diff options
Diffstat (limited to 'pkg/sentry/fsimpl')
27 files changed, 321 insertions, 186 deletions
diff --git a/pkg/sentry/fsimpl/devpts/devpts.go b/pkg/sentry/fsimpl/devpts/devpts.go index 346cca558..d8c237753 100644 --- a/pkg/sentry/fsimpl/devpts/devpts.go +++ b/pkg/sentry/fsimpl/devpts/devpts.go @@ -110,7 +110,7 @@ func (fstype *FilesystemType) newFilesystem(ctx context.Context, vfsObj *vfs.Vir } root.InodeAttrs.Init(ctx, creds, linux.UNNAMED_MAJOR, devMinor, 1, linux.ModeDirectory|0555) root.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) - root.EnableLeakCheck() + root.InitRefs() var rootD kernfs.Dentry rootD.InitRoot(&fs.Filesystem, root) diff --git a/pkg/sentry/fsimpl/devpts/root_inode_refs.go b/pkg/sentry/fsimpl/devpts/root_inode_refs.go index cbafd113a..9246cf66e 100644 --- a/pkg/sentry/fsimpl/devpts/root_inode_refs.go +++ b/pkg/sentry/fsimpl/devpts/root_inode_refs.go @@ -20,9 +20,6 @@ var rootInodeobj *rootInode // 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 rootInodeRefs struct { // refCount is composed of two fields: @@ -35,6 +32,13 @@ type rootInodeRefs struct { refCount int64 } +// InitRefs initializes r with one reference and, if enabled, activates leak +// checking. +func (r *rootInodeRefs) InitRefs() { + atomic.StoreInt64(&r.refCount, 1) + refsvfs2.Register(r) +} + // RefType implements refsvfs2.CheckedObject.RefType. func (r *rootInodeRefs) RefType() string { return fmt.Sprintf("%T", rootInodeobj)[1:] @@ -58,8 +62,7 @@ func (r *rootInodeRefs) EnableLeakCheck() { // ReadRefs returns the current number of references. The returned count is // inherently racy and is unsafe to use without external synchronization. func (r *rootInodeRefs) ReadRefs() int64 { - - return atomic.LoadInt64(&r.refCount) + 1 + return atomic.LoadInt64(&r.refCount) } // IncRef implements refs.RefCounter.IncRef. @@ -67,8 +70,10 @@ func (r *rootInodeRefs) ReadRefs() int64 { //go:nosplit func (r *rootInodeRefs) IncRef() { v := atomic.AddInt64(&r.refCount, 1) - refsvfs2.LogIncRef(r, v+1) - if v <= 0 { + if rootInodeenableLogging { + 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 *rootInodeRefs) IncRef() { //go:nosplit func (r *rootInodeRefs) 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 rootInodeenableLogging { + refsvfs2.LogTryIncRef(r, v) + } return true } @@ -107,12 +114,14 @@ func (r *rootInodeRefs) TryIncRef() bool { //go:nosplit func (r *rootInodeRefs) DecRef(destroy func()) { v := atomic.AddInt64(&r.refCount, -1) - refsvfs2.LogDecRef(r, v+1) + if rootInodeenableLogging { + 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/fuse/fusefs.go b/pkg/sentry/fsimpl/fuse/fusefs.go index 6de416da0..cd0eb56e5 100644 --- a/pkg/sentry/fsimpl/fuse/fusefs.go +++ b/pkg/sentry/fsimpl/fuse/fusefs.go @@ -219,16 +219,12 @@ func newFUSEFilesystem(ctx context.Context, devMinor uint32, opts *filesystemOpt } fuseFD := device.Impl().(*DeviceFD) - fs := &filesystem{ devMinor: devMinor, opts: opts, conn: conn, } - - fs.VFSFilesystem().IncRef() fuseFD.fs = fs - return fs, nil } @@ -288,7 +284,7 @@ func (fs *filesystem) newRoot(ctx context.Context, creds *auth.Credentials, mode i := &inode{fs: fs, nodeID: 1} i.InodeAttrs.Init(ctx, creds, linux.UNNAMED_MAJOR, fs.devMinor, 1, linux.ModeDirectory|0755) i.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) - i.EnableLeakCheck() + i.InitRefs() var d kernfs.Dentry d.InitRoot(&fs.Filesystem, i) @@ -301,7 +297,7 @@ func (fs *filesystem) newInode(ctx context.Context, nodeID uint64, attr linux.FU i.InodeAttrs.Init(ctx, &creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.FileMode(attr.Mode)) atomic.StoreUint64(&i.size, attr.Size) i.