diff options
| -rw-r--r-- | arch/x86/mm/pageattr.c | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index bf5e33f6a322..6c55fbdbd7e8 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -277,17 +277,12 @@ out_unlock: } static int -__change_page_attr(unsigned long address, unsigned long pfn, - pgprot_t mask_set, pgprot_t mask_clr) +__change_page_attr(unsigned long address, pgprot_t mask_set, pgprot_t mask_clr) { struct page *kpte_page; int level, err = 0; pte_t *kpte; -#ifdef CONFIG_X86_32 - BUG_ON(pfn > max_low_pfn); -#endif - repeat: kpte = lookup_address(address, &level); if (!kpte) @@ -298,17 +293,25 @@ repeat: BUG_ON(PageCompound(kpte_page)); if (level == PG_LEVEL_4K) { - pgprot_t new_prot = pte_pgprot(*kpte); pte_t new_pte, old_pte = *kpte; + pgprot_t new_prot = pte_pgprot(old_pte); + + if(!pte_val(old_pte)) { + WARN_ON_ONCE(1); + return -EINVAL; + } pgprot_val(new_prot) &= ~pgprot_val(mask_clr); pgprot_val(new_prot) |= pgprot_val(mask_set); new_prot = static_protections(new_prot, address); - new_pte = pfn_pte(pfn, canon_pgprot(new_prot)); - BUG_ON(pte_pfn(new_pte) != pte_pfn(old_pte)); - + /* + * We need to keep the pfn from the existing PTE, + * after all we're only going to change it's attributes + * not the memory it points to + */ + new_pte = pfn_pte(pte_pfn(old_pte), canon_pgprot(new_prot)); set_pte_atomic(kpte, new_pte); } else { err = split_large_page(kpte, address); @@ -337,11 +340,11 @@ static int change_page_attr_addr(unsigned long address, pgprot_t mask_set, pgprot_t mask_clr) { - unsigned long phys_addr = __pa(address); - unsigned long pfn = phys_addr >> PAGE_SHIFT; int err; #ifdef CONFIG_X86_64 + unsigned long phys_addr = __pa(address); + /* * If we are inside the high mapped kernel range, then we * fixup the low mapping first. __va() returns the virtual @@ -351,7 +354,7 @@ change_page_attr_addr(unsigned long address, pgprot_t mask_set, address = (unsigned long) __va(phys_addr); #endif - err = __change_page_attr(address, pfn, mask_set, mask_clr); + err = __change_page_attr(address, mask_set, mask_clr); if (err) return err; @@ -375,7 +378,7 @@ change_page_attr_addr(unsigned long address, pgprot_t mask_set, * everything between 0 and KERNEL_TEXT_SIZE, so do * not propagate lookup failures back to users: */ - __change_page_attr(address, pfn, mask_set, mask_clr); + __change_page_attr(address, mask_set, mask_clr); } #endif return err; |