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Pass information about map writableness to filesystems.

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This is necessary to implement file seals for memfds.

PiperOrigin-RevId: 225239394
Change-Id: Ib3f1ab31385afc4b24e96cd81a05ef1bebbcbb70
This commit is contained in:
Rahat Mahmood
2018-12-12 13:09:59 -08:00
committed by Shentubot
parent a2c868a098
commit 75e39eaa74
16 changed files with 162 additions and 71 deletions
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pkg/sentry/fs/binder/binder.go
+3 -3
View File
@@ -302,7 +302,7 @@ func (bp *Proc) Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallArgum
}
// AddMapping implements memmap.Mappable.AddMapping.
func (bp *Proc) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) error {
func (bp *Proc) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, _ bool) error {
bp.mu.Lock()
defer bp.mu.Unlock()
if bp.mapped.Length() != 0 {
@@ -320,12 +320,12 @@ func (bp *Proc) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar userm
}
// RemoveMapping implements memmap.Mappable.RemoveMapping.
func (bp *Proc) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) {
func (*Proc) RemoveMapping(context.Context, memmap.MappingSpace, usermem.AddrRange, uint64, bool) {
// Nothing to do. Notably, we don't free bp.mapped to allow another mmap.
}
// CopyMapping implements memmap.Mappable.CopyMapping.
func (bp *Proc) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64) error {
func (bp *Proc) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64, _ bool) error {
// Nothing to do. Notably, this is one case where CopyMapping isn't
// equivalent to AddMapping, as AddMapping would return EBUSY.
return nil
pkg/sentry/fs/copy_up.go
+4 -4
View File
@@ -270,13 +270,13 @@ func copyUpLocked(ctx context.Context, parent *Dirent, next *Dirent) error {
for seg := next.Inode.overlay.mappings.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()); err != nil {
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())
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)
upperMappable.RemoveMapping(ctx, m.MappingSpace, m.AddrRange, mr.Start, m.Writable)
}
}
return err
@@ -301,7 +301,7 @@ func copyUpLocked(ctx context.Context, parent *Dirent, next *Dirent) error {
if lowerMappable != nil {
for seg := next.Inode.overlay.mappings.FirstSegment(); seg.Ok(); seg = seg.NextSegment() {
for m := range seg.Value() {
lowerMappable.RemoveMapping(ctx, m.MappingSpace, m.AddrRange, seg.Start())
lowerMappable.RemoveMapping(ctx, m.MappingSpace, m.AddrRange, seg.Start(), m.Writable)
}
}
}
pkg/sentry/fs/fsutil/inode_cached.go
+6 -6
View File
@@ -686,10 +686,10 @@ func (rw *inodeReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error
}
// AddMapping implements memmap.Mappable.AddMapping.
func (c *CachingInodeOperations) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) error {
func (c *CachingInodeOperations) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) error {
// Hot path. Avoid defers.
c.mapsMu.Lock()
mapped := c.mappings.AddMapping(ms, ar, offset)
mapped := c.mappings.AddMapping(ms, ar, offset, writable)
// Do this unconditionally since whether we have c.backingFile.FD() >= 0
// can change across save/restore.
for _, r := range mapped {
@@ -705,10 +705,10 @@ func (c *CachingInodeOperations) AddMapping(ctx context.Context, ms memmap.Mappi
}
// RemoveMapping implements memmap.Mappable.RemoveMapping.
func (c *CachingInodeOperations) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) {
func (c *CachingInodeOperations) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) {
// Hot path. Avoid defers.
c.mapsMu.Lock()
unmapped := c.mappings.RemoveMapping(ms, ar, offset)
unmapped := c.mappings.RemoveMapping(ms, ar, offset, writable)
for _, r := range unmapped {
c.hostFileMapper.DecRefOn(r)
}
@@ -739,8 +739,8 @@ func (c *CachingInodeOperations) RemoveMapping(ctx context.Context, ms memmap.Ma
}
// CopyMapping implements memmap.Mappable.CopyMapping.
func (c *CachingInodeOperations) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64) error {
return c.AddMapping(ctx, ms, dstAR, offset)
func (c *CachingInodeOperations) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64, writable bool) error {
return c.AddMapping(ctx, ms, dstAR, offset, writable)
}
// Translate implements memmap.Mappable.Translate.
pkg/sentry/fs/fsutil/inode_cached_test.go
+4 -4
View File
@@ -305,7 +305,7 @@ func TestRead(t *testing.T) {
// be cached.
