diff options
Diffstat (limited to 'pkg/sentry/fs')
| -rw-r--r-- | pkg/sentry/fs/fsutil/file_range_set.go | 21 | ||||
| -rw-r--r-- | pkg/sentry/fs/fsutil/inode_cached.go | 4 | ||||
| -rw-r--r-- | pkg/sentry/fs/tmpfs/inode_file.go | 2 |
3 files changed, 21 insertions, 6 deletions
diff --git a/pkg/sentry/fs/fsutil/file_range_set.go b/pkg/sentry/fs/fsutil/file_range_set.go index 9197aeb88..1dc409d38 100644 --- a/pkg/sentry/fs/fsutil/file_range_set.go +++ b/pkg/sentry/fs/fsutil/file_range_set.go @@ -84,7 +84,8 @@ func (seg FileRangeIterator) FileRangeOf(mr memmap.MappableRange) memmap.FileRan // returns a successful partial read, Fill will call it repeatedly until all // bytes have been read.) EOF is handled consistently with the requirements of // mmap(2): bytes after EOF on the same page are zeroed; pages after EOF are -// invalid. +// invalid. fileSize is an upper bound on the file's size; bytes after fileSize +// will be zeroed without calling readAt. // // Fill may read offsets outside of required, but will never read offsets // outside of optional. It returns a non-nil error if any error occurs, even @@ -94,7 +95,7 @@ func (seg FileRangeIterator) FileRangeOf(mr memmap.MappableRange) memmap.FileRan // * required.Length() > 0. // * optional.IsSupersetOf(required). // * required and optional must be page-aligned. -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 { +func (frs *FileRangeSet) Fill(ctx context.Context, required, optional memmap.MappableRange, fileSize uint64, 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 { @@ -107,7 +108,21 @@ func (frs *FileRangeSet) Fill(ctx context.Context, required, optional memmap.Map 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) + n, err := func() (uint64, error) { + off := gr.Start + done + if off >= fileSize { + return 0, io.EOF + } + if off+dsts.NumBytes() > fileSize { + rd := fileSize - off + n, err := readAt(ctx, dsts.TakeFirst64(rd), off) + if n == rd && err == nil { + return n, io.EOF + } + return n, err + } + return readAt(ctx, dsts, off) + }() done += n dsts = dsts.DropFirst64(n) if err != nil { diff --git a/pkg/sentry/fs/fsutil/inode_cached.go b/pkg/sentry/fs/fsutil/inode_cached.go index 85a23432b..82eda3e43 100644 --- a/pkg/sentry/fs/fsutil/inode_cached.go +++ b/pkg/sentry/fs/fsutil/inode_cached.go @@ -644,7 +644,7 @@ func (rw *inodeReadWriter) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) { End: fs.OffsetPageEnd(int64(gapMR.End)), } optMR := gap.Range() - err := rw.c.cache.Fill(rw.ctx, reqMR, maxFillRange(reqMR, optMR), mem, usage.PageCache, rw.c.backingFile.ReadToBlocksAt) + err := rw.c.cache.Fill(rw.ctx, reqMR, maxFillRange(reqMR, optMR), uint64(rw.c.attr.Size), mem, usage.PageCache, rw.c.backingFile.ReadToBlocksAt) mem.MarkEvictable(rw.c, pgalloc.EvictableRange{optMR.Start, optMR.End}) seg, gap = rw.c.cache.Find(uint64(rw.offset)) if !seg.Ok() { @@ -870,7 +870,7 @@ func (c *CachingInodeOperations) Translate(ctx context.Context, required, option } mf := c.mfp.MemoryFile() - cerr := c.cache.Fill(ctx, required, maxFillRange(required, optional), mf, usage.PageCache, c.backingFile.ReadToBlocksAt) + cerr := c.cache.Fill(ctx, required, maxFillRange(required, optional), uint64(c.attr.Size), mf, usage.PageCache, c.backingFile.ReadToBlocksAt) var ts []memmap.Translation var translatedEnd uint64 diff --git a/pkg/sentry/fs/tmpfs/inode_file.go b/pkg/sentry/fs/tmpfs/inode_file.go index 1dc75291d..fc0498f17 100644 --- a/pkg/sentry/fs/tmpfs/inode_file.go +++ b/pkg/sentry/fs/tmpfs/inode_file.go @@ -613,7 +613,7 @@ func (f *fileInodeOperations) Translate(ctx context.Context, required, optional } mf := f.kernel.MemoryFile() - cerr := f.data.Fill(ctx, required, optional, mf, f.memUsage, func(_ context.Context, dsts safemem.BlockSeq, _ uint64) (uint64, error) { + cerr := f.data.Fill(ctx, required, optional, uint64(f.attr.Size), 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 }) |