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-rw-r--r--pkg/sentry/fsimpl/kernfs/inode_impl_util.go2
-rw-r--r--pkg/sentry/fsimpl/kernfs/kernfs.go16
-rw-r--r--pkg/sentry/fsimpl/kernfs/static_directory_refs.go33
-rw-r--r--pkg/sentry/fsimpl/kernfs/synthetic_directory_refs.go33
4 files changed, 55 insertions, 29 deletions
diff --git a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
index d83c17f83..eac578f25 100644
--- a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
@@ -660,7 +660,7 @@ var _ Inode = (*StaticDirectory)(nil)
func NewStaticDir(ctx context.Context, creds *auth.Credentials, devMajor, devMinor uint32, ino uint64, perm linux.FileMode, children map[string]Inode, fdOpts GenericDirectoryFDOptions) Inode {
inode := &StaticDirectory{}
inode.Init(ctx, creds, devMajor, devMinor, ino, perm, fdOpts)
- inode.EnableLeakCheck()
+ inode.InitRefs()
inode.OrderedChildren.Init(OrderedChildrenOptions{})
links := inode.OrderedChildren.Populate(children)
diff --git a/pkg/sentry/fsimpl/kernfs/kernfs.go b/pkg/sentry/fsimpl/kernfs/kernfs.go
index abb477c7d..c14abcff4 100644
--- a/pkg/sentry/fsimpl/kernfs/kernfs.go
+++ b/pkg/sentry/fsimpl/kernfs/kernfs.go
@@ -222,7 +222,9 @@ func (d *Dentry) IncRef() {
// d.refs may be 0 if d.fs.mu is locked, which serializes against
// d.cacheLocked().
r := atomic.AddInt64(&d.refs, 1)
- refsvfs2.LogIncRef(d, r)
+ if d.LogRefs() {
+ refsvfs2.LogIncRef(d, r)
+ }
}
// TryIncRef implements vfs.DentryImpl.TryIncRef.
@@ -233,7 +235,9 @@ func (d *Dentry) TryIncRef() bool {
return false
}
if atomic.CompareAndSwapInt64(&d.refs, r, r+1) {
- refsvfs2.LogTryIncRef(d, r+1)
+ if d.LogRefs() {
+ refsvfs2.LogTryIncRef(d, r+1)
+ }
return true
}
}
@@ -242,7 +246,9 @@ func (d *Dentry) TryIncRef() bool {
// DecRef implements vfs.DentryImpl.DecRef.
func (d *Dentry) DecRef(ctx context.Context) {
r := atomic.AddInt64(&d.refs, -1)
- refsvfs2.LogDecRef(d, r)
+ if d.LogRefs() {
+ refsvfs2.LogDecRef(d, r)
+ }
if r == 0 {
d.fs.mu.Lock()
d.cacheLocked(ctx)
@@ -254,7 +260,9 @@ func (d *Dentry) DecRef(ctx context.Context) {
func (d *Dentry) decRefLocked(ctx context.Context) {
r := atomic.AddInt64(&d.refs, -1)
- refsvfs2.LogDecRef(d, r)
+ if d.LogRefs() {
+ refsvfs2.LogDecRef(d, r)
+ }
if r == 0 {
d.cacheLocked(ctx)
} else if r < 0 {
diff --git a/pkg/sentry/fsimpl/kernfs/static_directory_refs.go b/pkg/sentry/fsimpl/kernfs/static_directory_refs.go
index d86cf76fe..cdf6374a3 100644
--- a/pkg/sentry/fsimpl/kernfs/static_directory_refs.go
+++ b/pkg/sentry/fsimpl/kernfs/static_directory_refs.go
@@ -20,9 +20,6 @@ var StaticDirectoryobj *StaticDirectory
// 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 StaticDirectoryRefs struct {
// refCount is composed of two fields:
@@ -35,6 +32,13 @@ type StaticDirectoryRefs struct {
refCount int64
}
+// InitRefs initializes r with one reference and, if enabled, activates leak
+// checking.
