syz-manager: prioritize manual repro requests

Explicitly enforce the prioritization rules. Add a test to verify them.

3 files changed, 62 insertions, 3 deletions

diff --git a/syz-manager/manager.go b/syz-manager/manager.go
index 105117ef0..b7c69558a 100644
--- a/syz-manager/manager.go
+++ b/syz-manager/manager.go
@@ -155,6 +155,7 @@ type Crash struct {
 	instanceName  string
 	fromHub       bool // this crash was created based on a repro from syz-hub
 	fromDashboard bool // .. or from dashboard
+	manual        bool
 	*report.Report
 }
 
@@ -1614,6 +1615,7 @@ func (mgr *Manager) dashboardReproTasks() {
 		if len(resp.CrashLog) > 0 {
 			mgr.externalReproQueue <- &Crash{
 				fromDashboard: true,
+				manual:        resp.Type == dashapi.ManualLog,
 				Report: &report.Report{
 					Title:  resp.Title,
 					Output: resp.CrashLog,
diff --git a/syz-manager/repro.go b/syz-manager/repro.go
index 8a4e75c27..3e2b2a315 100644
--- a/syz-manager/repro.go
+++ b/syz-manager/repro.go
@@ -127,14 +127,33 @@ func (m *reproManager) popCrash() *Crash {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
+	newBetter := func(base, new *Crash) bool {
+		// First, serve manual requests.
+		if new.manual != base.manual {
+			return new.manual
+		}
+		// Then, deprioritize hub reproducers.
+		if new.fromHub != base.fromHub {
+			return !new.fromHub
+		}
+		return false
+	}
+
+	idx := -1
 	for i, crash := range m.queue {
 		if m.reproducing[crash.FullTitle()] {
 			continue
 		}
-		m.queue = slices.Delete(m.queue, i, i+1)
-		return crash
+		if idx == -1 || newBetter(m.queue[idx], m.queue[i]) {
+			idx = i
+		}
+	}
+	if idx == -1 {
+		return nil
 	}
-	return nil
+	crash := m.queue[idx]
+	m.queue = slices.Delete(m.queue, idx, idx+1)
+	return crash
 }
 
 func (m *reproManager) Loop(ctx context.Context) {
diff --git a/syz-manager/repro_test.go b/syz-manager/repro_test.go
index 79b482d36..8042c7042 100644
--- a/syz-manager/repro_test.go
+++ b/syz-manager/repro_test.go
@@ -67,6 +67,44 @@ func TestReproManager(t *testing.T) {
 	t.Fatal("reserved VMs must have dropped to 0")
 }
 
+func TestReproOrder(t *testing.T) {
+	mock := &reproMgrMock{
+		run: make(chan runCallback),
+	}
+	obj := newReproManager(mock, 3, false)
+
+	// The right order is A B C.
+	crashes := []*Crash{
+		{
+			Report:        &report.Report{Title: "A"},
+			fromDashboard: true,
+			manual:        true,
+		},
+		{
+			Report:        &report.Report{Title: "B"},
+			fromDashboard: true,
+		},
+		{
+			Report:  &report.Report{Title: "C"},
+			fromHub: true,
+		},
+	}
+
+	obj.Enqueue(crashes[2])
+	obj.Enqueue(crashes[1])
+	obj.Enqueue(crashes[0])
+	assert.Equal(t, crashes[0], obj.popCrash())
+	assert.Equal(t, crashes[1], obj.popCrash())
+	assert.Equal(t, crashes[2], obj.popCrash())
+
+	obj.Enqueue(crashes[1])
+	obj.Enqueue(crashes[0])
+	obj.Enqueue(crashes[2])
+	assert.Equal(t, crashes[0], obj.popCrash())
+	assert.Equal(t, crashes[1], obj.popCrash())
+	assert.Equal(t, crashes[2], obj.popCrash())
+}
+
 type reproMgrMock struct {
 	reserved atomic.Int64
 	run      chan runCallback