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) - i.EnableLeakCheck() + i.InitRefs() return i } diff --git a/pkg/sentry/fsimpl/fuse/inode_refs.go b/pkg/sentry/fsimpl/fuse/inode_refs.go index 31cb3791f..37a39e976 100644 --- a/pkg/sentry/fsimpl/fuse/inode_refs.go +++ b/pkg/sentry/fsimpl/fuse/inode_refs.go @@ -20,9 +20,6 @@ var inodeobj *inode // 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 inodeRefs struct { // refCount is composed of two fields: @@ -35,6 +32,13 @@ type inodeRefs struct { refCount int64 } +// InitRefs initializes r with one reference and, if enabled, activates leak +// checking. +func (r *inodeRefs) InitRefs() { + atomic.StoreInt64(&r.refCount, 1) + refsvfs2.Register(r) +} + // RefType implements refsvfs2.CheckedObject.RefType. func (r *inodeRefs) RefType() string { return fmt.Sprintf("%T", inodeobj)[1:] @@ -58,8 +62,7 @@ func (r *inodeRefs) EnableLeakCheck() { // ReadRefs returns the current number of references. The returned count is // inherently racy and is unsafe to use without external synchronization. func (r *inodeRefs) ReadRefs() int64 { - - return atomic.LoadInt64(&r.refCount) + 1 + return atomic.LoadInt64(&r.refCount) } // IncRef implements refs.RefCounter.IncRef. @@ -67,8 +70,10 @@ func (r *inodeRefs) ReadRefs() int64 { //go:nosplit func (r *inodeRefs) IncRef() { v := atomic.AddInt64(&r.refCount, 1) - refsvfs2.LogIncRef(r, v+1) - if v <= 0 { + if inodeenableLogging { + 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 *inodeRefs) IncRef() { //go:nosplit func (r *inodeRefs) 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 inodeenableLogging { + refsvfs2.LogTryIncRef(r, v) + } return true } @@ -107,12 +114,14 @@ func (r *inodeRefs) TryIncRef() bool { //go:nosplit func (r *inodeRefs) DecRef(destroy func()) { v := atomic.AddInt64(&r.refCount, -1) - refsvfs2.LogDecRef(r, v+1) + if inodeenableLogging { + 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/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go index b59f62652..53bcc9986 100644 --- a/pkg/sentry/fsimpl/gofer/gofer.go +++ b/pkg/sentry/fsimpl/gofer/gofer.go @@ -1236,7 +1236,9 @@ func (d *dentry) IncRef() { // d.refs may be 0 if d.fs.renameMu is locked, which serializes against // d.checkCachingLocked(). r := atomic.AddInt64(&d.refs, 1) - refsvfs2.LogIncRef(d, r) + if d.LogRefs() { + refsvfs2.LogIncRef(d, r) + } } // TryIncRef implements vfs.DentryImpl.TryIncRef. @@ -1247,7 +1249,9 @@ 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 } } @@ -1267,7 +1271,9 @@ func (d *dentry) DecRef(ctx context.Context) { // responsible for ensuring that d.checkCachingLocked will be called later. func (d *dentry) decRefNoCaching() int64 { r := atomic.AddInt64(&d.refs, -1) - refsvfs2.LogDecRef(d, r) + if d.LogRefs() { + refsvfs2.LogDecRef(d, r) + } if r < 0 { panic("gofer.dentry.decRefNoCaching() called without holding a reference") } diff --git a/pkg/sentry/fsimpl/host/connected_endpoint_refs.go b/pkg/sentry/fsimpl/host/connected_endpoint_refs.go index faa9d2fd2..3f5f4ebc3 100644 --- a/pkg/sentry/fsimpl/host/connected_endpoint_refs.go +++ b/pkg/sentry/fsimpl/host/connected_endpoint_refs.go @@ -20,9 +20,6 @@ var ConnectedEndpointobj *ConnectedEndpoint // 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 ConnectedEndpointRefs struct { // refCount is composed of two fields: @@ -35,6 +32,13 @@ type ConnectedEndpointRefs struct { refCount int64 } +// InitRefs initializes r with one reference and, if enabled, activates leak +// checking. +func (r *ConnectedEndpointRefs) InitRefs() { + atomic.StoreInt64(&r.refCount, 1) + refsvfs2.Register(r) +} + // RefType implements refsvfs2.CheckedObject.RefType. func (r *ConnectedEndpointRefs) RefType() string { return fmt.Sprintf("%T", ConnectedEndpointobj)[1:] @@ -58,8 +62,7 @@ func (r *ConnectedEndpointRefs) EnableLeakCheck() { // ReadRefs returns the current number of references. The returned count is // inherently racy and is unsafe to use without external synchronization. func (r *ConnectedEndpointRefs) ReadRefs() int64 { - - return atomic.LoadInt64(&r.refCount) + 1 + return atomic.LoadInt64(&r.refCount) } // IncRef implements refs.RefCounter.IncRef. @@ -67,8 +70,10 @@ func (r *ConnectedEndpointRefs) ReadRefs() int64 { //go:nosplit func (r *ConnectedEndpointRefs) IncRef() { v := atomic.AddInt64(&r.refCount, 1) - refsvfs2.LogIncRef(r, v+1) - if v <= 0 { + if ConnectedEndpointenableLogging { + 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 *ConnectedEndpointRefs) IncRef() { //go:nosplit func (r *ConnectedEndpointRefs) 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 ConnectedEndpointenableLogging { + refsvfs2.LogTryIncRef(r, v) + } return true } @@ -107,12 +114,14 @@ func (r *ConnectedEndpointRefs) TryIncRef() bool { //go:nosplit func (r *ConnectedEndpointRefs) DecRef(destroy func()) { v := atomic.AddInt64(&r.refCount, -1) - refsvfs2.LogDecRef(r, v+1) + if ConnectedEndpointenableLogging { + 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/host/host.go b/pkg/sentry/fsimpl/host/host.go index 39b902a3e..435a21d77 100644 --- a/pkg/sentry/fsimpl/host/host.go +++ b/pkg/sentry/fsimpl/host/host.go @@ -126,8 +126,8 @@ func newInode(ctx context.Context, fs *filesystem, hostFD int, savable bool, fil isTTY: isTTY, savable: savable, } + i.InitRefs() i.CachedMappable.Init(hostFD) - i.EnableLeakCheck() // If the hostFD can return EWOULDBLOCK when set to non-blocking, do so and // handle blocking behavior in the sentry. diff --git a/pkg/sentry/fsimpl/host/inode_refs.go b/pkg/sentry/fsimpl/host/inode_refs.go index ef2f56522..4c850a7ac 100644 --- a/pkg/sentry/fsimpl/host/inode_refs.go +++ b/pkg/sentry/fsimpl/host/inode_refs.go @@ -20,9 +20,6 @@ var inodeobj *inode // 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 inodeRefs struct { // refCount is composed of two fields: @@ -35,6 +32,13 @@ type inodeRefs struct { refCount int64 } +// InitRefs initializes r with one reference and, if enabled, activates leak +// checking. +func (r *inodeRefs) InitRefs() { + atomic.StoreInt64(&r.refCount, 1) + refsvfs2.Register(r) +} + // RefType implements refsvfs2.CheckedObject.RefType. func (r *inodeRefs) RefType() string { return fmt.Sprintf("%T", inodeobj)[1:] @@ -58,8 +62,7 @@ func (r *inodeRefs) EnableLeakCheck() { // ReadRefs returns the current number of references. The returned count is // inherently racy and is unsafe to use without external synchronization. func (r *inodeRefs) ReadRefs() int64 { - - return atomic.LoadInt64(&r.refCount) + 1 + return atomic.LoadInt64(&r.refCount) } // IncRef implements refs.RefCounter.IncRef. @@ -67,8 +70,10 @@ func (r *inodeRefs) ReadRefs() int64 { //go:nosplit func (r *inodeRefs) IncRef() { v := atomic.AddInt64(&r.refCount, 1) - refsvfs2.LogIncRef(r, v+1) - if v <= 0 { + if inodeenableLogging { + 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 *inodeRefs) IncRef() { //go:nosplit func (r *inodeRefs) 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 inodeenableLogging { + refsvfs2.LogTryIncRef(r, v) + } return true } @@ -107,12 +114,14 @@ func (r *inodeRefs) TryIncRef() bool { //go:nosplit func (r *inodeRefs) DecRef(destroy func()) { v := atomic.AddInt64(&r.refCount, -1) - refsvfs2.LogDecRef(r, v+1) + if inodeenableLogging { + 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/host/socket.go b/pkg/sentry/fsimpl/host/socket.go index 8a447e29f..60acc367f 100644 --- a/pkg/sentry/fsimpl/host/socket.go +++ b/pkg/sentry/fsimpl/host/socket.go @@ -84,6 +84,8 @@ type ConnectedEndpoint struct { // init