On Fri, 5 Jan 2018, Dave Hansen wrote: > > --- a/arch/x86/platform/efi/efi_64.c > > +++ b/arch/x86/platform/efi/efi_64.c > > @@ -95,6 +95,12 @@ pgd_t * __init efi_call_phys_prolog(void > > save_pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE); > > vaddress = (unsigned long)__va(pgd * PGDIR_SIZE); > > set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), > > *pgd_offset_k(vaddress)); > > + /* > > + * pgprot API doesn't clear it for PGD > > + * > > + * Will be brought back automatically in _epilog() > > + */ > > + pgd_offset_k(pgd * PGDIR_SIZE)->pgd &= ~_PAGE_NX; > > } > > __flush_tlb_all(); > > Wait a sec... Where does the _PAGE_USER come from? Shouldn't we see > the &init_mm in there and *not* set _PAGE_USER?
That's because pgd_populate() uses _PAGE_TABLE and not _KERNPG_TABLE for reasons that are behind me. I did put this on my TODO list, but for later. (and yes, I tried clearing _PAGE_USER from init_mm's PGD, and no obvious breakages appeared, but I wanted to give it more thought later). -- Jiri Kosina SUSE Labs
