Commit | Line | Data |
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305b1523 JG |
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 | } | |
e4c031b4 | 27 | ptep = pte_offset_kernel(pmdp, addr); |
305b1523 JG |
28 | |
29 | pte = *ptep; | |
30 | pte = set(pte); | |
e4c031b4 | 31 | ptep_invalidate(&init_mm, addr, ptep); |
305b1523 | 32 | *ptep = pte; |
e4c031b4 | 33 | addr += PAGE_SIZE; |
305b1523 JG |
34 | } |
35 | } | |
36 | ||
37 | int set_memory_ro(unsigned long addr, int numpages) | |
38 | { | |
39 | change_page_attr(addr, numpages, pte_wrprotect); | |
40 | return 0; | |
41 | } | |
42 | EXPORT_SYMBOL_GPL(set_memory_ro); | |
43 | ||
44 | int set_memory_rw(unsigned long addr, int numpages) | |
45 | { | |
46 | change_page_attr(addr, numpages, pte_mkwrite); | |
47 | return 0; | |
48 | } | |
49 | EXPORT_SYMBOL_GPL(set_memory_rw); | |
50 | ||
51 | /* not possible */ | |
52 | int set_memory_nx(unsigned long addr, int numpages) | |
53 | { | |
54 | return 0; | |
55 | } | |
56 | EXPORT_SYMBOL_GPL(set_memory_nx); |