all: calc kaslr offset and remove kaslr_offset from module addr

2 files changed, 46 insertions, 1 deletions

diff --git a/pkg/cover/backend/modules.go b/pkg/cover/backend/modules.go
index c9501d34c..c96d4bd05 100644
--- a/pkg/cover/backend/modules.go
+++ b/pkg/cover/backend/modules.go
@@ -148,3 +148,44 @@ func searchModuleName(data []byte) string {
 	}
 	return string(data[pos+len(key) : end])
 }
+
+func getKaslrOffset(modules []*KernelModule, pcBase uint64) uint64 {
+	for _, mod := range modules {
+		if mod.Name == "" {
+			return mod.Addr - pcBase
+		}
+	}
+	return 0
+}
+
+// when CONFIG_RANDOMIZE_BASE=y, pc from kcov already removed kaslr_offset.
+func FixModules(localModules, modules []*KernelModule, pcBase uint64) []*KernelModule {
+	kaslrOffset := getKaslrOffset(modules, pcBase)
+	var modules1 []*KernelModule
+	for _, mod := range modules {
+		size := uint64(0)
+		path := ""
+		for _, modA := range localModules {
+			if modA.Name == mod.Name {
+				size = modA.Size
+				path = modA.Path
+				break
+			}
+		}
+		if path == "" {
+			continue
+		}
+		addr := mod.Addr - kaslrOffset
+		if mod.Name == "" {
+			// mod.Addr for core kernel from target is _stext addr
+			addr = 0
+		}
+		modules1 = append(modules1, &KernelModule{
+			Name: mod.Name,
+			Size: size,
+			Addr: addr,
+			Path: path,
+		})
+	}
+	return modules1
+}
diff --git a/pkg/cover/report_test.go b/pkg/cover/report_test.go
index 5fad4ebfc..ac0afd6c7 100644
--- a/pkg/cover/report_test.go
+++ b/pkg/cover/report_test.go
@@ -318,6 +318,10 @@ func generateReport(t *testing.T, target *targets.Target, test *Test) (*reports,
 			},
 		},
 	}
+	modules, err := backend.DiscoverModules(cfg.SysTarget, cfg.KernelObj, cfg.ModuleObj)
+	if err != nil {
+		return nil, err
+	}
 
 	// Deep copy, as we are going to modify progs. Our test generate multiple reports from the same
 	// test object in parallel. Without copying we have a datarace here.
@@ -326,7 +330,7 @@ func generateReport(t *testing.T, target *targets.Target, test *Test) (*reports,
 		progs = append(progs, Prog{Sig: p.Sig, Data: p.Data, PCs: append([]uint64{}, p.PCs...)})
 	}
 
-	rg, err := MakeReportGenerator(cfg, subsystem, nil, false)
+	rg, err := MakeReportGenerator(cfg, subsystem, modules, false)
 	if err != nil {
 		return nil, err
 	}