diff options
Diffstat (limited to 'pkg/sentry/fs/proc')
| -rw-r--r-- | pkg/sentry/fs/proc/exec_args.go | 2 | ||||
| -rw-r--r-- | pkg/sentry/fs/proc/task.go | 116 |
2 files changed, 50 insertions, 68 deletions
diff --git a/pkg/sentry/fs/proc/exec_args.go b/pkg/sentry/fs/proc/exec_args.go index 379429ab2..75dc5d204 100644 --- a/pkg/sentry/fs/proc/exec_args.go +++ b/pkg/sentry/fs/proc/exec_args.go @@ -107,7 +107,7 @@ func (f *execArgFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequen return 0, linuxerr.EINVAL } - m, err := getTaskMM(f.t) + m, err := getTaskMMIncRef(f.t) if err != nil { return 0, err } diff --git a/pkg/sentry/fs/proc/task.go b/pkg/sentry/fs/proc/task.go index 89a799b21..03f2a882d 100644 --- a/pkg/sentry/fs/proc/task.go +++ b/pkg/sentry/fs/proc/task.go @@ -41,10 +41,24 @@ import ( // LINT.IfChange -// getTaskMM returns t's MemoryManager. If getTaskMM succeeds, the MemoryManager's -// users count is incremented, and must be decremented by the caller when it is -// no longer in use. -func getTaskMM(t *kernel.Task) (*mm.MemoryManager, error) { +// getTaskMM gets the kernel task's MemoryManager. No additional reference is +// taken on mm here. This is safe because MemoryManager.destroy is required to +// leave the MemoryManager in a state where it's still usable as a +// DynamicBytesSource. +func getTaskMM(t *kernel.Task) *mm.MemoryManager { + var tmm *mm.MemoryManager + t.WithMuLocked(func(t *kernel.Task) { + if mm := t.MemoryManager(); mm != nil { + tmm = mm + } + }) + return tmm +} + +// getTaskMMIncRef returns t's MemoryManager. If getTaskMMIncRef succeeds, the +// MemoryManager's users count is incremented, and must be decremented by the +// caller when it is no longer in use. +func getTaskMMIncRef(t *kernel.Task) (*mm.MemoryManager, error) { if t.ExitState() == kernel.TaskExitDead { return nil, linuxerr.ESRCH } @@ -269,21 +283,18 @@ func (e *exe) executable() (file fsbridge.File, err error) { if err := checkTaskState(e.t); err != nil { return nil, err } - e.t.WithMuLocked(func(t *kernel.Task) { - mm := t.MemoryManager() - if mm == nil { - err = linuxerr.EACCES - return - } + mm := getTaskMM(e.t) + if mm == nil { + return nil, linuxerr.EACCES + } - // The MemoryManager may be destroyed, in which case - // MemoryManager.destroy will simply set the executable to nil - // (with locks held). - file = mm.Executable() - if file == nil { - err = linuxerr.ESRCH - } - }) + // The MemoryManager may be destroyed, in which case + // MemoryManager.destroy will simply set the executable to nil + // (with locks held). + file = mm.Executable() + if file == nil { + err = linuxerr.ESRCH + } return } @@ -463,7 +474,7 @@ func (m *memDataFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequen if dst.NumBytes() == 0 { return 0, nil } - mm, err := getTaskMM(m.t) + mm, err := getTaskMMIncRef(m.t) if err != nil { return 0, nil } @@ -494,22 +505,9 @@ func newMaps(ctx context.Context, t *kernel.Task, msrc *fs.MountSource) *fs.Inod return newProcInode(ctx, seqfile.NewSeqFile(ctx, &mapsData{t}), msrc, fs.SpecialFile, t) } -func (md *mapsData) mm() *mm.MemoryManager { - var tmm *mm.MemoryManager - md.t.WithMuLocked(func(t *kernel.Task) { - if mm := t.MemoryManager(); mm != nil { - // No additional reference is taken on mm here. This is safe - // because MemoryManager.destroy is required to leave the - // MemoryManager in a state where it's still usable as a SeqSource. - tmm = mm - } - }) - return tmm -} - // NeedsUpdate implements seqfile.SeqSource.NeedsUpdate. func (md *mapsData) NeedsUpdate(generation int64) bool { - if mm := md.mm(); mm != nil { + if mm := getTaskMM(md.t); mm != nil { return mm.NeedsUpdate(generation) } return true @@ -517,7 +515,7 @@ func (md *mapsData) NeedsUpdate(generation int64) bool { // ReadSeqFileData implements seqfile.SeqSource.ReadSeqFileData. func (md *mapsData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) { - if mm := md.mm(); mm != nil { + if mm := getTaskMM(md.t); mm != nil { return mm.ReadMapsSeqFileData(ctx, h) } return []seqfile.SeqData{}, 0 @@ -534,22 +532,9 @@ func newSmaps(ctx context.Context, t *kernel.Task, msrc *fs.MountSource) *fs.Ino return newProcInode(ctx, seqfile.NewSeqFile(ctx, &smapsData{t}), msrc, fs.SpecialFile, t) } -func (sd *smapsData) mm() *mm.MemoryManager { - var tmm *mm.MemoryManager - sd.t.WithMuLocked(func(t *kernel.Task) { - if mm := t.MemoryManager(); mm != nil { - // No additional reference is taken on mm here. This is safe - // because MemoryManager.destroy is required to leave the - // MemoryManager in a state where it's still usable as a SeqSource. - tmm = mm - } - }) - return tmm -} - // NeedsUpdate implements seqfile.SeqSource.NeedsUpdate. func (sd *smapsData) NeedsUpdate(generation int64) bool { - if mm := sd.mm(); mm != nil { + if mm := getTaskMM(sd.t); mm != nil { return mm.NeedsUpdate(generation) } return true @@ -557,7 +542,7 @@ func (sd *smapsData) NeedsUpdate(generation int64) bool { // ReadSeqFileData implements seqfile.SeqSource.ReadSeqFileData. func (sd *smapsData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) { - if mm := sd.mm(); mm != nil { + if mm := getTaskMM(sd.t); mm != nil { return mm.ReadSmapsSeqFileData(ctx, h) } return []seqfile.SeqData{}, 0 @@ -627,12 +612,10 @@ func (s *taskStatData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) fmt.Fprintf(&buf, "%d ", linux.ClockTFromDuration(s.t.StartTime().Sub(s.t.Kernel().Timekeeper().BootTime()))) var vss, rss uint64 - s.t.WithMuLocked(func(t *kernel.Task) { - if mm := t.MemoryManager(); mm != nil { - vss = mm.VirtualMemorySize() - rss = mm.ResidentSetSize() - } - }) + if mm := getTaskMM(s.t); mm != nil { + vss = mm.VirtualMemorySize() + rss = mm.ResidentSetSize() + } fmt.Fprintf(&buf, "%d %d ", vss, rss/hostarch.PageSize) // rsslim. @@ -677,12 +660,10 @@ func (s *statmData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([ } var vss, rss uint64 - s.t.WithMuLocked(func(t *kernel.Task) { - if mm := t.MemoryManager(); mm != nil { - vss = mm.VirtualMemorySize() - rss = mm.ResidentSetSize() - } - }) + if mm := getTaskMM(s.t); mm != nil { + vss = mm.VirtualMemorySize() + rss = mm.ResidentSetSize() + } var buf bytes.Buffer fmt.Fprintf(&buf, "%d %d 0 0 0 0 0\n", vss/hostarch.PageSize, rss/hostarch.PageSize) @@ -734,12 +715,13 @@ func (s *statusData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ( if fdTable := t.FDTable(); fdTable != nil { fds = fdTable.CurrentMaxFDs() } - if mm := t.MemoryManager(); mm != nil { - vss = mm.VirtualMemorySize() - rss = mm.ResidentSetSize() - data = mm.VirtualDataSize() - } }) + + if mm := getTaskMM(s.t); mm != nil { + vss = mm.VirtualMemorySize() + rss = mm.ResidentSetSize() + data = mm.VirtualDataSize() + } fmt.Fprintf(&buf, "FDSize:\t%d\n", fds) fmt.Fprintf(&buf, "VmSize:\t%d kB\n", vss>>10) fmt.Fprintf(&buf, "VmRSS:\t%d kB\n", rss>>10) @@ -925,7 +907,7 @@ func (f *auxvecFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequenc return 0, linuxerr.EINVAL } - m, err := getTaskMM(f.t) + m, err := getTaskMMIncRef(f.t) if err != nil { return 0, err } |