diff options
| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2012-07-26 08:53:06 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2012-07-26 16:24:14 +0200 |
| commit | 0f6f281b731d20bfe75c13f85d33f3f05b440222 (patch) | |
| tree | 0f8c23d3fca50dd2830ddc978501cd45a0057f45 /arch/s390/include | |
| parent | 8143adafd2d00b13f1db96ce06b6bf479e0bfe5b (diff) | |
s390/mm: downgrade page table after fork of a 31 bit process
The downgrade of the 4 level page table created by init_new_context is
currently done only in start_thread31. If a 31 bit process forks the
new mm uses a 4 level page table, including the task size of 2<<42
that goes along with it. This is incorrect as now a 31 bit process
can map memory beyond 2GB. Define arch_dup_mmap to do the downgrade
after fork.
Cc: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include')
| -rw-r--r-- | arch/s390/include/asm/mmu_context.h | 14 | ||||
| -rw-r--r-- | arch/s390/include/asm/processor.h | 2 |
2 files changed, 15 insertions, 1 deletions
diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h index 5c63615f134..077de7efc82 100644 --- a/arch/s390/include/asm/mmu_context.h +++ b/arch/s390/include/asm/mmu_context.h @@ -11,7 +11,6 @@ #include <asm/uaccess.h> #include <asm/tlbflush.h> #include <asm/ctl_reg.h> -#include <asm-generic/mm_hooks.h> static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm) @@ -91,4 +90,17 @@ static inline void activate_mm(struct mm_struct *prev, switch_mm(prev, next, current); } +static inline void arch_dup_mmap(struct mm_struct *oldmm, + struct mm_struct *mm) +{ +#ifdef CONFIG_64BIT + if (oldmm->context.asce_limit < mm->context.asce_limit) + crst_table_downgrade(mm, oldmm->context.asce_limit); +#endif +} + +static inline void arch_exit_mmap(struct mm_struct *mm) +{ +} + #endif /* __S390_MMU_CONTEXT_H */ diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index c40fa91e38a..11e4e323693 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -120,7 +120,9 @@ struct stack_frame { regs->psw.mask = psw_user_bits | PSW_MASK_BA; \ regs->psw.addr = new_psw | PSW_ADDR_AMODE; \ regs->gprs[15] = new_stackp; \ + __tlb_flush_mm(current->mm); \ crst_table_downgrade(current->mm, 1UL << 31); \ + update_mm(current->mm, current); \ } while (0) /* Forward declaration, a strange C thing */ |