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)
218