Add checklocks analyzer.

This validates that struct fields if annotated with "// checklocks:mu" where
"mu" is a mutex field in the same struct then access to the field is only
done with "mu" locked.

All types that are guarded by a mutex must be annotated with

// +checklocks:<mutex field name>

For more details please refer to README.md.

PiperOrigin-RevId: 360729328

2 files changed, 3 insertions, 0 deletions

diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index f47b39ccc..9ce6868df 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -760,6 +760,7 @@ func (e *endpoint) LockUser() {
 // protocol goroutine altogether.
 //
 // Precondition: e.LockUser() must have been called before calling e.UnlockUser()
+// +checklocks:e.mu
 func (e *endpoint) UnlockUser() {
 	// Lock segment queue before checking so that we avoid a race where
 	// segments can be queued between the time we check if queue is empty
@@ -800,6 +801,7 @@ func (e *endpoint) StopWork() {
 }
 
 // ResumeWork resumes packet processing. Only to be used in tests.
+// +checklocks:e.mu
 func (e *endpoint) ResumeWork() {
 	e.mu.Unlock()
 }
diff --git a/pkg/tcpip/transport/tcp/endpoint_state.go b/pkg/tcpip/transport/tcp/endpoint_state.go
index e4368026f..7c15690a3 100644
--- a/pkg/tcpip/transport/tcp/endpoint_state.go
+++ b/pkg/tcpip/transport/tcp/endpoint_state.go
@@ -25,6 +25,7 @@ import (
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 )
 
+// +checklocks:e.mu
 func (e *endpoint) drainSegmentLocked() {
 	// Drain only up to once.
 	if e.drainDone != nil {