1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <linux/export.h>
4 #include <linux/mm.h>
5 #include <asm/pgtable.h>
6 #include <asm/mem_encrypt.h>
7
8 static pgprot_t protection_map[16] __ro_after_init = {
9 [VM_NONE] = PAGE_NONE,
10 [VM_READ] = PAGE_READONLY,
11 [VM_WRITE] = PAGE_COPY,
12 [VM_WRITE | VM_READ] = PAGE_COPY,
13 [VM_EXEC] = PAGE_READONLY_EXEC,
14 [VM_EXEC | VM_READ] = PAGE_READONLY_EXEC,
15 [VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC,
16 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_EXEC,
17 [VM_SHARED] = PAGE_NONE,
18 [VM_SHARED | VM_READ] = PAGE_READONLY,
19 [VM_SHARED | VM_WRITE] = PAGE_SHARED,
20 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
21 [VM_SHARED | VM_EXEC] = PAGE_READONLY_EXEC,
22 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_EXEC,
23 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_EXEC,
24 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC
25 };
26
27 void add_encrypt_protection_map(void)
28 {
29 unsigned int i;
30
31 for (i = 0; i < ARRAY_SIZE(protection_map); i++)
32 protection_map[i] = pgprot_encrypted(protection_map[i]);
33 }
34
35 pgprot_t vm_get_page_prot(unsigned long vm_flags)
36 {
37 unsigned long val = pgprot_val(protection_map[vm_flags &
38 (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);
39
40 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
41 /*
42 * Take the 4 protection key bits out of the vma->vm_flags value and
43 * turn them in to the bits that we can put in to a pte.
44 *
45 * Only override these if Protection Keys are available (which is only
46 * on 64-bit).
47 */
48 if (vm_flags & VM_PKEY_BIT0)
49 val |= _PAGE_PKEY_BIT0;
50 if (vm_flags & VM_PKEY_BIT1)
51 val |= _PAGE_PKEY_BIT1;
52 if (vm_flags & VM_PKEY_BIT2)
53 val |= _PAGE_PKEY_BIT2;
54 if (vm_flags & VM_PKEY_BIT3)
55 val |= _PAGE_PKEY_BIT3;
56 #endif
57
58 val = __sme_set(val);
59 if (val & _PAGE_PRESENT)
60 val &= __supported_pte_mask;
61 return __pgprot(val);
62 }
63 EXPORT_SYMBOL(vm_get_page_prot);
64
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