var ms noopMappingSpace
ar := usermem.AddrRange{usermem.PageSize, 2 * usermem.PageSize}
if err := iops.AddMapping(ctx, ms, ar, usermem.PageSize); err != nil {
if err := iops.AddMapping(ctx, ms, ar, usermem.PageSize, true); err != nil {
t.Fatalf("AddMapping got %v, want nil", err)
}
mr := memmap.MappableRange{usermem.PageSize, 2 * usermem.PageSize}
@@ -334,7 +334,7 @@ func TestRead(t *testing.T) {
// Delete the memory mapping and expect it to cause the cached page to be
// uncached.
iops.RemoveMapping(ctx, ms, ar, usermem.PageSize)
iops.RemoveMapping(ctx, ms, ar, usermem.PageSize, true)
if cached := iops.cache.Span(); cached != 0 {
t.Fatalf("Span got %d, want 0", cached)
}
@@ -363,10 +363,10 @@ func TestWrite(t *testing.T) {
// Translate to force them to be cached.
var ms noopMappingSpace
ar := usermem.AddrRange{usermem.PageSize, 3 * usermem.PageSize}
if err := iops.AddMapping(ctx, ms, ar, usermem.PageSize); err != nil {
if err := iops.AddMapping(ctx, ms, ar, usermem.PageSize, true); err != nil {
t.Fatalf("AddMapping got %v, want nil", err)
}
defer iops.RemoveMapping(ctx, ms, ar, usermem.PageSize)
defer iops.RemoveMapping(ctx, ms, ar, usermem.PageSize, true)
mr := memmap.MappableRange{usermem.PageSize, 3 * usermem.PageSize}
if _, err := iops.Translate(ctx, mr, mr, usermem.Read); err != nil {
t.Fatalf("Translate got %v, want nil", err)
pkg/sentry/fs/overlay.go
+9 -9
View File
@@ -259,32 +259,32 @@ func (o *overlayEntry) isMappableLocked() bool {
}
// AddMapping implements memmap.Mappable.AddMapping.
func (o *overlayEntry) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) error {
func (o *overlayEntry) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) error {
o.mapsMu.Lock()
defer o.mapsMu.Unlock()
if err := o.inodeLocked().Mappable().AddMapping(ctx, ms, ar, offset); err != nil {
if err := o.inodeLocked().Mappable().AddMapping(ctx, ms, ar, offset, writable); err != nil {
return err
}
o.mappings.AddMapping(ms, ar, offset)
o.mappings.AddMapping(ms, ar, offset, writable)
return nil
}
// RemoveMapping implements memmap.Mappable.RemoveMapping.
func (o *overlayEntry) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) {
func (o *overlayEntry) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) {
o.mapsMu.Lock()
defer o.mapsMu.Unlock()
o.inodeLocked().Mappable().RemoveMapping(ctx, ms, ar, offset)
o.mappings.RemoveMapping(ms, ar, offset)
o.inodeLocked().Mappable().RemoveMapping(ctx, ms, ar, offset, writable)
o.mappings.RemoveMapping(ms, ar, offset, writable)
}
// CopyMapping implements memmap.Mappable.CopyMapping.
func (o *overlayEntry) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64) error {
func (o *overlayEntry) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64, writable bool) error {
o.mapsMu.Lock()
defer o.mapsMu.Unlock()
if err := o.inodeLocked().Mappable().CopyMapping(ctx, ms, srcAR, dstAR, offset); err != nil {
if err := o.inodeLocked().Mappable().CopyMapping(ctx, ms, srcAR, dstAR, offset, writable); err != nil {
return err
}
o.mappings.AddMapping(ms, dstAR, offset)
o.mappings.AddMapping(ms, dstAR, offset, writable)
return nil
}
pkg/sentry/fs/tmpfs/inode_file.go
+6 -6
View File
@@ -426,23 +426,23 @@ func (rw *fileReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error)
}
// AddMapping implements memmap.Mappable.AddMapping.
func (f *fileInodeOperations) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) error {
func (f *fileInodeOperations) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) error {
f.mapsMu.Lock()
defer f.mapsMu.Unlock()
f.mappings.AddMapping(ms, ar, offset)
f.mappings.AddMapping(ms, ar, offset, writable)
return nil
}
// RemoveMapping implements memmap.Mappable.RemoveMapping.
