From 702d9e584feb028ed7e2a6d2b103b8ea57622ff2 Mon Sep 17 00:00:00 2001 From: Carsten Otte Date: Thu, 26 Mar 2009 15:23:57 +0100 Subject: [PATCH] [S390] check addressing mode in s390_enable_sie The sie instruction requires address spaces to be switched to run proper. This patch verifies that this is the case in s390_enable_sie, otherwise the kernel would crash badly as soon as the process runs into sie. Signed-off-by: Carsten Otte Signed-off-by: Martin Schwidefsky --- arch/s390/mm/pgtable.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 6b6ddc4ea02b..9bf86125f6f3 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -258,6 +258,10 @@ int s390_enable_sie(void) struct task_struct *tsk = current; struct mm_struct *mm, *old_mm; + /* Do we have switched amode? If no, we cannot do sie */ + if (!switch_amode) + return -EINVAL; + /* Do we have pgstes? if yes, we are done */ if (tsk->mm->context.has_pgste) return 0;