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2874c5fd | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
ebb5e78c AS |
2 | /* |
3 | * Copyright (C) 2015 Imagination Technologies | |
4 | * Author: Alex Smith <alex.smith@imgtec.com> | |
ebb5e78c AS |
5 | */ |
6 | ||
7 | static inline bool FUNC(patch_vdso)(const char *path, void *vdso) | |
8 | { | |
9 | const ELF(Ehdr) *ehdr = vdso; | |
10 | void *shdrs; | |
11 | ELF(Shdr) *shdr; | |
12 | char *shstrtab, *name; | |
13 | uint16_t sh_count, sh_entsize, i; | |
ebb5e78c AS |
14 | |
15 | shdrs = vdso + FUNC(swap_uint)(ehdr->e_shoff); | |
16 | sh_count = swap_uint16(ehdr->e_shnum); | |
17 | sh_entsize = swap_uint16(ehdr->e_shentsize); | |
18 | ||
19 | shdr = shdrs + (sh_entsize * swap_uint16(ehdr->e_shstrndx)); | |
20 | shstrtab = vdso + FUNC(swap_uint)(shdr->sh_offset); | |
21 | ||
22 | for (i = 0; i < sh_count; i++) { | |
23 | shdr = shdrs + (i * sh_entsize); | |
24 | name = shstrtab + swap_uint32(shdr->sh_name); | |
25 | ||
26 | /* | |
27 | * Ensure there are no relocation sections - ld.so does not | |
28 | * relocate the VDSO so if there are relocations things will | |
29 | * break. | |
30 | */ | |
31 | switch (swap_uint32(shdr->sh_type)) { | |
32 | case SHT_REL: | |
33 | case SHT_RELA: | |
34 | fprintf(stderr, | |
35 | "%s: '%s' contains relocation sections\n", | |
36 | program_name, path); | |
37 | return false; | |
ebb5e78c AS |
38 | } |
39 | ||
40 | /* Check for existing sections. */ | |
41 | if (strcmp(name, ".MIPS.abiflags") == 0) { | |
42 | fprintf(stderr, | |
43 | "%s: '%s' already contains a '.MIPS.abiflags' section\n", | |
44 | program_name, path); | |
45 | return false; | |
46 | } | |
47 | ||
48 | if (strcmp(name, ".mips_abiflags") == 0) { | |
49 | strcpy(name, ".MIPS.abiflags"); | |
50 | shdr->sh_type = swap_uint32(SHT_MIPS_ABIFLAGS); | |
51 | shdr->sh_entsize = shdr->sh_size; | |
52 | } | |
53 | } | |
54 | ||
ebb5e78c AS |
55 | return true; |
56 | } | |
57 | ||
58 | static inline bool FUNC(get_symbols)(const char *path, void *vdso) | |
59 | { | |
60 | const ELF(Ehdr) *ehdr = vdso; | |
61 | void *shdrs, *symtab; | |
62 | ELF(Shdr) *shdr; | |
63 | const ELF(Sym) *sym; | |
64 | char *strtab, *name; | |
65 | uint16_t sh_count, sh_entsize, st_count, st_entsize, i, j; | |
66 | uint64_t offset; | |
67 | uint32_t flags; | |
68 | ||
69 | shdrs = vdso + FUNC(swap_uint)(ehdr->e_shoff); | |
70 | sh_count = swap_uint16(ehdr->e_shnum); | |
71 | sh_entsize = swap_uint16(ehdr->e_shentsize); | |
72 | ||
73 | for (i = 0; i < sh_count; i++) { | |
74 | shdr = shdrs + (i * sh_entsize); | |
75 | ||
76 | if (swap_uint32(shdr->sh_type) == SHT_SYMTAB) | |
77 | break; | |
78 | } | |
79 | ||
80 | if (i == sh_count) { | |
81 | fprintf(stderr, "%s: '%s' has no symbol table\n", program_name, | |
82 | path); | |
83 | return false; | |
84 | } | |
85 | ||
86 | /* Get flags */ | |
87 | flags = swap_uint32(ehdr->e_flags); | |
88 | if (elf_class == ELFCLASS64) | |
89 | elf_abi = ABI_N64; | |
90 | else if (flags & EF_MIPS_ABI2) | |
91 | elf_abi = ABI_N32; | |
92 | else | |
93 | elf_abi = ABI_O32; | |
94 | ||
95 | /* Get symbol table. */ | |
96 | symtab = vdso + FUNC(swap_uint)(shdr->sh_offset); | |
97 | st_entsize = FUNC(swap_uint)(shdr->sh_entsize); | |
98 | st_count = FUNC(swap_uint)(shdr->sh_size) / st_entsize; | |
99 | ||
100 | /* Get string table. */ | |
101 | shdr = shdrs + (swap_uint32(shdr->sh_link) * sh_entsize); | |
102 | strtab = vdso + FUNC(swap_uint)(shdr->sh_offset); | |
103 | ||
104 | /* Write offsets for symbols needed by the kernel. */ | |
105 | for (i = 0; vdso_symbols[i].name; i++) { | |
106 | if (!(vdso_symbols[i].abis & elf_abi)) | |
107 | continue; | |
108 | ||
109 | for (j = 0; j < st_count; j++) { | |
110 | sym = symtab + (j * st_entsize); | |
111 | name = strtab + swap_uint32(sym->st_name); | |
112 | ||
113 | if (!strcmp(name, vdso_symbols[i].name)) { | |
114 | offset = FUNC(swap_uint)(sym->st_value); | |
115 | ||
116 | fprintf(out_file, | |
117 | "\t.%s = 0x%" PRIx64 ",\n", | |
118 | vdso_symbols[i].offset_name, offset); | |
119 | break; | |
120 | } | |
121 | } | |
122 | ||
123 | if (j == st_count) { | |
124 | fprintf(stderr, | |
125 | "%s: '%s' is missing required symbol '%s'\n", | |
126 | program_name, path, vdso_symbols[i].name); | |
127 | return false; | |
128 | } | |
129 | } | |
130 | ||
131 | return true; | |
132 | } |