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1/* SPDX-License-Identifier: GPL-2.0 */
2#include <stdio.h>
3#include <stdlib.h>
4#include <stdarg.h>
5#include <string.h>
6#include <sys/types.h>
7#include <sys/stat.h>
8#include <sys/mman.h>
9#include <fcntl.h>
10#include <unistd.h>
11#include <elf.h>
12
13#include "elfconfig.h"
14
15/* On BSD-alike OSes elf.h defines these according to host's word size */
16#undef ELF_ST_BIND
17#undef ELF_ST_TYPE
18#undef ELF_R_SYM
19#undef ELF_R_TYPE
20
21#if KERNEL_ELFCLASS == ELFCLASS32
22
23#define Elf_Ehdr Elf32_Ehdr
24#define Elf_Shdr Elf32_Shdr
25#define Elf_Sym Elf32_Sym
26#define Elf_Addr Elf32_Addr
27#define Elf_Sword Elf64_Sword
28#define Elf_Section Elf32_Half
29#define ELF_ST_BIND ELF32_ST_BIND
30#define ELF_ST_TYPE ELF32_ST_TYPE
31
32#define Elf_Rel Elf32_Rel
33#define Elf_Rela Elf32_Rela
34#define ELF_R_SYM ELF32_R_SYM
35#define ELF_R_TYPE ELF32_R_TYPE
36#else
37
38#define Elf_Ehdr Elf64_Ehdr
39#define Elf_Shdr Elf64_Shdr
40#define Elf_Sym Elf64_Sym
41#define Elf_Addr Elf64_Addr
42#define Elf_Sword Elf64_Sxword
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)
98void *do_nofail(void *ptr, const char *expr);
99
100struct buffer {
101 char *p;
102 int pos;
103 int size;
104};
105
106void __attribute__((format(printf, 2, 3)))
107buf_printf(struct buffer *buf, const char *fmt, ...);
108
109void
110buf_write(struct buffer *buf, const char *s, int len);
111
112struct namespace_list {
113 struct namespace_list *next;
114 char namespace[0];
115};
116
117struct module {
118 struct module *next;
119 const char *name;
120 int gpl_compatible;
121 struct symbol *unres;
122 int seen;
123 int skip;
124 int has_init;
125 int has_cleanup;
126 struct buffer dev_table_buf;
127 char srcversion[25];
128 int is_dot_o;
129 // Required namespace dependencies
130 struct namespace_list *required_namespaces;
131 // Actual imported namespaces
132 struct namespace_list *imported_namespaces;
133};
134
135struct elf_info {
136 unsigned long size;
137 Elf_Ehdr *hdr;
138 Elf_Shdr *sechdrs;
139 Elf_Sym *symtab_start;
140 Elf_Sym *symtab_stop;
141 Elf_Section export_sec;
142 Elf_Section export_unused_sec;
143 Elf_Section export_gpl_sec;
144 Elf_Section export_unused_gpl_sec;
145 Elf_Section export_gpl_future_sec;
146 char *ksymtab_strings;
147 char *strtab;
148 char *modinfo;
149 unsigned int modinfo_len;
150
151 /* support for 32bit section numbers */
152
153 unsigned int num_sections; /* max_secindex + 1 */
154 unsigned int secindex_strings;
155 /* if Nth symbol table entry has .st_shndx = SHN_XINDEX,
156 * take shndx from symtab_shndx_start[N] instead */
157 Elf32_Word *symtab_shndx_start;
158 Elf32_Word *symtab_shndx_stop;
159};
160
161static inline int is_shndx_special(unsigned int i)
162{
163 return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
164}
165
166/*
167 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
168 * the way to -256..-1, to avoid conflicting with real section
169 * indices.
170 */
171#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
172
173/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
174static inline unsigned int get_secindex(const struct elf_info *info,
175 const Elf_Sym *sym)
176{
177 if (is_shndx_special(sym->st_shndx))
178 return SPECIAL(sym->st_shndx);
179 if (sym->st_shndx != SHN_XINDEX)
180 return sym->st_shndx;
181 return info->symtab_shndx_start[sym - info->symtab_start];
182}
183
184/* file2alias.c */
185extern unsigned int cross_build;
186void handle_moddevtable(struct module *mod, struct elf_info *info,
187 Elf_Sym *sym, const char *symname);
188void add_moddevtable(struct buffer *buf, struct module *mod);
189
190/* sumversion.c */
191void maybe_frob_rcs_version(const char *modfilename,
192 char *version,
193 void *modinfo,
194 unsigned long modinfo_offset);
195void get_src_version(const char *modname, char sum[], unsigned sumlen);
196
197/* from modpost.c */
198void *grab_file(const char *filename, unsigned long *size);
199char* get_next_line(unsigned long *pos, void *file, unsigned long size);
200void release_file(void *file, unsigned long size);
201
202void fatal(const char *fmt, ...);
203void warn(const char *fmt, ...);
204void merror(const char *fmt, ...);
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
79void *do_nofail(void *ptr, const char *expr);
80
81struct buffer {
82 char *p;
83 int pos;
84 int size;
85};
86
87void __attribute__((format(printf, 2, 3)))
88buf_printf(struct buffer *buf, const char *fmt, ...);
89
90void
91buf_write(struct buffer *buf, const char *s, int len);
92
93struct 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
112struct 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" */
136static 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 */
165static 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(name))
170 return false;
171 return !is_mapping_symbol(name);
172}
173
174/* symsearch.c */
175void symsearch_init(struct elf_info *elf);
176void symsearch_finish(struct elf_info *elf);
177Elf_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 */
182void handle_moddevtable(struct module *mod, struct elf_info *info,
183 Elf_Sym *sym, const char *symname);
184void add_moddevtable(struct buffer *buf, struct module *mod);
185
186/* sumversion.c */
187void get_src_version(const char *modname, char sum[], unsigned sumlen);
188
189/* from modpost.c */
190char *read_text_file(const char *filename);
191char *get_line(char **stringp);
192void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym);
193
194enum loglevel {
195 LOG_WARN,
196 LOG_ERROR,
197};
198
199void __attribute__((format(printf, 2, 3)))
200modpost_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...) do { error(fmt, ##args); exit(1); } while (1)