pkg/fuzzer/queue: refactor DynamicSource

Use a simpler implementation. Don't assume the nested Source may be nil.
google · May 16, 2024 · ad5321c · ad5321c
1 parent dc6371a
commit ad5321c
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Showing 3 changed files with 22 additions and 24 deletions.
diff --git a/pkg/fuzzer/queue/queue.go b/pkg/fuzzer/queue/queue.go
@@ -343,24 +343,23 @@ func (pq *PriorityQueue) Next() *Request {
  return pq.ops.Pop()
 }
 
-type DynamicSource struct {
- value atomic.Pointer[wrapSource]
+type DynamicSourceCtl struct {
+ value atomic.Pointer[Source]
 }
 
-type wrapSource struct {
- source Source
+// DynamicSource is assumed never to point to nil.
+func DynamicSource(source Source) *DynamicSourceCtl {
+ var ret DynamicSourceCtl
+ ret.Store(source)
+ return &ret
 }
 
-func (ds *DynamicSource) Store(source Source) {
- ds.value.Store(&wrapSource{source})
+func (ds *DynamicSourceCtl) Store(source Source) {
+ ds.value.Store(&source)
 }
 
-func (ds *DynamicSource) Next() *Request {
- val := ds.value.Load()
- if val == nil || val.source == nil {
- return nil
- }
- return val.source.Next()
+func (ds *DynamicSourceCtl) Next() *Request {
+ return (*ds.value.Load()).Next()
 }
 
 // Deduplicator() keeps track of the previously run requests to avoid re-running them.

diff --git a/syz-manager/rpc.go b/syz-manager/rpc.go
@@ -34,12 +34,10 @@ type RPCServer struct {
  checker *vminfo.Checker
  port int
 
- infoDone bool
- checkDone atomic.Bool
- checkFailures int
-
- checkerSource *queue.DynamicSource
- baseSource *queue.DynamicSource
+ infoDone bool
+ checkDone atomic.Bool
+ checkFailures int
+ baseSource *queue.DynamicSourceCtl
  enabledFeatures flatrpc.Feature
  setupFeatures flatrpc.Feature
  modules []cover.KernelModule
@@ -100,14 +98,15 @@ type RPCManagerView interface {
 }
 
 func startRPCServer(mgr *Manager) (*RPCServer, error) {
- var baseSource queue.DynamicSource
+ checker := vminfo.New(mgr.cfg)
+ baseSource := queue.DynamicSource(checker)
  serv := &RPCServer{
  mgr: mgr,
  cfg: mgr.cfg,
  target: mgr.target,
- checker: vminfo.New(mgr.cfg),
- baseSource: &baseSource,
- execSource: queue.Retry(&baseSource),
+ checker: checker,
+ baseSource: baseSource,
+ execSource: queue.Retry(baseSource),
  statExecs: mgr.statExecs,
  statExecRetries: stats.Create("exec retries",
  "Number of times a test program was restarted because the first run failed",

diff --git a/tools/syz-runtest/runtest.go b/tools/syz-runtest/runtest.go
@@ -66,6 +66,7 @@ func main() {
  pending: make(map[string]map[int64]bool),
  }
  mgr.checkFiles = mgr.checker.RequiredFiles()
+ mgr.source = queue.DynamicSource(mgr.checker)
  s, err := rpctype.NewRPCServer(cfg.RPC, "Manager", mgr)
  if err != nil {
  log.Fatalf("failed to create rpc server: %v", err)
@@ -96,7 +97,6 @@ func main() {
  }()
  }
  checkResult := <-mgr.checkResultC
- mgr.source.Store(mgr.checker)
  calls, _, features, err := mgr.checker.Run(checkResult.Files, checkResult.Features)
  if err != nil {
  log.Fatalf("failed to detect enabled syscalls: %v", err)
@@ -146,7 +146,7 @@ type Manager struct {
  vmStop chan bool
  port int
  debug bool
- source queue.DynamicSource
+ source *queue.DynamicSourceCtl
 
  reqMu sync.Mutex
  reqSeq int64