diff options
60 files changed, 523 insertions, 446 deletions
diff --git a/pkg/sentry/context/contexttest/BUILD b/pkg/sentry/context/contexttest/BUILD index bed156b70..ce4f1e42c 100644 --- a/pkg/sentry/context/contexttest/BUILD +++ b/pkg/sentry/context/contexttest/BUILD @@ -13,6 +13,8 @@ go_library( "//pkg/sentry/kernel/auth", "//pkg/sentry/kernel/time", "//pkg/sentry/limits", + "//pkg/sentry/memutil", + "//pkg/sentry/pgalloc", "//pkg/sentry/platform", "//pkg/sentry/platform/ptrace", "//pkg/sentry/uniqueid", diff --git a/pkg/sentry/context/contexttest/contexttest.go b/pkg/sentry/context/contexttest/contexttest.go index d5fd9f165..a29087775 100644 --- a/pkg/sentry/context/contexttest/contexttest.go +++ b/pkg/sentry/context/contexttest/contexttest.go @@ -16,6 +16,7 @@ package contexttest import ( + "os" "sync/atomic" "testing" "time" @@ -24,6 +25,8 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/auth" ktime "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/time" "gvisor.googlesource.com/gvisor/pkg/sentry/limits" + "gvisor.googlesource.com/gvisor/pkg/sentry/memutil" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace" "gvisor.googlesource.com/gvisor/pkg/sentry/uniqueid" @@ -35,6 +38,17 @@ import ( // Note that some filesystems may require a minimal kernel for testing, which // this test context does not provide. For such tests, see kernel/contexttest. func Context(tb testing.TB) context.Context { + const memfileName = "contexttest-memory" + memfd, err := memutil.CreateMemFD(memfileName, 0) + if err != nil { + tb.Fatalf("error creating application memory file: %v", err) + } + memfile := os.NewFile(uintptr(memfd), memfileName) + mf, err := pgalloc.NewMemoryFile(memfile) + if err != nil { + memfile.Close() + tb.Fatalf("error creating pgalloc.MemoryFile: %v", err) + } p, err := ptrace.New() if err != nil { tb.Fatal(err) @@ -43,6 +57,7 @@ func Context(tb testing.TB) context.Context { return &TestContext{ Context: context.Background(), l: limits.NewLimitSet(), + mf: mf, platform: p, otherValues: make(map[interface{}]interface{}), } @@ -53,6 +68,7 @@ func Context(tb testing.TB) context.Context { type TestContext struct { context.Context l *limits.LimitSet + mf *pgalloc.MemoryFile platform platform.Platform otherValues map[interface{}]interface{} } @@ -94,6 +110,10 @@ func (t *TestContext) Value(key interface{}) interface{} { switch key { case limits.CtxLimits: return t.l + case pgalloc.CtxMemoryFile: + return t.mf + case pgalloc.CtxMemoryFileProvider: + return t case platform.CtxPlatform: return t.platform case uniqueid.CtxGlobalUniqueID: @@ -112,6 +132,11 @@ func (t *TestContext) Value(key interface{}) interface{} { } } +// MemoryFile implements pgalloc.MemoryFileProvider.MemoryFile. +func (t *TestContext) MemoryFile() *pgalloc.MemoryFile { + return t.mf +} + // RootContext returns a Context that may be used in tests that need root // credentials. Uses ptrace as the platform.Platform. func RootContext(tb testing.TB) context.Context { diff --git a/pkg/sentry/fs/ashmem/BUILD b/pkg/sentry/fs/ashmem/BUILD index dcf620dca..ef1c31a3e 100644 --- a/pkg/sentry/fs/ashmem/BUILD +++ b/pkg/sentry/fs/ashmem/BUILD @@ -23,7 +23,6 @@ go_library( "//pkg/sentry/fs/tmpfs", "//pkg/sentry/kernel/time", "//pkg/sentry/memmap", - "//pkg/sentry/platform", "//pkg/sentry/usage", "//pkg/sentry/usermem", "//pkg/syserror", diff --git a/pkg/sentry/fs/binder/BUILD b/pkg/sentry/fs/binder/BUILD index 8a448175f..3710664d3 100644 --- a/pkg/sentry/fs/binder/BUILD +++ b/pkg/sentry/fs/binder/BUILD @@ -17,6 +17,7 @@ go_library( "//pkg/sentry/fs/fsutil", "//pkg/sentry/kernel", "//pkg/sentry/memmap", + "//pkg/sentry/pgalloc", "//pkg/sentry/platform", "//pkg/sentry/usage", "//pkg/sentry/usermem", diff --git a/pkg/sentry/fs/binder/binder.go b/pkg/sentry/fs/binder/binder.go index 19cd55e65..16fb4806f 100644 --- a/pkg/sentry/fs/binder/binder.go +++ b/pkg/sentry/fs/binder/binder.go @@ -25,6 +25,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil" "gvisor.googlesource.com/gvisor/pkg/sentry/kernel" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/usage" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" @@ -74,9 +75,9 @@ func NewDevice(ctx context.Context, owner fs.FileOwner, fp fs.FilePermissions) * // ioctl. func (bd *Device) GetFile(ctx context.Context, d *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { return fs.NewFile(ctx, d, flags, &Proc{ - bd: bd, - task: kernel.TaskFromContext(ctx), - platform: platform.FromContext(ctx), + bd: bd, + task: kernel.TaskFromContext(ctx), + mfp: pgalloc.MemoryFileProviderFromContext(ctx), }), nil } @@ -88,14 +89,14 @@ type Proc struct { fsutil.FileNoFsync `state:"nosave"` fsutil.FileNotDirReaddir `state:"nosave"` - bd *Device - task *kernel.Task - platform platform.Platform + bd *Device + task *kernel.Task + mfp pgalloc.MemoryFileProvider // mu protects fr. mu sync.Mutex `state:"nosave"` - // mapped is memory allocated from platform.Memory() by AddMapping. + // mapped is memory allocated from mfp.MemoryFile() by AddMapping. mapped platform.FileRange } @@ -104,7 +105,7 @@ func (bp *Proc) Release() { bp.mu.Lock() defer bp.mu.Unlock() if bp.mapped.Length() != 0 { - bp.platform.Memory().DecRef(bp.mapped) + bp.mfp.MemoryFile().DecRef(bp.mapped) } } @@ -204,7 +205,7 @@ func (bp *Proc) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar userm } // Binder only allocates and maps a single page up-front // (drivers/android/binder.c:binder_mmap() => binder_update_page_range()). - fr, err := bp.platform.Memory().Allocate(usermem.PageSize, usage.Anonymous) + fr, err := bp.mfp.MemoryFile().Allocate(usermem.PageSize, usage.Anonymous) if err != nil { return err } @@ -241,7 +242,7 @@ func (bp *Proc) Translate(ctx context.Context, required, optional memmap.Mappabl return []memmap.Translation{ { Source: memmap.MappableRange{0, usermem.PageSize}, - File: bp.platform.Memory(), + File: bp.mfp.MemoryFile(), Offset: bp.mapped.Start, }, }, err diff --git a/pkg/sentry/fs/dev/BUILD b/pkg/sentry/fs/dev/BUILD index e5b962c8c..6c4fdaba9 100644 --- a/pkg/sentry/fs/dev/BUILD +++ b/pkg/sentry/fs/dev/BUILD @@ -27,7 +27,7 @@ go_library( "//pkg/sentry/fs/tmpfs", "//pkg/sentry/memmap", "//pkg/sentry/mm", - "//pkg/sentry/platform", + "//pkg/sentry/pgalloc", "//pkg/sentry/safemem", "//pkg/sentry/usermem", "//pkg/syserror", diff --git a/pkg/sentry/fs/dev/null.go b/pkg/sentry/fs/dev/null.go index 73fd09058..83f43c203 100644 --- a/pkg/sentry/fs/dev/null.go +++ b/pkg/sentry/fs/dev/null.go @@ -21,7 +21,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" "gvisor.googlesource.com/gvisor/pkg/sentry/mm" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/waiter" ) @@ -115,7 +115,7 @@ var _ fs.FileOperations = (*zeroFileOperations)(nil) // ConfigureMMap implements fs.FileOperations.ConfigureMMap. func (*zeroFileOperations) ConfigureMMap(ctx context.Context, file *fs.File, opts *memmap.MMapOpts) error { - m, err := mm.NewSharedAnonMappable(opts.Length, platform.FromContext(ctx)) + m, err := mm.NewSharedAnonMappable(opts.Length, pgalloc.MemoryFileProviderFromContext(ctx)) if err != nil { return err } diff --git a/pkg/sentry/fs/fsutil/BUILD b/pkg/sentry/fs/fsutil/BUILD index d41fc17cc..01098675d 100644 --- a/pkg/sentry/fs/fsutil/BUILD +++ b/pkg/sentry/fs/fsutil/BUILD @@ -85,6 +85,7 @@ go_library( "//pkg/sentry/fs", "//pkg/sentry/kernel/time", "//pkg/sentry/memmap", + "//pkg/sentry/pgalloc", "//pkg/sentry/platform", "//pkg/sentry/safemem", "//pkg/sentry/socket/unix/transport", diff --git a/pkg/sentry/fs/fsutil/README.md b/pkg/sentry/fs/fsutil/README.md index 6e677890c..8be367334 100644 --- a/pkg/sentry/fs/fsutil/README.md +++ b/pkg/sentry/fs/fsutil/README.md @@ -112,11 +112,12 @@ finds the file that was mapped and its `CachingInodeOperations`. It then calls It may choose to allocate more memory (i.e. do "readahead") to minimize subsequent faults. -Memory that is allocated comes from a host tmpfs file (see `filemem.FileMem`). -The host tmpfs file memory is brought up to date with the contents of the mapped -file on its filesystem. The region of the host tmpfs file that reflects the -mapped file is then mapped into the host address space of the application so -that subsequent memory accesses do not repeatedly generate a `SIGSEGV`. +Memory that is allocated comes from a host tmpfs file (see +`pgalloc.MemoryFile`). The host tmpfs file memory is brought up to date with the +contents of the mapped file on its filesystem. The region of the host tmpfs file +that reflects the mapped file is then mapped into the host address space of the +application so that subsequent memory accesses do not repeatedly generate a +`SIGSEGV`. The range that was allocated, including any extra memory allocation to minimize faults, is marked dirty due to the write fault. This overcounts dirty memory if diff --git a/pkg/sentry/fs/fsutil/file_range_set.go b/pkg/sentry/fs/fsutil/file_range_set.go index dd7ab4b4a..32ebf64ff 100644 --- a/pkg/sentry/fs/fsutil/file_range_set.go +++ b/pkg/sentry/fs/fsutil/file_range_set.go @@ -21,6 +21,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/context" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/safemem" "gvisor.googlesource.com/gvisor/pkg/sentry/usage" @@ -77,7 +78,7 @@ func (seg FileRangeIterator) FileRangeOf(mr memmap.MappableRange) platform.FileR } // Fill attempts to ensure that all memmap.Mappable offsets in required are -// mapped to a platform.File offset, by allocating from mem with the given +// mapped to a platform.File offset, by allocating from mf with the given // memory usage kind and invoking readAt to store data into memory. (If readAt // returns a successful partial read, Fill will call it repeatedly until all // bytes have been read.) EOF is handled consistently with the requirements of @@ -90,7 +91,7 @@ func (seg FileRangeIterator) FileRangeOf(mr memmap.MappableRange) platform.FileR // // Preconditions: required.Length() > 0. optional.IsSupersetOf(required). // required and optional must be page-aligned. -func (frs *FileRangeSet) Fill(ctx context.Context, required, optional memmap.MappableRange, mem platform.Memory, kind usage.MemoryKind, readAt func(ctx context.Context, dsts safemem.BlockSeq, offset uint64) (uint64, error)) error { +func (frs *FileRangeSet) Fill(ctx context.Context, required, optional memmap.MappableRange, mf *pgalloc.MemoryFile, kind usage.MemoryKind, readAt func(ctx context.Context, dsts safemem.BlockSeq, offset uint64) (uint64, error)) error { gap := frs.LowerBoundGap(required.Start) for gap.Ok() && gap.Start() < required.End { if gap.Range().Length() == 0 { @@ -100,7 +101,7 @@ func (frs *FileRangeSet) Fill(ctx context.Context, required, optional memmap.Map gr := gap.Range().Intersect(optional) // Read data into the gap. - fr, err := platform.AllocateAndFill(mem, gr.Length(), kind, safemem.ReaderFunc(func(dsts safemem.BlockSeq) (uint64, error) { + fr, err := mf.AllocateAndFill(gr.Length(), kind, safemem.ReaderFunc(func(dsts safemem.BlockSeq) (uint64, error) { var done uint64 for !dsts.IsEmpty() { n, err := readAt(ctx, dsts, gr.Start+done) @@ -108,7 +109,7 @@ func (frs *FileRangeSet) Fill(ctx context.Context, required, optional memmap.Map dsts = dsts.DropFirst64(n) if err != nil { if err == io.EOF { - // platform.AllocateAndFill truncates down to a page + // MemoryFile.AllocateAndFill truncates down to a page // boundary, but FileRangeSet.Fill is supposed to // zero-fill to the end of the page in this case. donepgaddr, ok := usermem.Addr(done).RoundUp() @@ -143,20 +144,20 @@ func (frs *FileRangeSet) Fill(ctx context.Context, required, optional memmap.Map // corresponding platform.FileRanges. // // Preconditions: mr must be page-aligned. -func (frs *FileRangeSet) Drop(mr memmap.MappableRange, mem platform.Memory) { +func (frs *FileRangeSet) Drop(mr memmap.MappableRange, mf *pgalloc.MemoryFile) { seg := frs.LowerBoundSegment(mr.Start) for seg.Ok() && seg.Start() < mr.End { seg = frs.Isolate(seg, mr) - mem.DecRef(seg.FileRange()) + mf.DecRef(seg.FileRange()) seg = frs.Remove(seg).NextSegment() } } // DropAll removes all segments in mr, freeing the corresponding // platform.FileRanges. -func (frs *FileRangeSet) DropAll(mem platform.Memory) { +func (frs *FileRangeSet) DropAll(mf *pgalloc.MemoryFile) { for seg := frs.FirstSegment(); seg.Ok(); seg = seg.NextSegment() { - mem.DecRef(seg.FileRange()) + mf.DecRef(seg.FileRange()) } frs.RemoveAll() } @@ -164,7 +165,7 @@ func (frs *FileRangeSet) DropAll(mem platform.Memory) { // Truncate updates frs to reflect Mappable truncation to the given length: // bytes after the new EOF on the same page are zeroed, and pages after the new // EOF are freed. -func (frs *FileRangeSet) Truncate(end uint64, mem platform.Memory) { +func (frs *FileRangeSet) Truncate(end uint64, mf *pgalloc.MemoryFile) { pgendaddr, ok := usermem.Addr(end).RoundUp() if ok { pgend := uint64(pgendaddr) @@ -173,7 +174,7 @@ func (frs *FileRangeSet) Truncate(end uint64, mem platform.Memory) { frs.SplitAt(pgend) seg := frs.LowerBoundSegment(pgend) for seg.Ok() { - mem.DecRef(seg.FileRange()) + mf.DecRef(seg.FileRange()) seg = frs.Remove(seg).NextSegment() } @@ -189,7 +190,7 @@ func (frs *FileRangeSet) Truncate(end uint64, mem platform.Memory) { if seg.Ok() { fr := seg.FileRange() fr.Start += end - seg.Start() - ims, err := mem.MapInternal(fr, usermem.Write) + ims, err := mf.MapInternal(fr, usermem.Write) if err != nil { // There's no good recourse from here. This means // that we can't keep cached memory consistent with diff --git a/pkg/sentry/fs/fsutil/inode_cached.go b/pkg/sentry/fs/fsutil/inode_cached.go index ef11676b8..9bd923678 100644 --- a/pkg/sentry/fs/fsutil/inode_cached.go +++ b/pkg/sentry/fs/fsutil/inode_cached.go @@ -25,6 +25,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/time" ktime "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/time" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/safemem" "gvisor.googlesource.com/gvisor/pkg/sentry/usage" @@ -62,8 +63,8 @@ type CachingInodeOperations struct { // backingFile is a handle to a cached file object. backingFile CachedFileObject - // platform is used to allocate memory that caches backingFile's contents. - platform platform.Platform + // mfp is used to allocate memory that caches backingFile's contents. + mfp pgalloc.MemoryFileProvider // forcePageCache indicates the sentry page cache should be used regardless // of whether the platform supports host mapped I/O or not. This must not be @@ -96,7 +97,7 @@ type CachingInodeOperations struct { dataMu sync.RWMutex `state:"nosave"` // cache maps offsets into the cached file to offsets into - // platform.Memory() that store the file's data. + // mfp.MemoryFile() that store the file's data. // // cache is protected by dataMu. cache FileRangeSet @@ -148,13 +149,13 @@ type CachedFileObject interface { // NewCachingInodeOperations returns a new CachingInodeOperations backed by // a CachedFileObject and its initial unstable attributes. func NewCachingInodeOperations(ctx context.Context, backingFile CachedFileObject, uattr fs.UnstableAttr, forcePageCache bool) *CachingInodeOperations { - p := platform.FromContext(ctx) - if p == nil { - panic(fmt.Sprintf("context.Context %T lacks non-nil value for key %T", ctx, platform.CtxPlatform)) + mfp := pgalloc.MemoryFileProviderFromContext(ctx) + if mfp == nil { + panic(fmt.Sprintf("context.Context %T lacks non-nil value for key %T", ctx, pgalloc.CtxMemoryFileProvider)) } return &CachingInodeOperations{ backingFile: backingFile, - platform: p, + mfp: mfp, forcePageCache: forcePageCache, attr: uattr, hostFileMapper: NewHostFileMapper(), @@ -311,7 +312,7 @@ func (c *CachingInodeOperations) Truncate(ctx context.Context, inode *fs.Inode, // written back. c.dataMu.Lock() defer c.dataMu.Unlock() - c.cache.Truncate(uint64(size), c.platform.Memory()) + c.cache.Truncate(uint64(size), c.mfp.MemoryFile()) c.dirty.KeepClean(memmap.MappableRange{uint64(size), oldpgend}) return nil @@ -323,7 +324,7 @@ func (c *CachingInodeOperations) WriteOut(ctx context.Context, inode *fs.Inode) // Write dirty pages back. c.dataMu.Lock() - err := SyncDirtyAll(ctx, &c.cache, &c.dirty, uint64(c.attr.Size), c.platform.Memory(), c.backingFile.WriteFromBlocksAt) + err := SyncDirtyAll(ctx, &c.cache, &c.dirty, uint64(c.attr.Size), c.mfp.MemoryFile(), c.backingFile.WriteFromBlocksAt) c.dataMu.Unlock() if err != nil { c.attrMu.Unlock() @@ -527,7 +528,7 @@ func (rw *inodeReadWriter) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) { return 0, nil } - mem := rw.c.platform.Memory() + mem := rw.c.mfp.MemoryFile() var done uint64 seg, gap := rw.c.cache.Find(uint64(rw.offset)) for rw.offset < end { @@ -613,7 +614,7 @@ func (rw *inodeReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error return 0, nil } - mem := rw.c.platform.Memory() + mf := rw.c.mfp.MemoryFile() var done uint64 seg, gap := rw.c.cache.Find(uint64(rw.offset)) for rw.offset < end { @@ -622,7 +623,7 @@ func (rw *inodeReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error case seg.Ok() && seg.Start() < mr.End: // Get internal mappings from the cache. segMR := seg.Range().Intersect(mr) - ims, err := mem.MapInternal(seg.FileRangeOf(segMR), usermem.Write) + ims, err := mf.MapInternal(seg.FileRangeOf(segMR), usermem.Write) if err != nil { rw.maybeGrowFile() rw.c.dataMu.Unlock() @@ -711,13 +712,13 @@ func (c *CachingInodeOperations) RemoveMapping(ctx context.Context, ms memmap.Ma // Writeback dirty mapped memory now that there are no longer any // mappings that reference it. This is our naive memory eviction // strategy. - mem := c.platform.Memory() + mf := c.mfp.MemoryFile() c.dataMu.Lock() for _, r := range unmapped { - if err := SyncDirty(ctx, r, &c.cache, &c.dirty, uint64(c.attr.Size), c.platform.Memory(), c.backingFile.WriteFromBlocksAt); err != nil { + if err := SyncDirty(ctx, r, &c.cache, &c.dirty, uint64(c.attr.Size), mf, c.backingFile.WriteFromBlocksAt); err != nil { log.Warningf("Failed to writeback cached data %v: %v", r, err) } - c.cache.Drop(r, mem) + c.cache.Drop(r, mf) c.dirty.KeepClean(r) } c.dataMu.Unlock() @@ -760,8 +761,8 @@ func (c *CachingInodeOperations) Translate(ctx context.Context, required, option optional.End = pgend } - mem := c.platform.Memory() - cerr := c.cache.Fill(ctx, required, maxFillRange(required, optional), mem, usage.PageCache, c.backingFile.ReadToBlocksAt) + mf := c.mfp.MemoryFile() + cerr := c.cache.Fill(ctx, required, maxFillRange(required, optional), mf, usage.PageCache, c.backingFile.ReadToBlocksAt) var ts []memmap.Translation var translatedEnd uint64 @@ -769,7 +770,7 @@ func (c *CachingInodeOperations) Translate(ctx context.Context, required, option segMR := seg.Range().Intersect(optional) ts = append(ts, memmap.Translation{ Source: segMR, - File: mem, + File: mf, Offset: seg.FileRangeOf(segMR).Start, }) if at.Write { @@ -820,16 +821,17 @@ func (c *CachingInodeOperations) InvalidateUnsavable(ctx context.Context) error // Sync the cache's contents so that if we have a host fd after restore, // the remote file's contents are coherent. + mf := c.mfp.MemoryFile() c.dataMu.Lock() defer c.dataMu.Unlock() - if err := SyncDirtyAll(ctx, &c.cache, &c.dirty, uint64(c.attr.Size), c.platform.Memory(), c.backingFile.WriteFromBlocksAt); err != nil { + if err := SyncDirtyAll(ctx, &c.cache, &c.dirty, uint64(c.attr.Size), mf, c.backingFile.WriteFromBlocksAt); err != nil { return err } // Discard the cache so that it's not stored in saved state. This is safe // because per InvalidateUnsavable invariants, no new translations can have // been returned after we invalidated all existing translations above. - c.cache.DropAll(c.platform.Memory()) + c.cache.DropAll(mf) c.dirty.RemoveAll() return nil diff --git a/pkg/sentry/fs/proc/meminfo.go b/pkg/sentry/fs/proc/meminfo.go index b31258eed..620e93ce3 100644 --- a/pkg/sentry/fs/proc/meminfo.go +++ b/pkg/sentry/fs/proc/meminfo.go @@ -44,10 +44,10 @@ func (d *meminfoData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) return nil, 0 } - mem := d.k.Platform.Memory() - mem.UpdateUsage() + mf := d.k.MemoryFile() + mf.UpdateUsage() snapshot, totalUsage := usage.MemoryAccounting.Copy() - totalSize := usage.TotalMemory(mem.TotalSize(), totalUsage) + totalSize := usage.TotalMemory(mf.TotalSize(), totalUsage) anon := snapshot.Anonymous + snapshot.Tmpfs file := snapshot.PageCache + snapshot.Mapped // We don't actually have active/inactive LRUs, so just make up numbers. diff --git a/pkg/sentry/fs/tmpfs/inode_file.go b/pkg/sentry/fs/tmpfs/inode_file.go index 13d06684d..a98fbf0f1 100644 --- a/pkg/sentry/fs/tmpfs/inode_file.go +++ b/pkg/sentry/fs/tmpfs/inode_file.go @@ -52,7 +52,7 @@ type fileInodeOperations struct { fsutil.InodeSimpleExtendedAttributes - // kernel is used to allocate platform memory that stores the file's contents. + // kernel is used to allocate memory that stores the file's contents. kernel *kernel.Kernel // memUsage is the default memory usage that will be reported by this file. @@ -85,7 +85,7 @@ type fileInodeOperations struct { var _ fs.InodeOperations = (*fileInodeOperations)(nil) -// NewInMemoryFile returns a new file backed by p.Memory(). +// NewInMemoryFile returns a new file backed by Kernel.MemoryFile(). func NewInMemoryFile(ctx context.Context, usage usage.MemoryKind, uattr fs.UnstableAttr) fs.InodeOperations { return &fileInodeOperations{ attr: uattr, @@ -98,7 +98,7 @@ func NewInMemoryFile(ctx context.Context, usage usage.MemoryKind, uattr fs.Unsta func (f *fileInodeOperations) Release(context.Context) { f.dataMu.Lock() defer f.dataMu.Unlock() - f.data.DropAll(f.kernel.Platform.Memory()) + f.data.DropAll(f.kernel.MemoryFile()) } // Mappable implements fs.InodeOperations.Mappable. @@ -202,7 +202,7 @@ func (f *fileInodeOperations) Truncate(ctx context.Context, _ *fs.Inode, size in // and can remove them. f.dataMu.Lock() defer f.dataMu.Unlock() - f.data.Truncate(uint64(size), f.kernel.Platform.Memory()) + f.data.Truncate(uint64(size), f.kernel.MemoryFile()) return nil } @@ -312,7 +312,7 @@ func (rw *fileReadWriter) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) { return 0, nil } - mem := rw.f.kernel.Platform.Memory() + mf := rw.f.kernel.MemoryFile() var done uint64 seg, gap := rw.f.data.Find(uint64(rw.offset)) for rw.offset < end { @@ -320,7 +320,7 @@ func (rw *fileReadWriter) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) { switch { case seg.Ok(): // Get internal mappings. - ims, err := mem.MapInternal(seg.FileRangeOf(seg.Range().Intersect(mr)), usermem.Read) + ims, err := mf.MapInternal(seg.FileRangeOf(seg.Range().Intersect(mr)), usermem.Read) if err != nil { return done, err } @@ -378,7 +378,7 @@ func (rw *fileReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error) } }() - mem := rw.f.kernel.Platform.Memory() + mf := rw.f.kernel.MemoryFile() // Page-aligned mr for when we need to allocate memory. RoundUp can't // overflow since end is an int64. pgstartaddr := usermem.Addr(rw.offset).RoundDown() @@ -392,7 +392,7 @@ func (rw *fileReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error) switch { case seg.Ok(): // Get internal mappings. - ims, err := mem.MapInternal(seg.FileRangeOf(seg.Range().Intersect(mr)), usermem.Write) + ims, err := mf.MapInternal(seg.FileRangeOf(seg.Range().Intersect(mr)), usermem.Write) if err != nil { return done, err } @@ -412,7 +412,7 @@ func (rw *fileReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error) case gap.Ok(): // Allocate memory for the write. gapMR := gap.Range().Intersect(pgMR) - fr, err := mem.Allocate(gapMR.Length(), rw.f.memUsage) + fr, err := mf.Allocate(gapMR.Length(), rw.f.memUsage) if err != nil { return done, err } @@ -467,8 +467,8 @@ func (f *fileInodeOperations) Translate(ctx context.Context, required, optional optional.End = pgend } - mem := f.kernel.Platform.Memory() - cerr := f.data.Fill(ctx, required, optional, mem, f.memUsage, func(_ context.Context, dsts safemem.BlockSeq, _ uint64) (uint64, error) { + mf := f.kernel.MemoryFile() + cerr := f.data.Fill(ctx, required, optional, mf, f.memUsage, func(_ context.Context, dsts safemem.BlockSeq, _ uint64) (uint64, error) { // Newly-allocated pages are zeroed, so we don't need to do anything. return dsts.NumBytes(), nil }) @@ -479,7 +479,7 @@ func (f *fileInodeOperations) Translate(ctx context.Context, required, optional segMR := seg.Range().Intersect(optional) ts = append(ts, memmap.Translation{ Source: segMR, - File: mem, + File: mf, Offset: seg.FileRangeOf(segMR).Start, }) translatedEnd = segMR.End diff --git a/pkg/sentry/fs/tmpfs/tmpfs.go b/pkg/sentry/fs/tmpfs/tmpfs.go index 4b1762ce4..1a9d12c0b 100644 --- a/pkg/sentry/fs/tmpfs/tmpfs.go +++ b/pkg/sentry/fs/tmpfs/tmpfs.go @@ -74,7 +74,7 @@ type Dir struct { // InodeOperation methods to it. ramfsDir *ramfs.Dir - // kernel is used to allocate platform memory as storage for tmpfs Files. + // kernel is used to allocate memory as storage for tmpfs Files. kernel *kernel.Kernel } diff --git a/pkg/sentry/kernel/BUILD b/pkg/sentry/kernel/BUILD index d9bbfb556..4d34bc733 100644 --- a/pkg/sentry/kernel/BUILD +++ b/pkg/sentry/kernel/BUILD @@ -173,6 +173,7 @@ go_library( "//pkg/sentry/loader", "//pkg/sentry/memmap", "//pkg/sentry/mm", + "//pkg/sentry/pgalloc", "//pkg/sentry/platform", "//pkg/sentry/safemem", "//pkg/sentry/socket/netlink/port", @@ -212,7 +213,7 @@ go_test( "//pkg/sentry/kernel/kdefs", "//pkg/sentry/kernel/sched", "//pkg/sentry/limits", - "//pkg/sentry/platform", + "//pkg/sentry/pgalloc", "//pkg/sentry/time", "//pkg/sentry/usage", "//pkg/sentry/usermem", diff --git a/pkg/sentry/kernel/contexttest/BUILD b/pkg/sentry/kernel/contexttest/BUILD index 5769a3b28..bfb2a0b73 100644 --- a/pkg/sentry/kernel/contexttest/BUILD +++ b/pkg/sentry/kernel/contexttest/BUILD @@ -12,6 +12,7 @@ go_library( "//pkg/sentry/context", "//pkg/sentry/context/contexttest", "//pkg/sentry/kernel", + "//pkg/sentry/pgalloc", "//pkg/sentry/platform", ], ) diff --git a/pkg/sentry/kernel/contexttest/contexttest.go b/pkg/sentry/kernel/contexttest/contexttest.go index 9eb18e7e8..eb56a6a07 100644 --- a/pkg/sentry/kernel/contexttest/contexttest.go +++ b/pkg/sentry/kernel/contexttest/contexttest.go @@ -22,6 +22,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/context" "gvisor.googlesource.com/gvisor/pkg/sentry/context/contexttest" "gvisor.googlesource.com/gvisor/pkg/sentry/kernel" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" ) @@ -33,6 +34,7 @@ func Context(tb testing.TB) context.Context { k := &kernel.Kernel{ Platform: platform.FromContext(ctx), } + k.SetMemoryFile(pgalloc.MemoryFileFromContext(ctx)) ctx.