Messages in this thread Patch in this message | | | Date | Mon, 15 Apr 2019 10:46:07 +0200 (CEST) | From | Thomas Gleixner <> | Subject | [PATCH] x86/mm: Prevent bogus warnings with "noexec=off" |
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Xose reported warnings when NX is disabled on the kernel command line.
__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.vazquez@gmail.com> Signed-off-by: Thomas Gleixner <tglx@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));
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