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Diffstat (limited to 'pkg/sentry/fs/proc/task.go')
-rw-r--r--pkg/sentry/fs/proc/task.go210
1 files changed, 164 insertions, 46 deletions
diff --git a/pkg/sentry/fs/proc/task.go b/pkg/sentry/fs/proc/task.go
index 87184ec67..9cf7f2a62 100644
--- a/pkg/sentry/fs/proc/task.go
+++ b/pkg/sentry/fs/proc/task.go
@@ -22,21 +22,24 @@ import (
"strconv"
"gvisor.dev/gvisor/pkg/abi/linux"
- "gvisor.dev/gvisor/pkg/sentry/context"
+ "gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
"gvisor.dev/gvisor/pkg/sentry/fs/proc/device"
"gvisor.dev/gvisor/pkg/sentry/fs/proc/seqfile"
"gvisor.dev/gvisor/pkg/sentry/fs/ramfs"
+ "gvisor.dev/gvisor/pkg/sentry/fsbridge"
"gvisor.dev/gvisor/pkg/sentry/kernel"
"gvisor.dev/gvisor/pkg/sentry/limits"
"gvisor.dev/gvisor/pkg/sentry/mm"
"gvisor.dev/gvisor/pkg/sentry/usage"
- "gvisor.dev/gvisor/pkg/sentry/usermem"
"gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
"gvisor.dev/gvisor/pkg/waiter"
)
+// 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.
@@ -54,42 +57,53 @@ func getTaskMM(t *kernel.Task) (*mm.MemoryManager, error) {
return m, nil
}
+func checkTaskState(t *kernel.Task) error {
+ switch t.ExitState() {
+ case kernel.TaskExitZombie:
+ return syserror.EACCES
+ case kernel.TaskExitDead:
+ return syserror.ESRCH
+ }
+ return nil
+}
+
// taskDir represents a task-level directory.
//
// +stateify savable
type taskDir struct {
ramfs.Dir
- t *kernel.Task
- pidns *kernel.PIDNamespace
+ t *kernel.Task
}
var _ fs.InodeOperations = (*taskDir)(nil)
// newTaskDir creates a new proc task entry.
-func (p *proc) newTaskDir(t *kernel.Task, msrc *fs.MountSource, showSubtasks bool) *fs.Inode {
+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),
- // FIXME(b/123511468): create the correct io file for threads.
- "io": newIO(t, msrc),
- "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, showSubtasks, p.pidns),
- "statm": newStatm(t, msrc),
- "status": newStatus(t, msrc, p.pidns),
- "uid_map": newUIDMap(t, msrc),
- }
- if showSubtasks {
+ "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),
+ "net": newNetDir(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)
}
if len(p.cgroupControllers) > 0 {
@@ -171,7 +185,7 @@ func (f *subtasksFile) Readdir(ctx context.Context, file *fs.File, ser fs.Dentry
// Serialize "." and "..".
root := fs.RootFromContext(ctx)
if root != nil {
- defer root.DecRef()
+ defer root.DecRef(ctx)
}
dot, dotdot := file.Dirent.GetDotAttrs(root)
if err := dirCtx.DirEmit(".", dot); err != nil {
@@ -248,12 +262,13 @@ func newExe(t *kernel.Task, msrc *fs.MountSource) *fs.Inode {
return newProcInode(t, exeSymlink, msrc, fs.Symlink, t)
}
-func (e *exe) executable() (d *fs.Dirent, err error) {
+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 {
- // TODO(b/34851096): Check shouldn't allow Readlink once the
- // Task is zombied.
err = syserror.EACCES
return
}
@@ -261,9 +276,9 @@ func (e *exe) executable() (d *fs.Dirent, err error) {
// The MemoryManager may be destroyed, in which case
// MemoryManager.destroy will simply set the executable to nil
// (with locks held).
- d = mm.Executable()
- if d == nil {
- err = syserror.ENOENT
+ file = mm.Executable()
+ if file == nil {
+ err = syserror.ESRCH
}
})
return
@@ -280,17 +295,9 @@ func (e *exe) Readlink(ctx context.Context, inode *fs.Inode) (string, error) {
if err != nil {
return "", err
}
- defer exec.DecRef()
+ defer exec.DecRef(ctx)
- root := fs.RootFromContext(ctx)
- if root == nil {
- // This doesn't correspond to anything in Linux because the vfs is
- // global there.
