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| author | Andrei Vagin <avagin@google.com> | 2019-10-02 13:00:07 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2019-10-02 13:00:07 -0700 |
| commit | 9a875306dbabcf335a2abccc08119a1b67d0e51a (patch) | |
| tree | 0f72c12e951a5eee7156df7a5d63351bc89befa6 /pkg/sentry/kernel/sessions.go | |
| parent | 38bc0b6b6addd25ceec4f66ef1af41c1e61e2985 (diff) | |
| parent | 03ce4dd86c9acd6b6148f68d5d2cf025d8c254bb (diff) | |
Merge branch 'master' into pr_syscall_linux
Diffstat (limited to 'pkg/sentry/kernel/sessions.go')
| -rw-r--r-- | pkg/sentry/kernel/sessions.go | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/pkg/sentry/kernel/sessions.go b/pkg/sentry/kernel/sessions.go index e5f297478..047b5214d 100644 --- a/pkg/sentry/kernel/sessions.go +++ b/pkg/sentry/kernel/sessions.go @@ -328,8 +328,14 @@ func (tg *ThreadGroup) createSession() error { childTG.processGroup.incRefWithParent(pg) childTG.processGroup.decRefWithParent(oldParentPG) }) - tg.processGroup.decRefWithParent(oldParentPG) + // If tg.processGroup is an orphan, decRefWithParent will lock + // the signal mutex of each thread group in tg.processGroup. + // However, tg's signal mutex may already be locked at this + // point. We change tg's process group before calling + // decRefWithParent to avoid locking tg's signal mutex twice. + oldPG := tg.processGroup tg.processGroup = pg + oldPG.decRefWithParent(oldParentPG) } else { // The current process group may be nil only in the case of an // unparented thread group (i.e. the init process). This would |