Re: [PATCH] x86/ldt: Fix support_pte_mask filtering in map_ldt_struct()

From: Joerg Roedel
Date: Thu Apr 19 2018 - 10:11:42 EST


On Thu, Apr 19, 2018 at 03:00:11PM +0200, Borislav Petkov wrote:
> fb43d6cb91ef x86/mm: Do not auto-massage page protections <--- NOT OK

Hmm, that hunk from above patch looks suspicious:

- set_pgd(pgd + pgd_index(restore_jump_address), __pgd(__pa(pud) | _KERNPG_TABLE));
+ pgd_t new_pgd = __pgd(__pa(p4d) | pgprot_val(pgtable_prot));
+ set_pgd(pgd + pgd_index(restore_jump_address), new_pgd);

The old code used __pa(pud) while the new one uses __pa(p4d).

Boris, can you change that back to __pa(pud) and test please?


Thanks,

Joerg