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-rw-r--r--pkg/sentry/fsimpl/gofer/gofer.go28
-rw-r--r--pkg/sentry/fsimpl/gofer/regular_file.go39
-rw-r--r--pkg/sentry/kernel/semaphore/semaphore.go10
-rw-r--r--pkg/sentry/socket/hostinet/socket_unsafe.go2
4 files changed, 48 insertions, 31 deletions
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index ec8d58cc9..25d2e39d6 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -1161,6 +1161,13 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, opts *vfs
if !d.isSynthetic() {
if stat.Mask != 0 {
+ if stat.Mask&linux.STATX_SIZE != 0 {
+ // d.dataMu must be held around the update to both the remote
+ // file's size and d.size to serialize with writeback (which
+ // might otherwise write data back up to the old d.size after
+ // the remote file has been truncated).
+ d.dataMu.Lock()
+ }
if err := d.file.setAttr(ctx, p9.SetAttrMask{
Permissions: stat.Mask&linux.STATX_MODE != 0,
UID: stat.Mask&linux.STATX_UID != 0,
@@ -1180,13 +1187,16 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, opts *vfs
MTimeSeconds: uint64(stat.Mtime.Sec),
MTimeNanoSeconds: uint64(stat.Mtime.Nsec),
}); err != nil {
+ if stat.Mask&linux.STATX_SIZE != 0 {
+ d.dataMu.Unlock() // +checklocksforce: locked conditionally above
+ }
return err
}
if stat.Mask&linux.STATX_SIZE != 0 {
// d.size should be kept up to date, and privatized
// copy-on-write mappings of truncated pages need to be
// invalidated, even if InteropModeShared is in effect.
- d.updateSizeLocked(stat.Size)
+ d.updateSizeAndUnlockDataMuLocked(stat.Size) // +checklocksforce: locked conditionally above
}
}
if d.fs.opts.interop == InteropModeShared {
@@ -1249,6 +1259,14 @@ func (d *dentry) doAllocate(ctx context.Context, offset, length uint64, allocate
// Preconditions: d.metadataMu must be locked.
func (d *dentry) updateSizeLocked(newSize uint64) {
d.dataMu.Lock()
+ d.updateSizeAndUnlockDataMuLocked(newSize)
+}
+
+// Preconditions: d.metadataMu and d.dataMu must be locked.
+//
+// Postconditions: d.dataMu is unlocked.
+// +checklocksrelease:d.dataMu
+func (d *dentry) updateSizeAndUnlockDataMuLocked(newSize uint64) {
oldSize := d.size
atomic.StoreUint64(&d.size, newSize)
// d.dataMu must be unlocked to lock d.mapsMu and invalidate mappings
@@ -1257,9 +1275,9 @@ func (d *dentry) updateSizeLocked(newSize uint64) {
// contents beyond the new d.size. (We are still holding d.metadataMu,
// so we can't race with Write or another truncate.)
d.dataMu.Unlock()
- if d.size < oldSize {
+ if newSize < oldSize {
oldpgend, _ := hostarch.PageRoundUp(oldSize)
- newpgend, _ := hostarch.PageRoundUp(d.size)
+ newpgend, _ := hostarch.PageRoundUp(newSize)
if oldpgend != newpgend {
d.mapsMu.Lock()
d.mappings.Invalidate(memmap.MappableRange{newpgend, oldpgend}, memmap.InvalidateOpts{
@@ -1275,8 +1293,8 @@ func (d *dentry) updateSizeLocked(newSize uint64) {
// truncated pages have been removed from the remote file, they
// should be dropped without being written back.
d.dataMu.Lock()
- d.cache.Truncate(d.size, d.fs.mfp.MemoryFile())
- d.dirty.KeepClean(memmap.MappableRange{d.size, oldpgend})
+ d.cache.Truncate(newSize, d.fs.mfp.MemoryFile())
+ d.dirty.KeepClean(memmap.MappableRange{newSize, oldpgend})
d.dataMu.Unlock()
}
}
diff --git a/pkg/sentry/fsimpl/gofer/regular_file.go b/pkg/sentry/fsimpl/gofer/regular_file.go
index 91405fe66..947dbe05f 100644
--- a/pkg/sentry/fsimpl/gofer/regular_file.go
+++ b/pkg/sentry/fsimpl/gofer/regular_file.go
@@ -79,17 +79,22 @@ func (fd *regularFileFD) OnClose(ctx context.Context) error {
if !fd.vfsfd.IsWritable() {
return nil
}
- // Skip flushing if there are client-buffered writes, since (as with the
- // VFS1 client) we don't flush buffered writes on close anyway.
d := fd.dentry()
- if d.fs.opts.interop != InteropModeExclusive {
- return nil
- }
- d.dataMu.RLock()
- haveDirtyPages := !d.dirty.IsEmpty()
- d.dataMu.RUnlock()
- if haveDirtyPages {
- return nil
+ if d.fs.opts.interop == InteropModeExclusive {
+ // d may have dirty pages that we won't write back now (and wouldn't
+ // have in VFS1), making a flushf RPC ineffective. If this is the case,
+ // skip the flushf.
