trusty: Retrieve coverage PCs from coverage record

Adds the ability to retrieve and save program counter information from
the trusty coverage record data. PC information is saved to a .sancov
file, parseable by the LLVM sancov tool. Sancov can then symbolize and
display this coverage information for consumption by humans.

Adds a sancov dump to the libtrusty_coverage_test for testing.

Bug: 175221942
Test: atest libtrusty_coverage_test
Test: Retrieve sancov file and manually symbolize with sancov
Change-Id: I342ea2ca9abb87986b2904ff69415544ee6070fc

1 files changed, 11 insertions, 4 deletions

diff --git a/trusty/coverage/coverage_test.cpp b/trusty/coverage/coverage_test.cpp
index d8df7a46f..c1efca63b 100644
--- a/trusty/coverage/coverage_test.cpp
+++ b/trusty/coverage/coverage_test.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <android-base/stringprintf.h>
 #include <gtest/gtest.h>
 #include <trusty/coverage/coverage.h>
 #include <trusty/tipc.h>
@@ -27,6 +28,7 @@ using std::unique_ptr;
 
 #define TIPC_DEV "/dev/trusty-ipc-dev0"
 #define TEST_SRV_PORT "com.android.trusty.sancov.test.srv"
+#define TEST_SRV_MODULE "srv.syms.elf"
 
 namespace android {
 namespace trusty {
@@ -54,8 +56,8 @@ class CoverageTest : public ::testing::Test {
 };
 
 TEST_F(CoverageTest, CoverageReset) {
-    record_->Reset();
-    auto counter = record_->CountEdges();
+    record_->ResetFullRecord();
+    auto counter = record_->TotalEdgeCounts();
     ASSERT_EQ(counter, 0);
 }
 
@@ -69,7 +71,7 @@ TEST_F(CoverageTest, TestServerCoverage) {
 
     for (size_t i = 1; i < sizeof(magic) * 8; i++) {
         /* Reset coverage */
-        record_->Reset();
+        record_->ResetCounts();
 
         /* Send message to test server */
         uint32_t msg = magic & ~(mask << i);
@@ -81,10 +83,15 @@ TEST_F(CoverageTest, TestServerCoverage) {
         ASSERT_EQ(rc, sizeof(msg));
 
         /* Count number of non-unique blocks executed */
-        auto counter = record_->CountEdges();
+        auto counter = record_->TotalEdgeCounts();
         /* Each consecutive input should exercise more or same blocks */
         ASSERT_GE(counter, high_watermark);
         high_watermark = counter;
+
+        auto sancov_filename = android::base::StringPrintf(
+                "/data/local/tmp/" TEST_SRV_MODULE ".%d.sancov", getpid());
+        auto res = record_->SaveSancovFile(sancov_filename);
+        ASSERT_TRUE(res.ok());
     }
 
     ASSERT_GT(high_watermark, 0);