On 4/15/19 10:46 AM, Thomas Gleixner wrote: > Xose reported warnings when NX is disabled on the kernel command line.
Thank you for doing the dirty work. > > __early_set_fixmap() triggers: > > attempted to set unsupported pgprot: 8000000000000163 > bits: 8000000000000000 > supported: 7fffffffffffffff > > WARNING: CPU: 0 PID: 0 at arch/x86/include/asm/pgtable.h:537 > __early_set_fixmap+0xa2/0xff > > because it uses __default_kernel_pte_mask to mask out unsupported bits. > > Use __supported_pte_mask instead. > > Disabling NX on the command line also triggers the NX warning in the page > table mapping check: > > WARNING: CPU: 1 PID: 1 at arch/x86/mm/dump_pagetables.c:262 > note_page+0x2ae/0x650 > .... > > Make the warning depend on NX set in __supported_pte_mask. > > Reported-by: Xose Vazquez Perez <xose.vazq...@gmail.com> And Tested-by: Xose Vazquez Perez <xose.vazq...@gmail.com> > Signed-off-by: Thomas Gleixner <t...@linutronix.de> > --- > arch/x86/mm/dump_pagetables.c | 3 ++- > arch/x86/mm/ioremap.c | 2 +- > 2 files changed, 3 insertions(+), 2 deletions(-) > > --- a/arch/x86/mm/dump_pagetables.c > +++ b/arch/x86/mm/dump_pagetables.c > @@ -259,7 +259,8 @@ static void note_wx(struct pg_state *st) > #endif > /* Account the WX pages */ > st->wx_pages += npages; > - WARN_ONCE(1, "x86/mm: Found insecure W+X mapping at address %pS\n", > + WARN_ONCE(__supported_pte_mask & _PAGE_NX, > + "x86/mm: Found insecure W+X mapping at address %pS\n", > (void *)st->start_address); > } > > --- a/arch/x86/mm/ioremap.c > +++ b/arch/x86/mm/ioremap.c > @@ -825,7 +825,7 @@ void __init __early_set_fixmap(enum fixe > pte = early_ioremap_pte(addr); > > /* Sanitize 'prot' against any unsupported bits: */ > - pgprot_val(flags) &= __default_kernel_pte_mask; > + pgprot_val(flags) &= __supported_pte_mask; > > if (pgprot_val(flags)) > set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags)); >