func (f *fileInodeOperations) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) {
func (f *fileInodeOperations) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) {
f.mapsMu.Lock()
defer f.mapsMu.Unlock()
f.mappings.RemoveMapping(ms, ar, offset)
f.mappings.RemoveMapping(ms, ar, offset, writable)
}
// CopyMapping implements memmap.Mappable.CopyMapping.
func (f *fileInodeOperations) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64) error {
return f.AddMapping(ctx, ms, dstAR, offset)
func (f *fileInodeOperations) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64, writable bool) error {
return f.AddMapping(ctx, ms, dstAR, offset, writable)
}
// Translate implements memmap.Mappable.Translate.
pkg/sentry/kernel/shm/shm.go
+3 -3
View File
@@ -375,7 +375,7 @@ func (s *Shm) Msync(context.Context, memmap.MappableRange) error {
}
// AddMapping implements memmap.Mappable.AddMapping.
func (s *Shm) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) error {
func (s *Shm) AddMapping(ctx context.Context, _ memmap.MappingSpace, _ usermem.AddrRange, _ uint64, _ bool) error {
s.mu.Lock()
defer s.mu.Unlock()
s.attachTime = ktime.NowFromContext(ctx)
@@ -390,7 +390,7 @@ func (s *Shm) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem
}
// RemoveMapping implements memmap.Mappable.RemoveMapping.
func (s *Shm) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) {
func (s *Shm) RemoveMapping(ctx context.Context, _ memmap.MappingSpace, _ usermem.AddrRange, _ uint64, _ bool) {
s.mu.Lock()
defer s.mu.Unlock()
// TODO: RemoveMapping may be called during task exit, when ctx
@@ -411,7 +411,7 @@ func (s *Shm) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar user
}
// CopyMapping implements memmap.Mappable.CopyMapping.
func (s *Shm) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64) error {
func (*Shm) CopyMapping(context.Context, memmap.MappingSpace, usermem.AddrRange, usermem.AddrRange, uint64, bool) error {
return nil
}
pkg/sentry/memmap/mapping_set.go
+12 -6
View File
@@ -40,6 +40,7 @@ type MappingsOfRange map[MappingOfRange]struct{}
type MappingOfRange struct {
MappingSpace MappingSpace
AddrRange usermem.AddrRange
Writable bool
}
func (r MappingOfRange) invalidate(opts InvalidateOpts) {
@@ -92,6 +93,7 @@ func (mappingSetFunctions) Merge(r1 MappableRange, val1 MappingsOfRange, r2 Mapp
Start: k1.AddrRange.End,
End: k1.AddrRange.End + usermem.Addr(r2.Length()),
},
Writable: k1.Writable,
}
if _, ok := val2[k2]; !ok {
return nil, false
@@ -104,6 +106,7 @@ func (mappingSetFunctions) Merge(r1 MappableRange, val1 MappingsOfRange, r2 Mapp
Start: k1.AddrRange.Start,
End: k2.AddrRange.End,
},
Writable: k1.Writable,
}] = struct{}{}
}
@@ -129,6 +132,7 @@ func (mappingSetFunctions) Split(r MappableRange, val MappingsOfRange, split uin
Start: k.AddrRange.Start,
End: k.AddrRange.Start + offset,
},
Writable: k.Writable,
}
m1[k1] = struct{}{}
@@ -138,6 +142,7 @@ func (mappingSetFunctions) Split(r MappableRange, val MappingsOfRange, split uin
Start: k.AddrRange.Start + offset,
End: k.AddrRange.End,
},
Writable: k.Writable,
}
m2[k2] = struct{}{}
}
@@ -152,7 +157,7 @@ func (mappingSetFunctions) Split(r MappableRange, val MappingsOfRange, split uin
// indicating that ms maps addresses [0x4000, 0x6000) to MappableRange [0x0,
// 0x2000). Then for subsetRange = [0x1000, 0x2000), subsetMapping returns a
// MappingOfRange for which AddrRange = [0x5000, 0x6000).
func subsetMapping(wholeRange, subsetRange MappableRange, ms MappingSpace, addr usermem.Addr) MappingOfRange {
func subsetMapping(wholeRange, subsetRange MappableRange, ms MappingSpace, addr usermem.Addr, writable bool) MappingOfRange {
if !wholeRange.IsSupersetOf(subsetRange) {
panic(fmt.Sprintf("%v is not a superset of %v", wholeRange, subsetRange))
}
@@ -165,6 +170,7 @@ func subsetMapping(wholeRange, subsetRange MappableRange, ms MappingSpace, addr
Start: start,
End: start + usermem.Addr(subsetRange.Length()),
},
Writable: writable,
}
}
@@ -172,7 +178,7 @@ func subsetMapping(wholeRange, subsetRange MappableRange, ms MappingSpace, addr
// previously had no mappings.
