From 138c9021ca68d6f8a6fac3418995fee102a3cc22 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Tue, 8 Jul 2008 11:31:06 +0200 Subject: [S390] protect _PAGE_SPECIAL bit against mprotect Stop mprotect's pte_modify from wiping out the s390 pte_special bit, which caused oops thereafter when vm_normal_page thought X's abnormal was normal. Debugged-by: Ryan Hope Debugged-by: Zan Lynx Acked-by: Hugh Dickins Signed-off-by: Nick Piggin Signed-off-by: Martin Schwidefsky --- include/asm-s390/pgtable.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/asm-s390/pgtable.h b/include/asm-s390/pgtable.h index c7f4f8e3e29..bd0ea191dfa 100644 --- a/include/asm-s390/pgtable.h +++ b/include/asm-s390/pgtable.h @@ -223,6 +223,9 @@ extern char empty_zero_page[PAGE_SIZE]; #define _PAGE_SPECIAL 0x004 /* SW associated with special page */ #define __HAVE_ARCH_PTE_SPECIAL +/* Set of bits not changed in pte_modify */ +#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_SPECIAL) + /* Six different types of pages. */ #define _PAGE_TYPE_EMPTY 0x400 #define _PAGE_TYPE_NONE 0x401 @@ -681,7 +684,7 @@ static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *pt */ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { - pte_val(pte) &= PAGE_MASK; + pte_val(pte) &= _PAGE_CHG_MASK; pte_val(pte) |= pgprot_val(newprot); return pte; } -- cgit v1.2.3-70-g09d2