1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #include <byteswap.h> |
3 | #include <stdbool.h> |
4 | #include <stdio.h> |
5 | #include <stdlib.h> |
6 | #include <stdarg.h> |
7 | #include <string.h> |
8 | #include <sys/types.h> |
9 | #include <sys/stat.h> |
10 | #include <sys/mman.h> |
11 | #include <fcntl.h> |
12 | #include <unistd.h> |
13 | #include <elf.h> |
14 | #include "../../include/linux/module_symbol.h" |
15 | |
16 | #include "list.h" |
17 | #include "elfconfig.h" |
18 | |
19 | /* On BSD-alike OSes elf.h defines these according to host's word size */ |
20 | #undef ELF_ST_BIND |
21 | #undef ELF_ST_TYPE |
22 | #undef ELF_R_SYM |
23 | #undef ELF_R_TYPE |
24 | |
25 | #if KERNEL_ELFCLASS == ELFCLASS32 |
26 | |
27 | #define Elf_Ehdr Elf32_Ehdr |
28 | #define Elf_Shdr Elf32_Shdr |
29 | #define Elf_Sym Elf32_Sym |
30 | #define Elf_Addr Elf32_Addr |
31 | #define Elf_Section Elf32_Half |
32 | #define ELF_ST_BIND ELF32_ST_BIND |
33 | #define ELF_ST_TYPE ELF32_ST_TYPE |
34 | |
35 | #define Elf_Rel Elf32_Rel |
36 | #define Elf_Rela Elf32_Rela |
37 | #define ELF_R_SYM ELF32_R_SYM |
38 | #define ELF_R_TYPE ELF32_R_TYPE |
39 | #else |
40 | |
41 | #define Elf_Ehdr Elf64_Ehdr |
42 | #define Elf_Shdr Elf64_Shdr |
43 | #define Elf_Sym Elf64_Sym |
44 | #define Elf_Addr Elf64_Addr |
45 | #define Elf_Section Elf64_Half |
46 | #define ELF_ST_BIND ELF64_ST_BIND |
47 | #define ELF_ST_TYPE ELF64_ST_TYPE |
48 | |
49 | #define Elf_Rel Elf64_Rel |
50 | #define Elf_Rela Elf64_Rela |
51 | #define ELF_R_SYM ELF64_R_SYM |
52 | #define ELF_R_TYPE ELF64_R_TYPE |
53 | #endif |
54 | |
55 | #define bswap(x) \ |
56 | ({ \ |
57 | _Static_assert(sizeof(x) == 1 || sizeof(x) == 2 || \ |
58 | sizeof(x) == 4 || sizeof(x) == 8, "bug"); \ |
59 | (typeof(x))(sizeof(x) == 2 ? bswap_16(x) : \ |
60 | sizeof(x) == 4 ? bswap_32(x) : \ |
61 | sizeof(x) == 8 ? bswap_64(x) : \ |
62 | x); \ |
63 | }) |
64 | |
65 | #if KERNEL_ELFDATA != HOST_ELFDATA |
66 | |
67 | #define TO_NATIVE(x) (bswap(x)) |
68 | |
69 | #else /* endianness matches */ |
70 | |
71 | #define TO_NATIVE(x) (x) |
72 | |
73 | #endif |
74 | |
75 | #define NOFAIL(ptr) do_nofail((ptr), #ptr) |
76 | |
77 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) |
78 | |
79 | void *do_nofail(void *ptr, const char *expr); |
80 | |
81 | struct buffer { |
82 | char *p; |
83 | int pos; |
84 | int size; |
85 | }; |
86 | |
87 | void __attribute__((format(printf, 2, 3))) |
88 | buf_printf(struct buffer *buf, const char *fmt, ...); |
89 | |
90 | void |
91 | buf_write(struct buffer *buf, const char *s, int len); |
92 | |
93 | struct module { |
94 | struct list_head list; |
95 | struct list_head exported_symbols; |
96 | struct list_head unresolved_symbols; |
97 | bool is_gpl_compatible; |
98 | bool from_dump; /* true if module was loaded from *.symvers */ |
99 | bool is_vmlinux; |
100 | bool seen; |
101 | bool has_init; |
102 | bool has_cleanup; |
103 | struct buffer dev_table_buf; |
104 | char srcversion[25]; |
105 | // Missing namespace dependencies |
106 | struct list_head missing_namespaces; |
107 | // Actual imported namespaces |
108 | struct list_head imported_namespaces; |
109 | char name[]; |
110 | }; |
111 | |
112 | struct elf_info { |
113 | size_t size; |
114 | Elf_Ehdr *hdr; |
115 | Elf_Shdr *sechdrs; |
116 | Elf_Sym *symtab_start; |
117 | Elf_Sym *symtab_stop; |
118 | unsigned int export_symbol_secndx; /* .export_symbol section */ |
119 | char *strtab; |
120 | char *modinfo; |
121 | unsigned int modinfo_len; |
122 | |
123 | /* support for 32bit section numbers */ |
124 | |