//
// Preconditions: As for Mappable.AddMapping.
func (s *MappingSet) AddMapping(ms MappingSpace, ar usermem.AddrRange, offset uint64) []MappableRange {
func (s *MappingSet) AddMapping(ms MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) []MappableRange {
mr := MappableRange{offset, offset + uint64(ar.Length())}
var mapped []MappableRange
seg, gap := s.Find(mr.Start)
@@ -180,7 +186,7 @@ func (s *MappingSet) AddMapping(ms MappingSpace, ar usermem.AddrRange, offset ui
switch {
case seg.Ok() && seg.Start() < mr.End:
seg = s.Isolate(seg, mr)
seg.Value()[subsetMapping(mr, seg.Range(), ms, ar.Start)] = struct{}{}
seg.Value()[subsetMapping(mr, seg.Range(), ms, ar.Start, writable)] = struct{}{}
seg, gap = seg.NextNonEmpty()
case gap.Ok() && gap.Start() < mr.End:
@@ -199,7 +205,7 @@ func (s *MappingSet) AddMapping(ms MappingSpace, ar usermem.AddrRange, offset ui
// MappableRanges that now have no mappings.
//
// Preconditions: As for Mappable.RemoveMapping.
func (s *MappingSet) RemoveMapping(ms MappingSpace, ar usermem.AddrRange, offset uint64) []MappableRange {
func (s *MappingSet) RemoveMapping(ms MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) []MappableRange {
mr := MappableRange{offset, offset + uint64(ar.Length())}
var unmapped []MappableRange
@@ -213,7 +219,7 @@ func (s *MappingSet) RemoveMapping(ms MappingSpace, ar usermem.AddrRange, offset
// Remove this part of the mapping.
mappings := seg.Value()
delete(mappings, subsetMapping(mr, seg.Range(), ms, ar.Start))
delete(mappings, subsetMapping(mr, seg.Range(), ms, ar.Start, writable))
if len(mappings) == 0 {
unmapped = append(unmapped, seg.Range())
@@ -231,7 +237,7 @@ func (s *MappingSet) Invalidate(mr MappableRange, opts InvalidateOpts) {
for seg := s.LowerBoundSegment(mr.Start); seg.Ok() && seg.Start() < mr.End; seg = seg.NextSegment() {
segMR := seg.Range()
for m := range seg.Value() {
region := subsetMapping(segMR, segMR.Intersect(mr), m.MappingSpace, m.AddrRange.Start)
region := subsetMapping(segMR, segMR.Intersect(mr), m.MappingSpace, m.AddrRange.Start, m.Writable)
region.invalidate(opts)
}
}
pkg/sentry/memmap/mapping_set_test.go
+88 -14
View File
@@ -40,7 +40,7 @@ func TestAddRemoveMapping(t *testing.T) {
set := MappingSet{}
ms := &testMappingSpace{}
mapped := set.AddMapping(ms, usermem.AddrRange{0x10000, 0x12000}, 0x1000)
mapped := set.AddMapping(ms, usermem.AddrRange{0x10000, 0x12000}, 0x1000, true)
if got, want := mapped, []MappableRange{{0x1000, 0x3000}}; !reflect.DeepEqual(got, want) {
t.Errorf("AddMapping: got %+v, wanted %+v", got, want)
}
@@ -49,7 +49,7 @@ func TestAddRemoveMapping(t *testing.T) {
// [0x10000, 0x12000) => [0x1000, 0x3000)
t.Log(&set)
mapped = set.AddMapping(ms, usermem.AddrRange{0x20000, 0x21000}, 0x2000)
mapped = set.AddMapping(ms, usermem.AddrRange{0x20000, 0x21000}, 0x2000, true)
if len(mapped) != 0 {
t.Errorf("AddMapping: got %+v, wanted []", mapped)
}
@@ -59,7 +59,7 @@ func TestAddRemoveMapping(t *testing.T) {
// [0x11000, 0x12000) and [0x20000, 0x21000) => [0x2000, 0x3000)
