trusty: Allow fuzzing without coverage

Bug: 171750250
Test: m
Change-Id: I9e4cbf11fd223092f9ad800b35d0502c27f71e8f

trusty/coverage/coverage.cpp

@@ -29,6 +29,7 @@
 #include <trusty/coverage/record.h>
 #include <trusty/coverage/tipc.h>
 #include <trusty/tipc.h>
+#include <iostream>
 
 #define COVERAGE_CLIENT_PORT "com.android.trusty.coverage.client"
 
@@ -122,7 +123,9 @@ Result<void> CoverageRecord::Open() {
 
     int fd = tipc_connect(tipc_dev_.c_str(), COVERAGE_CLIENT_PORT);
     if (fd < 0) {
-        return ErrnoError() << "failed to connect to Trusty coverarge server: ";
+        // Don't error out to support fuzzing builds without coverage, e.g. for repros.
+        std::cerr << "WARNING!!! Failed to connect to Trusty coverarge server." << std::endl;
+        return {};
     }
     coverage_srv_fd_.reset(fd);
 
@@ -160,6 +163,10 @@ Result<void> CoverageRecord::Open() {
     return {};
 }
 
+bool CoverageRecord::IsOpen() {
+    return shm_;
+}
+
 void CoverageRecord::ResetFullRecord() {
     auto header_region = GetRegionBounds(COV_START);
     if (!header_region.ok()) {

trusty/coverage/include/trusty/coverage/coverage.h

@@ -47,6 +47,7 @@ class CoverageRecord {
 
     ~CoverageRecord();
     Result<void> Open();
+    bool IsOpen();
     void ResetFullRecord();
     void ResetCounts();
     void ResetPCs();

trusty/fuzz/counters.cpp

@@ -41,6 +41,10 @@ namespace trusty {
 namespace fuzz {
 
 ExtraCounters::ExtraCounters(coverage::CoverageRecord* record) : record_(record) {
+    if (!record_->IsOpen()) {
+        return;
+    }
+
     assert(fuzzer::ExtraCountersBegin());
     assert(fuzzer::ExtraCountersEnd());
 
@@ -51,10 +55,18 @@ ExtraCounters::ExtraCounters(coverage::CoverageRecord* record) : record_(record)
 }
 
 ExtraCounters::~ExtraCounters() {
+    if (!record_->IsOpen()) {
+        return;
+    }
+
     Flush();
 }
 
 void ExtraCounters::Reset() {
+    if (!record_->IsOpen()) {
+        return;
+    }
+
     record_->ResetCounts();
     fuzzer::ClearExtraCounters();
 }