(*contexttest.TestContext).RegisterValue(kernel.CtxKernel, k) return ctx } diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go index c6afae2e6..3533fd8f7 100644 --- a/pkg/sentry/kernel/kernel.go +++ b/pkg/sentry/kernel/kernel.go @@ -58,6 +58,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/limits" "gvisor.googlesource.com/gvisor/pkg/sentry/loader" "gvisor.googlesource.com/gvisor/pkg/sentry/mm" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/socket/netlink/port" sentrytime "gvisor.googlesource.com/gvisor/pkg/sentry/time" @@ -89,12 +90,14 @@ type Kernel struct { // All of the following fields are immutable unless otherwise specified. - // Platform is the platform that is used to execute tasks in the - // created Kernel. It is embedded so that Kernel can directly serve as - // Platform in mm logic and also serve as platform.MemoryProvider in - // filemem S/R logic. + // Platform is the platform that is used to execute tasks in the created + // Kernel. See comment on pgalloc.MemoryFileProvider for why Platform is + // embedded anonymously (the same issue applies). platform.Platform `state:"nosave"` + // mf provides application memory. + mf *pgalloc.MemoryFile `state:"nosave"` + // See InitKernelArgs for the meaning of these fields. featureSet *cpuid.FeatureSet timekeeper *Timekeeper @@ -229,7 +232,8 @@ type InitKernelArgs struct { // Init initialize the Kernel with no tasks. // -// Callers must manually set Kernel.Platform before caling Init. +// Callers must manually set Kernel.Platform and call Kernel.SetMemoryFile +// before calling Init. func (k *Kernel) Init(args InitKernelArgs) error { if args.FeatureSet == nil { return fmt.Errorf("FeatureSet is nil") @@ -332,15 +336,9 @@ func (k *Kernel) SaveTo(w io.Writer) error { log.Infof("Kernel save stats: %s", &stats) log.Infof("Kernel save took [%s].", time.Since(kernelStart)) - // Save the memory state. - // - // FIXME: In the future, this should not be dispatched via - // an abstract memory type. This should be dispatched to a single - // memory implementation that belongs to the kernel. (There is - // currently a single implementation anyways, it just needs to be - // "unabstracted" and reparented appropriately.) + // Save the memory file's state. memoryStart := time.Now() - if err := k.Platform.Memory().SaveTo(w); err != nil { + if err := k.mf.SaveTo(w); err != nil { return err } log.Infof("Memory save took [%s].", time.Since(memoryStart)) @@ -418,13 +416,9 @@ func (ts *TaskSet) unregisterEpollWaiters() { } // LoadFrom returns a new Kernel loaded from args. -func (k *Kernel) LoadFrom(r io.Reader, p platform.Platform, net inet.Stack) error { +func (k *Kernel) LoadFrom(r io.Reader, net inet.Stack) error { loadStart := time.Now() - if p == nil { - return fmt.Errorf("Platform is nil") - } - k.Platform = p k.networkStack = net initAppCores := k.applicationCores @@ -438,11 +432,9 @@ func (k *Kernel) LoadFrom(r io.Reader, p platform.Platform, net inet.Stack) erro log.Infof("Kernel load stats: %s", &stats) log.Infof("Kernel load took [%s].", time.Since(kernelStart)) - // Load the memory state. - // - // See the note in SaveTo. + // Load the memory file's state. memoryStart := time.Now() - if err := k.Platform.Memory().LoadFrom(r); err != nil { + if err := k.mf.LoadFrom(r); err != nil { return err } log.Infof("Memory load took [%s].", time.Since(memoryStart)) @@ -597,6 +589,10 @@ func (ctx *createProcessContext) Value(key interface{}) interface{} { return ctx.k.RealtimeClock() case limits.CtxLimits: return ctx.args.Limits + case pgalloc.CtxMemoryFile: + return ctx.k.mf + case pgalloc.CtxMemoryFileProvider: + return ctx.k case platform.CtxPlatform: return ctx.k case uniqueid.CtxGlobalUniqueID: @@ -1018,6 +1014,17 @@ func (k *Kernel) NowMonotonic() int64 { return now } +// SetMemoryFile sets Kernel.mf. SetMemoryFile must be called before Init or +// LoadFrom. +func (k *Kernel) SetMemoryFile(mf *pgalloc.MemoryFile) { + k.mf = mf +} + +// MemoryFile implements pgalloc.MemoryFileProvider.MemoryFile. +func (k *Kernel) MemoryFile() *pgalloc.MemoryFile { + return k.mf +} + // SupervisorContext returns a Context with maximum privileges in k. It should // only be used by goroutines outside the control of the emulated kernel // defined by e. @@ -1083,7 +1090,7 @@ func (k *Kernel) ListSockets(family int) []*refs.WeakRef { socks := []*refs.WeakRef{} if table, ok := k.socketTable[family]; ok { socks = make([]*refs.WeakRef, 0, len(table)) - for s, _ := range table { + for s := range table { socks = append(socks, s) } } @@ -1123,6 +1130,10 @@ func (ctx supervisorContext) Value(key interface{}) interface{} { case limits.CtxLimits: // No limits apply. return limits.NewLimitSet() + case pgalloc.CtxMemoryFile: + return ctx.k.mf + case pgalloc.CtxMemoryFileProvider: + return ctx.k case platform.CtxPlatform: return ctx.k case uniqueid.CtxGlobalUniqueID: diff --git a/pkg/sentry/kernel/memevent/memory_events.go b/pkg/sentry/kernel/memevent/memory_events.go index b6283c5d1..d09d6debf 100644 --- a/pkg/sentry/kernel/memevent/memory_events.go +++ b/pkg/sentry/kernel/memevent/memory_events.go @@ -95,7 +95,7 @@ func (m *MemoryEvents) run() { } func (m *MemoryEvents) emit() { - totalPlatform, err := m.k.Platform.Memory().TotalUsage() + totalPlatform, err := m.k.MemoryFile().TotalUsage() if err != nil { log.Warningf("Failed to fetch memory usage for memory events: %v", err) return diff --git a/pkg/sentry/kernel/shm/BUILD b/pkg/sentry/kernel/shm/BUILD index f45770eef..bc2089872 100644 --- a/pkg/sentry/kernel/shm/BUILD +++ b/pkg/sentry/kernel/shm/BUILD @@ -20,6 +20,7 @@ go_library( "//pkg/sentry/kernel/auth", "//pkg/sentry/kernel/time", "//pkg/sentry/memmap", + "//pkg/sentry/pgalloc", "//pkg/sentry/platform", "//pkg/sentry/usage", "//pkg/sentry/usermem", diff --git a/pkg/sentry/kernel/shm/shm.go b/pkg/sentry/kernel/shm/shm.go index 96414d060..4525aabf4 100644 --- a/pkg/sentry/kernel/shm/shm.go +++ b/pkg/sentry/kernel/shm/shm.go @@ -45,6 +45,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/auth" ktime "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/time" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/usage" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" @@ -199,19 +200,19 @@ func (r *Registry) FindOrCreate(ctx context.Context, pid int32, key Key, size ui // // Precondition: Caller must hold r.mu. func (r *Registry) newShm(ctx context.Context, pid int32, key Key, creator fs.FileOwner, perms fs.FilePermissions, size uint64) (*Shm, error) { - p := platform.FromContext(ctx) - if p == nil { - panic(fmt.Sprintf("context.Context %T lacks non-nil value for key %T", ctx, platform.CtxPlatform)) + mfp := pgalloc.MemoryFileProviderFromContext(ctx) + if mfp == nil { + panic(fmt.Sprintf("context.Context %T lacks non-nil value for key %T", ctx, pgalloc.CtxMemoryFileProvider)) } effectiveSize := uint64(usermem.Addr(size).MustRoundUp()) - fr, err := p.Memory().Allocate(effectiveSize, usage.Anonymous) + fr, err := mfp.MemoryFile().Allocate(effectiveSize, usage.Anonymous) if err != nil { return nil, err } shm := &Shm{ - p: p, + mfp: mfp, registry: r, creator: creator, size: size, @@ -312,7 +313,7 @@ type Shm struct { // destruction. refs.AtomicRefCount - p platform.Platform + mfp pgalloc.MemoryFileProvider // registry points to the shm registry containing this segment. Immutable. registry *Registry @@ -333,7 +334,7 @@ type Shm struct { // Invariant: effectiveSize must be a multiple of usermem.PageSize. effectiveSize uint64 - // fr is the offset into platform.Memory() that backs this contents of this + // fr is the offset into mfp.MemoryFile() that backs this contents of this // segment. Immutable. fr platform.FileRange @@ -452,7 +453,7 @@ func (s *Shm) Translate(ctx context.Context, required, optional memmap.MappableR return []memmap.Translation{ { Source: source, - File: s.p.Memory(), + File: s.mfp.MemoryFile(), Offset: s.fr.Start + source.Start, }, }, err @@ -599,7 +600,7 @@ func (s *Shm) Set(ctx context.Context, ds *linux.ShmidDS) error { } func (s *Shm) destroy() { - s.p.Memory().DecRef(s.fr) + s.mfp.MemoryFile().DecRef(s.fr) s.registry.remove(s) } diff --git a/pkg/sentry/kernel/task.go b/pkg/sentry/kernel/task.go index 702e40cce..e9f133c0b 100644 --- a/pkg/sentry/kernel/task.go +++ b/pkg/sentry/kernel/task.go @@ -29,6 +29,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/sched" ktime "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/time" "gvisor.googlesource.com/gvisor/pkg/sentry/limits" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/unimpl" "gvisor.googlesource.com/gvisor/pkg/sentry/uniqueid" @@ -587,6 +588,10 @@ func (t *Task) Value(key interface{}) interface{} { return t.k.RealtimeClock() case limits.CtxLimits: return t.tg.limits + case pgalloc.CtxMemoryFile: + return t.k.mf + case pgalloc.CtxMemoryFileProvider: + return t.k case platform.CtxPlatform: return t.k case uniqueid.CtxGlobalUniqueID: diff --git a/pkg/sentry/kernel/task_context.go b/pkg/sentry/kernel/task_context.go index ee3e49d17..d1c82f2aa 100644 --- a/pkg/sentry/kernel/task_context.go +++ b/pkg/sentry/kernel/task_context.go @@ -144,7 +144,7 @@ func (t *Task) Stack() *arch.Stack { // * fs: Binary FeatureSet func (k *Kernel) LoadTaskImage(ctx context.Context, mounts *fs.MountNamespace, root, wd *fs.Dirent, maxTraversals *uint, filename string, argv, envv []string, fs *cpuid.FeatureSet) (*TaskContext, *syserr.Error) { // Prepare a new user address space to load into. - m := mm.NewMemoryManager(k) + m := mm.NewMemoryManager(k, k) defer m.DecUsers(ctx) os, ac, name, err := loader.Load(ctx, m, mounts, root, wd, maxTraversals, fs, filename, argv, envv, k.extraAuxv, k.vdso) diff --git a/pkg/sentry/kernel/timekeeper.go b/pkg/sentry/kernel/timekeeper.go index 6bff80f13..d7bd85e78 100644 --- a/pkg/sentry/kernel/timekeeper.go +++ b/pkg/sentry/kernel/timekeeper.go @@ -21,6 +21,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/log" ktime "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/time" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" sentrytime "gvisor.googlesource.com/gvisor/pkg/sentry/time" ) @@ -85,9 +86,9 @@ type Timekeeper struct { // NewTimekeeper does not take ownership of paramPage. // // SetClocks must be called on the returned Timekeeper before it is usable. -func NewTimekeeper(platform platform.Platform, paramPage platform.FileRange) (*Timekeeper, error) { +func NewTimekeeper(mfp pgalloc.MemoryFileProvider, paramPage platform.FileRange) (*Timekeeper, error) { return &Timekeeper{ - params: NewVDSOParamPage(platform, paramPage), + params: NewVDSOParamPage(mfp, paramPage), }, nil } diff --git a/pkg/sentry/kernel/timekeeper_test.go b/pkg/sentry/kernel/timekeeper_test.go index 71674c21c..6084bcb18 100644 --- a/pkg/sentry/kernel/timekeeper_test.go +++ b/pkg/sentry/kernel/timekeeper_test.go @@ -18,7 +18,7 @@ import ( "testing" "gvisor.googlesource.com/gvisor/pkg/sentry/context/contexttest" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" sentrytime "gvisor.googlesource.com/gvisor/pkg/sentry/time" "gvisor.googlesource.com/gvisor/pkg/sentry/usage" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" @@ -53,13 +53,13 @@ func (c *mockClocks) GetTime(id sentrytime.ClockID) (int64, error) { // SetClocks called. func stateTestClocklessTimekeeper(tb testing.TB) *Timekeeper { ctx := contexttest.Context(tb) - p := platform.FromContext(ctx) - fr, err := p.Memory().Allocate(usermem.PageSize, usage.Anonymous) + mfp := pgalloc.MemoryFileProviderFromContext(ctx) + fr, err := mfp.MemoryFile().Allocate(usermem.PageSize, usage.Anonymous) if err != nil { tb.Fatalf("failed to allocate memory: %v", err) } return &Timekeeper{ - params: NewVDSOParamPage(p, fr), + params: NewVDSOParamPage(mfp, fr), } } diff --git a/pkg/sentry/kernel/vdso.go b/pkg/sentry/kernel/vdso.go index 0ec858a4a..3a35f1d00 100644 --- a/pkg/sentry/kernel/vdso.go +++ b/pkg/sentry/kernel/vdso.go @@ -18,6 +18,7 @@ import ( "fmt" "gvisor.googlesource.com/gvisor/pkg/binary" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/safemem" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" @@ -55,9 +56,9 @@ type vdsoParams struct { // // +stateify savable type VDSOParamPage struct { - // The parameter page is fr, allocated from platform.Memory(). - platform platform.Platform - fr platform.FileRange + // The parameter page is fr, allocated from mfp.MemoryFile(). + mfp pgalloc.MemoryFileProvider + fr platform.FileRange // seq is the current sequence count written to the page. // @@ -73,20 +74,20 @@ type VDSOParamPage struct { // // Preconditions: // -// * fr is a single page allocated from platform.Memory(). VDSOParamPage does +// * fr is a single page allocated from mfp.MemoryFile(). VDSOParamPage does // not take ownership of fr; it must remain allocated for the lifetime of the // VDSOParamPage. // // * VDSOParamPage must be the only writer to fr. // -// * platform.Memory().MapInternal(fr) must return a single safemem.Block. -func NewVDSOParamPage(platform platform.Platform, fr platform.FileRange) *VDSOParamPage { - return &VDSOParamPage{platform: platform, fr: fr} +// * mfp.MemoryFile().MapInternal(fr) must return a single safemem.Block. +func NewVDSOParamPage(mfp pgalloc.MemoryFileProvider, fr platform.FileRange) *VDSOParamPage { + return &VDSOParamPage{mfp: mfp, fr: fr} } // access returns a mapping of the param page. func (v *VDSOParamPage) access() (safemem.Block, error) { - bs, err := v.platform.Memory().MapInternal(v.fr, usermem.ReadWrite) + bs, err := v.mfp.MemoryFile().MapInternal(v.fr, usermem.ReadWrite) if err != nil { return safemem.Block{}, err } diff --git a/pkg/sentry/loader/BUILD b/pkg/sentry/loader/BUILD index 1ea260a4e..66300f25a 100644 --- a/pkg/sentry/loader/BUILD +++ b/pkg/sentry/loader/BUILD @@ -39,7 +39,7 @@ go_library( "//pkg/sentry/limits", "//pkg/sentry/memmap", "//pkg/sentry/mm", - "//pkg/sentry/platform", + "//pkg/sentry/pgalloc", "//pkg/sentry/safemem", "//pkg/sentry/uniqueid", "//pkg/sentry/usage", diff --git a/pkg/sentry/loader/vdso.go b/pkg/sentry/loader/vdso.go index c070c7316..273f6b5b9 100644 --- a/pkg/sentry/loader/vdso.go +++ b/pkg/sentry/loader/vdso.go @@ -28,7 +28,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" "gvisor.googlesource.com/gvisor/pkg/sentry/mm" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/safemem" "gvisor.googlesource.com/gvisor/pkg/sentry/uniqueid" "gvisor.googlesource.com/gvisor/pkg/sentry/usage" @@ -217,7 +217,7 @@ type VDSO struct { // PrepareVDSO validates the system VDSO and returns a VDSO, containing the // param page for updating by the kernel. -func PrepareVDSO(p platform.Platform) (*VDSO, error) { +func PrepareVDSO(mfp pgalloc.MemoryFileProvider) (*VDSO, error) { vdsoFile := newByteReaderFile(vdsoBin) // First make sure the VDSO is valid. vdsoFile does not use ctx, so a @@ -234,35 +234,36 @@ func PrepareVDSO(p platform.Platform) (*VDSO, error) { return nil, fmt.Errorf("VDSO size overflows? %#x", len(vdsoBin)) } - vdso, err := p.Memory().Allocate(uint64(size), usage.System) + mf := mfp.MemoryFile() + vdso, err := mf.Allocate(uint64(size), usage.System) if err != nil { return nil, fmt.Errorf("unable to allocate VDSO memory: %v", err) } - ims, err := p.Memory().MapInternal(vdso, usermem.ReadWrite) + ims, err := mf.MapInternal(vdso, usermem.ReadWrite) if err != nil { - p.Memory().DecRef(vdso) + mf.DecRef(vdso) return nil, fmt.Errorf("unable to map VDSO memory: %v", err) } _, err = safemem.CopySeq(ims, safemem.BlockSeqOf(safemem.BlockFromSafeSlice(vdsoBin))) if err != nil { - p.Memory().DecRef(vdso) + mf.DecRef(vdso) return nil, fmt.Errorf("unable to copy VDSO into memory: %v", err) } // Finally, allocate a param page for this VDSO. - paramPage, err := p.Memory().Allocate(usermem.PageSize, usage.System) + paramPage, err := mf.Allocate(usermem.PageSize, usage.System) if err != nil { - p.Memory().DecRef(vdso) + mf.DecRef(vdso) return nil, fmt.Errorf("unable to allocate VDSO param page: %v", err) } return &VDSO{ - ParamPage: mm.NewSpecialMappable("[vvar]", p, paramPage), + ParamPage: mm.NewSpecialMappable("[vvar]", mfp, paramPage), // TODO: Don't advertise the VDSO, as some applications may // not be able to handle multiple [vdso] hints. - vdso: mm.NewSpecialMappable("", p, vdso), + vdso: mm.NewSpecialMappable("", mfp, vdso), phdrs: info.phdrs, }, nil } diff --git a/pkg/sentry/memutil/memutil_unsafe.go b/pkg/sentry/memutil/memutil_unsafe.go index 8d9fc64fb..bc2c72f55 100644 --- a/pkg/sentry/memutil/memutil_unsafe.go +++ b/pkg/sentry/memutil/memutil_unsafe.go @@ -15,6 +15,7 @@ package memutil import ( + "fmt" "syscall" "unsafe" @@ -22,14 +23,17 @@ import ( ) // CreateMemFD creates a memfd file and returns the fd. -func CreateMemFD(name string, flags int) (fd int, err error) { +func CreateMemFD(name string, flags int) (int, error) { p, err := syscall.BytePtrFromString(name) if err != nil { return -1, err } - r0, _, e0 := syscall.Syscall(unix.SYS_MEMFD_CREATE, uintptr(unsafe.Pointer(p)), uintptr(flags), 0) - if e0 != 0 { - return -1, e0 + fd, _, e := syscall.Syscall(unix.SYS_MEMFD_CREATE, uintptr(unsafe.Pointer(p)), uintptr(flags), 0) + if e != 0 { + if e == syscall.ENOSYS { + return -1, fmt.Errorf("memfd_create(2) is not implemented. Check that you have Linux 3.17 or higher") + } + return -1, e } - return int(r0), nil + return int(fd), nil } diff --git a/pkg/sentry/mm/BUILD b/pkg/sentry/mm/BUILD index a85ffdef8..c78cb4280 100644 --- a/pkg/sentry/mm/BUILD +++ b/pkg/sentry/mm/BUILD @@ -111,6 +111,7 @@ go_library( "//pkg/sentry/kernel/shm", "//pkg/sentry/limits", "//pkg/sentry/memmap", + "//pkg/sentry/pgalloc", "//pkg/sentry/platform", "//pkg/sentry/platform/safecopy", "//pkg/sentry/safemem", @@ -133,6 +134,7 @@ go_test( "//pkg/sentry/context/contexttest", "//pkg/sentry/limits", "//pkg/sentry/memmap", + "//pkg/sentry/pgalloc", "//pkg/sentry/platform", "//pkg/sentry/usermem", "//pkg/syserror", diff --git a/pkg/sentry/mm/README.md b/pkg/sentry/mm/README.md index e485a5ca5..e6efbf565 100644 --- a/pkg/sentry/mm/README.md +++ b/pkg/sentry/mm/README.md @@ -153,7 +153,7 @@ manner, and the sentry handles the fault: represented by a host file descriptor and offset, since (as noted in "Background") this is the memory mapping primitive provided by the host kernel. In general, memory is allocated from a temporary host file using the - `filemem` package. Supposing that the sentry allocates offset 0x3000 from + `pgalloc` package. Supposing that the sentry allocates offset 0x3000 from host file "memory-file", the resulting state is: Sentry VMA: VA:0x400000 -> /tmp/foo:0x0 @@ -274,7 +274,7 @@ In the sentry: methods [`platform.AddressSpace.MapFile` and `platform.AddressSpace.Unmap`][platform]. -[filemem]: https://gvisor.googlesource.com/gvisor/+/master/pkg/sentry/platform/filemem/filemem.go [memmap]: https://gvisor.googlesource.com/gvisor/+/master/pkg/sentry/memmap/memmap.go [mm]: https://gvisor.googlesource.com/gvisor/+/master/pkg/sentry/mm/mm.go +[pgalloc]: https://gvisor.googlesource.com/gvisor/+/master/pkg/sentry/pgalloc/pgalloc.go [platform]: https://gvisor.googlesource.com/gvisor/+/master/pkg/sentry/platform/platform.go diff --git a/pkg/sentry/mm/aio_context.go b/pkg/sentry/mm/aio_context.go index 5e86d3b49..6cec6387a 100644 --- a/pkg/sentry/mm/aio_context.go +++ b/pkg/sentry/mm/aio_context.go @@ -21,6 +21,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/refs" "gvisor.googlesource.com/gvisor/pkg/sentry/context" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/usage" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" @@ -201,24 +202,24 @@ func (ctx *AIOContext) WaitChannel() (chan struct{}, bool) { type aioMappable struct { refs.AtomicRefCount - p platform.Platform - fr platform.FileRange + mfp pgalloc.MemoryFileProvider + fr platform.FileRange } var aioRingBufferSize = uint64(usermem.Addr(linux.AIORingSize).MustRoundUp()) -func newAIOMappable(p platform.Platform) (*aioMappable, error) { - fr, err := p.Memory().Allocate(aioRingBufferSize, usage.Anonymous) +func newAIOMappable(mfp pgalloc.MemoryFileProvider) (*aioMappable, error) { + fr, err := mfp.MemoryFile().Allocate(aioRingBufferSize, usage.Anonymous) if err != nil { return nil, err } - return &aioMappable{p: p, fr: fr}, nil + return &aioMappable{mfp: mfp, fr: fr}, nil } // DecRef implements refs.RefCounter.DecRef. func (m *aioMappable) DecRef() { m.AtomicRefCount.DecRefWithDestructor(func() { - m.p.Memory().DecRef(m.fr) + m.mfp.MemoryFile().DecRef(m.fr) }) } @@ -299,7 +300,7 @@ func (m *aioMappable) Translate(ctx context.Context, required, optional memmap.M return []memmap.Translation{ { Source: source, - File: m.p.Memory(), + File: m.mfp.MemoryFile(), Offset: m.fr.Start + source.Start, }, }, err @@ -320,7 +321,7 @@ func (mm *MemoryManager) NewAIOContext(ctx context.Context, events uint32) (uint // libaio peeks inside looking for a magic number. This function allocates // a page per context and keeps it set to zeroes to ensure it will not // match AIO_RING_MAGIC and make libaio happy. - m, err := newAIOMappable(mm.p) + m, err := newAIOMappable(mm.mfp) if err != nil { return 0, err } diff --git a/pkg/sentry/mm/lifecycle.go b/pkg/sentry/mm/lifecycle.go index 1ee8ae74e..a71286f14 100644 --- a/pkg/sentry/mm/lifecycle.go +++ b/pkg/sentry/mm/lifecycle.go @@ -23,14 +23,16 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/context" "gvisor.googlesource.com/gvisor/pkg/sentry/limits" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" ) // NewMemoryManager returns a new MemoryManager with no mappings and 1 user. -func NewMemoryManager(p platform.Platform) *MemoryManager { +func NewMemoryManager(p platform.Platform, mfp pgalloc.MemoryFileProvider) *MemoryManager { return &MemoryManager{ p: p, + mfp: mfp, haveASIO: p.SupportsAddressSpaceIO(), privateRefs: &privateRefs{}, users: 1, @@ -60,6 +62,7 @@ func (mm *MemoryManager) Fork(ctx context.Context) (*MemoryManager, error) { defer mm.mappingMu.RUnlock() mm2 := &MemoryManager{ p: mm.p, + mfp: mm.mfp, haveASIO: mm.haveASIO, layout: mm.layout, privateRefs: mm.privateRefs, diff --git a/pkg/sentry/mm/mm.go b/pkg/sentry/mm/mm.go index e2c636f38..6ed838d64 100644 --- a/pkg/sentry/mm/mm.go +++ b/pkg/sentry/mm/mm.go @@ -40,6 +40,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/arch" "gvisor.googlesource.com/gvisor/pkg/sentry/fs" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/safemem" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" @@ -50,10 +51,9 @@ import ( // // +stateify savable type MemoryManager struct { - // p is the platform. - // - // p is immutable. - p platform.Platform + // p and mfp are immutable. + p platform.Platform + mfp pgalloc.MemoryFileProvider // haveASIO is the cached result of p.SupportsAddressSpaceIO(). Aside from // eliminating an indirect call in the hot I/O path, this makes @@ -369,8 +369,8 @@ func (v *vma) loadRealPerms(b int) { // +stateify savable type pma struct { // file is the file mapped by this pma. Only pmas for which file == - // platform.Platform.Memory() may be saved. pmas hold a reference to the - // corresponding file range while they exist. + // MemoryManager.mfp.MemoryFile() may be saved. pmas hold a reference to + // the corresponding file range while they exist. file platform.File `state:"nosave"` // off is the offset into file at which this pma begins. @@ -387,7 +387,7 @@ type pma struct { // private is true if this pma represents private memory. // - // If private is true, file must be platform.Platform.Memory(), the pma + // If private is true, file must be MemoryManager.mfp.MemoryFile(), the pma // holds a reference on the mapped memory that is tracked in privateRefs, // and calls to Invalidate for which // memmap.InvalidateOpts.InvalidatePrivate is false should ignore the pma. @@ -405,9 +405,9 @@ type pma struct { type privateRefs struct { mu sync.Mutex `state:"nosave"` - // refs maps offsets into Platform.Memory() to the number of pmas (or, - // equivalently, MemoryManagers) that share ownership of the memory at that - // offset. + // refs maps offsets into MemoryManager.mfp.MemoryFile() to the number of + // pmas (or, equivalently, MemoryManagers) that share ownership of the + // memory at that offset. refs fileRefcountSet } diff --git a/pkg/sentry/mm/mm_test.go b/pkg/sentry/mm/mm_test.go index f2db43196..e12cb3bd1 100644 --- a/pkg/sentry/mm/mm_test.go +++ b/pkg/sentry/mm/mm_test.go @@ -22,6 +22,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/context/contexttest" "gvisor.googlesource.com/gvisor/pkg/sentry/limits" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" "gvisor.googlesource.com/gvisor/pkg/syserror" @@ -29,7 +30,8 @@ import ( func testMemoryManager(ctx context.Context) *MemoryManager { p := platform.FromContext(ctx) - mm := NewMemoryManager(p) + mfp := pgalloc.MemoryFileProviderFromContext(ctx) + mm := NewMemoryManager(p, mfp) mm.layout = arch.MmapLayout{ MinAddr: p.MinUserAddress(), MaxAddr: p.MaxUserAddress(), diff --git a/pkg/sentry/mm/pma.go b/pkg/sentry/mm/pma.go index d102035d8..bb779a45b 100644 --- a/pkg/sentry/mm/pma.go +++ b/pkg/sentry/mm/pma.go @@ -328,8 +328,8 @@ func (mm *MemoryManager) insertPMAsLocked(ctx context.Context, vseg vmaIterator, // Limit the range we allocate to ar, aligned to privateAllocUnit. maskAR := privateAligned(ar) allocAR := optAR.Intersect(maskAR) - mem := mm.p.Memory() - fr, err := mem.Allocate(uint64(allocAR.Length()), usage.Anonymous) + mf := mm.mfp.MemoryFile() + fr, err := mf.Allocate(uint64(allocAR.Length()), usage.Anonymous) if err != nil { return pgap, err } @@ -342,10 +342,10 @@ func (mm *MemoryManager) insertPMAsLocked(ctx context.Context, vseg vmaIterator, } mm.addRSSLocked(allocAR) - mem.IncRef(fr) + mf.IncRef(fr) return mm.pmas.Insert(pgap, allocAR, pma{ - file: mem, + file: mf, off: fr.Start, vmaEffectivePerms: vma.effectivePerms, vmaMaxPerms: vma.maxPerms, @@ -426,7 +426,7 @@ func (mm *MemoryManager) breakCopyOnWriteLocked(pseg pmaIterator, ar usermem.Add // Limit the range we copy to ar, aligned to privateAllocUnit. maskAR := privateAligned(ar) var invalidatedIterators, didUnmapAS bool - mem := mm.p.Memory() + mf := mm.mfp.MemoryFile() for { if mm.isPMACopyOnWriteLocked(pseg) { // Determine the range to copy. @@ -438,7 +438,7 @@ func (mm *MemoryManager) breakCopyOnWriteLocked(pseg pmaIterator, ar usermem.Add } // Copy contents. - fr, err := platform.AllocateAndFill(mem, uint64(copyAR.Length()), usage.Anonymous, &safemem.BlockSeqReader{mm.internalMappingsLocked(pseg, copyAR)}) + fr, err := mf.AllocateAndFill(uint64(copyAR.Length()), usage.Anonymous, &safemem.BlockSeqReader{mm.internalMappingsLocked(pseg, copyAR)}) if _, ok := err.