Re: [PATCH 01/30] x86, mm: do not set _PAGE_USER for init_mm page tables

[Dave Hansen]

On 11/08/2017 11:52 AM, Linus Torvalds wrote:
> On Wed, Nov 8, 2017 at 11:46 AM, Dave Hansen
> <dave.hansen@xxxxxxxxxxxxxxx> wrote:
>>
>> +
>>  static inline void pmd_populate_kernel(struct mm_struct *mm,
>>                                        pmd_t *pmd, pte_t *pte)
>>  {
>> +       pteval_t pgtable_flags = mm_pgtable_flags(mm);
> 
> Why is "pmd_populate_kernel()" using mm_pgtable_flags(mm)?
> 
> It should just use _KERNPG_TABLE unconditionally, shouldn't it?
> Nothing to do with init_mm, it's populating a _kernel_ page table
> regardless, no?

The end result is probably the same since a quick grep shows it only
ever getting called with init_mm or NULL.  But, yeah, it should probably
just be _PAGE_KERNEL directly.

I'll update it.