performs initialization required for creating new ConnectedEndpoints and // for restoring them. func (c *ConnectedEndpoint) init() *syserr.Error { + c.InitRefs() + family, err := syscall.GetsockoptInt(c.fd, syscall.SOL_SOCKET, syscall.SO_DOMAIN) if err != nil { return syserr.FromError(err) @@ -132,7 +134,6 @@ func NewConnectedEndpoint(ctx context.Context, hostFD int, addr string, saveable // ConnectedEndpointRefs start off with a single reference. We need two. e.IncRef() - e.EnableLeakCheck() return &e, nil } @@ -376,8 +377,7 @@ func NewSCMEndpoint(ctx context.Context, hostFD int, queue *waiter.Queue, addr s return nil, err } - // ConnectedEndpointRefs start off with a single reference. We need two. + // e starts off with a single reference. We need two. e.IncRef() - e.EnableLeakCheck() return &e, nil } 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 { diff --git a/pkg/sentry/fsimpl/overlay/overlay.go b/pkg/sentry/fsimpl/overlay/overlay.go index 73130bc8d..3492409b2 100644 --- a/pkg/sentry/fsimpl/overlay/overlay.go +++ b/pkg/sentry/fsimpl/overlay/overlay.go @@ -514,7 +514,9 @@ func (d *dentry) IncRef() { // d.refs may be 0 if d.fs.renameMu is locked, which serializes against // d.checkDropLocked(). r := atomic.AddInt64(&d.refs, 1) - refsvfs2.LogIncRef(d, r) + if d.LogRefs() { + refsvfs2.LogIncRef(d, r) + } } // TryIncRef implements vfs.DentryImpl.TryIncRef. @@ -525,7 +527,9 @@ 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 } } @@ -534,7 +538,9 @@ 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.renameMu.Lock() d.checkDropLocked(ctx) @@ -546,7 +552,9 @@ 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.checkDropLocked(ctx) } else if r < 0 { diff --git a/pkg/sentry/fsimpl/proc/fd_dir_inode_refs.go b/pkg/sentry/fsimpl/proc/fd_dir_inode_refs.go index 895298eb9..4644809bd 100644 --- a/pkg/sentry/fsimpl/proc/fd_dir_inode_refs.go +++ b/pkg/sentry/fsimpl/proc/fd_dir_inode_refs.go @@ -20,9 +20,6 @@ var fdDirInodeobj *fdDirInode // 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 fdDirInodeRefs struct { // refCount is composed of two fields: @@ -35,6 +32,13 @@ type fdDirInodeRefs struct { refCount int64 } +// InitRefs initializes r with one reference and, if enabled, activates leak +// checking. +func (r *fdDirInodeRefs) InitRefs() { + atomic.StoreInt64(&r.refCount, 1) + refsvfs2.Register(r) +} + // RefType implements refsvfs2.CheckedObject.RefType. func (r *fdDirInodeRefs) RefType() string { return fmt.Sprintf("%T", fdDirInodeobj)[1:] @@ -58,8 +62,7 @@ func (r *fdDirInodeRefs) EnableLeakCheck() { // ReadRefs returns the current number of references. The returned count is // inherently racy and is unsafe to use without external synchronization. func (r *fdDirInodeRefs) ReadRefs() int64 { - - return atomic.LoadInt64(&r.refCount) + 1 + return atomic.LoadInt64(&r.refCount) } // IncRef implements refs.RefCounter.IncRef. @@ -67,8 +70,10 @@ func (r *fdDirInodeRefs) ReadRefs() int64 { //go:nosplit func (r *fdDirInodeRefs) IncRef() { v := atomic.AddInt64(&r.refCount, 1) - refsvfs2.LogIncRef(r, v+1) - if v <= 0 { + if fdDirInodeenableLogging { + 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 *fdDirInodeRefs) IncRef() { //go:nosplit func (r *fdDirInodeRefs) 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 fdDirInodeenableLogging { + refsvfs2.LogTryIncRef(r, v) + } return true } @@ -107,12 +114,14 @@ func (r *fdDirInodeRefs) TryIncRef() bool { //go:nosplit func (r *fdDirInodeRefs) DecRef(destroy func()) { v := atomic.AddInt64(&r.refCount, -1) - refsvfs2.LogDecRef(r, v+1) + if fdDirInodeenableLogging { + 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/proc/fd_info_dir_inode_refs.go b/pkg/sentry/fsimpl/proc/fd_info_dir_inode_refs.go