1 // SPDX-License-Identifier: GPL-2.0-only <<
2 /* 1 /*
3 * Based on arch/arm/mm/mmap.c !! 2 * This file is subject to the terms and conditions of the GNU General Public
>> 3 * License. See the file "COPYING" in the main directory of this archive
>> 4 * for more details.
4 * 5 *
5 * Copyright (C) 2012 ARM Ltd. !! 6 * Copyright (C) 2011 Wind River Systems,
>> 7 * written by Ralf Baechle <ralf@linux-mips.org>
6 */ 8 */
7 !! 9 #include <linux/compiler.h>
8 #include <linux/io.h> !! 10 #include <linux/elf-randomize.h>
9 #include <linux/memblock.h> !! 11 #include <linux/errno.h>
10 #include <linux/mm.h> 12 #include <linux/mm.h>
11 #include <linux/types.h> !! 13 #include <linux/mman.h>
>> 14 #include <linux/export.h>
>> 15 #include <linux/personality.h>
>> 16 #include <linux/random.h>
>> 17 #include <linux/sched/signal.h>
>> 18 #include <linux/sched/mm.h>
>> 19
>> 20 unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */
>> 21 EXPORT_SYMBOL(shm_align_mask);
>> 22
>> 23 #define COLOUR_ALIGN(addr, pgoff) \
>> 24 ((((addr) + shm_align_mask) & ~shm_align_mask) + \
>> 25 (((pgoff) << PAGE_SHIFT) & shm_align_mask))
>> 26
>> 27 enum mmap_allocation_direction {UP, DOWN};
>> 28
>> 29 static unsigned long arch_get_unmapped_area_common(struct file *filp,
>> 30 unsigned long addr0, unsigned long len, unsigned long pgoff,
>> 31 unsigned long flags, enum mmap_allocation_direction dir)
>> 32 {
>> 33 struct mm_struct *mm = current->mm;
>> 34 struct vm_area_struct *vma;
>> 35 unsigned long addr = addr0;
>> 36 int do_color_align;
>> 37 struct vm_unmapped_area_info info = {};
>> 38
>> 39 if (unlikely(len > TASK_SIZE))
>> 40 return -ENOMEM;
>> 41
>> 42 if (flags & MAP_FIXED) {
>> 43 /* Even MAP_FIXED mappings must reside within TASK_SIZE */
>> 44 if (TASK_SIZE - len < addr)
>> 45 return -EINVAL;
>> 46
>> 47 /*
>> 48 * We do not accept a shared mapping if it would violate
>> 49 * cache aliasing constraints.
>> 50 */
>> 51 if ((flags & MAP_SHARED) &&
>> 52 ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
>> 53 return -EINVAL;
>> 54 return addr;
>> 55 }
12 56
13 #include <asm/cpufeature.h> !! 57 do_color_align = 0;
14 #include <asm/page.h> !! 58 if (filp || (flags & MAP_SHARED))
>> 59 do_color_align = 1;
>> 60
>> 61 /* requesting a specific address */
>> 62 if (addr) {
>> 63 if (do_color_align)
>> 64 addr = COLOUR_ALIGN(addr, pgoff);
>> 65 else
>> 66 addr = PAGE_ALIGN(addr);
>> 67
>> 68 vma = find_vma(mm, addr);
>> 69 if (TASK_SIZE - len >= addr &&
>> 70 (!vma || addr + len <= vm_start_gap(vma)))
>> 71 return addr;
>> 72 }
15 73
16 static pgprot_t protection_map[16] __ro_after_ !! 74 info.length = len;
17 [VM_NONE] !! 75 info.align_mask = do_color_align ? (PAGE_MASK & shm_align_mask) : 0;
18 [VM_READ] !! 76 info.align_offset = pgoff << PAGE_SHIFT;
19 [VM_WRITE] !! 77
20 [VM_WRITE | VM_READ] !! 78 if (dir == DOWN) {
21 /* PAGE_EXECONLY if Enhanced PAN */ !! 79 info.flags = VM_UNMAPPED_AREA_TOPDOWN;
22 [VM_EXEC] !! 80 info.low_limit = PAGE_SIZE;
23 [VM_EXEC | VM_READ] !! 81 info.high_limit = mm->mmap_base;
24 [VM_EXEC | VM_WRITE] !! 82 addr = vm_unmapped_area(&info);
25 [VM_EXEC | VM_WRITE | VM_READ] !! 83
26 [VM_SHARED] !! 84 if (!(addr & ~PAGE_MASK))
27 [VM_SHARED | VM_READ] !! 85 return addr;
28 [VM_SHARED | VM_WRITE] !! 86
29 [VM_SHARED | VM_WRITE | VM_READ] !! 87 /*
30 /* PAGE_EXECONLY if Enhanced PAN */ !! 88 * A failed mmap() very likely causes application failure,
31 [VM_SHARED | VM_EXEC] !! 89 * so fall back to the bottom-up function here. This scenario
32 [VM_SHARED | VM_EXEC | VM_READ] !! 90 * can happen with large stack limits and large mmap()
33 [VM_SHARED | VM_EXEC | VM_WRITE] !! 91 * allocations.