t.Log(&set)
mapped = set.AddMapping(ms, usermem.AddrRange{0x30000, 0x31000}, 0x4000)
mapped = set.AddMapping(ms, usermem.AddrRange{0x30000, 0x31000}, 0x4000, true)
if got, want := mapped, []MappableRange{{0x4000, 0x5000}}; !reflect.DeepEqual(got, want) {
t.Errorf("AddMapping: got %+v, wanted %+v", got, want)
}
@@ -70,7 +70,7 @@ func TestAddRemoveMapping(t *testing.T) {
// [0x30000, 0x31000) => [0x4000, 0x5000)
t.Log(&set)
mapped = set.AddMapping(ms, usermem.AddrRange{0x12000, 0x15000}, 0x3000)
mapped = set.AddMapping(ms, usermem.AddrRange{0x12000, 0x15000}, 0x3000, true)
if got, want := mapped, []MappableRange{{0x3000, 0x4000}, {0x5000, 0x6000}}; !reflect.DeepEqual(got, want) {
t.Errorf("AddMapping: got %+v, wanted %+v", got, want)
}
@@ -83,7 +83,7 @@ func TestAddRemoveMapping(t *testing.T) {
// [0x14000, 0x15000) => [0x5000, 0x6000)
t.Log(&set)
unmapped := set.RemoveMapping(ms, usermem.AddrRange{0x10000, 0x11000}, 0x1000)
unmapped := set.RemoveMapping(ms, usermem.AddrRange{0x10000, 0x11000}, 0x1000, true)
if got, want := unmapped, []MappableRange{{0x1000, 0x2000}}; !reflect.DeepEqual(got, want) {
t.Errorf("RemoveMapping: got %+v, wanted %+v", got, want)
}
@@ -95,7 +95,7 @@ func TestAddRemoveMapping(t *testing.T) {
// [0x14000, 0x15000) => [0x5000, 0x6000)
t.Log(&set)
unmapped = set.RemoveMapping(ms, usermem.AddrRange{0x20000, 0x21000}, 0x2000)
unmapped = set.RemoveMapping(ms, usermem.AddrRange{0x20000, 0x21000}, 0x2000, true)
if len(unmapped) != 0 {
t.Errorf("RemoveMapping: got %+v, wanted []", unmapped)
}
@@ -106,7 +106,7 @@ func TestAddRemoveMapping(t *testing.T) {
// [0x14000, 0x15000) => [0x5000, 0x6000)
t.Log(&set)
unmapped = set.RemoveMapping(ms, usermem.AddrRange{0x11000, 0x15000}, 0x2000)
unmapped = set.RemoveMapping(ms, usermem.AddrRange{0x11000, 0x15000}, 0x2000, true)
if got, want := unmapped, []MappableRange{{0x2000, 0x4000}, {0x5000, 0x6000}}; !reflect.DeepEqual(got, want) {
t.Errorf("RemoveMapping: got %+v, wanted %+v", got, want)
}
@@ -115,7 +115,7 @@ func TestAddRemoveMapping(t *testing.T) {
// [0x30000, 0x31000) => [0x4000, 0x5000)
t.Log(&set)
unmapped = set.RemoveMapping(ms, usermem.AddrRange{0x30000, 0x31000}, 0x4000)
unmapped = set.RemoveMapping(ms, usermem.AddrRange{0x30000, 0x31000}, 0x4000, true)
if got, want := unmapped, []MappableRange{{0x4000, 0x5000}}; !reflect.DeepEqual(got, want) {
t.Errorf("RemoveMapping: got %+v, wanted %+v", got, want)
}
@@ -125,7 +125,7 @@ func TestInvalidateWholeMapping(t *testing.T) {
set := MappingSet{}
ms := &testMappingSpace{}
set.AddMapping(ms, usermem.AddrRange{0x10000, 0x11000}, 0)
set.AddMapping(ms, usermem.AddrRange{0x10000, 0x11000}, 0, true)
// Mappings:
// [0x10000, 0x11000) => [0, 0x1000)
t.Log(&set)
@@ -139,7 +139,7 @@ func TestInvalidatePartialMapping(t *testing.T) {
set := MappingSet{}
ms := &testMappingSpace{}
set.AddMapping(ms, usermem.AddrRange{0x10000, 0x13000}, 0)
set.AddMapping(ms, usermem.AddrRange{0x10000, 0x13000}, 0, true)
// Mappings:
// [0x10000, 0x13000) => [0, 0x3000)
t.Log(&set)