(safecopy.BusError); ok { // If we got SIGBUS during the copy, deliver SIGBUS to // userspace (instead of SIGSEGV) if we're breaking @@ -449,7 +449,7 @@ func (mm *MemoryManager) breakCopyOnWriteLocked(pseg pmaIterator, ar usermem.Add return pseg.PrevGap(), invalidatedIterators, err } mm.incPrivateRef(fr) - mem.IncRef(fr) + mf.IncRef(fr) // Unmap all of maskAR, not just copyAR, to minimize host syscalls. // AddressSpace mappings must be removed before mm.decPrivateRef(). @@ -471,7 +471,7 @@ func (mm *MemoryManager) breakCopyOnWriteLocked(pseg pmaIterator, ar usermem.Add } pma.file.DecRef(pseg.fileRange()) - pma.file = mem + pma.file = mf pma.off = fr.Start pma.private = true pma.needCOW = false @@ -881,9 +881,9 @@ func (mm *MemoryManager) decPrivateRef(fr platform.FileRange) { refSet.MergeAdjacent(fr) mm.privateRefs.mu.Unlock() - mem := mm.p.Memory() + mf := mm.mfp.MemoryFile() for _, fr := range freed { - mem.DecRef(fr) + mf.DecRef(fr) } } diff --git a/pkg/sentry/mm/save_restore.go b/pkg/sentry/mm/save_restore.go index 6e7080a84..46e0e0754 100644 --- a/pkg/sentry/mm/save_restore.go +++ b/pkg/sentry/mm/save_restore.go @@ -37,12 +37,12 @@ func (mm *MemoryManager) InvalidateUnsavable(ctx context.Context) error { // beforeSave is invoked by stateify. func (mm *MemoryManager) beforeSave() { - mem := mm.p.Memory() + mf := mm.mfp.MemoryFile() for pseg := mm.pmas.FirstSegment(); pseg.Ok(); pseg = pseg.NextSegment() { - if pma := pseg.ValuePtr(); pma.file != mem { + if pma := pseg.ValuePtr(); pma.file != mf { // InvalidateUnsavable should have caused all such pmas to be // invalidated. - panic(fmt.Sprintf("Can't save pma %#v with non-Memory file of type %T:\n%s", pseg.Range(), pma.file, mm)) + panic(fmt.Sprintf("Can't save pma %#v with non-MemoryFile of type %T:\n%s", pseg.Range(), pma.file, mm)) } } } @@ -50,8 +50,8 @@ func (mm *MemoryManager) beforeSave() { // afterLoad is invoked by stateify. func (mm *MemoryManager) afterLoad() { mm.haveASIO = mm.p.SupportsAddressSpaceIO() - mem := mm.p.Memory() + mf := mm.mfp.MemoryFile() for pseg := mm.pmas.FirstSegment(); pseg.Ok(); pseg = pseg.NextSegment() { - pseg.ValuePtr().file = mem + pseg.ValuePtr().file = mf } } diff --git a/pkg/sentry/mm/special_mappable.go b/pkg/sentry/mm/special_mappable.go index 64d0dd3f6..aa94d7d6a 100644 --- a/pkg/sentry/mm/special_mappable.go +++ b/pkg/sentry/mm/special_mappable.go @@ -18,6 +18,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/refs" "gvisor.googlesource.com/gvisor/pkg/sentry/context" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/usage" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" @@ -33,24 +34,24 @@ import ( type SpecialMappable struct { refs.AtomicRefCount - p platform.Platform + mfp pgalloc.MemoryFileProvider fr platform.FileRange name string } // NewSpecialMappable returns a SpecialMappable that owns fr, which represents -// offsets in p.Memory() that contain the SpecialMappable's data. The +// offsets in mfp.MemoryFile() that contain the SpecialMappable's data. The // SpecialMappable will use the given name in /proc/[pid]/maps. // // Preconditions: fr.Length() != 0. -func NewSpecialMappable(name string, p platform.Platform, fr platform.FileRange) *SpecialMappable { - return &SpecialMappable{p: p, fr: fr, name: name} +func NewSpecialMappable(name string, mfp pgalloc.MemoryFileProvider, fr platform.FileRange) *SpecialMappable { + return &SpecialMappable{mfp: mfp, fr: fr, name: name} } // DecRef implements refs.RefCounter.DecRef. func (m *SpecialMappable) DecRef() { m.AtomicRefCount.DecRefWithDestructor(func() { - m.p.Memory().DecRef(m.fr) + m.mfp.MemoryFile().DecRef(m.fr) }) } @@ -99,7 +100,7 @@ func (m *SpecialMappable) Translate(ctx context.Context, required, optional memm return []memmap.Translation{ { Source: source, - File: m.p.Memory(), + File: m.mfp.MemoryFile(), Offset: m.fr.Start + source.Start, }, }, err @@ -109,19 +110,19 @@ func (m *SpecialMappable) Translate(ctx context.Context, required, optional memm // InvalidateUnsavable implements memmap.Mappable.InvalidateUnsavable. func (m *SpecialMappable) InvalidateUnsavable(ctx context.Context) error { - // Since data is stored in platform.Platform.Memory(), the contents of - // which are preserved across save/restore, we don't need to do anything. + // Since data is stored in pgalloc.MemoryFile, the contents of which are + // preserved across save/restore, we don't need to do anything. return nil } -// Platform returns the Platform whose Memory stores the SpecialMappable's -// contents. -func (m *SpecialMappable) Platform() platform.Platform { - return m.p +// MemoryFileProvider returns the MemoryFileProvider whose MemoryFile stores +// the SpecialMappable's contents. +func (m *SpecialMappable) MemoryFileProvider() pgalloc.MemoryFileProvider { + return m.mfp } -// FileRange returns the offsets into Platform().Memory() that store the -// SpecialMappable's contents. +// FileRange returns the offsets into MemoryFileProvider().MemoryFile() that +// store the SpecialMappable's contents. func (m *SpecialMappable) FileRange() platform.FileRange { return m.fr } @@ -137,7 +138,7 @@ func (m *SpecialMappable) Length() uint64 { // TODO: The use of SpecialMappable is a lazy code reuse hack. Linux // uses an ephemeral file created by mm/shmem.c:shmem_zero_setup(); we should // do the same to get non-zero device and inode IDs. -func NewSharedAnonMappable(length uint64, p platform.Platform) (*SpecialMappable, error) { +func NewSharedAnonMappable(length uint64, mfp pgalloc.MemoryFileProvider) (*SpecialMappable, error) { if length == 0 { return nil, syserror.EINVAL } @@ -145,10 +146,9 @@ func NewSharedAnonMappable(length uint64, p platform.Platform) (*SpecialMappable if !ok { return nil, syserror.EINVAL } - - fr, err := p.Memory().Allocate(uint64(alignedLen), usage.Anonymous) + fr, err := mfp.MemoryFile().Allocate(uint64(alignedLen), usage.Anonymous) if err != nil { return nil, err } - return NewSpecialMappable("/dev/zero (deleted)", p, fr), nil + return NewSpecialMappable("/dev/zero (deleted)", mfp, fr), nil } diff --git a/pkg/sentry/mm/syscalls.go b/pkg/sentry/mm/syscalls.go index fd6929e08..b56e0d3b9 100644 --- a/pkg/sentry/mm/syscalls.go +++ b/pkg/sentry/mm/syscalls.go @@ -24,7 +24,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/futex" "gvisor.googlesource.com/gvisor/pkg/sentry/limits" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" "gvisor.googlesource.com/gvisor/pkg/syserror" ) @@ -99,7 +99,7 @@ func (mm *MemoryManager) MMap(ctx context.Context, opts memmap.MMapOpts) (userme if opts.MappingIdentity != nil { return 0, syserror.EINVAL } - m, err := NewSharedAnonMappable(opts.Length, platform.FromContext(ctx)) + m, err := NewSharedAnonMappable(opts.Length, pgalloc.MemoryFileProviderFromContext(ctx)) if err != nil { return 0, err } @@ -965,7 +965,7 @@ func (mm *MemoryManager) Decommit(addr usermem.Addr, length uint64) error { // ensures that Decommit immediately reduces host memory usage. var didUnmapAS bool pseg := mm.pmas.LowerBoundSegment(ar.Start) - mem := mm.p.Memory() + mf := mm.mfp.MemoryFile() for vseg := mm.vmas.LowerBoundSegment(ar.Start); vseg.Ok() && vseg.Start() < ar.End; vseg = vseg.NextSegment() { vma := vseg.ValuePtr() if vma.mlockMode != memmap.MLockNone { @@ -984,7 +984,7 @@ func (mm *MemoryManager) Decommit(addr usermem.Addr, length uint64) error { if pma.private && !mm.isPMACopyOnWriteLocked(pseg) { psegAR := pseg.Range().Intersect(ar) if vsegAR.IsSupersetOf(psegAR) && vma.mappable == nil { - if err := mem.Decommit(pseg.fileRangeOf(psegAR)); err == nil { + if err := mf.Decommit(pseg.fileRangeOf(psegAR)); err == nil { pseg = pseg.NextSegment() continue } diff --git a/pkg/sentry/platform/filemem/BUILD b/pkg/sentry/pgalloc/BUILD index 1a61cfaa5..7efa55c20 100644 --- a/pkg/sentry/platform/filemem/BUILD +++ b/pkg/sentry/pgalloc/BUILD @@ -12,7 +12,7 @@ go_template_instance( imports = { "platform": "gvisor.googlesource.com/gvisor/pkg/sentry/platform", }, - package = "filemem", + package = "pgalloc", prefix = "usage", template = "//pkg/segment:generic_set", types = { @@ -24,14 +24,15 @@ go_template_instance( ) go_library( - name = "filemem", + name = "pgalloc", srcs = [ - "filemem.go", - "filemem_state.go", - "filemem_unsafe.go", + "context.go", + "pgalloc.go", + "pgalloc_unsafe.go", + "save_restore.go", "usage_set.go", ], - importpath = "gvisor.googlesource.com/gvisor/pkg/sentry/platform/filemem", + importpath = "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc", visibility = ["//pkg/sentry:internal"], deps = [ "//pkg/log", @@ -48,9 +49,9 @@ go_library( ) go_test( - name = "filemem_test", + name = "pgalloc_test", size = "small", - srcs = ["filemem_test.go"], - embed = [":filemem"], + srcs = ["pgalloc_test.go"], + embed = [":pgalloc"], deps = ["//pkg/sentry/usermem"], ) diff --git a/pkg/sentry/pgalloc/context.go b/pkg/sentry/pgalloc/context.go new file mode 100644 index 000000000..adc97e78f --- /dev/null +++ b/pkg/sentry/pgalloc/context.go @@ -0,0 +1,48 @@ +// Copyright 2019 Google Inc. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package pgalloc + +import ( + "gvisor.googlesource.com/gvisor/pkg/sentry/context" +) + +// contextID is this package's type for context.Context.Value keys. +type contextID int + +const ( + // CtxMemoryFile is a Context.Value key for a MemoryFile. + CtxMemoryFile contextID = iota + + // CtxMemoryFileProvider is a Context.Value key for a MemoryFileProvider. + CtxMemoryFileProvider +) + +// MemoryFileFromContext returns the MemoryFile used by ctx, or nil if no such +// MemoryFile exists. +func MemoryFileFromContext(ctx context.Context) *MemoryFile { + if v := ctx.Value(CtxMemoryFile); v != nil { + return v.(*MemoryFile) + } + return nil +} + +// MemoryFileProviderFromContext returns the MemoryFileProvider used by ctx, or nil if no such +// MemoryFileProvider exists. +func MemoryFileProviderFromContext(ctx context.Context) MemoryFileProvider { + if v := ctx.Value(CtxMemoryFileProvider); v != nil { + return v.