index 8e3458485..dbc7e3f5a 100644 --- a/pkg/sentry/fsimpl/proc/fd_info_dir_inode_refs.go +++ b/pkg/sentry/fsimpl/proc/fd_info_dir_inode_refs.go @@ -20,9 +20,6 @@ var fdInfoDirInodeobj *fdInfoDirInode // 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 fdInfoDirInodeRefs struct { // refCount is composed of two fields: @@ -35,6 +32,13 @@ type fdInfoDirInodeRefs struct { refCount int64 } +// InitRefs initializes r with one reference and, if enabled, activates leak +// checking. +func (r *fdInfoDirInodeRefs) InitRefs() { + atomic.StoreInt64(&r.refCount, 1) + refsvfs2.Register(r) +} + // RefType implements refsvfs2.CheckedObject.RefType. func (r *fdInfoDirInodeRefs) RefType() string { return fmt.Sprintf("%T", fdInfoDirInodeobj)[1:] @@ -58,8 +62,7 @@ func (r *fdInfoDirInodeRefs) EnableLeakCheck() { // ReadRefs returns the current number of references. The returned count is // inherently racy and is unsafe to use without external synchronization. func (r *fdInfoDirInodeRefs) ReadRefs() int64 { - - return atomic.LoadInt64(&r.refCount) + 1 + return atomic.LoadInt64(&r.refCount) } // IncRef implements refs.RefCounter.IncRef. @@ -67,8 +70,10 @@ func (r *fdInfoDirInodeRefs) ReadRefs() int64 { //go:nosplit func (r *fdInfoDirInodeRefs) IncRef() { v := atomic.AddInt64(&r.refCount, 1) - refsvfs2.LogIncRef(r, v+1) - if v <= 0 { + if fdInfoDirInodeenableLogging { + 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 *fdInfoDirInodeRefs) IncRef() { //go:nosplit func (r *fdInfoDirInodeRefs) 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 fdInfoDirInodeenableLogging { + refsvfs2.LogTryIncRef(r, v) + } return true } @@ -107,12 +114,14 @@ func (r *fdInfoDirInodeRefs) TryIncRef() bool { //go:nosplit func (r *fdInfoDirInodeRefs) DecRef(destroy func()) { v := atomic.AddInt64(&r.refCount, -1) - refsvfs2.LogDecRef(r, v+1) + if fdInfoDirInodeenableLogging { + 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/proc/subtasks.go b/pkg/sentry/fsimpl/proc/subtasks.go index cb3c5e0fd..e001d5032 100644 --- a/pkg/sentry/fsimpl/proc/subtasks.go +++ b/pkg/sentry/fsimpl/proc/subtasks.go @@ -60,7 +60,7 @@ func (fs *filesystem) newSubtasks(task *kernel.Task, pidns *kernel.PIDNamespace, // Note: credentials are overridden by taskOwnedInode. subInode.InodeAttrs.Init(task, task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) subInode.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) - subInode.EnableLeakCheck() + subInode.InitRefs() inode := &taskOwnedInode{Inode: subInode, owner: task} return inode diff --git a/pkg/sentry/fsimpl/proc/subtasks_inode_refs.go b/pkg/sentry/fsimpl/proc/subtasks_inode_refs.go index c609e618a..993251646 100644 --- a/pkg/sentry/fsimpl/proc/subtasks_inode_refs.go +++ b/pkg/sentry/fsimpl/proc/subtasks_inode_refs.go @@ -20,9 +20,6 @@ var subtasksInodeobj *subtasksInode // 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 subtasksInodeRefs struct { // refCount is composed of two fields: @@ -35,6 +32,13 @@ type subtasksInodeRefs struct { refCount int64 } +// InitRefs initializes r with one reference and, if enabled, activates leak +// checking. +func (r *subtasksInodeRefs) InitRefs() { + atomic.StoreInt64(&r.refCount, 1) + refsvfs2.Register(r) +} + // RefType implements refsvfs2.CheckedObject.RefType. func (r *subtasksInodeRefs) RefType() string { return fmt.Sprintf("%T", subtasksInodeobj)[1:] @@ -58,8 +62,7 @@ func (r *subtasksInodeRefs) EnableLeakCheck() { // ReadRefs returns the current number of references. The returned count is // inherently racy and is unsafe to use without external synchronization. func (r *subtasksInodeRefs) ReadRefs() int64 { - - return atomic.LoadInt64(&r.refCount) + 1 + return atomic.LoadInt64(&r.refCount) } // IncRef