This reverts commit d35abdb28824cf74f0a106a0f9c6f3ff700a35bf. task_lock() was added to ensure exit_mm() and thus exit_task_work() is not possible before task_work_add().
This is wrong, task_lock() must not be nested with write_lock(tasklist). And this is no longer needed, task_work_add() fails if it is called after exit_task_work(). Reported-by: Dave Jones <da...@redhat.com> Signed-off-by: Oleg Nesterov <o...@redhat.com> --- security/keys/keyctl.c | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 3364fbf..6cfc647 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -1486,7 +1486,6 @@ long keyctl_session_to_parent(void) oldwork = NULL; parent = me->real_parent; - task_lock(parent); /* the parent mustn't be init and mustn't be a kernel thread */ if (parent->pid <= 1 || !parent->mm) goto unlock; @@ -1530,7 +1529,6 @@ long keyctl_session_to_parent(void) if (!ret) newwork = NULL; unlock: - task_unlock(parent); write_unlock_irq(&tasklist_lock); rcu_read_unlock(); if (oldwork) -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/