+func (r *StaticDirectoryRefs) InitRefs() {
+ atomic.StoreInt64(&r.refCount, 1)
+ refsvfs2.Register(r)
+}
+
// RefType implements refsvfs2.CheckedObject.RefType.
func (r *StaticDirectoryRefs) RefType() string {
return fmt.Sprintf("%T", StaticDirectoryobj)[1:]
@@ -58,8 +62,7 @@ func (r *StaticDirectoryRefs) EnableLeakCheck() {
// ReadRefs returns the current number of references. The returned count is
// inherently racy and is unsafe to use without external synchronization.
func (r *StaticDirectoryRefs) ReadRefs() int64 {
-
- return atomic.LoadInt64(&r.refCount) + 1
+ return atomic.LoadInt64(&r.refCount)
}
// IncRef implements refs.RefCounter.IncRef.
@@ -67,8 +70,10 @@ func (r *StaticDirectoryRefs) ReadRefs() int64 {
//go:nosplit
func (r *StaticDirectoryRefs) IncRef() {
v := atomic.AddInt64(&r.refCount, 1)
- refsvfs2.LogIncRef(r, v+1)
- if v <= 0 {
+ if StaticDirectoryenableLogging {
+ 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 *StaticDirectoryRefs) IncRef() {
//go:nosplit
func (r *StaticDirectoryRefs) 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 StaticDirectoryenableLogging {
+ refsvfs2.LogTryIncRef(r, v)
+ }
return true
}
@@ -107,12 +114,14 @@ func (r *StaticDirectoryRefs) TryIncRef() bool {
//go:nosplit
func (r *StaticDirectoryRefs) DecRef(destroy func()) {
v := atomic.AddInt64(&r.refCount, -1)
- refsvfs2.LogDecRef(r, v+1)
+ if StaticDirectoryenableLogging {
+ 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 {
diff --git a/pkg/sentry/fsimpl/kernfs/synthetic_directory_refs.go b/pkg/sentry/fsimpl/kernfs/synthetic_directory_refs.go
index 446837e30..69b41668a 100644
--- a/pkg/sentry/fsimpl/kernfs/synthetic_directory_refs.go
+++ b/pkg/sentry/fsimpl/kernfs/synthetic_directory_refs.go
@@ -20,9 +20,6 @@ var syntheticDirectoryobj *syntheticDirectory
// 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 syntheticDirectoryRefs struct {
// refCount is composed of two fields:
@@ -35,6 +32,13 @@ type syntheticDirectoryRefs struct {
refCount int64
}
+// InitRefs initializes r with one reference and, if enabled, activates leak
+// checking.
+func (r *syntheticDirectoryRefs) InitRefs() {
+ atomic.StoreInt64(&r.refCount, 1)
+ refsvfs2.Register(r)
+}
+
// RefType implements refsvfs2.CheckedObject.RefType.
func (r *syntheticDirectoryRefs) RefType() string {
return fmt.Sprintf("%T", syntheticDirectoryobj)[1:]
@@ -58,8 +62,7 @@ func (r *syntheticDirectoryRefs) EnableLeakCheck() {
// ReadRefs returns the current number of references. The returned count is
// inherently racy and is unsafe to use without external synchronization.
func (r *syntheticDirectoryRefs) ReadRefs() int64 {
-
- return atomic.LoadInt64(&r.refCount) + 1
+ return atomic.LoadInt64(&r.refCount)
}
// IncRef implements refs.RefCounter.IncRef.
@@ -67,8 +70,10 @@ func (r *syntheticDirectoryRefs) ReadRefs() int64 {
//go:nosplit
func (r *syntheticDirectoryRefs) IncRef() {
v := atomic.AddInt64(&r.refCount, 1)
- refsvfs2.LogIncRef(r, v+1)
- if v <= 0 {
+ if syntheticDirectoryenableLogging {
+ 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 *syntheticDirectoryRefs) IncRef() {
//go:nosplit
func (r *syntheticDirectoryRefs) 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 syntheticDirectoryenableLogging {
+ refsvfs2.LogTryIncRef(r, v)
+ }
return true
}
@@ -107,12 +114,14 @@ func (r *syntheticDirectoryRefs) TryIncRef() bool {
//go:nosplit
func (r *syntheticDirectoryRefs) DecRef(destroy func()) {
v := atomic.AddInt64(&r.refCount, -1)
- refsvfs2.LogDecRef(r, v+1)
+ if syntheticDirectoryenableLogging {
+ 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 {
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-08 10:49:22 +0000