implements refs.RefCounter.IncRef. @@ -67,8 +70,10 @@ func (r *subtasksInodeRefs) ReadRefs() int64 { //go:nosplit func (r *subtasksInodeRefs) IncRef() { v := atomic.AddInt64(&r.refCount, 1) - refsvfs2.LogIncRef(r, v+1) - if v <= 0 { + if subtasksInodeenableLogging { + 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 *subtasksInodeRefs) IncRef() { //go:nosplit func (r *subtasksInodeRefs) 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 subtasksInodeenableLogging { + refsvfs2.LogTryIncRef(r, v) + } return true } @@ -107,12 +114,14 @@ func (r *subtasksInodeRefs) TryIncRef() bool { //go:nosplit func (r *subtasksInodeRefs) DecRef(destroy func()) { v := atomic.AddInt64(&r.refCount, -1) - refsvfs2.LogDecRef(r, v+1) + if subtasksInodeenableLogging { + 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/proc/task.go b/pkg/sentry/fsimpl/proc/task.go index 19011b010..dc46a09bc 100644 --- a/pkg/sentry/fsimpl/proc/task.go +++ b/pkg/sentry/fsimpl/proc/task.go @@ -91,7 +91,7 @@ func (fs *filesystem) newTaskInode(task *kernel.Task, pidns *kernel.PIDNamespace taskInode := &taskInode{task: task} // Note: credentials are overridden by taskOwnedInode. taskInode.InodeAttrs.Init(task, task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) - taskInode.EnableLeakCheck() + taskInode.InitRefs() inode := &taskOwnedInode{Inode: taskInode, owner: task} diff --git a/pkg/sentry/fsimpl/proc/task_fds.go b/pkg/sentry/fsimpl/proc/task_fds.go index d268b44be..3ec4471f5 100644 --- a/pkg/sentry/fsimpl/proc/task_fds.go +++ b/pkg/sentry/fsimpl/proc/task_fds.go @@ -128,7 +128,7 @@ func (fs *filesystem) newFDDirInode(task *kernel.Task) kernfs.Inode { }, } inode.InodeAttrs.Init(task, task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) - inode.EnableLeakCheck() + inode.InitRefs() inode.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) return inode } @@ -265,7 +265,7 @@ func (fs *filesystem) newFDInfoDirInode(task *kernel.Task) kernfs.Inode { }, } inode.InodeAttrs.Init(task, task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) - inode.EnableLeakCheck() + inode.InitRefs() inode.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) return inode } diff --git a/pkg/sentry/fsimpl/proc/task_inode_refs.go b/pkg/sentry/fsimpl/proc/task_inode_refs.go index 2ee58bd62..632251e75 100644 --- a/pkg/sentry/fsimpl/proc/task_inode_refs.go +++ b/pkg/sentry/fsimpl/proc/task_inode_refs.go @@ -20,9 +20,6 @@ var taskInodeobj *taskInode // 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 taskInodeRefs struct { // refCount is composed of two fields: @@ -35,6 +32,13 @@ type taskInodeRefs struct { refCount int64 } +// InitRefs initializes r with one reference and, if enabled, activates leak +// checking. +func (r *taskInodeRefs) InitRefs() { + atomic.StoreInt64(&r.refCount, 1) + refsvfs2.Register(r) +} + // RefType implements refsvfs2.CheckedObject.RefType. func (r *taskInodeRefs) RefType() string { return fmt.Sprintf("%T", taskInodeobj)[1:] @@ -58,8 +62,7 @@ func (r *taskInodeRefs) EnableLeakCheck() { // ReadRefs returns the current number of references. The returned count is // inherently racy and is unsafe to use without external synchronization. func (r *taskInodeRefs) ReadRefs() int64 { - - return atomic.LoadInt64(&r.refCount) + 1 + return atomic.LoadInt64(&r.refCount) } // IncRef implements refs.RefCounter.IncRef. @@ -67,8 +70,10 @@ func (r *taskInodeRefs) ReadRefs() int64 { //go:nosplit func (r *taskInodeRefs) IncRef() { v := atomic.AddInt64(&r.refCount, 1) - refsvfs2.LogIncRef(r, v+1) - if v <= 0 { + if taskInodeenableLogging { + 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 *taskInodeRefs) IncRef() { //go:nosplit func (r *taskInodeRefs) 