d61172b4b6
As discussed earlier, we attempt to enforce protection keys in software. However, the code checks all faults to ensure that they are not violating protection key permissions. It was assumed that all faults are either write faults where we check PKRU[key].WD (write disable) or read faults where we check the AD (access disable) bit. But, there is a third category of faults for protection keys: instruction faults. Instruction faults never run afoul of protection keys because they do not affect instruction fetches. So, plumb the PF_INSTR bit down in to the arch_vma_access_permitted() function where we do the protection key checks. We also add a new FAULT_FLAG_INSTRUCTION. This is because handle_mm_fault() is not passed the architecture-specific error_code where we keep PF_INSTR, so we need to encode the instruction fetch information in to the arch-generic fault flags. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210224.96928009@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
146 lines
3.7 KiB
C
146 lines
3.7 KiB
C
/*
|
|
* S390 version
|
|
*
|
|
* Derived from "include/asm-i386/mmu_context.h"
|
|
*/
|
|
|
|
#ifndef __S390_MMU_CONTEXT_H
|
|
#define __S390_MMU_CONTEXT_H
|
|
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/ctl_reg.h>
|
|
|
|
static inline int init_new_context(struct task_struct *tsk,
|
|
struct mm_struct *mm)
|
|
{
|
|
cpumask_clear(&mm->context.cpu_attach_mask);
|
|
atomic_set(&mm->context.attach_count, 0);
|
|
mm->context.flush_mm = 0;
|
|
mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
|
|
mm->context.asce_bits |= _ASCE_TYPE_REGION3;
|
|
#ifdef CONFIG_PGSTE
|
|
mm->context.alloc_pgste = page_table_allocate_pgste;
|
|
mm->context.has_pgste = 0;
|
|
mm->context.use_skey = 0;
|
|
#endif
|
|
mm->context.asce_limit = STACK_TOP_MAX;
|
|
crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
|
|
return 0;
|
|
}
|
|
|
|
#define destroy_context(mm) do { } while (0)
|
|
|
|
static inline void set_user_asce(struct mm_struct *mm)
|
|
{
|
|
S390_lowcore.user_asce = mm->context.asce_bits | __pa(mm->pgd);
|
|
if (current->thread.mm_segment.ar4)
|
|
__ctl_load(S390_lowcore.user_asce, 7, 7);
|
|
set_cpu_flag(CIF_ASCE);
|
|
}
|
|
|
|
static inline void clear_user_asce(void)
|
|
{
|
|
S390_lowcore.user_asce = S390_lowcore.kernel_asce;
|
|
|
|
__ctl_load(S390_lowcore.user_asce, 1, 1);
|
|
__ctl_load(S390_lowcore.user_asce, 7, 7);
|
|
}
|
|
|
|
static inline void load_kernel_asce(void)
|
|
{
|
|
unsigned long asce;
|
|
|
|
__ctl_store(asce, 1, 1);
|
|
if (asce != S390_lowcore.kernel_asce)
|
|
__ctl_load(S390_lowcore.kernel_asce, 1, 1);
|
|
set_cpu_flag(CIF_ASCE);
|
|
}
|
|
|
|
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
|
|
struct task_struct *tsk)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
|
|
S390_lowcore.user_asce = next->context.asce_bits | __pa(next->pgd);
|
|
if (prev == next)
|
|
return;
|
|
if (MACHINE_HAS_TLB_LC)
|
|
cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
|
|
/* Clear old ASCE by loading the kernel ASCE. */
|
|
__ctl_load(S390_lowcore.kernel_asce, 1, 1);
|
|
__ctl_load(S390_lowcore.kernel_asce, 7, 7);
|
|
atomic_inc(&next->context.attach_count);
|
|
atomic_dec(&prev->context.attach_count);
|
|
if (MACHINE_HAS_TLB_LC)
|
|
cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
|
|
}
|
|
|
|
#define finish_arch_post_lock_switch finish_arch_post_lock_switch
|
|
static inline void finish_arch_post_lock_switch(void)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
struct mm_struct *mm = tsk->mm;
|
|
|
|
load_kernel_asce();
|
|
if (mm) {
|
|
preempt_disable();
|
|
while (atomic_read(&mm->context.attach_count) >> 16)
|
|
cpu_relax();
|
|
|
|
cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
|
|
if (mm->context.flush_mm)
|
|
__tlb_flush_mm(mm);
|
|
preempt_enable();
|
|
}
|
|
set_fs(current->thread.mm_segment);
|
|
}
|
|
|
|
#define enter_lazy_tlb(mm,tsk) do { } while (0)
|
|
#define deactivate_mm(tsk,mm) do { } while (0)
|
|
|
|
static inline void activate_mm(struct mm_struct *prev,
|
|
struct mm_struct *next)
|
|
{
|
|
switch_mm(prev, next, current);
|
|
cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
|
|
set_user_asce(next);
|
|
}
|
|
|
|
static inline void arch_dup_mmap(struct mm_struct *oldmm,
|
|
struct mm_struct *mm)
|
|
{
|
|
if (oldmm->context.asce_limit < mm->context.asce_limit)
|
|
crst_table_downgrade(mm, oldmm->context.asce_limit);
|
|
}
|
|
|
|
static inline void arch_exit_mmap(struct mm_struct *mm)
|
|
{
|
|
}
|
|
|
|
static inline void arch_unmap(struct mm_struct *mm,
|
|
struct vm_area_struct *vma,
|
|
unsigned long start, unsigned long end)
|
|
{
|
|
}
|
|
|
|
static inline void arch_bprm_mm_init(struct mm_struct *mm,
|
|
struct vm_area_struct *vma)
|
|
{
|
|
}
|
|
|
|
static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
|
|
bool write, bool execute, bool foreign)
|
|
{
|
|
/* by default, allow everything */
|
|
return true;
|
|
}
|
|
|
|
static inline bool arch_pte_access_permitted(pte_t pte, bool write)
|
|
{
|
|
/* by default, allow everything */
|
|
return true;
|
|
}
|
|
#endif /* __S390_MMU_CONTEXT_H */
|