+ //
+ // Note that it's also possible to have dirty pages under other interop
+ // modes if forcePageCache is in effect; we conservatively assume that
+ // applications have some way of tolerating this and still want the
+ // flushf.
+ d.dataMu.RLock()
+ haveDirtyPages := !d.dirty.IsEmpty()
+ d.dataMu.RUnlock()
+ if haveDirtyPages {
+ return nil
+ }
}
d.handleMu.RLock()
defer d.handleMu.RUnlock()
@@ -707,14 +712,8 @@ func (fd *regularFileFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpt
return vfs.GenericConfigureMMap(&fd.vfsfd, d, opts)
}
-func (d *dentry) mayCachePages() bool {
- if d.fs.opts.forcePageCache {
- return true
- }
- if d.fs.opts.interop == InteropModeShared {
- return false
- }
- return atomic.LoadInt32(&d.mmapFD) >= 0
+func (fs *filesystem) mayCachePagesInMemoryFile() bool {
+ return fs.opts.forcePageCache || fs.opts.interop != InteropModeShared
}
// AddMapping implements memmap.Mappable.AddMapping.
@@ -726,7 +725,7 @@ func (d *dentry) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar host
for _, r := range mapped {
d.pf.hostFileMapper.IncRefOn(r)
}
- if d.mayCachePages() {
+ if d.fs.mayCachePagesInMemoryFile() {
// d.Evict() will refuse to evict memory-mapped pages, so tell the
// MemoryFile to not bother trying.
mf := d.fs.mfp.MemoryFile()
@@ -745,7 +744,7 @@ func (d *dentry) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar h
for _, r := range unmapped {
d.pf.hostFileMapper.DecRefOn(r)
}
- if d.mayCachePages() {
+ if d.fs.mayCachePagesInMemoryFile() {
// Pages that are no longer referenced by any application memory
// mappings are now considered unused; allow MemoryFile to evict them
// when necessary.
diff --git a/pkg/sentry/kernel/semaphore/semaphore.go b/pkg/sentry/kernel/semaphore/semaphore.go
index b7879d284..8610d3fc1 100644
--- a/pkg/sentry/kernel/semaphore/semaphore.go
+++ b/pkg/sentry/kernel/semaphore/semaphore.go
@@ -214,15 +214,14 @@ func (r *Registry) Remove(id ipc.ID, creds *auth.Credentials) error {
r.mu.Lock()
defer r.mu.Unlock()
- r.reg.Remove(id, creds)
-
index, found := r.findIndexByID(id)
if !found {
- // Inconsistent state.
- panic(fmt.Sprintf("unable to find an index for ID: %d", id))
+ return linuxerr.EINVAL
}
delete(r.indexes, index)
+ r.reg.Remove(id, creds)
+
return nil
}
@@ -245,7 +244,8 @@ func (r *Registry) newSetLocked(ctx context.Context, key ipc.Key, creator fs.Fil
index, found := r.findFirstAvailableIndex()
if !found {
- panic("unable to find an available index")
+ // See linux, ipc/sem.c:newary().
+ return nil, linuxerr.ENOSPC
}
r.indexes[index] = set.obj.ID
diff --git a/pkg/sentry/socket/hostinet/socket_unsafe.go b/pkg/sentry/socket/hostinet/socket_unsafe.go
index ccf4f534d..587f479eb 100644
--- a/pkg/sentry/socket/hostinet/socket_unsafe.go
+++ b/pkg/sentry/socket/hostinet/socket_unsafe.go
@@ -67,7 +67,7 @@ func ioctl(ctx context.Context, fd int, io usermem.IO, args arch.SyscallArgument
AddressSpaceActive: true,
})
return 0, err
- case unix.SIOCGIFFLAGS:
+ case unix.SIOCGIFFLAGS, unix.SIOCGIFCONF:
cc := &usermem.IOCopyContext{
Ctx: ctx,
IO: io,
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-20 07:24:23 +0000