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authorIan Lewis <ianlewis@google.com>2020-03-05 18:21:39 -0800
committergVisor bot <gvisor-bot@google.com>2020-03-05 18:23:01 -0800
commitda48fc6cca23a38faef51c5b5f8ae609940773a0 (patch)
tree21ce4007f01fc85c584f6da4e92fee35fa6d329d /pkg
parent9b64b658c1b9a4986bc5a4ebd9e5ddeb9f52dfa3 (diff)
Stub oom_score_adj and oom_score.
Adds an oom_score_adj and oom_score proc file stub. oom_score_adj accepts writes of values -1000 to 1000 and persists the value with the task. New tasks inherit the parent's oom_score_adj. oom_score is a read-only stub that always returns the value '0'. Issue #202 PiperOrigin-RevId: 299245355
Diffstat (limited to 'pkg')
-rw-r--r--pkg/sentry/fs/proc/task.go126
-rw-r--r--pkg/sentry/fsimpl/proc/task.go12
-rw-r--r--pkg/sentry/fsimpl/proc/task_files.go43
-rw-r--r--pkg/sentry/fsimpl/proc/tasks_test.go32
-rw-r--r--pkg/sentry/kernel/task.go33
-rw-r--r--pkg/sentry/kernel/task_clone.go6
-rw-r--r--pkg/sentry/kernel/task_start.go4
7 files changed, 218 insertions, 38 deletions
diff --git a/pkg/sentry/fs/proc/task.go b/pkg/sentry/fs/proc/task.go
index 8ab8d8a02..4e9b0fc00 100644
--- a/pkg/sentry/fs/proc/task.go
+++ b/pkg/sentry/fs/proc/task.go
@@ -72,24 +72,26 @@ var _ fs.InodeOperations = (*taskDir)(nil)
// newTaskDir creates a new proc task entry.
func (p *proc) newTaskDir(t *kernel.Task, msrc *fs.MountSource, isThreadGroup bool) *fs.Inode {
contents := map[string]*fs.Inode{
- "auxv": newAuxvec(t, msrc),
- "cmdline": newExecArgInode(t, msrc, cmdlineExecArg),
- "comm": newComm(t, msrc),
- "environ": newExecArgInode(t, msrc, environExecArg),
- "exe": newExe(t, msrc),
- "fd": newFdDir(t, msrc),
- "fdinfo": newFdInfoDir(t, msrc),
- "gid_map": newGIDMap(t, msrc),
- "io": newIO(t, msrc, isThreadGroup),
- "maps": newMaps(t, msrc),
- "mountinfo": seqfile.NewSeqFileInode(t, &mountInfoFile{t: t}, msrc),
- "mounts": seqfile.NewSeqFileInode(t, &mountsFile{t: t}, msrc),
- "ns": newNamespaceDir(t, msrc),
- "smaps": newSmaps(t, msrc),
- "stat": newTaskStat(t, msrc, isThreadGroup, p.pidns),
- "statm": newStatm(t, msrc),
- "status": newStatus(t, msrc, p.pidns),
- "uid_map": newUIDMap(t, msrc),
+ "auxv": newAuxvec(t, msrc),
+ "cmdline": newExecArgInode(t, msrc, cmdlineExecArg),
+ "comm": newComm(t, msrc),
+ "environ": newExecArgInode(t, msrc, environExecArg),
+ "exe": newExe(t, msrc),
+ "fd": newFdDir(t, msrc),
+ "fdinfo": newFdInfoDir(t, msrc),
+ "gid_map": newGIDMap(t, msrc),
+ "io": newIO(t, msrc, isThreadGroup),
+ "maps": newMaps(t, msrc),
+ "mountinfo": seqfile.NewSeqFileInode(t, &mountInfoFile{t: t}, msrc),
+ "mounts": seqfile.NewSeqFileInode(t, &mountsFile{t: t}, msrc),
+ "ns": newNamespaceDir(t, msrc),
+ "oom_score": newOOMScore(t, msrc),
+ "oom_score_adj": newOOMScoreAdj(t, msrc),
+ "smaps": newSmaps(t, msrc),
+ "stat": newTaskStat(t, msrc, isThreadGroup, p.pidns),
+ "statm": newStatm(t, msrc),
+ "status": newStatus(t, msrc, p.pidns),
+ "uid_map": newUIDMap(t, msrc),
}
if isThreadGroup {
contents["task"] = p.newSubtasks(t, msrc)
@@ -796,4 +798,92 @@ func (f *auxvecFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequenc
return int64(n), err
}
+// newOOMScore returns a oom_score file. It is a stub that always returns 0.