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 taskInodeenableLogging { + refsvfs2.LogTryIncRef(r, v) + } return true } @@ -107,12 +114,14 @@ func (r *taskInodeRefs) TryIncRef() bool { //go:nosplit func (r *taskInodeRefs) DecRef(destroy func()) { v := atomic.AddInt64(&r.refCount, -1) - refsvfs2.LogDecRef(r, v+1) + if taskInodeenableLogging { + 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/proc/tasks.go b/pkg/sentry/fsimpl/proc/tasks.go index b81ea14bf..151d1f10d 100644 --- a/pkg/sentry/fsimpl/proc/tasks.go +++ b/pkg/sentry/fsimpl/proc/tasks.go @@ -83,7 +83,7 @@ func (fs *filesystem) newTasksInode(ctx context.Context, k *kernel.Kernel, pidns cgroupControllers: cgroupControllers, } inode.InodeAttrs.Init(ctx, root, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0555) - inode.EnableLeakCheck() + inode.InitRefs() inode.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) links := inode.OrderedChildren.Populate(contents) diff --git a/pkg/sentry/fsimpl/proc/tasks_inode_refs.go b/pkg/sentry/fsimpl/proc/tasks_inode_refs.go index 71dcaed9e..0b2af4269 100644 --- a/pkg/sentry/fsimpl/proc/tasks_inode_refs.go +++ b/pkg/sentry/fsimpl/proc/tasks_inode_refs.go @@ -20,9 +20,6 @@ var tasksInodeobj *tasksInode // 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 tasksInodeRefs struct { // refCount is composed of two fields: @@ -35,6 +32,13 @@ type tasksInodeRefs struct { refCount int64 } +// InitRefs initializes r with one reference and, if enabled, activates leak +// checking. +func (r *tasksInodeRefs) InitRefs() { + atomic.StoreInt64(&r.refCount, 1) + refsvfs2.Register(r) +} + // RefType implements refsvfs2.CheckedObject.RefType. func (r *tasksInodeRefs) RefType() string { return fmt.Sprintf("%T", tasksInodeobj)[1:] @@ -58,8 +62,7 @@ func (r *tasksInodeRefs) EnableLeakCheck() { // ReadRefs returns the current number of references. The returned count is // inherently racy and is unsafe to use without external synchronization. func (r *tasksInodeRefs) ReadRefs() int64 { - - return atomic.LoadInt64(&r.refCount) + 1 + return atomic.LoadInt64(&r.refCount) } // IncRef implements refs.RefCounter.IncRef. @@ -67,8 +70,10 @@ func (r *tasksInodeRefs) ReadRefs() int64 { //go:nosplit func (r *tasksInodeRefs) IncRef() { v := atomic.AddInt64(&r.refCount, 1) - refsvfs2.LogIncRef(r, v+1) - if v <= 0 { + if tasksInodeenableLogging { + 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 *tasksInodeRefs) IncRef() { //go:nosplit func (r *tasksInodeRefs) 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 tasksInodeenableLogging { + refsvfs2.LogTryIncRef(r, v) + } return true } @@ -107,12 +114,14 @@ func (r *tasksInodeRefs) TryIncRef() bool { //go:nosplit func (r *tasksInodeRefs) DecRef(destroy func()) { v := atomic.AddInt64(&r.refCount, -1) - refsvfs2.LogDecRef(r, v+1) + if tasksInodeenableLogging { + 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/sys/dir_refs.go b/pkg/sentry/fsimpl/sys/dir_refs.go index 176a4bf98..a45aa7f78 100644 --- a/pkg/sentry/fsimpl/sys/dir_refs.go +++ b/pkg/sentry/fsimpl/sys/dir_refs.go @@ -20,9 +20,6 @@ var dirobj *dir // 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 dirRefs struct { // refCount is composed of two fields: @@ -35,6 +32,13 @@ type dirRefs struct { refCount int64 } +// InitRefs initializes r with one reference and, if enabled, activates leak +// checking. +func (r *dirRefs) InitRefs() { + atomic.StoreInt64(&r.refCount, 1) + refsvfs2.Register(r) +} + // RefType implements refsvfs2.CheckedObject.RefType. func (r *dirRefs) RefType() string { return fmt.Sprintf("%T", dirobj)[1:] @@ -58,8 +62,7 @@ func (r *dirRefs) EnableLeakCheck() { // ReadRefs returns the current number of references. The returned count is // inherently racy and is