diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/mm/pageattr_64.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/arch/x86/mm/pageattr_64.c b/arch/x86/mm/pageattr_64.c index 139795029fb..60cfb687f97 100644 --- a/arch/x86/mm/pageattr_64.c +++ b/arch/x86/mm/pageattr_64.c @@ -126,30 +126,36 @@ out_unlock: static int __change_page_attr(unsigned long address, struct page *page, pgprot_t prot) { - pgprot_t ref_prot2, oldprot; struct page *kpte_page; int level, err = 0; pte_t *kpte; + BUG_ON(PageHighMem(page)); + repeat: kpte = lookup_address(address, &level); if (!kpte) return 0; kpte_page = virt_to_page(kpte); - oldprot = pte_pgprot(*kpte); BUG_ON(PageLRU(kpte_page)); BUG_ON(PageCompound(kpte_page)); - prot = canon_pgprot(prot); + + /* + * 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)); if (level == 4) { - set_pte_atomic(kpte, mk_pte(page, prot)); + set_pte_atomic(kpte, mk_pte(page, canon_pgprot(prot))); } else { err = split_large_page(kpte, address); if (!err) goto repeat; } - return err; } |