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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.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)
1#include <stdio.h>
2#include <stdlib.h>
3#include <stdarg.h>
4#include <string.h>
5#include <sys/types.h>
6#include <sys/stat.h>
7#include <sys/mman.h>
8#include <fcntl.h>
9#include <unistd.h>
10#include <elf.h>
11
12#include "elfconfig.h"
13
14#if KERNEL_ELFCLASS == ELFCLASS32
15
16#define Elf_Ehdr Elf32_Ehdr
17#define Elf_Shdr Elf32_Shdr
18#define Elf_Sym Elf32_Sym
19#define Elf_Addr Elf32_Addr
20#define Elf_Sword Elf64_Sword
21#define Elf_Section Elf32_Half
22#define ELF_ST_BIND ELF32_ST_BIND
23#define ELF_ST_TYPE ELF32_ST_TYPE
24
25#define Elf_Rel Elf32_Rel
26#define Elf_Rela Elf32_Rela
27#define ELF_R_SYM ELF32_R_SYM
28#define ELF_R_TYPE ELF32_R_TYPE
29#else
30
31#define Elf_Ehdr Elf64_Ehdr
32#define Elf_Shdr Elf64_Shdr
33#define Elf_Sym Elf64_Sym
34#define Elf_Addr Elf64_Addr
35#define Elf_Sword Elf64_Sxword
36#define Elf_Section Elf64_Half
37#define ELF_ST_BIND ELF64_ST_BIND
38#define ELF_ST_TYPE ELF64_ST_TYPE
39
40#define Elf_Rel Elf64_Rel
41#define Elf_Rela Elf64_Rela
42#define ELF_R_SYM ELF64_R_SYM
43#define ELF_R_TYPE ELF64_R_TYPE
44#endif
45
46/* The 64-bit MIPS ELF ABI uses an unusual reloc format. */
47typedef struct
48{
49 Elf32_Word r_sym; /* Symbol index */
50 unsigned char r_ssym; /* Special symbol for 2nd relocation */
51 unsigned char r_type3; /* 3rd relocation type */
52 unsigned char r_type2; /* 2nd relocation type */
53 unsigned char r_type1; /* 1st relocation type */
54} _Elf64_Mips_R_Info;
55
56typedef union
57{
58 Elf64_Xword r_info_number;
59 _Elf64_Mips_R_Info r_info_fields;
60} _Elf64_Mips_R_Info_union;
61
62#define ELF64_MIPS_R_SYM(i) \
63 ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym)
64
65#define ELF64_MIPS_R_TYPE(i) \
66 ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1)
67
68#if KERNEL_ELFDATA != HOST_ELFDATA
69
70static inline void __endian(const void *src, void *dest, unsigned int size)
71{
72 unsigned int i;
73 for (i = 0; i < size; i++)
74 ((unsigned char*)dest)[i] = ((unsigned char*)src)[size - i-1];
75}
76
77#define TO_NATIVE(x) \
78({ \
79 typeof(x) __x; \
80 __endian(&(x), &(__x), sizeof(__x)); \
81 __x; \
82})
83
84#else /* endianness matches */
85
86#define TO_NATIVE(x) (x)
87
88#endif
89
90#define NOFAIL(ptr) do_nofail((ptr), #ptr)
91void *do_nofail(void *ptr, const char *expr);
92
93struct buffer {
94 char *p;
95 int pos;
96 int size;
97};
98
99void __attribute__((format(printf, 2, 3)))
100buf_printf(struct buffer *buf, const char *fmt, ...);
101
102void
103buf_write(struct buffer *buf, const char *s, int len);
104
105struct module {
106 struct module *next;
107 const char *name;
108 int gpl_compatible;
109 struct symbol *unres;
110 int seen;
111 int skip;
112 int has_init;
113 int has_cleanup;
114 struct buffer dev_table_buf;
115 char srcversion[25];
116 int is_dot_o;
117};
118
119struct elf_info {
120 unsigned long size;
121 Elf_Ehdr *hdr;
122 Elf_Shdr *sechdrs;
123 Elf_Sym *symtab_start;
124 Elf_Sym *symtab_stop;
125 Elf_Section export_sec;
126 Elf_Section export_unused_sec;
127 Elf_Section export_gpl_sec;
128 Elf_Section export_unused_gpl_sec;
129 Elf_Section export_gpl_future_sec;
130 char *strtab;
131 char *modinfo;
132 unsigned int modinfo_len;
133
134 /* support for 32bit section numbers */
135
136 unsigned int num_sections; /* max_secindex + 1 */
137 unsigned int secindex_strings;
138 /* if Nth symbol table entry has .st_shndx = SHN_XINDEX,
139 * take shndx from symtab_shndx_start[N] instead */
140 Elf32_Word *symtab_shndx_start;
141 Elf32_Word *symtab_shndx_stop;
142};
143
144static inline int is_shndx_special(unsigned int i)
145{
146 return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
147}
148
149/*
150 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
151 * the way to -256..-1, to avoid conflicting with real section
152 * indices.
153 */
154#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
155
156/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
157static inline unsigned int get_secindex(const struct elf_info *info,
158 const Elf_Sym *sym)
159{
160 if (is_shndx_special(sym->st_shndx))
161 return SPECIAL(sym->st_shndx);
162 if (sym->st_shndx != SHN_XINDEX)
163 return sym->st_shndx;
164 return info->symtab_shndx_start[sym - info->symtab_start];
165}
166
167/* file2alias.c */
168extern unsigned int cross_build;
169void handle_moddevtable(struct module *mod, struct elf_info *info,
170 Elf_Sym *sym, const char *symname);
171void add_moddevtable(struct buffer *buf, struct module *mod);
172
173/* sumversion.c */
174void maybe_frob_rcs_version(const char *modfilename,
175 char *version,
176 void *modinfo,
177 unsigned long modinfo_offset);
178void get_src_version(const char *modname, char sum[], unsigned sumlen);
179
180/* from modpost.c */
181void *grab_file(const char *filename, unsigned long *size);
182char* get_next_line(unsigned long *pos, void *file, unsigned long size);
183void release_file(void *file, unsigned long size);
184
185void fatal(const char *fmt, ...);
186void warn(const char *fmt, ...);
187void merror(const char *fmt, ...);