From d49f47f83d15f3142d482a29de76f45360e34082 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 10 May 2012 10:47:21 +0200 Subject: [PATCH] s390/pfault: add sanity check If the task that was found on an initial interrupt doesn't match the current task execute a WARN_ON_ONCE() and don't put the task to sleep. When this happened something went wrong between the interface of the hypervisor and the kernel. In such a case keep the tasks alive to avoid a hanging system. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/mm/fault.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index a9c11aa57450..72cec9ecd96c 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -584,6 +584,8 @@ static void pfault_interrupt(struct ext_code ext_code, } } else { /* signal bit not set -> a real page is missing. */ + if (WARN_ON_ONCE(tsk != current)) + goto out; if (tsk->thread.pfault_wait == 1) { /* Already on the list with a reference: put to sleep */ __set_task_state(tsk, TASK_UNINTERRUPTIBLE); @@ -606,6 +608,7 @@ static void pfault_interrupt(struct ext_code ext_code, set_tsk_need_resched(tsk); } } +out: spin_unlock(&pfault_lock); put_task_struct(tsk); } -- GitLab