syz-manager: Improve the computation of getVMOffset() on FreeBSD

On FreeBSD getVMOffset() always returned 0 instead of 0xffffffff.
This breaks the usage of addr2line. For now, just return always
0xffffffff on FreeBSD, since a more sophisticated logic doesn't
seem to be required by now.

Thanks to Dmitry for pointing out that this functions provides
the prefix address.

2 files changed, 10 insertions, 7 deletions

diff --git a/syz-manager/cover.go b/syz-manager/cover.go
index 6c05df174..deaac9064 100644
--- a/syz-manager/cover.go
+++ b/syz-manager/cover.go
@@ -25,7 +25,7 @@ var (
 	reportGenerator   *cover.ReportGenerator
 )
 
-func initCover(kernelObj, kernelObjName, kernelSrc, arch string) error {
+func initCover(kernelObj, kernelObjName, kernelSrc, arch, OS string) error {
 	if kernelObj == "" {
 		return fmt.Errorf("kernel_obj is not specified")
 	}
@@ -35,15 +35,15 @@ func initCover(kernelObj, kernelObjName, kernelSrc, arch string) error {
 	if err != nil {
 		return err
 	}
-	initCoverVMOffset, err = getVMOffset(vmlinux)
+	initCoverVMOffset, err = getVMOffset(vmlinux, OS)
 	return err
 }
 
-func generateCoverHTML(w io.Writer, kernelObj, kernelObjName, kernelSrc, arch string, cov cover.Cover) error {
+func generateCoverHTML(w io.Writer, kernelObj, kernelObjName, kernelSrc, arch, OS string, cov cover.Cover) error {
 	if len(cov) == 0 {
 		return fmt.Errorf("no coverage data available")
 	}
-	initCoverOnce.Do(func() { initCoverError = initCover(kernelObj, kernelObjName, kernelSrc, arch) })
+	initCoverOnce.Do(func() { initCoverError = initCover(kernelObj, kernelObjName, kernelSrc, arch, OS) })
 	if initCoverError != nil {
 		return initCoverError
 	}
@@ -54,7 +54,10 @@ func generateCoverHTML(w io.Writer, kernelObj, kernelObjName, kernelSrc, arch st
 	return reportGenerator.Do(w, pcs)
 }
 
-func getVMOffset(vmlinux string) (uint32, error) {
+func getVMOffset(vmlinux, OS string) (uint32, error) {
+	if OS == "freebsd" {
+		return 0xffffffff, nil
+	}
 	out, err := osutil.RunCmd(time.Hour, "", "readelf", "-SW", vmlinux)
 	if err != nil {
 		return 0, err
diff --git a/syz-manager/html.go b/syz-manager/html.go
index 2a05748f7..3f549b4d7 100644
--- a/syz-manager/html.go
+++ b/syz-manager/html.go
@@ -248,7 +248,7 @@ func (mgr *Manager) httpCoverCover(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if err := generateCoverHTML(w, mgr.cfg.KernelObj, mgr.sysTarget.KernelObject,
-		mgr.cfg.KernelSrc, mgr.cfg.TargetVMArch, cov); err != nil {
+		mgr.cfg.KernelSrc, mgr.cfg.TargetVMArch, mgr.cfg.TargetOS, cov); err != nil {
 		http.Error(w, fmt.Sprintf("failed to generate coverage profile: %v", err), http.StatusInternalServerError)
 		return
 	}
@@ -400,7 +400,7 @@ func (mgr *Manager) httpRawCover(w http.ResponseWriter, r *http.Request) {
 
 	initCoverOnce.Do(func() {
 		initCoverError = initCover(mgr.cfg.KernelObj, mgr.sysTarget.KernelObject,
-			mgr.cfg.KernelSrc, mgr.cfg.TargetArch)
+			mgr.cfg.KernelSrc, mgr.cfg.TargetArch, mgr.cfg.TargetOS)
 	})
 	if initCoverError != nil {
 		http.Error(w, initCoverError.Error(), http.StatusInternalServerError)