125 | unsigned int num_sections; /* max_secindex + 1 */ |
126 | unsigned int secindex_strings; |
127 | /* if Nth symbol table entry has .st_shndx = SHN_XINDEX, |
128 | * take shndx from symtab_shndx_start[N] instead */ |
129 | Elf32_Word *symtab_shndx_start; |
130 | Elf32_Word *symtab_shndx_stop; |
131 | |
132 | struct symsearch *symsearch; |
133 | }; |
134 | |
135 | /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */ |
136 | static inline unsigned int get_secindex(const struct elf_info *info, |
137 | const Elf_Sym *sym) |
138 | { |
139 | unsigned int index = sym->st_shndx; |
140 | |
141 | /* |
142 | * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available |
143 | * in the .symtab_shndx section. |
144 | */ |
145 | if (index == SHN_XINDEX) |
146 | return info->symtab_shndx_start[sym - info->symtab_start]; |
147 | |
148 | /* |
149 | * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of |
150 | * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real |
151 | * section indices. |
152 | */ |
153 | if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE) |
154 | return index - SHN_HIRESERVE - 1; |
155 | |
156 | return index; |
157 | } |
158 | |
159 | /* |
160 | * If there's no name there, ignore it; likewise, ignore it if it's |
161 | * one of the magic symbols emitted used by current tools. |
162 | * |
163 | * Internal symbols created by tools should be ignored by modpost. |
164 | */ |
165 | static inline bool is_valid_name(struct elf_info *elf, Elf_Sym *sym) |
166 | { |
167 | const char *name = elf->strtab + sym->st_name; |
168 | |
169 | if (!name || !strlen(s: name)) |
170 | return false; |
171 | return !is_mapping_symbol(str: name); |
172 | } |
173 | |
174 | /* symsearch.c */ |
175 | void symsearch_init(struct elf_info *elf); |
176 | void symsearch_finish(struct elf_info *elf); |
177 | Elf_Sym *symsearch_find_nearest(struct elf_info *elf, Elf_Addr addr, |
178 | unsigned int secndx, bool allow_negative, |
179 | Elf_Addr min_distance); |
180 | |
181 | /* file2alias.c */ |
182 | void handle_moddevtable(struct module *mod, struct elf_info *info, |
183 | Elf_Sym *sym, const char *symname); |
184 | void add_moddevtable(struct buffer *buf, struct module *mod); |
185 | |
186 | /* sumversion.c */ |
187 | void get_src_version(const char *modname, char sum[], unsigned sumlen); |
188 | |
189 | /* from modpost.c */ |
190 | char *read_text_file(const char *filename); |
191 | char *get_line(char **stringp); |
192 | void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym); |
193 | |
194 | enum loglevel { |
195 | LOG_WARN, |
196 | LOG_ERROR, |
197 | LOG_FATAL |
198 | }; |
199 | |
200 | void modpost_log(enum loglevel loglevel, const char *fmt, ...); |
201 | |
202 | /* |
203 | * warn - show the given message, then let modpost continue running, still |
204 | * allowing modpost to exit successfully. This should be used when |
205 | * we still allow to generate vmlinux and modules. |
206 | * |
207 | * error - show the given message, then let modpost continue running, but fail |
208 | * in the end. This should be used when we should stop building vmlinux |
209 | * or modules, but we can continue running modpost to catch as many |
210 | * issues as possible. |
211 | * |
212 | * fatal - show the given message, and bail out immediately. This should be |
213 | * used when there is no point to continue running modpost. |
214 | */ |
215 | #define warn(fmt, args...) modpost_log(LOG_WARN, fmt, ##args) |
216 | #define error(fmt, args...) modpost_log(LOG_ERROR, fmt, ##args) |
217 | #define fatal(fmt, args...) modpost_log(LOG_FATAL, fmt, ##args) |
218 | |