| Jan Glauber | 305b152 | 2011-03-15 17:08:22 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright IBM Corp. 2011 |
| 3 | * Author(s): Jan Glauber <jang@linux.vnet.ibm.com> |
| 4 | */ |
| 5 | #include <linux/module.h> |
| 6 | #include <linux/mm.h> |
| 7 | #include <linux/hugetlb.h> |
| 8 | #include <asm/pgtable.h> |
| 9 | |
| 10 | static void change_page_attr(unsigned long addr, int numpages, |
| 11 | pte_t (*set) (pte_t)) |
| 12 | { |
| 13 | pte_t *ptep, pte; |
| 14 | pmd_t *pmdp; |
| 15 | pud_t *pudp; |
| 16 | pgd_t *pgdp; |
| 17 | int i; |
| 18 | |
| 19 | for (i = 0; i < numpages; i++) { |
| 20 | pgdp = pgd_offset(&init_mm, addr); |
| 21 | pudp = pud_offset(pgdp, addr); |
| 22 | pmdp = pmd_offset(pudp, addr); |
| 23 | if (pmd_huge(*pmdp)) { |
| 24 | WARN_ON_ONCE(1); |
| 25 | continue; |
| 26 | } |
| 27 | ptep = pte_offset_kernel(pmdp, addr + i * PAGE_SIZE); |
| 28 | |
| 29 | pte = *ptep; |
| 30 | pte = set(pte); |
| 31 | ptep_invalidate(&init_mm, addr + i * PAGE_SIZE, ptep); |
| 32 | *ptep = pte; |
| 33 | } |
| 34 | } |
| 35 | |
| 36 | int set_memory_ro(unsigned long addr, int numpages) |
| 37 | { |
| 38 | change_page_attr(addr, numpages, pte_wrprotect); |
| 39 | return 0; |
| 40 | } |
| 41 | EXPORT_SYMBOL_GPL(set_memory_ro); |
| 42 | |
| 43 | int set_memory_rw(unsigned long addr, int numpages) |
| 44 | { |
| 45 | change_page_attr(addr, numpages, pte_mkwrite); |
| 46 | return 0; |
| 47 | } |
| 48 | EXPORT_SYMBOL_GPL(set_memory_rw); |
| 49 | |
| 50 | /* not possible */ |
| 51 | int set_memory_nx(unsigned long addr, int numpages) |
| 52 | { |
| 53 | return 0; |
| 54 | } |
| 55 | EXPORT_SYMBOL_GPL(set_memory_nx); |