@@ -153,8 +153,8 @@ func TestInvalidateMultipleMappings(t *testing.T) {
set := MappingSet{}
ms := &testMappingSpace{}
set.AddMapping(ms, usermem.AddrRange{0x10000, 0x11000}, 0)
set.AddMapping(ms, usermem.AddrRange{0x20000, 0x21000}, 0x2000)
set.AddMapping(ms, usermem.AddrRange{0x10000, 0x11000}, 0, true)
set.AddMapping(ms, usermem.AddrRange{0x20000, 0x21000}, 0x2000, true)
// Mappings:
// [0x10000, 0x11000) => [0, 0x1000)
// [0x12000, 0x13000) => [0x2000, 0x3000)
@@ -170,8 +170,8 @@ func TestInvalidateOverlappingMappings(t *testing.T) {
ms1 := &testMappingSpace{}
ms2 := &testMappingSpace{}
set.AddMapping(ms1, usermem.AddrRange{0x10000, 0x12000}, 0)
set.AddMapping(ms2, usermem.AddrRange{0x20000, 0x22000}, 0x1000)
set.AddMapping(ms1, usermem.AddrRange{0x10000, 0x12000}, 0, true)
set.AddMapping(ms2, usermem.AddrRange{0x20000, 0x22000}, 0x1000, true)
// Mappings:
// ms1:[0x10000, 0x12000) => [0, 0x2000)
// ms2:[0x11000, 0x13000) => [0x1000, 0x3000)
@@ -184,3 +184,77 @@ func TestInvalidateOverlappingMappings(t *testing.T) {
t.Errorf("Invalidate: ms1: got %+v, wanted %+v", got, want)
}
}
func TestMixedWritableMappings(t *testing.T) {
set := MappingSet{}
ms := &testMappingSpace{}
mapped := set.AddMapping(ms, usermem.AddrRange{0x10000, 0x12000}, 0x1000, true)
if got, want := mapped, []MappableRange{{0x1000, 0x3000}}; !reflect.DeepEqual(got, want) {
t.Errorf("AddMapping: got %+v, wanted %+v", got, want)
}
// Mappings:
// [0x10000, 0x12000) writable => [0x1000, 0x3000)
t.Log(&set)
mapped = set.AddMapping(ms, usermem.AddrRange{0x20000, 0x22000}, 0x2000, false)
if got, want := mapped, []MappableRange{{0x3000, 0x4000}}; !reflect.DeepEqual(got, want) {
t.Errorf("AddMapping: got %+v, wanted %+v", got, want)
}
// Mappings:
// [0x10000, 0x11000) writable => [0x1000, 0x2000)
// [0x11000, 0x12000) writable and [0x20000, 0x21000) readonly => [0x2000, 0x3000)
// [0x21000, 0x22000) readonly => [0x3000, 0x4000)
t.Log(&set)
// Unmap should fail because we specified the readonly map address range, but
// asked to unmap a writable segment.
unmapped := set.RemoveMapping(ms, usermem.AddrRange{0x20000, 0x21000}, 0x2000, true)
if len(unmapped) != 0 {
t.Errorf("RemoveMapping: got %+v, wanted []", unmapped)
}
// Readonly mapping removed, but writable mapping still exists in the range,
// so no mappable range fully unmapped.
unmapped = set.RemoveMapping(ms, usermem.AddrRange{0x20000, 0x21000}, 0x2000, false)
if len(unmapped) != 0 {
t.Errorf("RemoveMapping: got %+v, wanted []", unmapped)
}
// Mappings:
// [0x10000, 0x12000) writable => [0x1000, 0x3000)
// [0x21000, 0x22000) readonly => [0x3000, 0x4000)
t.Log(&set)
unmapped = set.RemoveMapping(ms, usermem.AddrRange{0x11000, 0x12000}, 0x2000, true)
if got, want := unmapped, []MappableRange{{0x2000, 0x3000}}; !reflect.DeepEqual(got, want) {
t.Errorf("RemoveMapping: got %+v, wanted %+v", got, want)
}
// Mappings:
// [0x10000, 0x12000) writable => [0x1000, 0x3000)
// [0x21000, 0x22000) readonly => [0x3000, 0x4000)
t.Log(&set)
// Unmap should fail since writable bit doesn't match.
