1 /* SPDX-License-Identifier: GPL-2.0 */
2 #include <stdbool.h>
3 #include <stdio.h>
4 #include <stdlib.h>
5 #include <stdarg.h>
6 #include <string.h>
7 #include <sys/types.h>
8 #include <sys/stat.h>
9 #include <sys/mman.h>
10 #include <fcntl.h>
11 #include <unistd.h>
12 #include <elf.h>
13
14 #include "list.h"
15 #include "elfconfig.h"
16
17 /* On BSD-alike OSes elf.h defines these according to host's word size */
18 #undef ELF_ST_BIND
19 #undef ELF_ST_TYPE
20 #undef ELF_R_SYM
21 #undef ELF_R_TYPE
22
23 #if KERNEL_ELFCLASS == ELFCLASS32
24
25 #define Elf_Ehdr Elf32_Ehdr
26 #define Elf_Shdr Elf32_Shdr
27 #define Elf_Sym Elf32_Sym
28 #define Elf_Addr Elf32_Addr
29 #define Elf_Section Elf32_Half
30 #define ELF_ST_BIND ELF32_ST_BIND
31 #define ELF_ST_TYPE ELF32_ST_TYPE
32
33 #define Elf_Rel Elf32_Rel
34 #define Elf_Rela Elf32_Rela
35 #define ELF_R_SYM ELF32_R_SYM
36 #define ELF_R_TYPE ELF32_R_TYPE
37 #else
38
39 #define Elf_Ehdr Elf64_Ehdr
40 #define Elf_Shdr Elf64_Shdr
41 #define Elf_Sym Elf64_Sym
42 #define Elf_Addr Elf64_Addr
43 #define Elf_Section Elf64_Half
44 #define ELF_ST_BIND ELF64_ST_BIND
45 #define ELF_ST_TYPE ELF64_ST_TYPE
46
47 #define Elf_Rel Elf64_Rel
48 #define Elf_Rela Elf64_Rela
49 #define ELF_R_SYM ELF64_R_SYM
50 #define ELF_R_TYPE ELF64_R_TYPE
51 #endif
52
53 #if KERNEL_ELFDATA != HOST_ELFDATA
54
__endian(const void * src,void * dest,unsigned int size)55 static inline void __endian(const void *src, void *dest, unsigned int size)
56 {
57 unsigned int i;
58 for (i = 0; i < size; i++)
59 ((unsigned char*)dest)[i] = ((unsigned char*)src)[size - i-1];
60 }
61
62 #define TO_NATIVE(x) \
63 ({ \
64 typeof(x) __x; \
65 __endian(&(x), &(__x), sizeof(__x)); \
66 __x; \
67 })
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
133 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
get_secindex(const struct elf_info * info,const Elf_Sym * sym)134 static inline unsigned int get_secindex(const struct elf_info *info,
135 const Elf_Sym *sym)
136 {
137 unsigned int index = sym->st_shndx;
138
139 /*
140 * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available
141 * in the .symtab_shndx section.
142 */
143 if (index == SHN_XINDEX)
144 return info->symtab_shndx_start[sym - info->symtab_start];
145
146 /*
147 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
148 * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real
149 * section indices.
150 */
151 if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE)
152 return index - SHN_HIRESERVE - 1;
153
154 return index;
155 }
156
157 /* file2alias.c */
158 void handle_moddevtable(struct module *mod, struct elf_info *info,
159 Elf_Sym *sym, const char *symname);
160 void add_moddevtable(struct buffer *buf, struct module *mod);
161
162 /* sumversion.c */
163 void get_src_version(const char *modname, char sum[], unsigned sumlen);
164
165 /* from modpost.c */
166 char *read_text_file(const char *filename);
167 char *get_line(char **stringp);
168 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym);
169
170 enum loglevel {
171 LOG_WARN,
172 LOG_ERROR,
173 LOG_FATAL
174 };
175
176 void modpost_log(enum loglevel loglevel, const char *fmt, ...);
177
178 /*
179 * warn - show the given message, then let modpost continue running, still
180 * allowing modpost to exit successfully. This should be used when
181 * we still allow to generate vmlinux and modules.
182 *
183 * error - show the given message, then let modpost continue running, but fail
184 * in the end. This should be used when we should stop building vmlinux
185 * or modules, but we can continue running modpost to catch as many
186 * issues as possible.
187 *
188 * fatal - show the given message, and bail out immediately. This should be
189 * used when there is no point to continue running modpost.
190 */
191 #define warn(fmt, args...) modpost_log(LOG_WARN, fmt, ##args)
192 #define error(fmt, args...) modpost_log(LOG_ERROR, fmt, ##args)
193 #define fatal(fmt, args...) modpost_log(LOG_FATAL, fmt, ##args)
194