dashboard/app: try 1 repro per day until we have at least syz repro

Bugs without repros are not actionable sometimes.

Fixes #627

dashboard/app/api.go

@@ -52,7 +52,10 @@ type JSONHandler func(c context.Context, r *http.Request) (interface{}, error)
 type APIHandler func(c context.Context, r *http.Request, payload []byte) (interface{}, error)
 type APINamespaceHandler func(c context.Context, ns string, r *http.Request, payload []byte) (interface{}, error)
 
-const maxReproPerBug = 10
+const (
+	maxReproPerBug   = 10
+	reproRetryPeriod = 24 * time.Hour // try 1 repro per day until we have at least syz repro
+)
 
 // Overridable for testing.
 var timeNow = func(c context.Context) time.Time {
@@ -572,6 +575,7 @@ func reportCrash(c context.Context, ns string, req *dashapi.Crash) (*Bug, error)
 		}
 		if reproLevel != ReproLevelNone {
 			bug.NumRepro++
+			bug.LastReproTime = now
 		}
 		if bug.ReproLevel < reproLevel {
 			bug.ReproLevel = reproLevel
@@ -674,12 +678,14 @@ func apiReportFailedRepro(c context.Context, ns string, r *http.Request, payload
 	if bug == nil {
 		return nil, fmt.Errorf("%v: can't find bug for crash %q", ns, req.Title)
 	}
+	now := timeNow(c)
 	tx := func(c context.Context) error {
 		bug := new(Bug)
 		if err := datastore.Get(c, bugKey, bug); err != nil {
 			return fmt.Errorf("failed to get bug: %v", err)
 		}
 		bug.NumRepro++
+		bug.LastReproTime = now
 		if _, err := datastore.Put(c, bugKey, bug); err != nil {
 			return fmt.Errorf("failed to put bug: %v", err)
 		}
@@ -825,22 +831,23 @@ func isActiveBug(c context.Context, bug *Bug) (bool, error) {
 }
 
 func needRepro(c context.Context, bug *Bug) bool {
-	if !needReproForBug(bug) {
+	if !needReproForBug(c, bug) {
 		return false
 	}
 	canon, err := canonicalBug(c, bug)
 	if err != nil {
 		log.Errorf(c, "failed to get canonical bug: %v", err)
 		return false
 	}
-	return needReproForBug(canon)
+	return needReproForBug(c, canon)
 }
 
-func needReproForBug(bug *Bug) bool {
+func needReproForBug(c context.Context, bug *Bug) bool {
 	return bug.ReproLevel < ReproLevelC &&
-		bug.NumRepro < maxReproPerBug &&
 		len(bug.Commits) == 0 &&
-		bug.Title != corruptedReportTitle
+		bug.Title != corruptedReportTitle &&
+		(bug.NumRepro < maxReproPerBug ||
+			bug.ReproLevel == ReproLevelNone && timeSince(c, bug.LastReproTime) > reproRetryPeriod)
 }
 
 func putText(c context.Context, ns, tag string, data []byte, dedup bool) (int64, error) {

dashboard/app/entities.go

@@ -77,6 +77,7 @@ type Bug struct {
 	FirstTime      time.Time
 	LastTime       time.Time
 	LastSavedCrash time.Time
+	LastReproTime  time.Time
 	Closed         time.Time
 	Reporting      []BugReporting
 	Commits        []string

dashboard/app/repro_test.go

@@ -7,6 +7,7 @@ package dash
 
 import (
 	"testing"
+	"time"
 
 	"github.com/google/syzkaller/dashboard/dashapi"
 )
@@ -87,17 +88,29 @@ func testNeedRepro3(t *testing.T, crashCtor func(c *Ctx) *dashapi.Crash) {
 	for i := 0; i < maxReproPerBug; i++ {
 		resp, _ := c.client.ReportCrash(crash1)
 		c.expectEQ(resp.NeedRepro, true)
-
 		needRepro, _ := c.client.NeedRepro(testCrashID(crash1))
 		c.expectEQ(needRepro, true)
 		c.client.ReportFailedRepro(testCrashID(crash1))
 	}
 
-	resp, _ := c.client.ReportCrash(crash1)
-	c.expectEQ(resp.NeedRepro, false)
-
-	needRepro, _ := c.client.NeedRepro(testCrashID(crash1))
-	c.expectEQ(needRepro, false)
+	for i := 0; i < 3; i++ {
+		// No more repros today.
+		c.advanceTime(time.Hour)
+		resp, _ := c.client.ReportCrash(crash1)
+		c.expectEQ(resp.NeedRepro, false)
+		needRepro, _ := c.client.NeedRepro(testCrashID(crash1))
+		c.expectEQ(needRepro, false)
+
+		// Then another repro after a day.
+		c.advanceTime(25 * time.Hour)
+		for j := 0; j < 2; j++ {
+			resp, _ := c.client.ReportCrash(crash1)
+			c.expectEQ(resp.NeedRepro, true)
+			needRepro, _ := c.client.NeedRepro(testCrashID(crash1))
+			c.expectEQ(needRepro, true)
+		}
+		c.client.ReportFailedRepro(testCrashID(crash1))
+	}
 }
 
 func TestNeedRepro3_normal(t *testing.T)      { testNeedRepro3(t, normalCrash) }
@@ -116,16 +129,24 @@ func testNeedRepro4(t *testing.T, crashCtor func(c *Ctx) *dashapi.Crash) {
 	for i := 0; i < maxReproPerBug-1; i++ {
 		resp, _ := c.client.ReportCrash(crash1)
 		c.expectEQ(resp.NeedRepro, true)
-
 		needRepro, _ := c.client.NeedRepro(testCrashID(crash1))
 		c.expectEQ(needRepro, true)
 	}
 
 	resp, _ := c.client.ReportCrash(crash1)
 	c.expectEQ(resp.NeedRepro, false)
-
 	needRepro, _ := c.client.NeedRepro(testCrashID(crash1))
 	c.expectEQ(needRepro, false)
+
+	// No more repros even after a day.
+	c.advanceTime(25 * time.Hour)
+	crash1.ReproOpts = nil
+	crash1.ReproSyz = nil
+
+	resp, _ = c.client.ReportCrash(crash1)
+	c.expectEQ(resp.NeedRepro, false)
+	needRepro, _ = c.client.NeedRepro(testCrashID(crash1))
+	c.expectEQ(needRepro, false)
 }
 
 func TestNeedRepro4_normal(t *testing.T)      { testNeedRepro4(t, normalCrash) }