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Diffstat (limited to 'pkg/sentry/mm/aio_mappable_refs.go')
-rw-r--r--pkg/sentry/mm/aio_mappable_refs.go33
1 files changed, 21 insertions, 12 deletions
diff --git a/pkg/sentry/mm/aio_mappable_refs.go b/pkg/sentry/mm/aio_mappable_refs.go
index 9d94bf879..500477c1f 100644
--- a/pkg/sentry/mm/aio_mappable_refs.go
+++ b/pkg/sentry/mm/aio_mappable_refs.go
@@ -20,9 +20,6 @@ var aioMappableobj *aioMappable
// Refs implements refs.RefCounter. It keeps a reference count using atomic
// operations and calls the destructor when the count reaches zero.
//
-// Note that the number of references is actually refCount + 1 so that a default
-// zero-value Refs object contains one reference.
-//
// +stateify savable
type aioMappableRefs struct {
// refCount is composed of two fields:
@@ -35,6 +32,13 @@ type aioMappableRefs struct {
refCount int64
}
+// InitRefs initializes r with one reference and, if enabled, activates leak
+// checking.
+func (r *aioMappableRefs) InitRefs() {
+ atomic.StoreInt64(&r.refCount, 1)
+ refsvfs2.Register(r)
+}
+
// RefType implements refsvfs2.CheckedObject.RefType.
func (r *aioMappableRefs) RefType() string {
return fmt.Sprintf("%T", aioMappableobj)[1:]
@@ -58,8 +62,7 @@ func (r *aioMappableRefs) EnableLeakCheck() {
// ReadRefs returns the current number of references. The returned count is
// inherently racy and is unsafe to use without external synchronization.
func (r *aioMappableRefs) ReadRefs() int64 {
-
- return atomic.LoadInt64(&r.refCount) + 1
+ return atomic.LoadInt64(&r.refCount)
}
// IncRef implements refs.RefCounter.IncRef.
@@ -67,8 +70,10 @@ func (r *aioMappableRefs) ReadRefs() int64 {
//go:nosplit
func (r *aioMappableRefs) IncRef() {
v := atomic.AddInt64(&r.refCount, 1)
- refsvfs2.LogIncRef(r, v+1)
- if v <= 0 {
+ if aioMappableenableLogging {
+ refsvfs2.LogIncRef(r, v)
+ }
+ if v <= 1 {
panic(fmt.Sprintf("Incrementing non-positive count %p on %s", r, r.RefType()))
}
}
@@ -82,14 +87,16 @@ func (r *aioMappableRefs) IncRef() {
//go:nosplit
func (r *aioMappableRefs) TryIncRef() bool {
const speculativeRef = 1 << 32
- if v := atomic.AddInt64(&r.refCount, speculativeRef); int32(v) < 0 {
+ if v := atomic.AddInt64(&r.refCount, speculativeRef); int32(v) == 0 {
atomic.AddInt64(&r.refCount, -speculativeRef)
return false
}
v := atomic.AddInt64(&r.refCount, -speculativeRef+1)
- refsvfs2.LogTryIncRef(r, v+1)
+ if aioMappableenableLogging {
+ refsvfs2.LogTryIncRef(r, v)
+ }
return true
}
@@ -107,12 +114,14 @@ func (r *aioMappableRefs) TryIncRef() bool {
//go:nosplit
func (r *aioMappableRefs) DecRef(destroy func()) {
v := atomic.AddInt64(&r.refCount, -1)
- refsvfs2.LogDecRef(r, v+1)
+ if aioMappableenableLogging {
+ refsvfs2.LogDecRef(r, v+1)
+ }
switch {
- case v < -1:
+ case v < 0:
panic(fmt.Sprintf("Decrementing non-positive ref count %p, owned by %s", r, r.RefType()))
- case v == -1:
+ case v == 0:
refsvfs2.Unregister(r)
if destroy != nil {