diff options
| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2012-07-26 08:53:06 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-09 08:31:31 -0700 |
| commit | cd1af8b7d386e6b3991252650c16b3e9d5a03b65 (patch) | |
| tree | 93fc53558ab9ad563fb4d58b5f3b7f6a62e85215 /arch/s390/include | |
| parent | 554c9a0c6f72a8a5c44962b82f495d95e547b4b3 (diff) | |
s390/mm: downgrade page table after fork of a 31 bit process
commit 0f6f281b731d20bfe75c13f85d33f3f05b440222 upstream.
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.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 5d09e405c54d..5d211f70d83d 100644 --- a/arch/s390/include/asm/mmu_context.h +++ b/arch/s390/include/asm/mmu_context.h @@ -13,7 +13,6 @@ #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) @@ -93,4 +92,17 @@ 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 d499b30ea487..8b6f62e1c36b 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -129,7 +129,9 @@ 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 */ |