4 files changed, 23 insertions, 17 deletions

diff --git a/src/cpu/inorder/cpu.cc b/src/cpu/inorder/cpu.cc
index 3dad7d1f4..5815775f9 100644
--- a/src/cpu/inorder/cpu.cc
+++ b/src/cpu/inorder/cpu.cc
@@ -786,9 +786,9 @@ InOrderCPU::init()
     BaseCPU::init();
 
     for (ThreadID tid = 0; tid < numThreads; ++tid) {
-        // Set inSyscall so that the CPU doesn't squash when initially
+        // Set noSquashFromTC so that the CPU doesn't squash when initially
         // setting up registers.
-        thread[tid]->inSyscall = true;
+        thread[tid]->noSquashFromTC = true;
         // Initialise the ThreadContext's memory proxies
         thread[tid]->initMemProxies(thread[tid]->getTC());
     }
@@ -800,9 +800,9 @@ InOrderCPU::init()
         }
     }
 
-    // Clear inSyscall.
+    // Clear noSquashFromTC.
     for (ThreadID tid = 0; tid < numThreads; ++tid)
-        thread[tid]->inSyscall = false;
+        thread[tid]->noSquashFromTC = false;
 
     // Call Initializiation Routine for Resource Pool
     resPool->init();
diff --git a/src/cpu/inorder/inorder_dyn_inst.cc b/src/cpu/inorder/inorder_dyn_inst.cc
index 760c63948..dcf0ce6ae 100644
--- a/src/cpu/inorder/inorder_dyn_inst.cc
+++ b/src/cpu/inorder/inorder_dyn_inst.cc
@@ -220,12 +220,12 @@ InOrderDynInst::execute()
     // when using the TC during an instruction's execution
     // (specifically for instructions that have side-effects that use
     // the TC).  Fix this.
-    bool in_syscall = this->thread->inSyscall;
-    this->thread->inSyscall = true;
+    bool no_squash_from_TC = this->thread->noSquashFromTC;
+    this->thread->noSquashFromTC = true;
 
     this->fault = this->staticInst->execute(this, this->traceData);
 
-    this->thread->inSyscall = in_syscall;
+    this->thread->noSquashFromTC = no_squash_from_TC;
 
     return this->fault;
 }
@@ -244,12 +244,12 @@ InOrderDynInst::initiateAcc()
     // when using the TC during an instruction's execution
     // (specifically for instructions that have side-effects that use
     // the TC).  Fix this.
-    bool in_syscall = this->thread->inSyscall;
-    this->thread->inSyscall = true;
+    bool no_squash_from_TC = this->thread->noSquashFromTC;
+    this->thread->noSquashFromTC = true;
 
     this->fault = this->staticInst->initiateAcc(this, this->traceData);
 
-    this->thread->inSyscall = in_syscall;
+    this->thread->noSquashFromTC = no_squash_from_TC;
 
     return this->fault;
 }
diff --git a/src/cpu/inorder/thread_context.cc b/src/cpu/inorder/thread_context.cc
index 16ffd5b0f..b8662ef4c 100644
--- a/src/cpu/inorder/thread_context.cc
+++ b/src/cpu/inorder/thread_context.cc
@@ -90,10 +90,10 @@ InOrderThreadContext::takeOverFrom(ThreadContext *old_context)
     copyArchRegs(old_context);
 
     thread->funcExeInst = old_context->readFuncExeInst();
- 
+
     old_context->setStatus(ThreadContext::Halted);
 
-    thread->inSyscall = false;
+    thread->noSquashFromTC = false;
     thread->trapPending = false;
 }
 
@@ -159,7 +159,7 @@ InOrderThreadContext::serialize(std::ostream &os)
 void
 InOrderThreadContext::unserialize(Checkpoint *cp, const std::string &section)
 {
-    panic("unserialize unimplemented");    
+    panic("unserialize unimplemented");
 }
 
 
diff --git a/src/cpu/inorder/thread_state.hh b/src/cpu/inorder/thread_state.hh
index 34c146b42..4472bf1dd 100644
--- a/src/cpu/inorder/thread_state.hh
+++ b/src/cpu/inorder/thread_state.hh
@@ -61,10 +61,15 @@ class InOrderThreadState : public ThreadState {
     InOrderCPU *cpu;
 
   public:
-    /** Whether or not the thread is currently in syscall mode, and
-     * thus able to be externally updated without squashing.
+    /* This variable controls if writes to a thread context should cause a all
+     * dynamic/speculative state to be thrown away. Nominally this is the
+     * desired behavior because the external thread context write has updated
+     * some state that could be used by an inflight instruction, however there
+     * are some cases like in a fault/trap handler where this behavior would
+     * lead to successive restarts and forward progress couldn't be made. This
+     * variable controls if the squashing will occur.
      */
-    bool inSyscall;
+    bool noSquashFromTC;
 
     /** Whether or not the thread is currently waiting on a trap, and
      * thus able to be externally updated without squashing.
@@ -75,7 +80,8 @@ class InOrderThreadState : public ThreadState {
                        Process *_process)
         : ThreadState(reinterpret_cast<BaseCPU*>(_cpu), _thread_num,
                       _process),
-          cpu(_cpu), inSyscall(0), trapPending(0), lastGradIsBranch(false)
+          cpu(_cpu), noSquashFromTC(false), trapPending(false),
+          lastGradIsBranch(false)
     { }
 
     /** Handles the syscall. */