From: Joerg Roedel <jroedel@xxxxxxx> With PAE paging we don't have PGD and P4D levels in the page-table, instead the PUD level is the highest one. In PAE page-tables at the top-level most bits we usually set with _KERNPG_TABLE are reserved, resulting in a #GP when they are loaded by the processor. Work around this by populating PUD entries in the user page-table only with _PAGE_PRESENT set. I am pretty sure there is a cleaner way to do this, but until I find it use this #ifdef solution. Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> --- arch/x86/mm/pti.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index 20be21301a59..6b6bfd13350e 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -202,8 +202,12 @@ static __init pmd_t *pti_user_pagetable_walk_pmd(unsigned long address) unsigned long new_pmd_page = __get_free_page(gfp); if (!new_pmd_page) return NULL; - +#ifdef CONFIG_X86_PAE + /* TODO: There must be a cleaner way to do this */ + set_pud(pud, __pud(_PAGE_PRESENT | __pa(new_pmd_page))); +#else set_pud(pud, __pud(_KERNPG_TABLE | __pa(new_pmd_page))); +#endif } return pmd_offset(pud, address); -- 2.13.6 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