unmapped = set.RemoveMapping(ms, usermem.AddrRange{0x10000, 0x12000}, 0x1000, false)
if len(unmapped) != 0 {
t.Errorf("RemoveMapping: got %+v, wanted []", unmapped)
}
unmapped = set.RemoveMapping(ms, usermem.AddrRange{0x10000, 0x12000}, 0x1000, true)
if got, want := unmapped, []MappableRange{{0x1000, 0x2000}}; !reflect.DeepEqual(got, want) {
t.Errorf("RemoveMapping: got %+v, wanted %+v", got, want)
}
// Mappings:
// [0x21000, 0x22000) readonly => [0x3000, 0x4000)
t.Log(&set)
unmapped = set.RemoveMapping(ms, usermem.AddrRange{0x21000, 0x22000}, 0x3000, false)
if got, want := unmapped, []MappableRange{{0x3000, 0x4000}}; !reflect.DeepEqual(got, want) {
t.Errorf("RemoveMapping: got %+v, wanted %+v", got, want)
}
}
pkg/sentry/memmap/memmap.go
+12 -5
View File
@@ -36,16 +36,22 @@ type Mappable interface {
// AddMapping notifies the Mappable of a mapping from addresses ar in ms to
// offsets [offset, offset+ar.Length()) in this Mappable.
//
// The writable flag indicates whether the backing data for a Mappable can
// be modified through the mapping. Effectively, this means a shared mapping
// where Translate may be called with at.Write == true. This is a property
// established at mapping creation and must remain constant throughout the
// lifetime of the mapping.
//
// Preconditions: offset+ar.Length() does not overflow.
AddMapping(ctx context.Context, ms MappingSpace, ar usermem.AddrRange, offset uint64) error
AddMapping(ctx context.Context, ms MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) error
// RemoveMapping notifies the Mappable of the removal of a mapping from
// addresses ar in ms to offsets [offset, offset+ar.Length()) in this
// Mappable.
//
// Preconditions: offset+ar.Length() does not overflow. The removed mapping
// must exist.
RemoveMapping(ctx context.Context, ms MappingSpace, ar usermem.AddrRange, offset uint64)
// must exist. writable must match the corresponding call to AddMapping.
RemoveMapping(ctx context.Context, ms MappingSpace, ar usermem.AddrRange, offset uint64, writable bool)
// CopyMapping notifies the Mappable of an attempt to copy a mapping in ms
// from srcAR to dstAR. For most Mappables, this is equivalent to
@@ -56,8 +62,9 @@ type Mappable interface {
// MappingSpace; it is analogous to Linux's vm_operations_struct::mremap.
//
// Preconditions: offset+srcAR.Length() and offset+dstAR.Length() do not
// overflow. The mapping at srcAR must exist.
CopyMapping(ctx context.Context, ms MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64) error
// overflow. The mapping at srcAR must exist. writable must match the
// corresponding call to AddMapping.
CopyMapping(ctx context.Context, ms MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64, writable bool) error
// Translate returns the Mappable's current mappings for at least the range
// of offsets specified by required, and at most the range of offsets
pkg/sentry/mm/aio_context.go
+3 -3
View File
@@ -244,7 +244,7 @@ func (m *aioMappable) Msync(ctx context.Context, mr memmap.MappableRange) error
}
// AddMapping implements memmap.Mappable.AddMapping.
func (m *aioMappable) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) error {
func (m *aioMappable) AddMapping(_ context.Context, _ memmap.MappingSpace, ar usermem.AddrRange, offset uint64, _ bool) error {
// Don't allow mappings to be expanded (in Linux, fs/aio.c:aio_ring_mmap()
// sets VM_DONTEXPAND).
if offset != 0 || uint64(ar.Length()) != aioRingBufferSize {
@@ -254,11 +254,11 @@ func (m *aioMappable) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar
}
// RemoveMapping implements memmap.Mappable.RemoveMapping.
func (m *aioMappable) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) {
func (m *aioMappable) RemoveMapping(context.Context, memmap.MappingSpace, usermem.AddrRange, uint64, bool) {
}
// CopyMapping implements memmap.Mappable.CopyMapping.
func (m *aioMappable) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64) error {
func (m *aioMappable) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64, _ bool) error {
// Don't allow mappings to be expanded (in Linux, fs/aio.c:aio_ring_mmap()
// sets VM_DONTEXPAND).
