dashboard: extract subsystems for saved crashes

Invoke the extractor code at pkg/subsystem and store the result into the
Bug entity.

Augment the Maintainers content by per-subsystem emails.

6 files changed, 75 insertions, 15 deletions

diff --git a/dashboard/app/api.go b/dashboard/app/api.go
index 253a6be96..f7f139f86 100644
--- a/dashboard/app/api.go
+++ b/dashboard/app/api.go
@@ -23,6 +23,7 @@ import (
 	"github.com/google/syzkaller/pkg/auth"
 	"github.com/google/syzkaller/pkg/email"
 	"github.com/google/syzkaller/pkg/hash"
+	"github.com/google/syzkaller/pkg/subsystem"
 	"github.com/google/syzkaller/sys/targets"
 	"golang.org/x/net/context"
 	"google.golang.org/appengine/v2"
@@ -700,6 +701,7 @@ func apiReportCrash(c context.Context, ns string, r *http.Request, payload []byt
 	return resp, nil
 }
 
+// nolint: gocyclo
 func reportCrash(c context.Context, build *Build, req *dashapi.Crash) (*Bug, error) {
 	assets, err := parseCrashAssets(c, req)
 	if err != nil {
@@ -736,19 +738,21 @@ func reportCrash(c context.Context, build *Build, req *dashapi.Crash) (*Bug, err
 	} else if len(req.ReproSyz) != 0 {
 		reproLevel = ReproLevelSyz
 	}
+	newSubsystems := []string{}
 	save := reproLevel != ReproLevelNone ||
 		bug.NumCrashes < int64(maxCrashes()) ||
 		now.Sub(bug.LastSavedCrash) > time.Hour ||
 		bug.NumCrashes%20 == 0 ||
 		!stringInList(bug.MergedTitles, req.Title)
 	if save {
+		newSubsystems = detectCrashSubsystems(req, build)
+		log.Infof(c, "determined subsystems: %q", newSubsystems)
 		if err := saveCrash(c, ns, req, bug, bugKey, build, assets); err != nil {
 			return nil, err
 		}
 	} else {
 		log.Infof(c, "not saving crash for %q", bug.Title)
 	}
-
 	tx := func(c context.Context) error {
 		bug = new(Bug)
 		if err := db.Get(c, bugKey, bug); err != nil {
@@ -769,6 +773,9 @@ func reportCrash(c context.Context, build *Build, req *dashapi.Crash) (*Bug, err
 		if len(req.Report) != 0 {
 			bug.HasReport = true
 		}
+		for _, name := range newSubsystems {
+			bug.addSubsystem(BugSubsystem{name})
+		}
 		bug.increaseCrashStats(now)
 		bug.HappenedOn = mergeString(bug.HappenedOn, build.Manager)
 		// Migration of older entities (for new bugs Title is always in MergedTitles).
@@ -801,6 +808,22 @@ func parseCrashAssets(c context.Context, req *dashapi.Crash) ([]Asset, error) {
 	return assets, nil
 }
 
+func detectCrashSubsystems(req *dashapi.Crash, build *Build) []string {
+	if build.OS == targets.Linux {
+		extractor := subsystem.MakeLinuxSubsystemExtractor()
+		return extractor.Extract(&subsystem.Crash{
+			GuiltyFiles: req.GuiltyFiles,
+			SyzRepro:    string(req.ReproSyz),
+		})
+	}
+	return nil
+}
+
+func subsystemMaintainers(ns, subsystemName string) []string {
+	nsConfig := config.Namespaces[ns]
+	return nsConfig.Subsystems.SubsystemCc(subsystemName)
+}
+
 func (crash *Crash) UpdateReportingPriority(build *Build, bug *Bug) {
 	prio := int64(kernelRepoInfo(build).ReportingPriority) * 1e6
 	divReproPrio := int64(1)
diff --git a/dashboard/app/config.go b/dashboard/app/config.go
index 52a98beb4..c2ea93fe4 100644
--- a/dashboard/app/config.go
+++ b/dashboard/app/config.go
@@ -100,6 +100,15 @@ type Config struct {
 	Repos []KernelRepo
 	// If not nil, bugs in this namespace will be exported to the specified Kcidb.
 	Kcidb *KcidbConfig
+	// Subsystems config.
+	Subsystems SubsystemsConfig
+}
+
+// SubsystemsConfig describes how to generate the list of kernel subsystems and the rules of
+// subsystem inference / bug reporting.
+type SubsystemsConfig struct {
+	// IMPORTANT: this interface is experimental and will likely change in the future.
+	SubsystemCc func(name string) []string
 }
 
 // ObsoletingConfig describes how bugs without reproducer should be obsoleted.
@@ -339,6 +348,9 @@ func checkNamespace(ns string, cfg *Config, namespaces, clientNames map[string]b
 	if cfg.Kcidb != nil {
 		checkKcidb(ns, cfg.Kcidb)
 	}
+	if cfg.Subsystems.SubsystemCc == nil {
+		cfg.Subsystems.SubsystemCc = func(string) []string { return nil }
+	}
 	checkKernelRepos(ns, cfg)
 	checkNamespaceReporting(ns, cfg)
 }
diff --git a/dashboard/app/entities.go b/dashboard/app/entities.go
index 2cbd891eb..97d4c7012 100644
--- a/dashboard/app/entities.go
+++ b/dashboard/app/entities.go
@@ -129,6 +129,15 @@ type BugSubsystem struct {
 	Name string
 }
 
