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6dd8b1a0 CM |
1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | ||
3 | #include <linux/coredump.h> | |
4 | #include <linux/elfcore.h> | |
5 | #include <linux/kernel.h> | |
6 | #include <linux/mm.h> | |
7 | ||
8 | #include <asm/cpufeature.h> | |
9 | #include <asm/mte.h> | |
10 | ||
ef770d18 | 11 | #define for_each_mte_vma(vmi, vma) \ |
6dd8b1a0 | 12 | if (system_supports_mte()) \ |
ef770d18 | 13 | for_each_vma(vmi, vma) \ |
6dd8b1a0 CM |
14 | if (vma->vm_flags & VM_MTE) |
15 | ||
16 | static unsigned long mte_vma_tag_dump_size(struct vm_area_struct *vma) | |
17 | { | |
18 | if (vma->vm_flags & VM_DONTDUMP) | |
19 | return 0; | |
20 | ||
21 | return vma_pages(vma) * MTE_PAGE_TAG_STORAGE; | |
22 | } | |
23 | ||
24 | /* Derived from dump_user_range(); start/end must be page-aligned */ | |
25 | static int mte_dump_tag_range(struct coredump_params *cprm, | |
26 | unsigned long start, unsigned long end) | |
27 | { | |
16decce2 | 28 | int ret = 1; |
6dd8b1a0 | 29 | unsigned long addr; |
16decce2 | 30 | void *tags = NULL; |
6dd8b1a0 CM |
31 | |
32 | for (addr = start; addr < end; addr += PAGE_SIZE) { | |
6dd8b1a0 CM |
33 | struct page *page = get_dump_page(addr); |
34 | ||
35 | /* | |
36 | * get_dump_page() returns NULL when encountering an empty | |
37 | * page table entry that would otherwise have been filled with | |
38 | * the zero page. Skip the equivalent tag dump which would | |
39 | * have been all zeros. | |
40 | */ | |
41 | if (!page) { | |
42 | dump_skip(cprm, MTE_PAGE_TAG_STORAGE); | |
43 | continue; | |
44 | } | |
45 | ||
46 | /* | |
47 | * Pages mapped in user space as !pte_access_permitted() (e.g. | |
48 | * PROT_EXEC only) may not have the PG_mte_tagged flag set. | |
49 | */ | |
50 | if (!test_bit(PG_mte_tagged, &page->flags)) { | |
51 | put_page(page); | |
52 | dump_skip(cprm, MTE_PAGE_TAG_STORAGE); | |
53 | continue; | |
54 | } | |
55 | ||
16decce2 CM |
56 | if (!tags) { |
57 | tags = mte_allocate_tag_storage(); | |
58 | if (!tags) { | |
59 | put_page(page); | |
60 | ret = 0; | |
61 | break; | |
62 | } | |
63 | } | |
64 | ||
6dd8b1a0 CM |
65 | mte_save_page_tags(page_address(page), tags); |
66 | put_page(page); | |
16decce2 CM |
67 | if (!dump_emit(cprm, tags, MTE_PAGE_TAG_STORAGE)) { |
68 | mte_free_tag_storage(tags); | |
69 | ret = 0; | |
70 | break; | |
71 | } | |
6dd8b1a0 CM |
72 | } |
73 | ||
16decce2 CM |
74 | if (tags) |
75 | mte_free_tag_storage(tags); | |
76 | ||
77 | return ret; | |
6dd8b1a0 CM |
78 | } |
79 | ||
80 | Elf_Half elf_core_extra_phdrs(void) | |
81 | { | |
82 | struct vm_area_struct *vma; | |
83 | int vma_count = 0; | |
ef770d18 | 84 | VMA_ITERATOR(vmi, current->mm, 0); |
6dd8b1a0 | 85 | |
ef770d18 | 86 | for_each_mte_vma(vmi, vma) |
6dd8b1a0 CM |
87 | vma_count++; |
88 | ||
89 | return vma_count; | |
90 | } | |
91 | ||
92 | int elf_core_write_extra_phdrs(struct coredump_params *cprm, loff_t offset) | |
93 | { | |
94 | struct vm_area_struct *vma; | |
ef770d18 | 95 | VMA_ITERATOR(vmi, current->mm, 0); |
6dd8b1a0 | 96 | |
ef770d18 | 97 | for_each_mte_vma(vmi, vma) { |
6dd8b1a0 CM |
98 | struct elf_phdr phdr; |
99 | ||
c35fe2a6 | 100 | phdr.p_type = PT_AARCH64_MEMTAG_MTE; |
6dd8b1a0 CM |
101 | phdr.p_offset = offset; |
102 | phdr.p_vaddr = vma->vm_start; | |
103 | phdr.p_paddr = 0; | |
104 | phdr.p_filesz = mte_vma_tag_dump_size(vma); | |
105 | phdr.p_memsz = vma->vm_end - vma->vm_start; | |
106 | offset += phdr.p_filesz; | |
107 | phdr.p_flags = 0; | |
108 | phdr.p_align = 0; | |
109 | ||
110 | if (!dump_emit(cprm, &phdr, sizeof(phdr))) | |
111 | return 0; | |
112 | } | |
113 | ||
114 | return 1; | |
115 | } | |
116 | ||
117 | size_t elf_core_extra_data_size(void) | |
118 | { | |
119 | struct vm_area_struct *vma; | |
120 | size_t data_size = 0; | |
ef770d18 | 121 | VMA_ITERATOR(vmi, current->mm, 0); |
6dd8b1a0 | 122 | |
ef770d18 | 123 | for_each_mte_vma(vmi, vma) |
6dd8b1a0 CM |
124 | data_size += mte_vma_tag_dump_size(vma); |
125 | ||
126 | return data_size; | |
127 | } | |
128 | ||
129 | int elf_core_write_extra_data(struct coredump_params *cprm) | |
130 | { | |
131 | struct vm_area_struct *vma; | |
ef770d18 | 132 | VMA_ITERATOR(vmi, current->mm, 0); |
6dd8b1a0 | 133 | |
ef770d18 | 134 | for_each_mte_vma(vmi, vma) { |
6dd8b1a0 CM |
135 | if (vma->vm_flags & VM_DONTDUMP) |
136 | continue; | |
137 | ||
138 | if (!mte_dump_tag_range(cprm, vma->vm_start, vma->vm_end)) | |
139 | return 0; | |
140 | } | |
141 | ||
142 | return 1; | |
143 | } |