From 0b89ede629637c03b9a728fb08bfe6ed51de9be7 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 31 Aug 2017 12:30:54 +0200 Subject: [PATCH] s390/mm: fork vs. 5 level page tabel The mm->context.asce field of a new process is not set up correctly in case of a fork with a 5 level page table. Add the missing case to init_new_context(). Fixes: 1aea9b3f9210 ("s390/mm: implement 5 level pages tables") Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/mmu_context.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h index 4541ac44b35f..24bc41622a98 100644 --- a/arch/s390/include/asm/mmu_context.h +++ b/arch/s390/include/asm/mmu_context.h @@ -44,6 +44,11 @@ static inline int init_new_context(struct task_struct *tsk, mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | _ASCE_USER_BITS | _ASCE_TYPE_REGION3; break; + case -PAGE_SIZE: + /* forked 5-level task, set new asce with new_mm->pgd */ + mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | + _ASCE_USER_BITS | _ASCE_TYPE_REGION1; + break; case 1UL << 53: /* forked 4-level task, set new asce with new mm->pgd */ mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | -- 2.39.2