pkg/fuzzer/queue: retry inputs from crashed VMs

Mark some requests as Important. The Retry() layer will give them one
more chance even if they were not executed due to a VM crash.

For now, the only important requests are related to triage, candidates
and pkg/vminfo tests.

Add tests for retry.go.

1 files changed, 10 insertions, 0 deletions

diff --git a/pkg/fuzzer/queue/queue.go b/pkg/fuzzer/queue/queue.go
index 14d4ace78..48b912846 100644
--- a/pkg/fuzzer/queue/queue.go
+++ b/pkg/fuzzer/queue/queue.go
@@ -40,11 +40,16 @@ type Request struct {
 	BinaryFile string // If set, it's executed instead of Prog.
 	Repeat     int    // Repeats in addition to the first run.
 
+	// Important requests will be retried even from crashed VMs.
+	Important bool
+
 	// The callback will be called on request completion in the LIFO order.
 	// If it returns false, all further processing will be stopped.
 	// It allows wrappers to intercept Done() requests.
 	callback DoneCallback
 
+	onceCrashed bool
+
 	mu     sync.Mutex
 	result *Result
 	done   chan struct{}
@@ -91,6 +96,11 @@ func (r *Request) Wait(ctx context.Context) *Result {
 	}
 }
 
+// Risky() returns true if there's a substantial risk of the input crashing the VM.
+func (r *Request) Risky() bool {
+	return r.onceCrashed
+}
+
 func (r *Request) hash() hash.Sig {
 	buf := new(bytes.Buffer)
 	if r.ExecOpts != nil {