+func (bug *Bug) addSubsystem(subsystem BugSubsystem) {
+	for _, item := range bug.Tags.Subsystems {
+		if item.Name == subsystem.Name {
+			return
+		}
+	}
+	bug.Tags.Subsystems = append(bug.Tags.Subsystems, subsystem)
+}
+
 func (bug *Bug) Load(ps []db.Property) error {
 	if err := db.LoadStruct(bug, ps); err != nil {
 		return err
diff --git a/dashboard/app/reporting.go b/dashboard/app/reporting.go
index aa615f47c..97727532a 100644
--- a/dashboard/app/reporting.go
+++ b/dashboard/app/reporting.go
@@ -591,13 +591,15 @@ func fillBugReport(c context.Context, rep *dashapi.BugReport, bug *Bug, bugRepor
 	rep.KernelConfigLink = externalLink(c, textKernelConfig, build.KernelConfig)
 	rep.SyzkallerCommit = build.SyzkallerCommit
 	rep.NoRepro = build.Type == BuildFailed
+	for _, item := range bug.Tags.Subsystems {
+		rep.Subsystems = append(rep.Subsystems, dashapi.BugSubsystem{Name: item.Name})
+		rep.Maintainers = email.MergeEmailLists(rep.Maintainers,
+			subsystemMaintainers(rep.Namespace, item.Name))
+	}
 	for _, addr := range bug.UNCC {
 		rep.CC = email.RemoveFromEmailList(rep.CC, addr)
 		rep.Maintainers = email.RemoveFromEmailList(rep.Maintainers, addr)
 	}
-	for _, item := range bug.Tags.Subsystems {
-		rep.Subsystems = append(rep.Subsystems, dashapi.BugSubsystem{Name: item.Name})
-	}
 	return nil
 }
 
diff --git a/pkg/subsystem/extract.go b/pkg/subsystem/extract.go
index caf80636e..181c15835 100644
--- a/pkg/subsystem/extract.go
+++ b/pkg/subsystem/extract.go
@@ -7,11 +7,11 @@ import (
 	"regexp"
 
 	"github.com/google/syzkaller/prog"
-	"github.com/google/syzkaller/sys/targets"
 )
 
 type SubsystemExtractor struct {
-	CallToSubsystems func(call string) []string
+	pathToSubsystems func(path string) []string
+	callToSubsystems func(call string) []string
 }
 
 // Crash contains the subset of Crash fields relevant for subsystem extraction.
@@ -21,21 +21,26 @@ type Crash struct {
 	SyzRepro    string
 }
 
+func MakeLinuxSubsystemExtractor() *SubsystemExtractor {
+	return &SubsystemExtractor{
+		pathToSubsystems: linuxPathToSubsystems,
+	}
+}
+
 func (se *SubsystemExtractor) Extract(crash *Crash) []string {
 	retMap := map[string]bool{}
 	// Currently we only have the dumbest possible implementation of subsystem detection.
-	if crash.OS == targets.Linux {
-		for _, guiltyPath := range crash.GuiltyFiles {
-			if vfsPathRegexp.MatchString(guiltyPath) {
-				retMap["vfs"] = true
-				break
+	if se.pathToSubsystems != nil {
+		for _, path := range crash.GuiltyFiles {
+			for _, value := range se.pathToSubsystems(path) {
+				retMap[value] = true
 			}
 		}
 	}
-	if se.CallToSubsystems != nil {
+	if se.callToSubsystems != nil {
 		callSet, _, _ := prog.CallSet([]byte(crash.SyzRepro))
 		for call := range callSet {
-			for _, subsystem := range se.CallToSubsystems(call) {
+			for _, subsystem := range se.callToSubsystems(call) {
 				retMap[subsystem] = true
 			}
 		}
@@ -47,6 +52,14 @@ func (se *SubsystemExtractor) Extract(crash *Crash) []string {
 	return retSlice
 }
 
+func linuxPathToSubsystems(path string) []string {
+	ret := []string{}
+	if vfsPathRegexp.MatchString(path) {
+		ret = append(ret, "vfs")
+	}
+	return ret
+}
+
 var (
 	vfsPathRegexp = regexp.MustCompile(`^fs/[^/]+\.c`)
 )
diff --git a/pkg/subsystem/extract_test.go b/pkg/subsystem/extract_test.go
index 936f4fa8e..29512f460 100644
--- a/pkg/subsystem/extract_test.go
+++ b/pkg/subsystem/extract_test.go
@@ -12,7 +12,7 @@ import (
 )
 
 func TestSimpleLinuxExtract(t *testing.T) {
-	se := &SubsystemExtractor{}
+	se := MakeLinuxSubsystemExtractor()
 
 	ret := se.Extract(&Crash{
 		OS: targets.Linux,
@@ -34,7 +34,8 @@ func TestSimpleLinuxExtract(t *testing.T) {
 
 func TestProgCallRules(t *testing.T) {
 	se := &SubsystemExtractor{
-		CallToSubsystems: func(call string) []string {
+		pathToSubsystems: linuxPathToSubsystems,
+		callToSubsystems: func(call string) []string {
 			ret := map[string][]string{
 				// Intentionally add some that are not present in the test below.
 				"test":               {"test"},