diff options
| -rw-r--r-- | pkg/sentry/fsimpl/gofer/gofer.go | 26 | ||||
| -rw-r--r-- | pkg/sentry/kernel/kernel.go | 2 | ||||
| -rw-r--r-- | pkg/sentry/syscalls/linux/vfs2/ioctl.go | 29 |
3 files changed, 46 insertions, 11 deletions
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go index 0d88a328e..ac051b3a7 100644 --- a/pkg/sentry/fsimpl/gofer/gofer.go +++ b/pkg/sentry/fsimpl/gofer/gofer.go @@ -835,6 +835,14 @@ func (d *dentry) statTo(stat *linux.Statx) { stat.Mask = linux.STATX_TYPE | linux.STATX_MODE | linux.STATX_NLINK | linux.STATX_UID | linux.STATX_GID | linux.STATX_ATIME | linux.STATX_MTIME | linux.STATX_CTIME | linux.STATX_INO | linux.STATX_SIZE | linux.STATX_BLOCKS | linux.STATX_BTIME stat.Blksize = atomic.LoadUint32(&d.blockSize) stat.Nlink = atomic.LoadUint32(&d.nlink) + if stat.Nlink == 0 { + // The remote filesystem doesn't support link count; just make + // something up. This is consistent with Linux, where + // fs/inode.c:inode_init_always() initializes link count to 1, and + // fs/9p/vfs_inode_dotl.c:v9fs_stat2inode_dotl() doesn't touch it if + // it's not provided by the remote filesystem. + stat.Nlink = 1 + } stat.UID = atomic.LoadUint32(&d.uid) stat.GID = atomic.LoadUint32(&d.gid) stat.Mode = uint16(atomic.LoadUint32(&d.mode)) @@ -1346,23 +1354,21 @@ func (d *dentry) ensureSharedHandle(ctx context.Context, read, write, trunc bool } // incLinks increments link count. -// -// Preconditions: d.nlink != 0 && d.nlink < math.MaxUint32. func (d *dentry) incLinks() { - v := atomic.AddUint32(&d.nlink, 1) - if v < 2 { - panic(fmt.Sprintf("dentry.nlink is invalid (was 0 or overflowed): %d", v)) + if atomic.LoadUint32(&d.nlink) == 0 { + // The remote filesystem doesn't support link count. + return } + atomic.AddUint32(&d.nlink, 1) } // decLinks decrements link count. -// -// Preconditions: d.nlink > 1. func (d *dentry) decLinks() { - v := atomic.AddUint32(&d.nlink, ^uint32(0)) - if v == 0 { - panic(fmt.Sprintf("dentry.nlink must be greater than 0: %d", v)) + if atomic.LoadUint32(&d.nlink) == 0 { + // The remote filesystem doesn't support link count. + return } + atomic.AddUint32(&d.nlink, ^uint32(0)) } // fileDescription is embedded by gofer implementations of diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go index bcbeb6a39..52491da7a 100644 --- a/pkg/sentry/kernel/kernel.go +++ b/pkg/sentry/kernel/kernel.go @@ -892,7 +892,7 @@ func (k *Kernel) CreateProcess(args CreateProcessArgs) (*ThreadGroup, ThreadID, if mntnsVFS2 == nil { // MountNamespaceVFS2 adds a reference to the namespace, which is // transferred to the new process. - mntnsVFS2 = k.GlobalInit().Leader().MountNamespaceVFS2() + mntnsVFS2 = k.globalInit.Leader().MountNamespaceVFS2() } // Get the root directory from the MountNamespace. root := args.MountNamespaceVFS2.Root() diff --git a/pkg/sentry/syscalls/linux/vfs2/ioctl.go b/pkg/sentry/syscalls/linux/vfs2/ioctl.go index 5a2418da9..0399c0db4 100644 --- a/pkg/sentry/syscalls/linux/vfs2/ioctl.go +++ b/pkg/sentry/syscalls/linux/vfs2/ioctl.go @@ -15,6 +15,7 @@ package vfs2 import ( + "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/syserror" @@ -30,6 +31,34 @@ func Ioctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall } defer file.DecRef() + // Handle ioctls that apply to all FDs. + switch args[1].Int() { + case linux.FIONCLEX: + t.FDTable().SetFlagsVFS2(fd, kernel.FDFlags{ + CloseOnExec: false, + }) + return 0, nil, nil + + case linux.FIOCLEX: + t.FDTable().SetFlagsVFS2(fd, kernel.FDFlags{ + CloseOnExec: true, + }) + return 0, nil, nil + + case linux.FIONBIO: + var set int32 + if _, err := t.CopyIn(args[2].Pointer(), &set); err != nil { + return 0, nil, err + } + flags := file.StatusFlags() + if set != 0 { + flags |= linux.O_NONBLOCK + } else { + flags &^= linux.O_NONBLOCK + } + return 0, nil, file.SetStatusFlags(t, t.Credentials(), flags) + } + ret, err := file.Ioctl(t, t.MemoryManager(), args) return ret, nil, err } |