plugin/tracing: fix extended trace on umapped memory areas

When a register in the extended trace was dereferenced and the value
was smaller than the memory pool size, but the address was not mapped
an assertion occured and the tracing plugin terminated the
simulator. Now the dereferenced memory address is checked for being
mapped and not being smaller than the memory pool.

Change-Id: I9ac954988ef860969679f9f360814c5e4b66f473

src/core/sal/Memory.hpp

@@ -60,6 +60,14 @@ public:
 	 * @param src Pointer to data to be copied.
 	 */
 	virtual void setBytes(guest_address_t addr, size_t cnt, void const *src) = 0;
+	/**
+	 * Checks whether memory is mapped and available.
+	 * @param addr The guest address to check.
+	 */
+	virtual bool isMapped(guest_address_t addr) {
+		// default implementation
+		return addr < getPoolSize();
+	}
 };
 
 } // end-of-namespace: fail

src/core/sal/bochs/BochsMemory.hpp

@@ -103,6 +103,17 @@ public:
 		else
 			return (reinterpret_cast<host_address_t>(hostAddr)); // okay
 	}
+
+	/**
+	 * Checks whether memory is mapped and available.
+	 * @param addr The guest address to check.
+	 */
+	virtual bool isMapped(guest_address_t addr) {
+		host_address_t hostaddr = guestToHost(addr);
+		if (hostaddr == (host_address_t)ADDR_INV)
+			return false;
+		return true;
+	}
 };
 
 } // end-of-namespace: fail

src/plugins/tracing/TracingPlugin.cc

@@ -133,7 +133,7 @@ bool TracingPlugin::run()
 						Trace_Event_Extended_Registers *er = ext.add_registers();
 						er->set_id((*it)->getId());
 						er->set_value(simulator.getCPU(0).getRegisterContent(*it));
-						if (er->value() <= mm.getPoolSize() - 4) {
+						if (mm.isMapped(er->value())) {
 							uint32_t value_deref;
 							mm.getBytes(er->value(), 4, &value_deref);
 							er->set_value_deref(value_deref);