1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * ARC700 mmap
4 *
5 * (started from arm version - for VIPT alias handling)
6 *
7 * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
8 */
9
10 #include <linux/fs.h>
11 #include <linux/mm.h>
12 #include <linux/mman.h>
13 #include <linux/sched/mm.h>
14
15 #include <asm/cacheflush.h>
16
17 /*
18 * Ensure that shared mappings are correctly aligned to
19 * avoid aliasing issues with VIPT caches.
20 * We need to ensure that
21 * a specific page of an object is always mapped at a multiple of
22 * SHMLBA bytes.
23 */
24 unsigned long
25 arch_get_unmapped_area(struct file *filp, unsigned long addr,
26 unsigned long len, unsigned long pgoff, unsigned long flags)
27 {
28 struct mm_struct *mm = current->mm;
29 struct vm_area_struct *vma;
30 struct vm_unmapped_area_info info = {};
31
32 /*
33 * We enforce the MAP_FIXED case.
34 */
35 if (flags & MAP_FIXED) {
36 if (flags & MAP_SHARED &&
37 (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
38 return -EINVAL;
39 return addr;
40 }
41
42 if (len > TASK_SIZE)
43 return -ENOMEM;
44
45 if (addr) {
46 addr = PAGE_ALIGN(addr);
47
48 vma = find_vma(mm, addr);
49 if (TASK_SIZE - len >= addr &&
50 (!vma || addr + len <= vm_start_gap(vma)))
51 return addr;
52 }
53
54 info.length = len;
55 info.low_limit = mm->mmap_base;
56 info.high_limit = TASK_SIZE;
57 info.align_offset = pgoff << PAGE_SHIFT;
58 return vm_unmapped_area(&info);
59 }
60
61 static const pgprot_t protection_map[16] = {
62 [VM_NONE] = PAGE_U_NONE,
63 [VM_READ] = PAGE_U_R,
64 [VM_WRITE] = PAGE_U_R,
65 [VM_WRITE | VM_READ] = PAGE_U_R,
66 [VM_EXEC] = PAGE_U_X_R,
67 [VM_EXEC | VM_READ] = PAGE_U_X_R,
68 [VM_EXEC | VM_WRITE] = PAGE_U_X_R,
69 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_U_X_R,
70 [VM_SHARED] = PAGE_U_NONE,
71 [VM_SHARED | VM_READ] = PAGE_U_R,
72 [VM_SHARED | VM_WRITE] = PAGE_U_W_R,
73 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_U_W_R,
74 [VM_SHARED | VM_EXEC] = PAGE_U_X_R,
75 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_U_X_R,
76 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_U_X_W_R,
77 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_U_X_W_R
78 };
79 DECLARE_VM_GET_PAGE_PROT
80
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