if offset != 0 || uint64(dstAR.Length()) != aioRingBufferSize {
pkg/sentry/mm/lifecycle.go
+1 -1
View File
@@ -81,7 +81,7 @@ func (mm *MemoryManager) Fork(ctx context.Context) (*MemoryManager, error) {
vmaAR := srcvseg.Range()
// Inform the Mappable, if any, of the new mapping.
if vma.mappable != nil {
if err := vma.mappable.AddMapping(ctx, mm2, vmaAR, vma.off); err != nil {
if err := vma.mappable.AddMapping(ctx, mm2, vmaAR, vma.off, vma.isMappableAsWritable()); err != nil {
mm2.removeVMAsLocked(ctx, mm2.applicationAddrRange())
return nil, err
}
pkg/sentry/mm/mm.go
+4
View File
@@ -349,6 +349,10 @@ func (v *vma) loadRealPerms(b int) {
}
}
func (v *vma) isMappableAsWritable() bool {
return !v.private && v.maxPerms.Write
}
// pma represents a platform mapping area.
//
// +stateify savable
pkg/sentry/mm/special_mappable.go
+3 -3
View File
@@ -76,16 +76,16 @@ func (m *SpecialMappable) Msync(ctx context.Context, mr memmap.MappableRange) er
}
// AddMapping implements memmap.Mappable.AddMapping.
func (m *SpecialMappable) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) error {
func (*SpecialMappable) AddMapping(context.Context, memmap.MappingSpace, usermem.AddrRange, uint64, bool) error {
return nil
}
// RemoveMapping implements memmap.Mappable.RemoveMapping.
func (m *SpecialMappable) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64) {
func (*SpecialMappable) RemoveMapping(context.Context, memmap.MappingSpace, usermem.AddrRange, uint64, bool) {
}
// CopyMapping implements memmap.Mappable.CopyMapping.
func (m *SpecialMappable) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64) error {
func (*SpecialMappable) CopyMapping(context.Context, memmap.MappingSpace, usermem.AddrRange, usermem.AddrRange, uint64, bool) error {
return nil
}
pkg/sentry/mm/syscalls.go
+2 -2
View File
@@ -443,7 +443,7 @@ func (mm *MemoryManager) MRemap(ctx context.Context, oldAddr usermem.Addr, oldSi
return 0, syserror.EINVAL
}
// Inform the Mappable, if any, of the new mapping.
if err := vma.mappable.CopyMapping(ctx, mm, oldAR, newAR, vseg.mappableOffsetAt(oldAR.Start)); err != nil {
if err := vma.mappable.CopyMapping(ctx, mm, oldAR, newAR, vseg.mappableOffsetAt(oldAR.Start), vma.isMappableAsWritable()); err != nil {
return 0, err
}
}
@@ -498,7 +498,7 @@ func (mm *MemoryManager) MRemap(ctx context.Context, oldAddr usermem.Addr, oldSi
// Now that pmas have been moved to newAR, we can notify vma.mappable that
// oldAR is no longer mapped.
if vma.mappable != nil {
vma.mappable.RemoveMapping(ctx, mm, oldAR, vma.off)
vma.mappable.RemoveMapping(ctx, mm, oldAR, vma.off, vma.isMappableAsWritable())
}
return newAR.Start, nil
pkg/sentry/mm/vma.go
+2 -2
View File
@@ -65,7 +65,7 @@ func (mm *MemoryManager) createVMALocked(ctx context.Context, opts memmap.MMapOp
// Inform the Mappable, if any, of the new mapping.
if opts.Mappable != nil {
if err := opts.Mappable.AddMapping(ctx, mm, ar, opts.Offset); err != nil {
if err := opts.Mappable.AddMapping(ctx, mm, ar, opts.Offset, !opts.Private && opts.MaxPerms.Write); err != nil {
return vmaIterator{}, usermem.AddrRange{}, err
}
}
@@ -332,7 +332,7 @@ func (mm *MemoryManager) removeVMAsLocked(ctx context.Context, ar usermem.AddrRa
vmaAR := vseg.Range()
vma := vseg.ValuePtr()
if vma.mappable != nil {
vma.mappable.RemoveMapping(ctx, mm, vmaAR, vma.off)
vma.mappable.RemoveMapping(ctx, mm, vmaAR, vma.off, vma.isMappableAsWritable())
}
if vma.id != nil {
vma.id.DecRef()