diff options
| -rw-r--r-- | pkg/sentry/fs/proc/proc.go | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/pkg/sentry/fs/proc/proc.go b/pkg/sentry/fs/proc/proc.go index d727e1bc9..b2a8d639c 100644 --- a/pkg/sentry/fs/proc/proc.go +++ b/pkg/sentry/fs/proc/proc.go @@ -111,6 +111,13 @@ func (p *proc) newSelf(ctx context.Context, msrc *fs.MountSource) *fs.Inode { return newFile(s, msrc, fs.Symlink, nil) } +// newThreadSelf returns a new "threadSelf" node. +func (p *proc) newThreadSelf(ctx context.Context, msrc *fs.MountSource) *fs.Inode { + s := &threadSelf{pidns: p.pidns} + s.InitSymlink(ctx, fs.RootOwner, "") + return newFile(s, msrc, fs.Symlink, nil) +} + // newStubProcFsFile returns a procfs file with constant contents. func (p *proc) newStubProcFSFile(ctx context.Context, msrc *fs.MountSource, c []byte) *fs.Inode { u := &stubProcFSFile{ @@ -134,6 +141,28 @@ func (s *self) Readlink(ctx context.Context, inode *fs.Inode) (string, error) { return "", ramfs.ErrInvalidOp } +// threadSelf is more magical than "self" link. +type threadSelf struct { + ramfs.Symlink + + pidns *kernel.PIDNamespace +} + +// Readlink implements fs.InodeOperations.Readlink. +func (s *threadSelf) Readlink(ctx context.Context, inode *fs.Inode) (string, error) { + if t := kernel.TaskFromContext(ctx); t != nil { + tgid := s.pidns.IDOfThreadGroup(t.ThreadGroup()) + tid := s.pidns.IDOfTask(t) + if tid == 0 || tgid == 0 { + return "", ramfs.ErrNotFound + } + return fmt.Sprintf("%d/task/%d", tgid, tid), nil + } + + // Who is reading this link? + return "", ramfs.ErrInvalidOp +} + // Lookup loads an Inode at name into a Dirent. func (p *proc) Lookup(ctx context.Context, dir *fs.Inode, name string) (*fs.Dirent, error) { // Is it one of the static ones? @@ -151,8 +180,9 @@ func (p *proc) Lookup(ctx context.Context, dir *fs.Inode, name string) (*fs.Dire } return p.newNetDir(ctx, dir.MountSource) }, - "self": func() *fs.Inode { return p.newSelf(ctx, dir.MountSource) }, - "sys": func() *fs.Inode { return p.newSysDir(ctx, dir.MountSource) }, + "self": func() *fs.Inode { return p.newSelf(ctx, dir.MountSource) }, + "sys": func() *fs.Inode { return p.newSysDir(ctx, dir.MountSource) }, + "thread-self": func() *fs.Inode { return p.newThreadSelf(ctx, dir.MountSource) }, } if nf, ok := nfs[name]; ok { return fs.NewDirent(nf(), name), nil |