34 [VM_SHARED | VM_EXEC | VM_WRITE | VM_R !! 92 */
35 }; !! 93 }
36 94
37 /* !! 95 info.low_limit = mm->mmap_base;
38 * You really shouldn't be using read() or wri !! 96 info.high_limit = TASK_SIZE;
39 * away in the future. !! 97 return vm_unmapped_area(&info);
40 */ <<
41 int valid_phys_addr_range(phys_addr_t addr, si <<
42 { <<
43 /* <<
44 * Check whether addr is covered by a <<
45 * MEMBLOCK_NOMAP attribute, and wheth <<
46 * entire range. In theory, this could <<
47 * if the range is covered by distinct <<
48 * that only differ in other attribute <<
49 * attributes have been defined, and i <<
50 * follows that /dev/mem read() calls <<
51 * such boundaries. <<
52 */ <<
53 return memblock_is_region_memory(addr, <<
54 memblock_is_map_memory(addr); <<
55 } 98 }
56 99
57 /* !! 100 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,
58 * Do not allow /dev/mem mappings beyond the s !! 101 unsigned long len, unsigned long pgoff, unsigned long flags,
59 */ !! 102 vm_flags_t vm_flags)
60 int valid_mmap_phys_addr_range(unsigned long p <<
61 { 103 {
62 return !(((pfn << PAGE_SHIFT) + size) !! 104 return arch_get_unmapped_area_common(filp,
>> 105 addr0, len, pgoff, flags, UP);
63 } 106 }
64 107
65 static int __init adjust_protection_map(void) !! 108 /*
>> 109 * There is no need to export this but sched.h declares the function as
>> 110 * extern so making it static here results in an error.
>> 111 */
>> 112 unsigned long arch_get_unmapped_area_topdown(struct file *filp,
>> 113 unsigned long addr0, unsigned long len, unsigned long pgoff,
>> 114 unsigned long flags, vm_flags_t vm_flags)
66 { 115 {
67 /* !! 116 return arch_get_unmapped_area_common(filp,
68 * With Enhanced PAN we can honour the !! 117 addr0, len, pgoff, flags, DOWN);
69 * there is no PAN override with such <<
70 */ <<
71 if (cpus_have_cap(ARM64_HAS_EPAN)) { <<
72 protection_map[VM_EXEC] = PAGE <<
73 protection_map[VM_EXEC | VM_SH <<
74 } <<
75 <<
76 if (lpa2_is_enabled()) <<
77 for (int i = 0; i < ARRAY_SIZE <<
78 pgprot_val(protection_ <<
79 <<
80 return 0; <<
81 } 118 }
82 arch_initcall(adjust_protection_map); <<
83 119
84 pgprot_t vm_get_page_prot(unsigned long vm_fla !! 120 bool __virt_addr_valid(const volatile void *kaddr)
85 { 121 {
86 pteval_t prot = pgprot_val(protection_ !! 122 unsigned long vaddr = (unsigned long)kaddr;
87 (VM_READ|VM <<
88 123
89 if (vm_flags & VM_ARM64_BTI) !! 124 if ((vaddr < PAGE_OFFSET) || (vaddr >= MAP_BASE))
90 prot |= PTE_GP; !! 125 return false;
91 <<
92 /* <<
93 * There are two conditions required f <<
94 * memory type: (1) the user requested <<
95 * mmap() or mprotect() and (2) the co <<
96 * register (1) as VM_MTE in the vma-> <<
97 * VM_MTE_ALLOWED. Note that the latte <<
98 * mmap() call since mprotect() does n <<
99 * Checking for VM_MTE only is suffici <<
100 * does not permit (VM_MTE & !VM_MTE_A <<
101 */ <<
102 if (vm_flags & VM_MTE) <<
103 prot |= PTE_ATTRINDX(MT_NORMAL <<
104 <<
105 #ifdef CONFIG_ARCH_HAS_PKEYS <<
106 if (system_supports_poe()) { <<
107 if (vm_flags & VM_PKEY_BIT0) <<
108 prot |= PTE_PO_IDX_0; <<
109 if (vm_flags & VM_PKEY_BIT1) <<
110 prot |= PTE_PO_IDX_1; <<
111 if (vm_flags & VM_PKEY_BIT2) <<
112 prot |= PTE_PO_IDX_2; <<
113 } <<
114 #endif <<
115 126
116 return __pgprot(prot); !! 127 return pfn_valid(PFN_DOWN(virt_to_phys(kaddr)));
117 } 128 }
118 EXPORT_SYMBOL(vm_get_page_prot); !! 129 EXPORT_SYMBOL_GPL(__virt_addr_valid);
119 130
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