CPA: Add a BUG_ON checking for someone setting the kernel text NX Someone setting NX on the kernel text tends to result in nasty failures and triple faults, so BUG_ON early for that. Does not cover __inittext. Signed-off-by: Andi Kleen Acked-by: Jan Beulich --- arch/x86/mm/pageattr_32.c | 8 ++++++++ 1 file changed, 8 insertions(+) Index: linux/arch/x86/mm/pageattr_32.c =================================================================== --- linux.orig/arch/x86/mm/pageattr_32.c +++ linux/arch/x86/mm/pageattr_32.c @@ -242,6 +242,14 @@ __change_page_attr(struct page *page, pg BUG_ON(PageLRU(kpte_page)); BUG_ON(PageCompound(kpte_page)); + /* + * Better fail early if someone sets the kernel text to NX. + * Does not cover __inittext + */ + BUG_ON(address >= (unsigned long)&_text && + address < (unsigned long)&_etext && + (pgprot_val(prot) & _PAGE_NX)); + set_tlb_flush(address, cache_attr_changed(*kpte, prot, level), level < 3);