+// TODO(gvisor.dev/issue/1967)
+func newOOMScore(t *kernel.Task, msrc *fs.MountSource) *fs.Inode {
+ return newStaticProcInode(t, msrc, []byte("0\n"))
+}
+
+// oomScoreAdj is a file containing the oom_score adjustment for a task.
+//
+// +stateify savable
+type oomScoreAdj struct {
+ fsutil.SimpleFileInode
+
+ t *kernel.Task
+}
+
+// +stateify savable
+type oomScoreAdjFile struct {
+ fsutil.FileGenericSeek `state:"nosave"`
+ fsutil.FileNoIoctl `state:"nosave"`
+ fsutil.FileNoMMap `state:"nosave"`
+ fsutil.FileNoSplice `state:"nosave"`
+ fsutil.FileNoopFlush `state:"nosave"`
+ fsutil.FileNoopFsync `state:"nosave"`
+ fsutil.FileNoopRelease `state:"nosave"`
+ fsutil.FileNotDirReaddir `state:"nosave"`
+ fsutil.FileUseInodeUnstableAttr `state:"nosave"`
+ waiter.AlwaysReady `state:"nosave"`
+
+ t *kernel.Task
+}
+
+// newOOMScoreAdj returns a oom_score_adj file.
+func newOOMScoreAdj(t *kernel.Task, msrc *fs.MountSource) *fs.Inode {
+ i := &oomScoreAdj{
+ SimpleFileInode: *fsutil.NewSimpleFileInode(t, fs.RootOwner, fs.FilePermsFromMode(0644), linux.PROC_SUPER_MAGIC),
+ t: t,
+ }
+ return newProcInode(t, i, msrc, fs.SpecialFile, t)
+}
+
+// Truncate implements fs.InodeOperations.Truncate. Truncate is called when
+// O_TRUNC is specified for any kind of existing Dirent but is not called via
+// (f)truncate for proc files.
+func (*oomScoreAdj) Truncate(context.Context, *fs.Inode, int64) error {
+ return nil
+}
+
+// GetFile implements fs.InodeOperations.GetFile.
+func (o *oomScoreAdj) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) {
+ return fs.NewFile(ctx, dirent, flags, &oomScoreAdjFile{t: o.t}), nil
+}
+
+// Read implements fs.FileOperations.Read.
+func (f *oomScoreAdjFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, offset int64) (int64, error) {
+ if offset != 0 {
+ return 0, io.EOF
+ }
+ adj, err := f.t.OOMScoreAdj()
+ if err != nil {
+ return 0, err
+ }
+ adjBytes := []byte(strconv.FormatInt(int64(adj), 10) + "\n")
+ n, err := dst.CopyOut(ctx, adjBytes)
+ return int64(n), err
+}
+
+// Write implements fs.FileOperations.Write.
+func (f *oomScoreAdjFile) Write(ctx context.Context, _ *fs.File, src usermem.IOSequence, offset int64) (int64, error) {
+ if src.NumBytes() == 0 {
+ return 0, nil
+ }
+
+ // Limit input size so as not to impact performance if input size is large.
+ src = src.TakeFirst(usermem.PageSize - 1)
+
+ var v int32
+ n, err := usermem.CopyInt32StringInVec(ctx, src.IO, src.Addrs, &v, src.Opts)
+ if err != nil {
+ return 0, err
+ }
+
+ if err := f.t.SetOOMScoreAdj(v); err != nil {
+ return 0, err
+ }
+
+ return n, nil
+}
+
// LINT.ThenChange(../../fsimpl/proc/task.go|../../fsimpl/proc/task_files.go)
diff --git a/pkg/sentry/fsimpl/proc/task.go b/pkg/sentry/fsimpl/proc/task.go
index 2d814668a..18e5cd6f6 100644
--- a/pkg/sentry/fsimpl/proc/task.go
+++ b/pkg/sentry/fsimpl/proc/task.go
@@ -62,11 +62,13 @@ func newTaskInode(inoGen InoGenerator, task *kernel.Task, pidns *kernel.PIDNames
"pid": newNamespaceSymlink(task, inoGen.NextIno(), "pid"),
"user": newNamespaceSymlink(task, inoGen.NextIno(), "user"),
}),
- "smaps": newTaskOwnedFile(task, inoGen.NextIno(), 0444, &smapsData{task: task}),
- "stat": newTaskOwnedFile(task, inoGen.NextIno(), 0444, &taskStatData{task: task, pidns: pidns, tgstats: isThreadGroup}),
- "statm": newTaskOwnedFile(task, inoGen.NextIno(), 0444, &statmData{task: task}),
- "status": newTaskOwnedFile(task, inoGen.NextIno(), 0444, &statusData{task: task, pidns: pidns}),
- "uid_map": newTaskOwnedFile(task, inoGen.NextIno(), 0644, &idMapData{task: task, gids: false}),
+ "oom_score": newTaskOwnedFile(task, inoGen.NextIno(), 0444, newStaticFile("0\n")),