(MemoryFileProvider) + } + return nil +} diff --git a/pkg/sentry/platform/filemem/filemem.go b/pkg/sentry/pgalloc/pgalloc.go index f41c70ba5..0754e608f 100644 --- a/pkg/sentry/platform/filemem/filemem.go +++ b/pkg/sentry/pgalloc/pgalloc.go @@ -12,15 +12,14 @@ // See the License for the specific language governing permissions and // limitations under the License. -// Package filemem provides a reusable implementation of platform.Memory. -// -// It enables memory to be sourced from a memfd file. +// Package pgalloc contains the page allocator subsystem, which manages memory +// that may be mapped into application address spaces. // // Lock order: // -// filemem.FileMem.mu -// filemem.FileMem.mappingsMu -package filemem +// pgalloc.MemoryFile.mu +// pgalloc.MemoryFile.mappingsMu +package pgalloc import ( "fmt" @@ -32,7 +31,6 @@ import ( "time" "gvisor.googlesource.com/gvisor/pkg/log" - "gvisor.googlesource.com/gvisor/pkg/sentry/memutil" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/safemem" "gvisor.googlesource.com/gvisor/pkg/sentry/usage" @@ -40,9 +38,10 @@ import ( "gvisor.googlesource.com/gvisor/pkg/syserror" ) -// FileMem is a platform.Memory that allocates from a host file that it owns. -type FileMem struct { - // Filemem models the backing file as follows: +// MemoryFile is a platform.File whose pages may be allocated to arbitrary +// users. +type MemoryFile struct { + // MemoryFile owns a single backing file, which is modeled as follows: // // Each page in the file can be committed or uncommitted. A page is // committed if the host kernel is spending resources to store its contents @@ -56,17 +55,17 @@ type FileMem struct { // committed. This is the only event that can cause a uncommitted page to // be committed. // - // fallocate(FALLOC_FL_PUNCH_HOLE) (FileMem.Decommit) causes committed + // fallocate(FALLOC_FL_PUNCH_HOLE) (MemoryFile.Decommit) causes committed // pages to be uncommitted. This is the only event that can cause a // committed page to be uncommitted. // - // Filemem's accounting is based on identifying the set of committed pages. - // Since filemem does not have direct access to the MMU, tracking reads and - // writes to uncommitted pages to detect commitment would introduce - // additional page faults, which would be prohibitively expensive. Instead, - // filemem queries the host kernel to determine which pages are committed. + // Memory accounting is based on identifying the set of committed pages. + // Since we do not have direct access to the MMU, tracking reads and writes + // to uncommitted pages to detect commitment would introduce additional + // page faults, which would be prohibitively expensive. Instead, we query + // the host kernel to determine which pages are committed. - // file is the backing memory file. The file pointer is immutable. + // file is the backing file. The file pointer is immutable. file *os.File mu sync.Mutex @@ -134,11 +133,12 @@ type FileMem struct { // transitions from false to true. reclaimCond sync.Cond - // Filemem pages are mapped into the local address space on the granularity - // of large pieces called chunks. mappings is a []uintptr that stores, for - // each chunk, the start address of a mapping of that chunk in the current - // process' address space, or 0 if no such mapping exists. Once a chunk is - // mapped, it is never remapped or unmapped until the filemem is destroyed. + // Pages from the backing file are mapped into the local address space on + // the granularity of large pieces called chunks. mappings is a []uintptr + // that stores, for each chunk, the start address of a mapping of that + // chunk in the current process' address space, or 0 if no such mapping + // exists. Once a chunk is mapped, it is never remapped or unmapped until + // the MemoryFile is destroyed. // // Mutating the mappings slice or its contents requires both holding // mappingsMu and using atomic memory operations. (The slice is mutated @@ -146,9 +146,8 @@ type FileMem struct { // mutation of the slice's contents is the assignment of a mapping to a // chunk that was previously unmapped.) Reading the slice or its contents // only requires *either* holding mappingsMu or using atomic memory - // operations. This allows FileMem.AccessPhysical to avoid locking in the + // operations. This allows MemoryFile.MapInternal to avoid locking in the // common case where chunk mappings already exist. - mappingsMu sync.Mutex mappings atomic.Value } @@ -160,10 +159,8 @@ type usageInfo struct { // kind is the usage kind. kind usage.MemoryKind - // knownCommitted indicates whether this region is known to be - // committed. If this is false, then the region may or may not have - // been touched. If it is true however, then mincore (below) has - // indicated that the page is present at least once. + // knownCommitted is true if the tracked region is definitely committed. + // (If it is false, the tracked region may or may not be committed.) knownCommitted bool refs uint64 @@ -180,12 +177,18 @@ const ( maxPage = math.MaxUint64 &^ (usermem.PageSize - 1) ) -// newFromFile creates a FileMem backed by the given file. -func newFromFile(file *os.File) (*FileMem, error) { +// NewMemoryFile creates a MemoryFile backed by the given file. If +// NewMemoryFile succeeds, ownership of file is transferred to the returned +// MemoryFile. +func NewMemoryFile(file *os.File) (*MemoryFile, error) { + // Truncate the file to 0 bytes first to ensure that it's empty. + if err := file.Truncate(0); err != nil { + return nil, err + } if err := file.Truncate(initialSize); err != nil { return nil, err } - f := &FileMem{ + f := &MemoryFile{ fileSize: initialSize, file: file, // No pages are reclaimable. DecRef will always be able to @@ -199,57 +202,59 @@ func newFromFile(file *os.File) (*FileMem, error) { // The Linux kernel contains an optional feature called "Integrity // Measurement Architecture" (IMA). If IMA is enabled, it will checksum // binaries the first time they are mapped PROT_EXEC. This is bad news for - // executable pages mapped from FileMem, which can grow to terabytes in - // (sparse) size. If IMA attempts to checksum a file that large, it will - // allocate all of the sparse pages and quickly exhaust all memory. + // executable pages mapped from our backing file, which can grow to + // terabytes in (sparse) size. If IMA attempts to checksum a file that + // large, it will allocate all of the sparse pages and quickly exhaust all + // memory. // // Work around IMA by immediately creating a temporary PROT_EXEC mapping, - // while FileMem is still small. IMA will ignore any future mappings. + // while the backing file is still small. IMA will ignore any future + // mappings. m, _, errno := syscall.Syscall6( syscall.SYS_MMAP, 0, usermem.PageSize, syscall.PROT_EXEC, syscall.MAP_SHARED, - f.file.Fd(), + file.Fd(), 0) if errno != 0 { - // This isn't fatal to filemem (IMA may not even be in use). Log the - // error, but don't return it. - log.Warningf("Failed to pre-map FileMem PROT_EXEC: %v", errno) + // This isn't fatal (IMA may not even be in use). Log the error, but + // don't return it. + log.Warningf("Failed to pre-map MemoryFile PROT_EXEC: %v", errno) } else { - syscall.Syscall( + if _, _, errno := syscall.Syscall( syscall.SYS_MUNMAP, m, usermem.PageSize, - 0) + 0); errno != 0 { + panic(fmt.Sprintf("failed to unmap PROT_EXEC MemoryFile mapping: %v", errno)) + } } return f, nil } -// New creates a FileMem backed by a memfd file. -func New(name string) (*FileMem, error) { - fd, err := memutil.CreateMemFD(name, 0) - if err != nil { - if e, ok := err.(syscall.Errno); ok && e == syscall.ENOSYS { - return nil, fmt.Errorf("memfd_create(2) is not implemented. Check that you have Linux 3.17 or higher") - } - return nil, err - } - return newFromFile(os.NewFile(uintptr(fd), name)) -} - -// Destroy implements platform.Memory.Destroy. -func (f *FileMem) Destroy() { +// Destroy releases all resources used by f. +// +// Preconditions: All pages allocated by f have been freed. +// +// Postconditions: None of f's methods may be called after Destroy. +func (f *MemoryFile) Destroy() { f.mu.Lock() defer f.mu.Unlock() f.destroyed = true f.reclaimCond.Signal() } -// Allocate implements platform.Memory.Allocate. -func (f *FileMem) Allocate(length uint64, kind usage.MemoryKind) (platform.FileRange, error) { +// Allocate returns a range of initially-zeroed pages of the given length with +// the given accounting kind and a single reference held by the caller. When +// the last reference on an allocated page is released, ownership of the page +// is returned to the MemoryFile, allowing it to be returned by a future call +// to Allocate. +// +// Preconditions: length must be page-aligned and non-zero. +func (f *MemoryFile) Allocate(length uint64, kind usage.MemoryKind) (platform.FileRange, error) { if length == 0 || length%usermem.PageSize != 0 { panic(fmt.Sprintf("invalid allocation length: %#x", length)) } @@ -301,7 +306,7 @@ func (f *FileMem) Allocate(length uint64, kind usage.MemoryKind) (platform.FileR kind: kind, refs: 1, }) { - panic(fmt.Sprintf("allocating %v: failed to insert into f.usage:\n%v", fr, &f.usage)) + panic(fmt.Sprintf("allocating %v: failed to insert into usage set:\n%v", fr, &f.usage)) } if minUnallocatedPage < start { @@ -349,14 +354,46 @@ func findUnallocatedRange(usage *usageSet, start, length, alignment uint64) (uin return start, firstPage } +// AllocateAndFill allocates memory of the given kind and fills it by calling +// r.ReadToBlocks() repeatedly until either length bytes are read or a non-nil +// error is returned. It returns the memory filled by r, truncated down to the +// nearest page. If this is shorter than length bytes due to an error returned +// by r.ReadToBlocks(), it returns that error. +// +// Preconditions: length > 0. length must be page-aligned. +func (f *MemoryFile) AllocateAndFill(length uint64, kind usage.MemoryKind, r safemem.Reader) (platform.FileRange, error) { + fr, err := f.Allocate(length, kind) + if err != nil { + return platform.FileRange{}, err + } + dsts, err := f.MapInternal(fr, usermem.Write) + if err != nil { + f.DecRef(fr) + return platform.FileRange{}, err + } + n, err := safemem.ReadFullToBlocks(r, dsts) + un := uint64(usermem.Addr(n).RoundDown()) + if un < length { + // Free unused memory and update fr to contain only the memory that is + // still allocated. + f.DecRef(platform.FileRange{fr.Start + un, fr.End}) + fr.End = fr.Start + un + } + return fr, err +} + // fallocate(2) modes, defined in Linux's include/uapi/linux/falloc.h. const ( _FALLOC_FL_KEEP_SIZE = 1 _FALLOC_FL_PUNCH_HOLE = 2 ) -// Decommit implements platform.Memory.Decommit. -func (f *FileMem) Decommit(fr platform.FileRange) error { +// Decommit releases resources associated with maintaining the contents of the +// given pages. If Decommit succeeds, future accesses of the decommitted pages +// will read zeroes. +// +// Preconditions: fr.Length() > 0. +func (f *MemoryFile) Decommit(fr platform.FileRange) error { if !fr.WellFormed() || fr.Length() == 0 || fr.Start%usermem.PageSize != 0 || fr.End%usermem.PageSize != 0 { panic(fmt.Sprintf("invalid range: %v", fr)) } @@ -376,7 +413,7 @@ func (f *FileMem) Decommit(fr platform.FileRange) error { return nil } -func (f *FileMem) markDecommitted(fr platform.FileRange) { +func (f *MemoryFile) markDecommitted(fr platform.FileRange) { f.mu.Lock() defer f.mu.Unlock() // Since we're changing the knownCommitted attribute, we need to merge @@ -398,8 +435,9 @@ func (f *FileMem) markDecommitted(fr platform.FileRange) { } // runReclaim implements the reclaimer goroutine, which continuously decommits -// reclaimable frames in order to reduce memory usage. -func (f *FileMem) runReclaim() { +// reclaimable pages in order to reduce memory usage and make them available +// for allocation. +func (f *MemoryFile) runReclaim() { for { fr, ok := f.findReclaimable() if !ok { @@ -408,14 +446,14 @@ func (f *FileMem) runReclaim() { if err := f.Decommit(fr); err != nil { log.Warningf("Reclaim failed to decommit %v: %v", fr, err) - // Zero the frames manually. This won't reduce memory usage, but at - // least ensures that the frames will be zero when reallocated. + // Zero the pages manually. This won't reduce memory usage, but at + // least ensures that the pages will be zero when reallocated. f.forEachMappingSlice(fr, func(bs []byte) { for i := range bs { bs[i] = 0 } }) - // Pretend the frames were decommitted even though they weren't, + // Pretend the pages were decommitted even though they weren't, // since the memory accounting implementation has no idea how to // deal with this. f.markDecommitted(fr) @@ -427,7 +465,7 @@ func (f *FileMem) runReclaim() { f.mu.Lock() defer f.mu.Unlock() if !f.destroyed { - panic("findReclaimable broke out of reclaim loop, but f.destroyed is no longer set") + panic("findReclaimable broke out of reclaim loop, but destroyed is no longer set") } f.file.Close() // Ensure that any attempts to use f.file.Fd() fail instead of getting a fd @@ -438,7 +476,7 @@ func (f *FileMem) runReclaim() { if m != 0 { _, _, errno := syscall.Syscall(syscall.SYS_MUNMAP, m, chunkSize, 0) if errno != 0 { - log.Warningf("Failed to unmap mapping %#x for filemem chunk %d: %v", m, i, errno) + log.Warningf("Failed to unmap mapping %#x for MemoryFile chunk %d: %v", m, i, errno) } } } @@ -446,7 +484,7 @@ func (f *FileMem) runReclaim() { f.mappings.Store([]uintptr{}) } -func (f *FileMem) findReclaimable() (platform.FileRange, bool) { +func (f *MemoryFile) findReclaimable() (platform.FileRange, bool) { f.mu.Lock() defer f.mu.Unlock() for { @@ -468,30 +506,30 @@ func (f *FileMem) findReclaimable() (platform.FileRange, bool) { return seg.Range(), true } } - f.reclaimable = false // No pages are reclaimable. + f.reclaimable = false f.minReclaimablePage = maxPage } } -func (f *FileMem) markReclaimed(fr platform.FileRange) { +func (f *MemoryFile) markReclaimed(fr platform.FileRange) { f.mu.Lock() defer f.mu.Unlock() seg := f.usage.FindSegment(fr.Start) // All of fr should be mapped