false;
+        if (toEL == EL3) {
+            if (!inSecureState(tc) && ArmSystem::haveEL(tc, EL2))
+                lower_32 = ELIs32(tc, EL2);
+            else
+                lower_32 = ELIs32(tc, EL1);
+        } else {
+            lower_32 = ELIs32(tc, static_cast<ExceptionLevel>(toEL - 1));
+        }
+
+        if (lower_32)
+            return vals.lowerEL32Offset;
+        return vals.lowerEL64Offset;
+    }
+}
+
 // void
 // SupervisorCall::setSyndrome64(ThreadContext *tc, MiscRegIndex esr_idx)
 // {

src/arch/arm/faults.hh

diff --git a/src/arch/arm/faults.hh b/src/arch/arm/faults.hh
index bec2c0e..6ae4c06 100644
--- a/src/arch/arm/faults.hh
+++ b/src/arch/arm/faults.hh
@@ -191,7 +191,7 @@
     virtual void annotate(AnnotationIDs id, uint64_t val) {}
     virtual FaultStat& countStat() = 0;
     virtual FaultOffset offset(ThreadContext *tc) = 0;
-    virtual FaultOffset offset64() = 0;
+    virtual FaultOffset offset64(ThreadContext *tc) = 0;
     virtual OperatingMode nextMode() = 0;
     virtual bool routeToMonitor(ThreadContext *tc) const = 0;
     virtual bool routeToHyp(ThreadContext *tc) const { return false; }
@@ -221,17 +221,7 @@
     FaultStat & countStat() override { return vals.count; }
     FaultOffset offset(ThreadContext *tc) override;
 
-    FaultOffset offset64() override {
-        if (toEL == fromEL) {
-            if (opModeIsT(fromMode))
-                return vals.currELTOffset;
-            return vals.currELHOffset;
-        } else {
-            if (from64)
-                return vals.lowerEL64Offset;
-            return vals.lowerEL32Offset;
-        }
-    }
+    FaultOffset offset64(ThreadContext *tc) override;
 
     OperatingMode nextMode() override { return vals.nextMode; }
     virtual bool routeToMonitor(ThreadContext *tc) const override {