+ "oom_score_adj": newTaskOwnedFile(task, inoGen.NextIno(), 0644, &oomScoreAdj{task: task}),
+ "smaps": newTaskOwnedFile(task, inoGen.NextIno(), 0444, &smapsData{task: task}),
+ "stat": newTaskOwnedFile(task, inoGen.NextIno(), 0444, &taskStatData{task: task, pidns: pidns, tgstats: isThreadGroup}),
+ "statm": newTaskOwnedFile(task, inoGen.NextIno(), 0444, &statmData{task: task}),
+ "status": newTaskOwnedFile(task, inoGen.NextIno(), 0444, &statusData{task: task, pidns: pidns}),
+ "uid_map": newTaskOwnedFile(task, inoGen.NextIno(), 0644, &idMapData{task: task, gids: false}),
}
if isThreadGroup {
contents["task"] = newSubtasks(task, pidns, inoGen, cgroupControllers)
diff --git a/pkg/sentry/fsimpl/proc/task_files.go b/pkg/sentry/fsimpl/proc/task_files.go
index efd3b3453..5a231ac86 100644
--- a/pkg/sentry/fsimpl/proc/task_files.go
+++ b/pkg/sentry/fsimpl/proc/task_files.go
@@ -525,3 +525,46 @@ func (i *ioData) Generate(ctx context.Context, buf *bytes.Buffer) error {
fmt.Fprintf(buf, "cancelled_write_bytes: %d\n", io.BytesWriteCancelled)
return nil
}
+
+// oomScoreAdj is a stub of the /proc/<pid>/oom_score_adj file.
+//
+// +stateify savable
+type oomScoreAdj struct {
+ kernfs.DynamicBytesFile
+
+ task *kernel.Task
+}
+
+var _ vfs.WritableDynamicBytesSource = (*oomScoreAdj)(nil)
+
+// Generate implements vfs.DynamicBytesSource.Generate.
+func (o *oomScoreAdj) Generate(ctx context.Context, buf *bytes.Buffer) error {
+ adj, err := o.task.OOMScoreAdj()
+ if err != nil {
+ return err
+ }
+ fmt.Fprintf(buf, "%d\n", adj)
+ return nil
+}
+
+// Write implements vfs.WritableDynamicBytesSource.Write.
+func (o *oomScoreAdj) Write(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) {
+ if src.NumBytes() == 0 {
+ return 0, nil
+ }
+
+ // Limit input size so as not to impact performance if input size is large.
+ src = src.TakeFirst(usermem.PageSize - 1)
+
+ var v int32
+ n, err := usermem.CopyInt32StringInVec(ctx, src.IO, src.Addrs, &v, src.Opts)
+ if err != nil {
+ return 0, err
+ }
+
+ if err := o.task.SetOOMScoreAdj(v); err != nil {
+ return 0, err
+ }
+
+ return n, nil
+}
diff --git a/pkg/sentry/fsimpl/proc/tasks_test.go b/pkg/sentry/fsimpl/proc/tasks_test.go
index c5d531fe0..0eb401619 100644
--- a/pkg/sentry/fsimpl/proc/tasks_test.go
+++ b/pkg/sentry/fsimpl/proc/tasks_test.go
@@ -63,21 +63,23 @@ var (
"thread-self": threadSelfLink.NextOff,
}
taskStaticFiles = map[string]testutil.DirentType{
- "auxv": linux.DT_REG,
- "cgroup": linux.DT_REG,
- "cmdline": linux.DT_REG,
- "comm": linux.DT_REG,
- "environ": linux.DT_REG,
- "gid_map": linux.DT_REG,
- "io": linux.DT_REG,
- "maps": linux.DT_REG,
- "ns": linux.DT_DIR,
- "smaps": linux.DT_REG,
- "stat": linux.DT_REG,
- "statm": linux.DT_REG,
- "status": linux.DT_REG,
- "task": linux.DT_DIR,
- "uid_map": linux.DT_REG,
+ "auxv": linux.DT_REG,
+ "cgroup": linux.DT_REG,
+ "cmdline": linux.DT_REG,
+ "comm": linux.DT_REG,
+ "environ": linux.DT_REG,
+ "gid_map": linux.DT_REG,
+ "io": linux.DT_REG,
+ "maps": linux.DT_REG,
+ "ns": linux.DT_DIR,
+ "oom_score": linux.DT_REG,
+ "oom_score_adj": linux.DT_REG,
+ "smaps": linux.DT_REG,
+ "stat": linux.DT_REG,
+ "statm": linux.DT_REG,
+ "status": linux.DT_REG,
+ "task": linux.DT_DIR,
+ "uid_map": linux.DT_REG,
}
)
diff --git a/pkg/sentry/kernel/task.go b/pkg/sentry/kernel/task.go
index 2cee2e6ed..c0dbbe890 100644
--- a/pkg/sentry/kernel/task.go
+++ b/pkg/sentry/kernel/task.go
@@ -37,6 +37,7 @@ import (
"gvisor.dev/gvisor/pkg/sentry/usage"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/sync"
+ "gvisor.dev/gvisor/pkg/syserror"
"gvisor.dev/gvisor/pkg/usermem"
"gvisor.dev/gvisor/pkg/waiter"
)
@@ -554,6 +555,13 @@ type Task struct {
//
// startTime is protected by mu.