to a single uncommitted reclaimable segment // accounted to System. if !seg.Ok() { - panic(fmt.Sprintf("Reclaimed pages %v include unreferenced pages:\n%v", fr, &f.usage)) + panic(fmt.Sprintf("reclaimed pages %v include unreferenced pages:\n%v", fr, &f.usage)) } if !seg.Range().IsSupersetOf(fr) { - panic(fmt.Sprintf("Reclaimed pages %v are not entirely contained in segment %v with state %v:\n%v", fr, seg.Range(), seg.Value(), &f.usage)) + panic(fmt.Sprintf("reclaimed pages %v are not entirely contained in segment %v with state %v:\n%v", fr, seg.Range(), seg.Value(), &f.usage)) } if got, want := seg.Value(), (usageInfo{ kind: usage.System, knownCommitted: false, refs: 0, }); got != want { - panic(fmt.Sprintf("Reclaimed pages %v in segment %v has incorrect state %v, wanted %v:\n%v", fr, seg.Range(), got, want, &f.usage)) + panic(fmt.Sprintf("reclaimed pages %v in segment %v has incorrect state %v, wanted %v:\n%v", fr, seg.Range(), got, want, &f.usage)) } // Deallocate reclaimed pages. Even though all of seg is reclaimable, the // caller of markReclaimed may not have decommitted it, so we can only mark @@ -504,7 +542,7 @@ func (f *FileMem) markReclaimed(fr platform.FileRange) { } // IncRef implements platform.File.IncRef. -func (f *FileMem) IncRef(fr platform.FileRange) { +func (f *MemoryFile) IncRef(fr platform.FileRange) { if !fr.WellFormed() || fr.Length() == 0 || fr.Start%usermem.PageSize != 0 || fr.End%usermem.PageSize != 0 { panic(fmt.Sprintf("invalid range: %v", fr)) } @@ -523,7 +561,7 @@ func (f *FileMem) IncRef(fr platform.FileRange) { } // DecRef implements platform.File.DecRef. -func (f *FileMem) DecRef(fr platform.FileRange) { +func (f *MemoryFile) DecRef(fr platform.FileRange) { if !fr.WellFormed() || fr.Length() == 0 || fr.Start%usermem.PageSize != 0 || fr.End%usermem.PageSize != 0 { panic(fmt.Sprintf("invalid range: %v", fr)) } @@ -563,7 +601,7 @@ func (f *FileMem) DecRef(fr platform.FileRange) { } // MapInternal implements platform.File.MapInternal. -func (f *FileMem) MapInternal(fr platform.FileRange, at usermem.AccessType) (safemem.BlockSeq, error) { +func (f *MemoryFile) MapInternal(fr platform.FileRange, at usermem.AccessType) (safemem.BlockSeq, error) { if !fr.WellFormed() || fr.Length() == 0 { panic(fmt.Sprintf("invalid range: %v", fr)) } @@ -589,7 +627,7 @@ func (f *FileMem) MapInternal(fr platform.FileRange, at usermem.AccessType) (saf // forEachMappingSlice invokes fn on a sequence of byte slices that // collectively map all bytes in fr. -func (f *FileMem) forEachMappingSlice(fr platform.FileRange, fn func([]byte)) error { +func (f *MemoryFile) forEachMappingSlice(fr platform.FileRange, fn func([]byte)) error { mappings := f.mappings.Load().([]uintptr) for chunkStart := fr.Start &^ chunkMask; chunkStart < fr.End; chunkStart += chunkSize { chunk := int(chunkStart >> chunkShift) @@ -614,7 +652,7 @@ func (f *FileMem) forEachMappingSlice(fr platform.FileRange, fn func([]byte)) er return nil } -func (f *FileMem) getChunkMapping(chunk int) ([]uintptr, uintptr, error) { +func (f *MemoryFile) getChunkMapping(chunk int) ([]uintptr, uintptr, error) { f.mappingsMu.Lock() defer f.mappingsMu.Unlock() // Another thread may have replaced f.mappings altogether due to file @@ -640,12 +678,13 @@ func (f *FileMem) getChunkMapping(chunk int) ([]uintptr, uintptr, error) { } // FD implements platform.File.FD. -func (f *FileMem) FD() int { +func (f *MemoryFile) FD() int { return int(f.file.Fd()) } -// UpdateUsage implements platform.Memory.UpdateUsage. -func (f *FileMem) UpdateUsage() error { +// UpdateUsage ensures that the memory usage statistics in +// usage.MemoryAccounting are up to date. +func (f *MemoryFile) UpdateUsage() error { f.mu.Lock() defer f.mu.Unlock() @@ -681,7 +720,7 @@ func (f *FileMem) UpdateUsage() error { // in bs, sets committed[i] to 1 if the page is committed and 0 otherwise. // // Precondition: f.mu must be held. -func (f *FileMem) updateUsageLocked(currentUsage uint64, checkCommitted func(bs []byte, committed []byte) error) error { +func (f *MemoryFile) updateUsageLocked(currentUsage uint64, checkCommitted func(bs []byte, committed []byte) error) error { // Track if anything changed to elide the merge. In the common case, we // expect all segments to be committed and no merge to occur. changedAny := false @@ -692,11 +731,11 @@ func (f *FileMem) updateUsageLocked(currentUsage uint64, checkCommitted func(bs // Adjust the swap usage to reflect reality. if f.usageExpected < currentUsage { - // Since no pages may be decommitted while we hold usageMu, we - // know that usage may have only increased since we got the - // last current usage. Therefore, if usageExpected is still - // short of currentUsage, we must assume that the difference is - // in pages that have been swapped. + // Since no pages may be marked decommitted while we hold mu, we + // know that usage may have only increased since we got the last + // current usage. Therefore, if usageExpected is still short of + // currentUsage, we must assume that the difference is in pages + // that have been swapped. newUsageSwapped := currentUsage - f.usageExpected if f.usageSwapped < newUsageSwapped { usage.MemoryAccounting.Inc(newUsageSwapped-f.usageSwapped, usage.System) @@ -822,8 +861,10 @@ func (f *FileMem) updateUsageLocked(currentUsage uint64, checkCommitted func(bs return nil } -// TotalUsage implements platform.Memory.TotalUsage. -func (f *FileMem) TotalUsage() (uint64, error) { +// TotalUsage returns an aggregate usage for all memory statistics except +// Mapped (which is external to MemoryFile). This is generally much cheaper +// than UpdateUsage, but will not provide a fine-grained breakdown. +func (f *MemoryFile) TotalUsage() (uint64, error) { // Stat the underlying file to discover the underlying usage. stat(2) // always reports the allocated block count in units of 512 bytes. This // includes pages in the page cache and swapped pages. @@ -834,15 +875,17 @@ func (f *FileMem) TotalUsage() (uint64, error) { return uint64(stat.Blocks * 512), nil } -// TotalSize implements platform.Memory.TotalSize. -func (f *FileMem) TotalSize() uint64 { +// TotalSize returns the current size of the backing file in bytes, which is an +// upper bound on the amount of memory that can currently be allocated from the +// MemoryFile. The value returned by TotalSize is permitted to change. +func (f *MemoryFile) TotalSize() uint64 { f.mu.Lock() defer f.mu.Unlock() return uint64(f.fileSize) } -// File returns the memory file used by f. -func (f *FileMem) File() *os.File { +// File returns the backing file. +func (f *MemoryFile) File() *os.File { return f.file } @@ -850,8 +893,8 @@ func (f *FileMem) File() *os.File { // // Note that because f.String locks f.mu, calling f.String internally // (including indirectly through the fmt package) risks recursive locking. -// Within the filemem package, use f.usage directly instead. -func (f *FileMem) String() string { +// Within the pgalloc package, use f.usage directly instead. +func (f *MemoryFile) String() string { f.mu.Lock() defer f.mu.Unlock() return f.usage.String() diff --git a/pkg/sentry/platform/filemem/filemem_test.go b/pkg/sentry/pgalloc/pgalloc_test.go index 9becec25f..726623c1a 100644 --- a/pkg/sentry/platform/filemem/filemem_test.go +++ b/pkg/sentry/pgalloc/pgalloc_test.go @@ -12,7 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. -package filemem +package pgalloc import ( "testing" diff --git a/pkg/sentry/platform/filemem/filemem_unsafe.go b/pkg/sentry/pgalloc/pgalloc_unsafe.go index 776aed74d..33b0a68a8 100644 --- a/pkg/sentry/platform/filemem/filemem_unsafe.go +++ b/pkg/sentry/pgalloc/pgalloc_unsafe.go @@ -12,7 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. -package filemem +package pgalloc import ( "reflect" diff --git a/pkg/sentry/platform/filemem/filemem_state.go b/pkg/sentry/pgalloc/save_restore.go index 964e2aaaa..21024e656 100644 --- a/pkg/sentry/platform/filemem/filemem_state.go +++ b/pkg/sentry/pgalloc/save_restore.go @@ -12,7 +12,7 @@ // See the License for the specific language governing permissions and // limitations under the License. -package filemem +package pgalloc import ( "bytes" @@ -28,8 +28,8 @@ import ( "gvisor.googlesource.com/gvisor/pkg/state" ) -// SaveTo implements platform.Memory.SaveTo. -func (f *FileMem) SaveTo(w io.Writer) error { +// SaveTo writes f's state to the given stream. +func (f *MemoryFile) SaveTo(w io.Writer) error { // Wait for reclaim. f.mu.Lock() defer f.mu.Unlock() @@ -103,18 +103,13 @@ func (f *FileMem) SaveTo(w io.Writer) error { if err != nil { return err } - - // Update accounting for restored pages. We need to do this here since - // these segments are marked as "known committed", and will be skipped - // over on accounting scans. - usage.MemoryAccounting.Inc(seg.Range().Length(), seg.Value().kind) } return nil } -// LoadFrom implements platform.Memory.LoadFrom. -func (f *FileMem) LoadFrom(r io.Reader) error { +// LoadFrom loads MemoryFile state from the given stream. +func (f *MemoryFile) LoadFrom(r io.Reader) error { // Load metadata. if err := state.Load(r, &f.fileSize, nil); err != nil { return err @@ -192,3 +187,19 @@ func (f *FileMem) LoadFrom(r io.Reader) error { return nil } + +// MemoryFileProvider provides the MemoryFile method. +// +// This type exists to work around a save/restore defect. The only object in a +// saved object graph that S/R allows to be replaced at time of restore is the +// starting point of the restore, kernel.Kernel. However, the MemoryFile +// changes between save and restore as well, so objects that need persistent +// access to the MemoryFile must instead store a pointer to the Kernel and call +// Kernel.MemoryFile() as required. In most cases, depending on the kernel +// package directly would create a package dependency loop, so the stored +// pointer must instead be a MemoryProvider interface object. Correspondingly, +// kernel.Kernel is the only implementation of this interface. +type MemoryFileProvider interface { + // MemoryFile returns the Kernel MemoryFile. + MemoryFile() *MemoryFile +} diff --git a/pkg/sentry/platform/kvm/BUILD b/pkg/sentry/platform/kvm/BUILD index b7bf88249..9999e58f4 100644 --- a/pkg/sentry/platform/kvm/BUILD +++ b/pkg/sentry/platform/kvm/BUILD @@ -34,7 +34,6 @@ go_library( "//pkg/log", "//pkg/sentry/arch", "//pkg/sentry/platform", - "//pkg/sentry/platform/filemem", "//pkg/sentry/platform/interrupt", "//pkg/sentry/platform/procid", "//pkg/sentry/platform/ring0", diff --git a/pkg/sentry/platform/kvm/address_space.go b/pkg/sentry/platform/kvm/address_space.go index 6d8d8e65b..f2f7ab1e8 100644 --- a/pkg/sentry/platform/kvm/address_space.go +++ b/pkg/sentry/platform/kvm/address_space.go @@ -20,7 +20,6 @@ import ( "gvisor.googlesource.com/gvisor/pkg/atomicbitops" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform/filemem" "gvisor.googlesource.com/gvisor/pkg/sentry/platform/ring0/pagetables" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" ) @@ -76,9 +75,6 @@ type addressSpace struct { // Note that the page tables themselves are not locked. mu sync.Mutex - // filemem is the memory instance. - filemem *filemem.FileMem - // machine is the underlying machine. machine *machine diff --git a/pkg/sentry/platform/kvm/kvm.go b/pkg/sentry/platform/kvm/kvm.go index d4f50024d..c5a4435b1 100644 --- a/pkg/sentry/platform/kvm/kvm.go +++ b/pkg/sentry/platform/kvm/kvm.go @@ -23,7 +23,6 @@ import ( "gvisor.googlesource.com/gvisor/pkg/cpuid" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform/filemem" "gvisor.googlesource.com/gvisor/pkg/sentry/platform/ring0" "gvisor.googlesource.com/gvisor/pkg/sentry/platform/ring0/pagetables" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" @@ -33,9 +32,6 @@ import ( type KVM struct { platform.NoCPUPreemptionDetection - // filemem is our memory source. - *filemem.FileMem - // machine is the backing VM. machine *machine } @@ -56,12 +52,6 @@ func OpenDevice() (*os.File, error) { // New returns a new KVM-based implementation of the platform interface. func New(deviceFile *os.File) (*KVM, error) { - // Allocate physical memory for the vCPUs. - fm, err := filemem.New("kvm-memory") - if err != nil { - return nil, err - } - fd := deviceFile.Fd() // Ensure global initialization is done. @@ -90,7 +80,6 @@ func New(deviceFile *os.File) (*KVM, error) { // All set. return &KVM{ - FileMem: fm, machine: machine, }, nil } @@ -140,7 +129,6 @@ func (k *KVM) NewAddressSpace(_ interface{}) (platform.AddressSpace, <-chan stru // Return the new address space. return &addressSpace{ - filemem: k.FileMem, machine: k.machine, pageTables: pageTables, dirtySet: k.machine.newDirtySet(), @@ -153,8 +141,3 @@ func (k *KVM) NewContext() platform.Context { machine: k.machine, } } - -// Memory returns the platform memory used to do allocations. -func (k *KVM) Memory() platform.Memory { - return