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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 __get_unaligned_t(type, ptr) ({ \
69 const struct { type x; } __attribute__((__packed__)) *__pptr = \
70 (typeof(__pptr))(ptr); \
71 __pptr->x; \
72})
73
74#define get_unaligned(ptr) __get_unaligned_t(typeof(*(ptr)), (ptr))
75
76#define get_unaligned_native(ptr) \
77({ \
78 typeof(*(ptr)) _val = get_unaligned(ptr); \
79 TO_NATIVE(_val); \
80})
81
82#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
83
84#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
85
86struct buffer {
87 char *p;
88 int pos;
89 int size;
90};
91
92void __attribute__((format(printf, 2, 3)))
93buf_printf(struct buffer *buf, const char *fmt, ...);
94
95void
96buf_write(struct buffer *buf, const char *s, int len);
97
98/**
99 * struct module_alias - auto-generated MODULE_ALIAS()
100 *
101 * @node: linked to module::aliases
102 * @str: a string for MODULE_ALIAS()
103 */
104struct module_alias {
105 struct list_head node;
106 char str[];
107};
108
109/**
110 * struct module - represent a module (vmlinux or *.ko)
111 *
112 * @dump_file: path to the .symvers file if loaded from a file
113 * @aliases: list head for module_aliases
114 */
115struct module {
116 struct list_head list;
117 struct list_head exported_symbols;
118 struct list_head unresolved_symbols;
119 const char *dump_file;
120 bool is_gpl_compatible;
121 bool is_vmlinux;
122 bool seen;
123 bool has_init;
124 bool has_cleanup;
125 char srcversion[25];
126 // Missing namespace dependencies
127 struct list_head missing_namespaces;
128 // Actual imported namespaces
129 struct list_head imported_namespaces;
130 struct list_head aliases;
131 char name[];
132};
133
134struct 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 unsigned int export_symbol_secndx; /* .export_symbol section */
141 char *strtab;
142 char *modinfo;
143 unsigned int modinfo_len;
144
145 /* support for 32bit section numbers */
146
147 unsigned int num_sections; /* max_secindex + 1 */
148 unsigned int secindex_strings;
149 /* if Nth symbol table entry has .st_shndx = SHN_XINDEX,
150 * take shndx from symtab_shndx_start[N] instead */
151 Elf32_Word *symtab_shndx_start;
152 Elf32_Word *symtab_shndx_stop;
153
154 struct symsearch *symsearch;
155};
156
157/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
158static inline unsigned int get_secindex(const struct elf_info *info,
159 const Elf_Sym *sym)
160{
161 unsigned int index = sym->st_shndx;
162
163 /*
164 * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available
165 * in the .symtab_shndx section.
166 */
167 if (index == SHN_XINDEX)
168 return info->symtab_shndx_start[sym - info->symtab_start];
169
170 /*
171 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
172 * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real
173 * section indices.
174 */
175 if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE)
176 return index - SHN_HIRESERVE - 1;
177
178 return index;
179}
180
181/*
182 * If there's no name there, ignore it; likewise, ignore it if it's
183 * one of the magic symbols emitted used by current tools.
184 *
185 * Internal symbols created by tools should be ignored by modpost.
186 */
187static inline bool is_valid_name(struct elf_info *elf, Elf_Sym *sym)
188{
189 const char *name = elf->strtab + sym->st_name;
190
191 if (!name || !strlen(name))
192 return false;
193 return !is_mapping_symbol(name);
194}
195
196/* symsearch.c */
197void symsearch_init(struct elf_info *elf);
198void symsearch_finish(struct elf_info *elf);
199Elf_Sym *symsearch_find_nearest(struct elf_info *elf, Elf_Addr addr,
200 unsigned int secndx, bool allow_negative,
201 Elf_Addr min_distance);
202
203/* file2alias.c */
204void handle_moddevtable(struct module *mod, struct elf_info *info,
205 Elf_Sym *sym, const char *symname);
206
207/* sumversion.c */
208void get_src_version(const char *modname, char sum[], unsigned sumlen);
209
210/* from modpost.c */
211extern bool target_is_big_endian;
212extern bool host_is_big_endian;
213char *read_text_file(const char *filename);
214char *get_line(char **stringp);
215void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym);
216
217void __attribute__((format(printf, 2, 3)))
218modpost_log(bool is_error, const char *fmt, ...);
219
220/*
221 * warn - show the given message, then let modpost continue running, still
222 * allowing modpost to exit successfully. This should be used when
223 * we still allow to generate vmlinux and modules.
224 *
225 * error - show the given message, then let modpost continue running, but fail
226 * in the end. This should be used when we should stop building vmlinux
227 * or modules, but we can continue running modpost to catch as many
228 * issues as possible.
229 *
230 * fatal - show the given message, and bail out immediately. This should be
231 * used when there is no point to continue running modpost.
232 */
233#define warn(fmt, args...) modpost_log(false, fmt, ##args)
234#define error(fmt, args...) modpost_log(true, fmt, ##args)
235#define fatal(fmt, args...) do { error(fmt, ##args); exit(1); } while (1)
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. */
54typedef 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
63typedef 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
77static 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
101void *do_nofail(void *ptr, const char *expr);
102
103struct buffer {
104 char *p;
105 int pos;
106 int size;
107};
108
109void __attribute__((format(printf, 2, 3)))
110buf_printf(struct buffer *buf, const char *fmt, ...);
111
112void
113buf_write(struct buffer *buf, const char *s, int len);
114
115struct 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
134struct 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
154static 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" */
160static 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 */
184void handle_moddevtable(struct module *mod, struct elf_info *info,
185 Elf_Sym *sym, const char *symname);
186void add_moddevtable(struct buffer *buf, struct module *mod);
187
188/* sumversion.c */
189void get_src_version(const char *modname, char sum[], unsigned sumlen);
190
191/* from modpost.c */
192char *read_text_file(const char *filename);
193char *get_line(char **stringp);
194void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym);
195
196enum loglevel {
197 LOG_WARN,
198 LOG_ERROR,
199 LOG_FATAL
200};
201
202void 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)