xref: /openbmc/linux/scripts/mod/modpost.h (revision 462cd772)
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. */
54 typedef 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 
63 typedef 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 
77 static 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 
101 void *do_nofail(void *ptr, const char *expr);
102 
103 struct buffer {
104 	char *p;
105 	int pos;
106 	int size;
107 };
108 
109 void __attribute__((format(printf, 2, 3)))
110 buf_printf(struct buffer *buf, const char *fmt, ...);
111 
112 void
113 buf_write(struct buffer *buf, const char *s, int len);
114 
115 struct 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 
134 struct 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 
154 static 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" */
160 static 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 */
184 void handle_moddevtable(struct module *mod, struct elf_info *info,
185 			Elf_Sym *sym, const char *symname);
186 void add_moddevtable(struct buffer *buf, struct module *mod);
187 
188 /* sumversion.c */
189 void get_src_version(const char *modname, char sum[], unsigned sumlen);
190 
191 /* from modpost.c */
192 char *read_text_file(const char *filename);
193 char *get_line(char **stringp);
194 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym);
195 
196 enum loglevel {
197 	LOG_WARN,
198 	LOG_ERROR,
199 	LOG_FATAL
200 };
201 
202 void 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)
220