Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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_types.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#define TO_NATIVE(x) \
66 (target_is_big_endian == host_is_big_endian ? x : bswap(x))
67
68#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
69
70#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
71
72struct buffer {
73 char *p;
74 int pos;
75 int size;
76};
77
78void __attribute__((format(printf, 2, 3)))
79buf_printf(struct buffer *buf, const char *fmt, ...);
80
81void
82buf_write(struct buffer *buf, const char *s, int len);
83
84/**
85 * struct module_alias - auto-generated MODULE_ALIAS()
86 *
87 * @node: linked to module::aliases
88 * @str: a string for MODULE_ALIAS()
89 */
90struct module_alias {
91 struct list_head node;
92 char str[];
93};
94
95/**
96 * struct module - represent a module (vmlinux or *.ko)
97 *
98 * @aliases: list head for module_aliases
99 */
100struct module {
101 struct list_head list;
102 struct list_head exported_symbols;
103 struct list_head unresolved_symbols;
104 bool is_gpl_compatible;
105 bool from_dump; /* true if module was loaded from *.symvers */
106 bool is_vmlinux;
107 bool seen;
108 bool has_init;
109 bool has_cleanup;
110 char srcversion[25];
111 // Missing namespace dependencies
112 struct list_head missing_namespaces;
113 // Actual imported namespaces
114 struct list_head imported_namespaces;
115 struct list_head aliases;
116 char name[];
117};
118
119struct elf_info {
120 size_t size;
121 Elf_Ehdr *hdr;
122 Elf_Shdr *sechdrs;
123 Elf_Sym *symtab_start;
124 Elf_Sym *symtab_stop;
125 unsigned int export_symbol_secndx; /* .export_symbol section */
126 char *strtab;
127 char *modinfo;
128 unsigned int modinfo_len;
129
130 /* support for 32bit section numbers */
131
132 unsigned int num_sections; /* max_secindex + 1 */
133 unsigned int secindex_strings;
134 /* if Nth symbol table entry has .st_shndx = SHN_XINDEX,
135 * take shndx from symtab_shndx_start[N] instead */
136 Elf32_Word *symtab_shndx_start;
137 Elf32_Word *symtab_shndx_stop;
138
139 struct symsearch *symsearch;
140};
141
142/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
143static inline unsigned int get_secindex(const struct elf_info *info,
144 const Elf_Sym *sym)
145{
146 unsigned int index = sym->st_shndx;
147
148 /*
149 * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available
150 * in the .symtab_shndx section.
151 */
152 if (index == SHN_XINDEX)
153 return info->symtab_shndx_start[sym - info->symtab_start];
154
155 /*
156 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
157 * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real
158 * section indices.
159 */
160 if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE)
161 return index - SHN_HIRESERVE - 1;
162
163 return index;
164}
165
166/*
167 * If there's no name there, ignore it; likewise, ignore it if it's
168 * one of the magic symbols emitted used by current tools.
169 *
170 * Internal symbols created by tools should be ignored by modpost.
171 */
172static inline bool is_valid_name(struct elf_info *elf, Elf_Sym *sym)
173{
174 const char *name = elf->strtab + sym->st_name;
175
176 if (!name || !strlen(name))
177 return false;
178 return !is_mapping_symbol(name);
179}
180
181/* symsearch.c */
182void symsearch_init(struct elf_info *elf);
183void symsearch_finish(struct elf_info *elf);
184Elf_Sym *symsearch_find_nearest(struct elf_info *elf, Elf_Addr addr,
185 unsigned int secndx, bool allow_negative,
186 Elf_Addr min_distance);
187
188/* file2alias.c */
189void handle_moddevtable(struct module *mod, struct elf_info *info,
190 Elf_Sym *sym, const char *symname);
191
192/* sumversion.c */
193void get_src_version(const char *modname, char sum[], unsigned sumlen);
194
195/* from modpost.c */
196extern bool target_is_big_endian;
197extern bool host_is_big_endian;
198char *read_text_file(const char *filename);
199char *get_line(char **stringp);
200void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym);
201
202void __attribute__((format(printf, 2, 3)))
203modpost_log(bool is_error, const char *fmt, ...);
204
205/*
206 * warn - show the given message, then let modpost continue running, still
207 * allowing modpost to exit successfully. This should be used when
208 * we still allow to generate vmlinux and modules.
209 *
210 * error - show the given message, then let modpost continue running, but fail
211 * in the end. This should be used when we should stop building vmlinux
212 * or modules, but we can continue running modpost to catch as many
213 * issues as possible.
214 *
215 * fatal - show the given message, and bail out immediately. This should be
216 * used when there is no point to continue running modpost.
217 */
218#define warn(fmt, args...) modpost_log(false, fmt, ##args)
219#define error(fmt, args...) modpost_log(true, fmt, ##args)
220#define fatal(fmt, args...) do { error(fmt, ##args); exit(1); } while (1)