syz-manager: make vmlinux optional

It's currently both optional and non optional.
We require it to be non-empty, but at the same time allow fake "-"
which effectively means "no vmlinux". Make it optional.

6 files changed, 16 insertions, 12 deletions

diff --git a/docs/configuration.md b/docs/configuration.md
index 180affe19..c5f1134a8 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -11,7 +11,8 @@ following keys in its top-level object:
      - `<workdir>/corpus.db`: corpus with interesting programs
      - `<workdir>/instance-x`: per VM instance temporary files
  - `syzkaller`: Location of the `syzkaller` checkout.
- - `vmlinux`: Location of the `vmlinux` file that corresponds to the kernel being tested.
+ - `vmlinux`: Location of the `vmlinux` file that corresponds to the kernel being tested
+   (used for report symbolization and coverage reports, optional).
  - `procs`: Number of parallel test processes in each VM (4 or 8 would be a reasonable number).
  - `leak`: Detect memory leaks with kmemleak.
  - `image`: Location of the disk image file for the QEMU instance; a copy of this file is passed as the
diff --git a/docs/setup_linux-host_android-device_arm64-kernel.md b/docs/setup_linux-host_android-device_arm64-kernel.md
index e7d6fa744..51e1deb3d 100644
--- a/docs/setup_linux-host_android-device_arm64-kernel.md
+++ b/docs/setup_linux-host_android-device_arm64-kernel.md
@@ -19,7 +19,6 @@ $ NDK=/path/to/android/ndk make TARGETOS=android TARGETARCH=arm64
 	"http": "localhost:50000",
 	"workdir": "/gopath/src/github.com/google/syzkaller/workdir",
 	"syzkaller": "/gopath/src/github.com/google/syzkaller",
-	"vmlinux": "-",
 	"sandbox": "none",
 	"procs": 8,
 	"type": "adb",
diff --git a/syz-manager/cover.go b/syz-manager/cover.go
index 502cc6097..d6d90dc67 100644
--- a/syz-manager/cover.go
+++ b/syz-manager/cover.go
@@ -66,6 +66,13 @@ func initAllCover(vmlinux string) {
 	// Running nm on vmlinux may takes 200 microsecond and being called during symbolization of every crash,
 	// so also do it asynchronously on start and reuse the value during each crash.
 	go func() {
+		defer func() {
+			close(allCoverReady)
+			close(allSymbolsReady)
+		}()
+		if vmlinux == "" {
+			return
+		}
 		pcs, err := coveredPCs(vmlinux)
 		if err == nil {
 			sort.Sort(uint64Array(pcs))
@@ -78,8 +85,6 @@ func initAllCover(vmlinux string) {
 		if err != nil {
 			Logf(0, "failed to run nm on %v: %v", vmlinux, err)
 		}
-		close(allCoverReady)
-		close(allSymbolsReady)
 	}()
 }
 
diff --git a/syz-manager/html.go b/syz-manager/html.go
index 3f8e026ac..2ceb4fc48 100644
--- a/syz-manager/html.go
+++ b/syz-manager/html.go
@@ -168,6 +168,10 @@ func (mgr *Manager) httpCover(w http.ResponseWriter, r *http.Request) {
 	mgr.mu.Lock()
 	defer mgr.mu.Unlock()
 
+	if mgr.cfg.Vmlinux == "" {
+		http.Error(w, fmt.Sprintf("no vmlinux in config file"), http.StatusInternalServerError)
+		return
+	}
 	var cov cover.Cover
 	if sig := r.FormValue("input"); sig != "" {
 		cov = mgr.corpus[sig].Cover
diff --git a/syz-manager/manager.go b/syz-manager/manager.go
index 6b79022ff..35bab59f6 100644
--- a/syz-manager/manager.go
+++ b/syz-manager/manager.go
@@ -754,8 +754,8 @@ func (mgr *Manager) saveRepro(res *repro.Result, hub bool) {
 }
 
 func (mgr *Manager) symbolizeReport(text []byte) []byte {
-	if len(text) == 0 {
-		return nil
+	if len(text) == 0 || mgr.cfg.Vmlinux == "" {
+		return text
 	}
 	<-allSymbolsReady
 	symbolized, err := report.Symbolize(mgr.cfg.Vmlinux, text, allSymbols)
@@ -1149,12 +1149,10 @@ func (mgr *Manager) collectUsedFiles() {
 	addUsedFile(cfg.SyzExecprogBin)
 	addUsedFile(cfg.SyzExecutorBin)
 	addUsedFile(cfg.Sshkey)
+	addUsedFile(cfg.Vmlinux)
 	if cfg.Image != "9p" {
 		addUsedFile(cfg.Image)
 	}
-	if cfg.Vmlinux != "-" {
-		addUsedFile(cfg.Vmlinux)
-	}
 }
 
 func (mgr *Manager) checkUsedFiles() {
diff --git a/syz-manager/mgrconfig/mgrconfig.go b/syz-manager/mgrconfig/mgrconfig.go
index d76282d50..b0e3935bb 100644
--- a/syz-manager/mgrconfig/mgrconfig.go
+++ b/syz-manager/mgrconfig/mgrconfig.go
@@ -125,9 +125,6 @@ func load(data []byte, filename string) (*Config, error) {
 	if cfg.Workdir == "" {
 		return nil, fmt.Errorf("config param workdir is empty")
 	}
-	if cfg.Vmlinux == "" {
-		return nil, fmt.Errorf("config param vmlinux is empty")
-	}
 	if cfg.Type == "" {
 		return nil, fmt.Errorf("config param type is empty")
 	}