From 1c0535297067179a822ba2dd9a6fe13a8be5a666 Mon Sep 17 00:00:00 2001 From: Jamie Liu Date: Fri, 13 Mar 2020 13:17:59 -0700 Subject: Fix oom_score_adj. - Make oomScoreAdj a ThreadGroup field (Linux: signal_struct::oom_score_adj). - Avoid deadlock caused by Task.OOMScoreAdj()/SetOOMScoreAdj() locking Task.mu and TaskSet.mu in the wrong order (via Task.ExitState()). PiperOrigin-RevId: 300814698 --- pkg/sentry/fsimpl/proc/task_files.go | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'pkg/sentry/fsimpl/proc') diff --git a/pkg/sentry/fsimpl/proc/task_files.go b/pkg/sentry/fsimpl/proc/task_files.go index 5a231ac86..4d3332771 100644 --- a/pkg/sentry/fsimpl/proc/task_files.go +++ b/pkg/sentry/fsimpl/proc/task_files.go @@ -539,11 +539,10 @@ 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 + if o.task.ExitState() == kernel.TaskExitDead { + return syserror.ESRCH } - fmt.Fprintf(buf, "%d\n", adj) + fmt.Fprintf(buf, "%d\n", o.task.OOMScoreAdj()) return nil } @@ -562,6 +561,9 @@ func (o *oomScoreAdj) Write(ctx context.Context, src usermem.IOSequence, offset return 0, err } + if o.task.ExitState() == kernel.TaskExitDead { + return 0, syserror.ESRCH + } if err := o.task.SetOOMScoreAdj(v); err != nil { return 0, err } -- cgit v1.2.3