dev: Fix undefined behaviuor in i8254xGBe

This patch fixes a rather unfortunate oversight where the annotation
pointer was used even though it is null. Somehow the code still works,
but UBSan is rather unhappy. The use is now guarded, and the variable
is initialised in the constructor (as well as init()).

2 files changed, 17 insertions, 10 deletions

diff --git a/src/dev/i8254xGBe.cc b/src/dev/i8254xGBe.cc
index 70dba7c22..213ad580a 100644
--- a/src/dev/i8254xGBe.cc
+++ b/src/dev/i8254xGBe.cc
@@ -58,7 +58,7 @@ using namespace iGbReg;
 using namespace Net;
 
 IGbE::IGbE(const Params *p)
-    : EtherDevice(p), etherInt(NULL),  drainManager(NULL),
+    : EtherDevice(p), etherInt(NULL), cpa(NULL), drainManager(NULL),
       rxFifo(p->rx_fifo_size), txFifo(p->tx_fifo_size), rxTick(false),
       txTick(false), txFifoTick(false), rxDmaPacket(false), pktOffset(0),
       fetchDelay(p->fetch_delay), wbDelay(p->wb_delay), 
@@ -2390,7 +2390,7 @@ IGbE::txWire()
 
     anPq("TXQ", "TX FIFO Q");
     if (etherInt->sendPacket(txFifo.front())) {
-        cpa->hwQ(CPA::FL_NONE, sys, macAddr, "TXQ", "WireQ", 0);
+        anQ("TXQ", "WireQ");
         if (DTRACE(EthernetSM)) {
             IpPtr ip(txFifo.front());
             if (ip)
diff --git a/src/dev/i8254xGBe.hh b/src/dev/i8254xGBe.hh
index 295712717..27439740d 100644
--- a/src/dev/i8254xGBe.hh
+++ b/src/dev/i8254xGBe.hh
@@ -182,31 +182,38 @@ class IGbE : public EtherDevice
     void checkDrain();
 
     void anBegin(std::string sm, std::string st, int flags = CPA::FL_NONE) {
-        cpa->hwBegin((CPA::flags)flags, sys, macAddr, sm, st);
+        if (cpa)
+            cpa->hwBegin((CPA::flags)flags, sys, macAddr, sm, st);
     }
 
-    void anQ(std::string sm, std::string q) { 
-        cpa->hwQ(CPA::FL_NONE, sys, macAddr, sm, q, macAddr);
+    void anQ(std::string sm, std::string q) {
+        if (cpa)
+            cpa->hwQ(CPA::FL_NONE, sys, macAddr, sm, q, macAddr);
     }
 
     void anDq(std::string sm, std::string q) {
-        cpa->hwDq(CPA::FL_NONE, sys, macAddr, sm, q, macAddr);
+        if (cpa)
+            cpa->hwDq(CPA::FL_NONE, sys, macAddr, sm, q, macAddr);
     }
 
     void anPq(std::string sm, std::string q, int num = 1) {
-        cpa->hwPq(CPA::FL_NONE, sys, macAddr, sm, q, macAddr, NULL, num);
+        if (cpa)
+            cpa->hwPq(CPA::FL_NONE, sys, macAddr, sm, q, macAddr, NULL, num);
     }
 
     void anRq(std::string sm, std::string q, int num = 1) {
-        cpa->hwRq(CPA::FL_NONE, sys, macAddr, sm, q, macAddr, NULL, num);
+        if (cpa)
+            cpa->hwRq(CPA::FL_NONE, sys, macAddr, sm, q, macAddr, NULL, num);
     }
 
     void anWe(std::string sm, std::string q) {
-        cpa->hwWe(CPA::FL_NONE, sys, macAddr, sm, q, macAddr);
+        if (cpa)
+            cpa->hwWe(CPA::FL_NONE, sys, macAddr, sm, q, macAddr);
     }
 
     void anWf(std::string sm, std::string q) {
-        cpa->hwWf(CPA::FL_NONE, sys, macAddr, sm, q, macAddr);
+        if (cpa)
+            cpa->hwWf(CPA::FL_NONE, sys, macAddr, sm, q, macAddr);
     }