diff options
Diffstat (limited to 'pkg/sentry/fsimpl/overlay/copy_up.go')
| -rw-r--r-- | pkg/sentry/fsimpl/overlay/copy_up.go | 78 |
1 files changed, 0 insertions, 78 deletions
diff --git a/pkg/sentry/fsimpl/overlay/copy_up.go b/pkg/sentry/fsimpl/overlay/copy_up.go index 360b77ef6..c589b4746 100644 --- a/pkg/sentry/fsimpl/overlay/copy_up.go +++ b/pkg/sentry/fsimpl/overlay/copy_up.go @@ -23,7 +23,6 @@ import ( "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/fspath" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" - "gvisor.dev/gvisor/pkg/sentry/memmap" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" @@ -82,8 +81,6 @@ func (d *dentry) copyUpLocked(ctx context.Context) error { Start: d.parent.upperVD, Path: fspath.Parse(d.name), } - // Used during copy-up of memory-mapped regular files. - var mmapOpts *memmap.MMapOpts cleanupUndoCopyUp := func() { var err error if ftype == linux.S_IFDIR { @@ -139,25 +136,6 @@ func (d *dentry) copyUpLocked(ctx context.Context) error { break } } - d.mapsMu.Lock() - defer d.mapsMu.Unlock() - if d.wrappedMappable != nil { - // We may have memory mappings of the file on the lower layer. - // Switch to mapping the file on the upper layer instead. - mmapOpts = &memmap.MMapOpts{ - Perms: usermem.ReadWrite, - MaxPerms: usermem.ReadWrite, - } - if err := newFD.ConfigureMMap(ctx, mmapOpts); err != nil { - cleanupUndoCopyUp() - return err - } - if mmapOpts.MappingIdentity != nil { - mmapOpts.MappingIdentity.DecRef(ctx) - } - // Don't actually switch Mappables until the end of copy-up; see - // below for why. - } if err := newFD.SetStat(ctx, vfs.SetStatOptions{ Stat: linux.Statx{ Mask: linux.STATX_UID | linux.STATX_GID, @@ -287,62 +265,6 @@ func (d *dentry) copyUpLocked(ctx context.Context) error { atomic.StoreUint64(&d.ino, upperStat.Ino) } - if mmapOpts != nil && mmapOpts.Mappable != nil { - // Note that if mmapOpts != nil, then d.mapsMu is locked for writing - // (from the S_IFREG path above). - - // Propagate mappings of d to the new Mappable. Remember which mappings - // we added so we can remove them on failure. - upperMappable := mmapOpts.Mappable - allAdded := make(map[memmap.MappableRange]memmap.MappingsOfRange) - for seg := d.lowerMappings.FirstSegment(); seg.Ok(); seg = seg.NextSegment() { - added := make(memmap.MappingsOfRange) - for m := range seg.Value() { - if err := upperMappable.AddMapping(ctx, m.MappingSpace, m.AddrRange, seg.Start(), m.Writable); err != nil { - for m := range added { - upperMappable.RemoveMapping(ctx, m.MappingSpace, m.AddrRange, seg.Start(), m.Writable) - } - for mr, mappings := range allAdded { - for m := range mappings { - upperMappable.RemoveMapping(ctx, m.MappingSpace, m.AddrRange, mr.Start, m.Writable) - } - } - return err - } - added[m] = struct{}{} - } - allAdded[seg.Range()] = added - } - - // Switch to the new Mappable. We do this at the end of copy-up - // because: - // - // - We need to switch Mappables (by changing d.wrappedMappable) before - // invalidating Translations from the old Mappable (to pick up - // Translations from the new one). - // - // - We need to lock d.dataMu while changing d.wrappedMappable, but - // must invalidate Translations with d.dataMu unlocked (due to lock - // ordering). - // - // - Consequently, once we unlock d.dataMu, other threads may - // immediately observe the new (copied-up) Mappable, which we want to - // delay until copy-up is guaranteed to succeed. - d.dataMu.Lock() - lowerMappable := d.wrappedMappable - d.wrappedMappable = upperMappable - d.dataMu.Unlock() - d.lowerMappings.InvalidateAll(memmap.InvalidateOpts{}) - - // Remove mappings from the old Mappable. - for seg := d.lowerMappings.FirstSegment(); seg.Ok(); seg = seg.NextSegment() { - for m := range seg.Value() { - lowerMappable.RemoveMapping(ctx, m.MappingSpace, m.AddrRange, seg.Start(), m.Writable) - } - } - d.lowerMappings.RemoveAll() - } - atomic.StoreUint32(&d.copiedUp, 1) return nil } |