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-rw-r--r--pkg/sentry/fs/fsutil/file_range_set.go31
-rw-r--r--pkg/sentry/fs/fsutil/host_file_mapper.go12
-rw-r--r--pkg/sentry/fs/fsutil/inode_cached.go21
3 files changed, 42 insertions, 22 deletions
diff --git a/pkg/sentry/fs/fsutil/file_range_set.go b/pkg/sentry/fs/fsutil/file_range_set.go
index bbafebf03..1dc409d38 100644
--- a/pkg/sentry/fs/fsutil/file_range_set.go
+++ b/pkg/sentry/fs/fsutil/file_range_set.go
@@ -70,7 +70,9 @@ func (seg FileRangeIterator) FileRange() memmap.FileRange {
// FileRangeOf returns the FileRange mapped by mr.
//
-// Preconditions: seg.Range().IsSupersetOf(mr). mr.Length() != 0.
+// Preconditions:
+// * seg.Range().IsSupersetOf(mr).
+// * mr.Length() != 0.
func (seg FileRangeIterator) FileRangeOf(mr memmap.MappableRange) memmap.FileRange {
frstart := seg.Value() + (mr.Start - seg.Start())
return memmap.FileRange{frstart, frstart + mr.Length()}
@@ -82,15 +84,18 @@ 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
// if the error only affects offsets in optional, but not in required.
//
-// 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, mf *pgalloc.MemoryFile, kind usage.MemoryKind, readAt func(ctx context.Context, dsts safemem.BlockSeq, offset uint64) (uint64, error)) error {
+// 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, 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 {
@@ -103,7 +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/host_file_mapper.go b/pkg/sentry/fs/fsutil/host_file_mapper.go
index ef0113b52..1390a9a7f 100644
--- a/pkg/sentry/fs/fsutil/host_file_mapper.go
+++ b/pkg/sentry/fs/fsutil/host_file_mapper.go
@@ -80,7 +80,9 @@ func NewHostFileMapper() *HostFileMapper {
// IncRefOn increments the reference count on all offsets in mr.
//
-// Preconditions: mr.Length() != 0. mr.Start and mr.End must be page-aligned.
+// Preconditions:
+// * mr.Length() != 0.
+// * mr.Start and mr.End must be page-aligned.
func (f *HostFileMapper) IncRefOn(mr memmap.MappableRange) {
f.refsMu.Lock()
defer f.refsMu.Unlock()
@@ -97,7 +99,9 @@ func (f *HostFileMapper) IncRefOn(mr memmap.MappableRange) {
// DecRefOn decrements the reference count on all offsets in mr.
//
-// Preconditions: mr.Length() != 0. mr.Start and mr.End must be page-aligned.
+// Preconditions:
+// * mr.Length() != 0.
+// * mr.Start and mr.End must be page-aligned.
func (f *HostFileMapper) DecRefOn(mr memmap.MappableRange) {
f.refsMu.Lock()
defer f.refsMu.Unlock()
@@ -204,7 +208,9 @@ func (f *HostFileMapper) UnmapAll() {
}
}
-// Preconditions: f.mapsMu must be locked. f.mappings[chunkStart] == m.
+// Preconditions:
+// * f.mapsMu must be locked.
+// * f.mappings[chunkStart] == m.
func (f *HostFileMapper) unmapAndRemoveLocked(chunkStart uint64, m mapping) {
if _, _, errno := syscall.Syscall(syscall.SYS_MUNMAP, m.addr, chunkSize, 0); errno != 0 {
// This leaks address space and is unexpected, but is otherwise
diff --git a/pkg/sentry/fs/fsutil/inode_cached.go b/pkg/sentry/fs/fsutil/inode_cached.go
index fe8b0b6ac..82eda3e43 100644
--- a/pkg/sentry/fs/fsutil/inode_cached.go
+++ b/pkg/sentry/fs/fsutil/inode_cached.go
@@ -22,7 +22,6 @@ import (
"gvisor.dev/gvisor/pkg/log"
"gvisor.dev/gvisor/pkg/safemem"
"gvisor.dev/gvisor/pkg/sentry/fs"
- "gvisor.dev/gvisor/pkg/sentry/kernel/time"
ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
"gvisor.dev/gvisor/pkg/sentry/memmap"
"gvisor.dev/gvisor/pkg/sentry/pgalloc"
@@ -444,7 +443,7 @@ func (c *CachingInodeOperations) TouchAccessTime(ctx context.Context, inode *fs.
// time.
//
// Preconditions: c.attrMu is locked for writing.
-func (c *CachingInodeOperations) touchAccessTimeLocked(now time.Time) {
+func (c *CachingInodeOperations) touchAccessTimeLocked(now ktime.Time) {
c.attr.AccessTime = now
c.dirtyAttr.AccessTime = true
}
@@ -461,7 +460,7 @@ func (c *CachingInodeOperations) TouchModificationAndStatusChangeTime(ctx contex
// and status change times in-place to the current time.
//
// Preconditions: c.attrMu is locked for writing.
-func (c *CachingInodeOperations) touchModificationAndStatusChangeTimeLocked(now time.Time) {
+func (c *CachingInodeOperations) touchModificationAndStatusChangeTimeLocked(now ktime.Time) {
c.attr.ModificationTime = now
c.dirtyAttr.ModificationTime = true
c.attr.StatusChangeTime = now
@@ -480,7 +479,7 @@ func (c *CachingInodeOperations) TouchStatusChangeTime(ctx context.Context) {
// in-place to the current time.
//
// Preconditions: c.attrMu is locked for writing.
-func (c *CachingInodeOperations) touchStatusChangeTimeLocked(now time.Time) {
+func (c *CachingInodeOperations) touchStatusChangeTimeLocked(now ktime.Time) {
c.attr.StatusChangeTime = now
c.dirtyAttr.StatusChangeTime = true
}
@@ -645,7 +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() {
@@ -672,9 +671,6 @@ func (rw *inodeReadWriter) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) {
// Continue.
seg, gap = gap.NextSegment(), FileRangeGapIterator{}
}
-
- default:
- break
}
}
unlock()
@@ -684,7 +680,9 @@ func (rw *inodeReadWriter) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) {
// maybeGrowFile grows the file's size if data has been written past the old
// size.
//
-// Preconditions: rw.c.attrMu and rw.c.dataMu bust be locked.
+// Preconditions:
+// * rw.c.attrMu must be locked.
+// * rw.c.dataMu must be locked.
func (rw *inodeReadWriter) maybeGrowFile() {
// If the write ends beyond the file's previous size, it causes the
// file to grow.
@@ -766,9 +764,6 @@ func (rw *inodeReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error
// Continue.
seg, gap = gap.NextSegment(), FileRangeGapIterator{}
-
- default:
- break
}
}
rw.maybeGrowFile()
@@ -875,7 +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
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-28 15:33:46 +0000