startTime ktime.Time
+
+ // oomScoreAdj is the task's OOM score adjustment. This is currently not
+ // used but is maintained for consistency.
+ // TODO(gvisor.dev/issue/1967)
+ //
+ // oomScoreAdj is protected by mu, and is owned by the task goroutine.
+ oomScoreAdj int32
}
func (t *Task) savePtraceTracer() *Task {
@@ -847,3 +855,28 @@ func (t *Task) AbstractSockets() *AbstractSocketNamespace {
func (t *Task) ContainerID() string {
return t.containerID
}
+
+// OOMScoreAdj gets the task's OOM score adjustment.
+func (t *Task) OOMScoreAdj() (int32, error) {
+ t.mu.Lock()
+ defer t.mu.Unlock()
+ if t.ExitState() == TaskExitDead {
+ return 0, syserror.ESRCH
+ }
+ return t.oomScoreAdj, nil
+}
+
+// SetOOMScoreAdj sets the task's OOM score adjustment. The value should be
+// between -1000 and 1000 inclusive.
+func (t *Task) SetOOMScoreAdj(adj int32) error {
+ t.mu.Lock()
+ defer t.mu.Unlock()
+ if t.ExitState() == TaskExitDead {
+ return syserror.ESRCH
+ }
+ if adj > 1000 || adj < -1000 {
+ return syserror.EINVAL
+ }
+ t.oomScoreAdj = adj
+ return nil
+}
diff --git a/pkg/sentry/kernel/task_clone.go b/pkg/sentry/kernel/task_clone.go
index 78866f280..dda502bb8 100644
--- a/pkg/sentry/kernel/task_clone.go
+++ b/pkg/sentry/kernel/task_clone.go
@@ -264,6 +264,11 @@ func (t *Task) Clone(opts *CloneOptions) (ThreadID, *SyscallControl, error) {
rseqSignature = t.rseqSignature
}
+ adj, err := t.OOMScoreAdj()
+ if err != nil {
+ return 0, nil, err
+ }
+
cfg := &TaskConfig{
Kernel: t.k,
ThreadGroup: tg,
@@ -282,6 +287,7 @@ func (t *Task) Clone(opts *CloneOptions) (ThreadID, *SyscallControl, error) {
RSeqAddr: rseqAddr,
RSeqSignature: rseqSignature,
ContainerID: t.ContainerID(),
+ OOMScoreAdj: adj,
}
if opts.NewThreadGroup {
cfg.Parent = t
diff --git a/pkg/sentry/kernel/task_start.go b/pkg/sentry/kernel/task_start.go
index a5035bb7f..2bbf48bb8 100644
--- a/pkg/sentry/kernel/task_start.go
+++ b/pkg/sentry/kernel/task_start.go
@@ -93,6 +93,9 @@ type TaskConfig struct {
// ContainerID is the container the new task belongs to.
ContainerID string
+
+ // oomScoreAdj is the task's OOM score adjustment.
+ OOMScoreAdj int32
}
// NewTask creates a new task defined by cfg.
@@ -143,6 +146,7 @@ func (ts *TaskSet) newTask(cfg *TaskConfig) (*Task, error) {
rseqSignature: cfg.RSeqSignature,
futexWaiter: futex.NewWaiter(),
containerID: cfg.ContainerID,
+ oomScoreAdj: cfg.OOMScoreAdj,
}
t.creds.Store(cfg.Credentials)
t.endStopCond.L = &t.tg.signalHandlers.mu