diff options
author | Dean Deng <deandeng@google.com> | 2020-11-09 08:30:29 -0800 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2020-11-09 08:33:17 -0800 |
commit | 0fb5353e45f166460d5846576c20479072207a06 (patch) | |
tree | f88e4472c07f56e4d34b14743e1a3afaafab62e1 /pkg/sentry/vfs | |
parent | 78cce3a46b953cab00731f8afacf7e9e7f4dc751 (diff) |
Initialize references with a value of 1.
This lets us avoid treating a value of 0 as one reference. All references
using the refsvfs2 template must call InitRefs() before the reference is
incremented/decremented, or else a panic will occur. Therefore, it should be
pretty easy to identify missing InitRef calls during testing.
Updates #1486.
PiperOrigin-RevId: 341411151
Diffstat (limited to 'pkg/sentry/vfs')
-rw-r--r-- | pkg/sentry/vfs/file_description.go | 2 | ||||
-rw-r--r-- | pkg/sentry/vfs/filesystem.go | 2 | ||||
-rw-r--r-- | pkg/sentry/vfs/mount.go | 13 |
3 files changed, 12 insertions, 5 deletions
diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go index 546e445aa..936f9fc71 100644 --- a/pkg/sentry/vfs/file_description.go +++ b/pkg/sentry/vfs/file_description.go @@ -133,7 +133,7 @@ func (fd *FileDescription) Init(impl FileDescriptionImpl, flags uint32, mnt *Mou } } - fd.EnableLeakCheck() + fd.InitRefs() // Remove "file creation flags" to mirror the behavior from file.f_flags in // fs/open.c:do_dentry_open. diff --git a/pkg/sentry/vfs/filesystem.go b/pkg/sentry/vfs/filesystem.go index c93d94634..2c4b81e78 100644 --- a/pkg/sentry/vfs/filesystem.go +++ b/pkg/sentry/vfs/filesystem.go @@ -48,7 +48,7 @@ type Filesystem struct { // Init must be called before first use of fs. func (fs *Filesystem) Init(vfsObj *VirtualFilesystem, fsType FilesystemType, impl FilesystemImpl) { - fs.EnableLeakCheck() + fs.InitRefs() fs.vfs = vfsObj fs.fsType = fsType fs.impl = impl diff --git a/pkg/sentry/vfs/mount.go b/pkg/sentry/vfs/mount.go index 3ea981ad4..d865fd603 100644 --- a/pkg/sentry/vfs/mount.go +++ b/pkg/sentry/vfs/mount.go @@ -169,7 +169,7 @@ func (vfs *VirtualFilesystem) NewMountNamespace(ctx context.Context, creds *auth Owner: creds.UserNamespace, mountpoints: make(map[*Dentry]uint32), } - mntns.EnableLeakCheck() + mntns.InitRefs() mntns.root = newMount(vfs, fs, root, mntns, opts) return mntns, nil } @@ -477,7 +477,9 @@ func (mnt *Mount) tryIncMountedRef() bool { return false } if atomic.CompareAndSwapInt64(&mnt.refs, r, r+1) { - refsvfs2.LogTryIncRef(mnt, r+1) + if mnt.LogRefs() { + refsvfs2.LogTryIncRef(mnt, r+1) + } return true } } @@ -488,12 +490,17 @@ func (mnt *Mount) IncRef() { // In general, negative values for mnt.refs are valid because the MSB is // the eager-unmount bit. r := atomic.AddInt64(&mnt.refs, 1) - refsvfs2.LogIncRef(mnt, r) + if mnt.LogRefs() { + refsvfs2.LogIncRef(mnt, r) + } } // DecRef decrements mnt's reference count. func (mnt *Mount) DecRef(ctx context.Context) { r := atomic.AddInt64(&mnt.refs, -1) + if mnt.LogRefs() { + refsvfs2.LogDecRef(mnt, r) + } if r&^math.MinInt64 == 0 { // mask out MSB refsvfs2.Unregister(mnt) mnt.destroy(ctx) |