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-rw-r--r--include/linux/mman.h29
-rw-r--r--mm/mmap.c5
-rw-r--r--mm/mprotect.c2
3 files changed, 32 insertions, 4 deletions
diff --git a/include/linux/mman.h b/include/linux/mman.h
index dab8892e6ff1..30d1073bac3b 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -34,6 +34,32 @@ static inline void vm_unacct_memory(long pages)
34} 34}
35 35
36/* 36/*
37 * Allow architectures to handle additional protection bits
38 */
39
40#ifndef arch_calc_vm_prot_bits
41#define arch_calc_vm_prot_bits(prot) 0
42#endif
43
44#ifndef arch_vm_get_page_prot
45#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
46#endif
47
48#ifndef arch_validate_prot
49/*
50 * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have
51 * already been masked out.
52 *
53 * Returns true if the prot flags are valid
54 */
55static inline int arch_validate_prot(unsigned long prot)
56{
57 return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0;
58}
59#define arch_validate_prot arch_validate_prot
60#endif
61
62/*
37 * Optimisation macro. It is equivalent to: 63 * Optimisation macro. It is equivalent to:
38 * (x & bit1) ? bit2 : 0 64 * (x & bit1) ? bit2 : 0
39 * but this version is faster. 65 * but this version is faster.
@@ -51,7 +77,8 @@ calc_vm_prot_bits(unsigned long prot)
51{ 77{
52 return _calc_vm_trans(prot, PROT_READ, VM_READ ) | 78 return _calc_vm_trans(prot, PROT_READ, VM_READ ) |
53 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) | 79 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) |
54 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC ); 80 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC) |
81 arch_calc_vm_prot_bits(prot);
55} 82}
56 83
57/* 84/*
diff --git a/mm/mmap.c b/mm/mmap.c
index 3354fdd83d4b..1d102b956fd8 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -72,8 +72,9 @@ pgprot_t protection_map[16] = {
72 72
73pgprot_t vm_get_page_prot(unsigned long vm_flags) 73pgprot_t vm_get_page_prot(unsigned long vm_flags)
74{ 74{
75 return protection_map[vm_flags & 75 return __pgprot(pgprot_val(protection_map[vm_flags &
76 (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]; 76 (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
77 pgprot_val(arch_vm_get_page_prot(vm_flags)));
77} 78}
78EXPORT_SYMBOL(vm_get_page_prot); 79EXPORT_SYMBOL(vm_get_page_prot);
79 80
diff --git a/mm/mprotect.c b/mm/mprotect.c
index a5bf31c27375..ecfaa5844b5f 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -239,7 +239,7 @@ sys_mprotect(unsigned long start, size_t len, unsigned long prot)
239 end = start + len; 239 end = start + len;
240 if (end <= start) 240 if (end <= start)
241 return -ENOMEM; 241 return -ENOMEM;
242 if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) 242 if (!arch_validate_prot(prot))
243 return -EINVAL; 243 return -EINVAL;
244 244
245 reqprot = prot; 245 reqprot = prot;