k.FileMem -} diff --git a/pkg/sentry/platform/kvm/kvm_test.go b/pkg/sentry/platform/kvm/kvm_test.go index fff463a6e..361200622 100644 --- a/pkg/sentry/platform/kvm/kvm_test.go +++ b/pkg/sentry/platform/kvm/kvm_test.go @@ -48,7 +48,6 @@ func kvmTest(t testHarness, setup func(*KVM), fn func(*vCPU) bool) { t.Fatalf("error creating KVM instance: %v", err) } defer k.machine.Destroy() - defer k.FileMem.Destroy() // Call additional setup. if setup != nil { diff --git a/pkg/sentry/platform/platform.go b/pkg/sentry/platform/platform.go index b2ce851da..d1c9458ea 100644 --- a/pkg/sentry/platform/platform.go +++ b/pkg/sentry/platform/platform.go @@ -19,17 +19,15 @@ package platform import ( "fmt" - "io" "gvisor.googlesource.com/gvisor/pkg/abi/linux" "gvisor.googlesource.com/gvisor/pkg/sentry/arch" "gvisor.googlesource.com/gvisor/pkg/sentry/safemem" - "gvisor.googlesource.com/gvisor/pkg/sentry/usage" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" ) -// Platform provides abstractions for execution contexts (Context) and memory -// management (Memory, AddressSpace). +// Platform provides abstractions for execution contexts (Context, +// AddressSpace). type Platform interface { // SupportsAddressSpaceIO returns true if AddressSpaces returned by this // Platform support AddressSpaceIO methods. @@ -87,9 +85,6 @@ type Platform interface { // NewContext returns a new execution context. NewContext() Context - // Memory returns memory for allocations. - Memory() Memory - // PreemptAllCPUs causes all concurrent calls to Context.Switch(), as well // as the first following call to Context.Switch() for each Context, to // return ErrContextCPUPreempted. @@ -352,84 +347,3 @@ type File interface { func (fr FileRange) String() string { return fmt.Sprintf("[%#x, %#x)", fr.Start, fr.End) } - -// Memory represents an allocatable File that may be mapped into any -// AddressSpace associated with the same Platform. -type Memory interface { - File - - // Allocate returns a range of initially-zeroed pages of the given length - // with the given accounting kind and a single reference held by the - // caller. When the last reference on an allocated page is released, - // ownership of the page is returned to the Memory, allowing it to be - // returned by a future call to Allocate. - // - // Preconditions: length must be page-aligned and non-zero. - Allocate(length uint64, kind usage.MemoryKind) (FileRange, error) - - // Decommit releases resources associated with maintaining the contents of - // the given frames. If Decommit succeeds, future accesses of the - // decommitted frames will read zeroes. - // - // Preconditions: fr.Length() > 0. - Decommit(fr FileRange) error - - // UpdateUsage updates the memory usage statistics. This must be called - // before the relevant memory statistics in usage.MemoryAccounting can - // be considered accurate. - UpdateUsage() error - - // TotalUsage returns an aggregate usage for all memory statistics - // except Mapped (which is external to the Memory implementation). This - // is generally much cheaper than UpdateUsage, but will not provide a - // fine-grained breakdown. - TotalUsage() (uint64, error) - - // TotalSize returns the current maximum size of the Memory in bytes. The - // value returned by TotalSize is permitted to change. - TotalSize() uint64 - - // Destroy releases all resources associated with the Memory. - // - // Preconditions: There are no remaining uses of any of the freed memory's - // frames. - // - // Postconditions: None of the Memory's methods may be called after Destroy. - Destroy() - - // SaveTo saves the memory state to the given stream, which will - // generally be a statefile. - SaveTo(w io.Writer) error - - // LoadFrom loads the memory state from the given stream, which will - // generally be a statefile. - LoadFrom(r io.Reader) error -} - -// AllocateAndFill allocates memory of the given kind from mem and fills it by -// calling r.ReadToBlocks() repeatedly until either length bytes are read or a -// non-nil error is returned. It returns the memory filled by r, truncated down -// to the nearest page. If this is shorter than length bytes due to an error -// returned by r.ReadToBlocks(), it returns that error. -// -// Preconditions: length > 0. length must be page-aligned. -func AllocateAndFill(mem Memory, length uint64, kind usage.MemoryKind, r safemem.Reader) (FileRange, error) { - fr, err := mem.Allocate(length, kind) - if err != nil { - return FileRange{}, err - } - dsts, err := mem.MapInternal(fr, usermem.Write) - if err != nil { - mem.DecRef(fr) - return FileRange{}, err - } - n, err := safemem.ReadFullToBlocks(r, dsts) - un := uint64(usermem.Addr(n).RoundDown()) - if un < length { - // Free unused memory and update fr to contain only the memory that is - // still allocated. - mem.DecRef(FileRange{fr.Start + un, fr.End}) - fr.End = fr.Start + un - } - return fr, err -} diff --git a/pkg/sentry/platform/ptrace/BUILD b/pkg/sentry/platform/ptrace/BUILD index f86790942..e9e4a0d16 100644 --- a/pkg/sentry/platform/ptrace/BUILD +++ b/pkg/sentry/platform/ptrace/BUILD @@ -23,7 +23,6 @@ go_library( "//pkg/seccomp", "//pkg/sentry/arch", "//pkg/sentry/platform", - "//pkg/sentry/platform/filemem", "//pkg/sentry/platform/interrupt", "//pkg/sentry/platform/procid", "//pkg/sentry/platform/safecopy", diff --git a/pkg/sentry/platform/ptrace/ptrace.go b/pkg/sentry/platform/ptrace/ptrace.go index 8d3f6ac9a..3c0713e95 100644 --- a/pkg/sentry/platform/ptrace/ptrace.go +++ b/pkg/sentry/platform/ptrace/ptrace.go @@ -50,7 +50,6 @@ import ( "gvisor.googlesource.com/gvisor/pkg/abi/linux" "gvisor.googlesource.com/gvisor/pkg/sentry/arch" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform/filemem" "gvisor.googlesource.com/gvisor/pkg/sentry/platform/interrupt" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" ) @@ -181,7 +180,6 @@ func (c *context) Interrupt() { type PTrace struct { platform.MMapMinAddr platform.NoCPUPreemptionDetection - *filemem.FileMem } // New returns a new ptrace-based implementation of the platform interface. @@ -202,12 +200,7 @@ func New() (*PTrace, error) { globalPool.master = master }) - fm, err := filemem.New("ptrace-memory") - if err != nil { - return nil, err - } - - return &PTrace{FileMem: fm}, nil + return &PTrace{}, nil } // SupportsAddressSpaceIO implements platform.Platform.SupportsAddressSpaceIO. @@ -243,8 +236,3 @@ func (p *PTrace) NewAddressSpace(_ interface{}) (platform.AddressSpace, <-chan s func (*PTrace) NewContext() platform.Context { return &context{} } - -// Memory returns the platform memory used to do allocations. -func (p *PTrace) Memory() platform.Memory { - return p.FileMem -} diff --git a/pkg/sentry/state/BUILD b/pkg/sentry/state/BUILD index 42c459acc..69385e23c 100644 --- a/pkg/sentry/state/BUILD +++ b/pkg/sentry/state/BUILD @@ -16,7 +16,6 @@ go_library( "//pkg/log", "//pkg/sentry/inet", "//pkg/sentry/kernel", - "//pkg/sentry/platform", "//pkg/sentry/watchdog", "//pkg/state/statefile", ], diff --git a/pkg/sentry/state/state.go b/pkg/sentry/state/state.go index 70b33f190..67db78a56 100644 --- a/pkg/sentry/state/state.go +++ b/pkg/sentry/state/state.go @@ -22,7 +22,6 @@ import ( "gvisor.googlesource.com/gvisor/pkg/log" "gvisor.googlesource.com/gvisor/pkg/sentry/inet" "gvisor.googlesource.com/gvisor/pkg/sentry/kernel" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/watchdog" "gvisor.googlesource.com/gvisor/pkg/state/statefile" ) @@ -95,7 +94,7 @@ type LoadOpts struct { } // Load loads the given kernel, setting the provided platform and stack. -func (opts LoadOpts) Load(k *kernel.Kernel, p platform.Platform, n inet.Stack) error { +func (opts LoadOpts) Load(k *kernel.Kernel, n inet.Stack) error { // Open the file. r, m, err := statefile.NewReader(opts.Source, opts.Key) if err != nil { @@ -105,5 +104,5 @@ func (opts LoadOpts) Load(k *kernel.Kernel, p platform.Platform, n inet.Stack) e previousMetadata = m // Restore the Kernel object graph. - return k.LoadFrom(r, p, n) + return k.LoadFrom(r, n) } diff --git a/pkg/sentry/syscalls/linux/sys_sysinfo.go b/pkg/sentry/syscalls/linux/sys_sysinfo.go index 5eeb3ba58..6f7acf98f 100644 --- a/pkg/sentry/syscalls/linux/sys_sysinfo.go +++ b/pkg/sentry/syscalls/linux/sys_sysinfo.go @@ -25,10 +25,10 @@ import ( func Sysinfo(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { addr := args[0].Pointer() - mem := t.Kernel().Platform.Memory() - mem.UpdateUsage() + mf := t.Kernel().MemoryFile() + mf.UpdateUsage() _, totalUsage := usage.MemoryAccounting.Copy() - totalSize := usage.TotalMemory(mem.TotalSize(), totalUsage) + totalSize := usage.TotalMemory(mf.TotalSize(), totalUsage) // Only a subset of the fields in sysinfo_t make sense to return. si := linux.Sysinfo{ diff --git a/pkg/sentry/usage/memory.go b/pkg/sentry/usage/memory.go index 7e065cb76..5be9ed9c6 100644 --- a/pkg/sentry/usage/memory.go +++ b/pkg/sentry/usage/memory.go @@ -122,9 +122,6 @@ func Init() error { const name = "memory-usage" fd, err := memutil.CreateMemFD(name, 0) if err != nil { - if e, ok := err.(syscall.Errno); ok && e == syscall.ENOSYS { - return fmt.Errorf("memfd_create(2) is not implemented. Check that you have Linux 3.17 or higher") - } return fmt.Errorf("error creating usage file: %v", err) } file := os.NewFile(uintptr(fd), name) diff --git a/runsc/boot/BUILD b/runsc/boot/BUILD index daa197437..df9907e52 100644 --- a/runsc/boot/BUILD +++ b/runsc/boot/BUILD @@ -51,6 +51,8 @@ go_library( "//pkg/sentry/kernel/kdefs", "//pkg/sentry/limits", "//pkg/sentry/loader", + "//pkg/sentry/memutil", + "//pkg/sentry/pgalloc", "//pkg/sentry/platform", "//pkg/sentry/platform/kvm", "//pkg/sentry/platform/ptrace", diff --git a/runsc/boot/controller.go b/runsc/boot/controller.go index a864be720..14e1eba5b 100644 --- a/runsc/boot/controller.go +++ b/runsc/boot/controller.go @@ -332,6 +332,11 @@ func (cm *containerManager) Restore(o *RestoreOpts, _ *struct{}) error { k := &kernel.Kernel{ Platform: p, } + mf, err := createMemoryFile() + if err != nil { + return fmt.Errorf("creating memory file: %v", err) + } + k.SetMemoryFile(mf) cm.l.k = k // Set up the restore environment. @@ -362,7 +367,7 @@ func (cm *containerManager) Restore(o *RestoreOpts, _ *struct{}) error { loadOpts := state.LoadOpts{ Source: o.FilePayload.Files[0], } - if err := loadOpts.Load(k, p, networkStack); err != nil { + if err := loadOpts.Load(k, networkStack); err != nil { return err } @@ -384,7 +389,7 @@ func (cm *containerManager) Restore(o *RestoreOpts, _ *struct{}) error { cm.l.mu.Lock() eid := execID{cid: o.SandboxID} cm.l.processes = map[execID]*execProcess{ - eid: &execProcess{ + eid: { tg: cm.l.k.GlobalInit(), }, } diff --git a/runsc/boot/events.go b/runsc/boot/events.go index f954b8c0b..717adfedd 100644 --- a/runsc/boot/events.go +++ b/runsc/boot/events.go @@ -68,7 +68,7 @@ func (cm *containerManager) Event(_ *struct{}, out *Event) error { } func (s *Stats) populateMemory(k *kernel.Kernel) { - mem := k.Platform.Memory() + mem := k.MemoryFile() mem.UpdateUsage() _, totalUsage := usage.MemoryAccounting.Copy() s.Memory.Usage = MemoryEntry{ diff --git a/runsc/boot/loader.go b/runsc/boot/loader.go index 9ebe64dce..56cb137f0 100644 --- a/runsc/boot/loader.go +++ b/runsc/boot/loader.go @@ -37,6 +37,8 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/kernel" "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/auth" "gvisor.googlesource.com/gvisor/pkg/sentry/loader" + "gvisor.googlesource.com/gvisor/pkg/sentry/memutil" + "gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/platform/kvm" "gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace" @@ -189,6 +191,13 @@ func New(args Args) (*Loader, error) { Platform: p, } + // Create memory file. + mf, err := createMemoryFile() + if err != nil { + return nil, fmt.Errorf("creating memory file: %v", err) + } + k.SetMemoryFile(mf) + // Create VDSO. // // Pass k as the platform since it is savable, unlike the actual platform. @@ -297,7 +306,7 @@ func New(args Args) (*Loader, error) { stdioFDs: args.StdioFDs, rootProcArgs: procArgs, sandboxID: args.ID, - processes: map[execID]*execProcess{eid: &execProcess{}}, + processes: map[execID]*execProcess{eid: {}}, } // We don't care about child signals; some platforms can generate a @@ -404,6 +413,21 @@ func createPlatform(conf *Config, deviceFD int) (platform.Platform, error) { } } +func createMemoryFile() (*pgalloc.MemoryFile, error) { + const memfileName = "runsc-memory" + memfd, err := memutil.CreateMemFD(memfileName, 0) + if err != nil { + return nil, fmt.Errorf("error creating memfd: %v", err) + } + memfile := os.NewFile(uintptr(memfd), memfileName) + mf, err := pgalloc.NewMemoryFile(memfile) + if err != nil { + memfile.Close() + return nil, fmt.Errorf("error creating pgalloc.MemoryFile: %v", err) + } + return mf, nil +} + // Run runs the root container.. func (l *Loader) Run() error { err := l.run() |