xref: /openbmc/linux/scripts/mod/modpost.h (revision 046b212a)
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 #if KERNEL_ELFDATA != HOST_ELFDATA
54 
55 static inline void __endian(const void *src, void *dest, unsigned int size)
56 {
57 	unsigned int i;
58 	for (i = 0; i < size; i++)
59 		((unsigned char*)dest)[i] = ((unsigned char*)src)[size - i-1];
60 }
61 
62 #define TO_NATIVE(x)						\
63 ({								\
64 	typeof(x) __x;						\
65 	__endian(&(x), &(__x), sizeof(__x));			\
66 	__x;							\
67 })
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 
79 void *do_nofail(void *ptr, const char *expr);
80 
81 struct buffer {
82 	char *p;
83 	int pos;
84 	int size;
85 };
86 
87 void __attribute__((format(printf, 2, 3)))
88 buf_printf(struct buffer *buf, const char *fmt, ...);
89 
90 void
91 buf_write(struct buffer *buf, const char *s, int len);
92 
93 struct 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 
112 struct 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 
133 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
134 static inline unsigned int get_secindex(const struct elf_info *info,
135 					const Elf_Sym *sym)
136 {
137 	unsigned int index = sym->st_shndx;
138 
139 	/*
140 	 * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available
141 	 * in the .symtab_shndx section.
142 	 */
143 	if (index == SHN_XINDEX)
144 		return info->symtab_shndx_start[sym - info->symtab_start];
145 
146 	/*
147 	 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
148 	 * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real
149 	 * section indices.
150 	 */
151 	if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE)
152 		return index - SHN_HIRESERVE - 1;
153 
154 	return index;
155 }
156 
157 /* file2alias.c */
158 void handle_moddevtable(struct module *mod, struct elf_info *info,
159 			Elf_Sym *sym, const char *symname);
160 void add_moddevtable(struct buffer *buf, struct module *mod);
161 
162 /* sumversion.c */
163 void get_src_version(const char *modname, char sum[], unsigned sumlen);
164 
165 /* from modpost.c */
166 char *read_text_file(const char *filename);
167 char *get_line(char **stringp);
168 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym);
169 
170 enum loglevel {
171 	LOG_WARN,
172 	LOG_ERROR,
173 	LOG_FATAL
174 };
175 
176 void modpost_log(enum loglevel loglevel, const char *fmt, ...);
177 
178 /*
179  * warn - show the given message, then let modpost continue running, still
180  *        allowing modpost to exit successfully. This should be used when
181  *        we still allow to generate vmlinux and modules.
182  *
183  * error - show the given message, then let modpost continue running, but fail
184  *         in the end. This should be used when we should stop building vmlinux
185  *         or modules, but we can continue running modpost to catch as many
186  *         issues as possible.
187  *
188  * fatal - show the given message, and bail out immediately. This should be
189  *         used when there is no point to continue running modpost.
190  */
191 #define warn(fmt, args...)	modpost_log(LOG_WARN, fmt, ##args)
192 #define error(fmt, args...)	modpost_log(LOG_ERROR, fmt, ##args)
193 #define fatal(fmt, args...)	modpost_log(LOG_FATAL, fmt, ##args)
194