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 /* The 64-bit MIPS ELF ABI uses an unusual reloc format. */
54 typedef struct
55 {
56 Elf32_Word r_sym; /* Symbol index */
57 unsigned char r_ssym; /* Special symbol for 2nd relocation */
58 unsigned char r_type3; /* 3rd relocation type */
59 unsigned char r_type2; /* 2nd relocation type */
60 unsigned char r_type1; /* 1st relocation type */
61 } _Elf64_Mips_R_Info;
62
63 typedef union
64 {
65 Elf64_Xword r_info_number;
66 _Elf64_Mips_R_Info r_info_fields;
67 } _Elf64_Mips_R_Info_union;
68
69 #define ELF64_MIPS_R_SYM(i) \
70 ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym)
71
72 #define ELF64_MIPS_R_TYPE(i) \
73 ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1)
74
75 #if KERNEL_ELFDATA != HOST_ELFDATA
76
__endian(const void * src,void * dest,unsigned int size)77 static inline void __endian(const void *src, void *dest, unsigned int size)
78 {
79 unsigned int i;
80 for (i = 0; i < size; i++)
81 ((unsigned char*)dest)[i] = ((unsigned char*)src)[size - i-1];
82 }
83
84 #define TO_NATIVE(x) \
85 ({ \
86 typeof(x) __x; \
87 __endian(&(x), &(__x), sizeof(__x)); \
88 __x; \
89 })
90
91 #else /* endianness matches */
92
93 #define TO_NATIVE(x) (x)
94
95 #endif
96
97 #define NOFAIL(ptr) do_nofail((ptr), #ptr)
98
99 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
100
101 void *do_nofail(void *ptr, const char *expr);
102
103 struct buffer {
104 char *p;
105 int pos;
106 int size;
107 };
108
109 void __attribute__((format(printf, 2, 3)))
110 buf_printf(struct buffer *buf, const char *fmt, ...);
111
112 void
113 buf_write(struct buffer *buf, const char *s, int len);
114
115 struct module {
116 struct list_head list;
117 struct list_head exported_symbols;
118 struct list_head unresolved_symbols;
119 bool is_gpl_compatible;
120 bool from_dump; /* true if module was loaded from *.symvers */
121 bool is_vmlinux;
122 bool seen;
123 bool has_init;
124 bool has_cleanup;
125 struct buffer dev_table_buf;
126 char srcversion[25];
127 // Missing namespace dependencies
128 struct list_head missing_namespaces;
129 // Actual imported namespaces
130 struct list_head imported_namespaces;
131 char name[];
132 };
133
134 struct elf_info {
135 size_t size;
136 Elf_Ehdr *hdr;
137 Elf_Shdr *sechdrs;
138 Elf_Sym *symtab_start;
139 Elf_Sym *symtab_stop;
140 char *strtab;
141 char *modinfo;
142 unsigned int modinfo_len;
143
144 /* support for 32bit section numbers */
145
146 unsigned int num_sections; /* max_secindex + 1 */
147 unsigned int secindex_strings;
148 /* if Nth symbol table entry has .st_shndx = SHN_XINDEX,
149 * take shndx from symtab_shndx_start[N] instead */
150 Elf32_Word *symtab_shndx_start;
151 Elf32_Word *symtab_shndx_stop;
152 };
153
is_shndx_special(unsigned int i)154 static inline int is_shndx_special(unsigned int i)
155 {
156 return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
157 }
158
159 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
get_secindex(const struct elf_info * info,const Elf_Sym * sym)160 static inline unsigned int get_secindex(const struct elf_info *info,
161 const Elf_Sym *sym)
162 {
163 unsigned int index = sym->st_shndx;
164
165 /*
166 * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available
167 * in the .symtab_shndx section.
168 */
169 if (index == SHN_XINDEX)
170 return info->symtab_shndx_start[sym - info->symtab_start];
171
172 /*
173 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
174 * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real
175 * section indices.
176 */
177 if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE)
178 return index - SHN_HIRESERVE - 1;
179
180 return index;
181 }
182
183 /* file2alias.c */
184 void handle_moddevtable(struct module *mod, struct elf_info *info,
185 Elf_Sym *sym, const char *symname);
186 void add_moddevtable(struct buffer *buf, struct module *mod);
187
188 /* sumversion.c */
189 void get_src_version(const char *modname, char sum[], unsigned sumlen);
190
191 /* from modpost.c */
192 char *read_text_file(const char *filename);
193 char *get_line(char **stringp);
194 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym);
195
196 enum loglevel {
197 LOG_WARN,
198 LOG_ERROR,
199 LOG_FATAL
200 };
201
202 void modpost_log(enum loglevel loglevel, const char *fmt, ...);
203
204 /*
205 * warn - show the given message, then let modpost continue running, still
206 * allowing modpost to exit successfully. This should be used when
207 * we still allow to generate vmlinux and modules.
208 *
209 * error - show the given message, then let modpost continue running, but fail
210 * in the end. This should be used when we should stop building vmlinux
211 * or modules, but we can continue running modpost to catch as many
212 * issues as possible.
213 *
214 * fatal - show the given message, and bail out immediately. This should be
215 * used when there is no point to continue running modpost.
216 */
217 #define warn(fmt, args...) modpost_log(LOG_WARN, fmt, ##args)
218 #define error(fmt, args...) modpost_log(LOG_ERROR, fmt, ##args)
219 #define fatal(fmt, args...) modpost_log(LOG_FATAL, fmt, ##args)
220