unsafe to use without external synchronization. func (r *dirRefs) ReadRefs() int64 { - - return atomic.LoadInt64(&r.refCount) + 1 + return atomic.LoadInt64(&r.refCount) } // IncRef implements refs.RefCounter.IncRef. @@ -67,8 +70,10 @@ func (r *dirRefs) ReadRefs() int64 { //go:nosplit func (r *dirRefs) IncRef() { v := atomic.AddInt64(&r.refCount, 1) - refsvfs2.LogIncRef(r, v+1) - if v <= 0 { + if direnableLogging { + 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 *dirRefs) IncRef() { //go:nosplit func (r *dirRefs) 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 direnableLogging { + refsvfs2.LogTryIncRef(r, v) + } return true } @@ -107,12 +114,14 @@ func (r *dirRefs) TryIncRef() bool { //go:nosplit func (r *dirRefs) DecRef(destroy func()) { v := atomic.AddInt64(&r.refCount, -1) - refsvfs2.LogDecRef(r, v+1) + if direnableLogging { + 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/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go index 506a2a0f0..79bc3fe88 100644 --- a/pkg/sentry/fsimpl/sys/sys.go +++ b/pkg/sentry/fsimpl/sys/sys.go @@ -160,7 +160,7 @@ func (fs *filesystem) newDir(ctx context.Context, creds *auth.Credentials, mode d := &dir{} d.InodeAttrs.Init(ctx, creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0755) d.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) - d.EnableLeakCheck() + d.InitRefs() d.IncLinks(d.OrderedChildren.Populate(contents)) return d } diff --git a/pkg/sentry/fsimpl/tmpfs/inode_refs.go b/pkg/sentry/fsimpl/tmpfs/inode_refs.go index eff30ca09..51ee15409 100644 --- a/pkg/sentry/fsimpl/tmpfs/inode_refs.go +++ b/pkg/sentry/fsimpl/tmpfs/inode_refs.go @@ -20,9 +20,6 @@ var inodeobj *inode // 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 inodeRefs struct { // refCount is composed of two fields: @@ -35,6 +32,13 @@ type inodeRefs struct { refCount int64 } +// InitRefs initializes r with one reference and, if enabled, activates leak +// checking. +func (r *inodeRefs) InitRefs() { + atomic.StoreInt64(&r.refCount, 1) + refsvfs2.Register(r) +} + // RefType implements refsvfs2.CheckedObject.RefType. func (r *inodeRefs) RefType() string { return fmt.Sprintf("%T", inodeobj)[1:] @@ -58,8 +62,7 @@ func (r *inodeRefs) EnableLeakCheck() { // ReadRefs returns the current number of references. The returned count is // inherently racy and is unsafe to use without external synchronization. func (r *inodeRefs) ReadRefs() int64 { - - return atomic.LoadInt64(&r.refCount) + 1 + return atomic.LoadInt64(&r.refCount) } // IncRef implements refs.RefCounter.IncRef. @@ -67,8 +70,10 @@ func (r *inodeRefs) ReadRefs() int64 { //go:nosplit func (r *inodeRefs) IncRef() { v := atomic.AddInt64(&r.refCount, 1) - refsvfs2.LogIncRef(r, v+1) - if v <= 0 { + if inodeenableLogging { + 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 *inodeRefs) IncRef() { //go:nosplit func (r *inodeRefs) 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 inodeenableLogging { + refsvfs2.LogTryIncRef(r, v) + } return true } @@ -107,12 +114,14 @@ func (r *inodeRefs) TryIncRef() bool { //go:nosplit func (r *inodeRefs) DecRef(destroy func()) { v := atomic.AddInt64(&r.refCount, -1) - refsvfs2.LogDecRef(r, v+1) + if inodeenableLogging { + 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/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go index 4ce859d57..85a3dfe20 100644 --- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go +++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go @@ -402,7 +402,7 @@ func (i *inode) init(impl interface{}, fs *filesystem, kuid auth.KUID, kgid auth i.mtime = now // i.nlink initialized by caller i.impl = impl - i.refs.EnableLeakCheck() + i.refs.InitRefs() } // incLinksLocked increments i's link count. |