- return "", syserror.EINVAL
- }
- defer root.DecRef()
- n, _ := exec.FullName(root)
- return n, nil
+ return exec.PathnameWithDeleted(ctx), nil
}
// namespaceSymlink represents a symlink in the namespacefs, such as the files
@@ -316,11 +323,22 @@ func newNamespaceSymlink(t *kernel.Task, msrc *fs.MountSource, name string) *fs.
return newProcInode(t, n, msrc, fs.Symlink, t)
}
+// Readlink reads the symlink value.
+func (n *namespaceSymlink) Readlink(ctx context.Context, inode *fs.Inode) (string, error) {
+ if err := checkTaskState(n.t); err != nil {
+ return "", err
+ }
+ return n.Symlink.Readlink(ctx, inode)
+}
+
// Getlink implements fs.InodeOperations.Getlink.
func (n *namespaceSymlink) Getlink(ctx context.Context, inode *fs.Inode) (*fs.Dirent, error) {
if !kernel.ContextCanTrace(ctx, n.t, false) {
return nil, syserror.EACCES
}
+ if err := checkTaskState(n.t); err != nil {
+ return nil, err
+ }
// Create a new regular file to fake the namespace file.
iops := fsutil.NewNoReadWriteFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0777), linux.PROC_SUPER_MAGIC)
@@ -605,6 +623,10 @@ func (s *statusData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) (
fmt.Fprintf(&buf, "CapEff:\t%016x\n", creds.EffectiveCaps)
fmt.Fprintf(&buf, "CapBnd:\t%016x\n", creds.BoundingCaps)
fmt.Fprintf(&buf, "Seccomp:\t%d\n", s.t.SeccompMode())
+ // We unconditionally report a single NUMA node. See
+ // pkg/sentry/syscalls/linux/sys_mempolicy.go.
+ fmt.Fprintf(&buf, "Mems_allowed:\t1\n")
+ fmt.Fprintf(&buf, "Mems_allowed_list:\t0\n")
return []seqfile.SeqData{{Buf: buf.Bytes(), Handle: (*statusData)(nil)}}, 0
}
@@ -619,8 +641,11 @@ type ioData struct {
ioUsage
}
-func newIO(t *kernel.Task, msrc *fs.MountSource) *fs.Inode {
- return newProcInode(t, seqfile.NewSeqFile(t, &ioData{t.ThreadGroup()}), msrc, fs.SpecialFile, t)
+func newIO(t *kernel.Task, msrc *fs.MountSource, isThreadGroup bool) *fs.Inode {
+ if isThreadGroup {
+ return newProcInode(t, seqfile.NewSeqFile(t, &ioData{t.ThreadGroup()}), msrc, fs.SpecialFile, t)
+ }
+ return newProcInode(t, seqfile.NewSeqFile(t, &ioData{t}), msrc, fs.SpecialFile, t)
}
// NeedsUpdate returns whether the generation is old or not.
@@ -639,7 +664,7 @@ func (i *ioData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]se
io.Accumulate(i.IOUsage())
var buf bytes.Buffer
- fmt.Fprintf(&buf, "char: %d\n", io.CharsRead)
+ fmt.Fprintf(&buf, "rchar: %d\n", io.CharsRead)
fmt.Fprintf(&buf, "wchar: %d\n", io.CharsWritten)
fmt.Fprintf(&buf, "syscr: %d\n", io.ReadSyscalls)
fmt.Fprintf(&buf, "syscw: %d\n", io.WriteSyscalls)
@@ -794,3 +819,96 @@ func (f *auxvecFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequenc
n, err := dst.CopyOut(ctx, buf[offset:])
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 f.t.ExitState() == kernel.TaskExitDead {
+ return 0, syserror.ESRCH
+ }
+ var buf bytes.Buffer
+ fmt.Fprintf(&buf, "%d\n", f.t.OOMScoreAdj())
+ if offset >= int64(buf.Len()) {
+ return 0, io.EOF
+ }
+ n, err := dst.CopyOut(ctx, buf.Bytes()[offset:])
+ 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 f.t.ExitState() == kernel.TaskExitDead {
+ return 0, syserror.ESRCH
+ }
+ 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)
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-07 22:39:12 +0000