FreeBSD/Linux Kernel Cross Reference
sys/sys/linker.h
1 /*-
2 * Copyright (c) 1997-2000 Doug Rabson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29 #ifndef _SYS_LINKER_H_
30 #define _SYS_LINKER_H_
31
32 #ifdef _KERNEL
33
34 #include <machine/elf.h>
35 #include <sys/kobj.h>
36
37 #ifdef MALLOC_DECLARE
38 MALLOC_DECLARE(M_LINKER);
39 #endif
40
41 struct mod_depend;
42
43 /*
44 * Object representing a file which has been loaded by the linker.
45 */
46 typedef struct linker_file* linker_file_t;
47 typedef TAILQ_HEAD(, linker_file) linker_file_list_t;
48
49 typedef caddr_t linker_sym_t; /* opaque symbol */
50 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */
51 typedef int (*linker_function_name_callback_t)(const char *, void *);
52
53 /*
54 * expanded out linker_sym_t
55 */
56 typedef struct linker_symval {
57 const char* name;
58 caddr_t value;
59 size_t size;
60 } linker_symval_t;
61
62 struct common_symbol {
63 STAILQ_ENTRY(common_symbol) link;
64 char* name;
65 caddr_t address;
66 };
67
68 struct linker_file {
69 KOBJ_FIELDS;
70 int refs; /* reference count */
71 int userrefs; /* kldload(2) count */
72 int flags;
73 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */
74 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */
75 char* filename; /* file which was loaded */
76 int id; /* unique id */
77 caddr_t address; /* load address */
78 size_t size; /* size of file */
79 int ndeps; /* number of dependencies */
80 linker_file_t* deps; /* list of dependencies */
81 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */
82 TAILQ_HEAD(, module) modules; /* modules in this file */
83 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */
84 };
85
86 /*
87 * Object implementing a class of file (a.out, elf, etc.)
88 */
89 typedef struct linker_class *linker_class_t;
90 typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
91
92 struct linker_class {
93 KOBJ_CLASS_FIELDS;
94 TAILQ_ENTRY(linker_class) link; /* list of all file classes */
95 };
96
97 /*
98 * The "file" for the kernel.
99 */
100 extern linker_file_t linker_kernel_file;
101
102 /*
103 * Add a new file class to the linker.
104 */
105 int linker_add_class(linker_class_t _cls);
106
107 /*
108 * Load a kernel module.
109 */
110 int linker_load_module(const char *_kldname, const char *_modname,
111 struct linker_file *_parent, struct mod_depend *_verinfo,
112 struct linker_file **_lfpp);
113
114 /*
115 * Obtain a reference to a module, loading it if required.
116 */
117 int linker_reference_module(const char* _modname, struct mod_depend *_verinfo,
118 linker_file_t* _result);
119
120 /*
121 * Find a currently loaded file given its filename.
122 */
123 linker_file_t linker_find_file_by_name(const char* _filename);
124
125 /*
126 * Find a currently loaded file given its file id.
127 */
128 linker_file_t linker_find_file_by_id(int _fileid);
129
130 /*
131 * Called from a class handler when a file is laoded.
132 */
133 linker_file_t linker_make_file(const char* _filename, linker_class_t _cls);
134
135 /*
136 * Unload a file, freeing up memory.
137 */
138 int linker_file_unload(linker_file_t _file, int flags);
139
140 /*
141 * Add a dependency to a file.
142 */
143 int linker_file_add_dependency(linker_file_t _file, linker_file_t _dep);
144
145 /*
146 * Lookup a symbol in a file. If deps is TRUE, look in dependencies
147 * if not found in file.
148 */
149 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name,
150 int _deps);
151
152 /*
153 * Lookup a linker set in a file. Return pointers to the first entry,
154 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {}
155 * void *start is really: "struct yoursetmember ***start;"
156 */
157 int linker_file_lookup_set(linker_file_t _file, const char *_name,
158 void *_start, void *_stop, int *_count);
159
160 /*
161 * This routine is responsible for finding dependencies of userland
162 * initiated kldload(2)'s of files.
163 */
164 int linker_load_dependencies(linker_file_t _lf);
165
166 /*
167 * DDB Helpers, tuned specifically for ddb/db_kld.c
168 */
169 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
170 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
171 long *_diffp);
172 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
173
174
175 #endif /* _KERNEL */
176
177 /*
178 * Module information subtypes
179 */
180 #define MODINFO_END 0x0000 /* End of list */
181 #define MODINFO_NAME 0x0001 /* Name of module (string) */
182 #define MODINFO_TYPE 0x0002 /* Type of module (string) */
183 #define MODINFO_ADDR 0x0003 /* Loaded address */
184 #define MODINFO_SIZE 0x0004 /* Size of module */
185 #define MODINFO_EMPTY 0x0005 /* Has been deleted */
186 #define MODINFO_ARGS 0x0006 /* Parameters string */
187 #define MODINFO_METADATA 0x8000 /* Module-specfic */
188
189 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */
190 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */
191 #define MODINFOMD_SSYM 0x0003 /* start of symbols */
192 #define MODINFOMD_ESYM 0x0004 /* end of symbols */
193 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */
194 /* These values are MD on these two platforms */
195 #if !defined(__sparc64__) && !defined(__powerpc__)
196 #define MODINFOMD_ENVP 0x0006 /* envp[] */
197 #define MODINFOMD_HOWTO 0x0007 /* boothowto */
198 #define MODINFOMD_KERNEND 0x0008 /* kernend */
199 #endif
200 #define MODINFOMD_SHDR 0x0009 /* section header table */
201 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */
202
203 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */
204
205 #ifdef _KERNEL
206 #define MD_FETCH(mdp, info, type) ({ \
207 type *__p; \
208 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \
209 __p ? *__p : 0; \
210 })
211 #endif
212
213 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */
214
215 #ifdef _KERNEL
216
217 /*
218 * Module lookup
219 */
220 extern caddr_t preload_metadata;
221 extern caddr_t preload_search_by_name(const char *_name);
222 extern caddr_t preload_search_by_type(const char *_type);
223 extern caddr_t preload_search_next_name(caddr_t _base);
224 extern caddr_t preload_search_info(caddr_t _mod, int _inf);
225 extern void preload_delete_name(const char *_name);
226 extern void preload_bootstrap_relocate(vm_offset_t _offset);
227
228 #ifdef KLD_DEBUG
229
230 extern int kld_debug;
231 #define KLD_DEBUG_FILE 1 /* file load/unload */
232 #define KLD_DEBUG_SYM 2 /* symbol lookup */
233
234 #define KLD_DPF(cat, args) \
235 do { \
236 if (kld_debug & KLD_DEBUG_##cat) printf args; \
237 } while (0)
238
239 #else
240
241 #define KLD_DPF(cat, args)
242
243 #endif
244
245 typedef Elf_Addr elf_lookup_fn(linker_file_t, Elf_Word, int);
246
247 /* Support functions */
248 int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu);
249 int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu);
250 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Word _symidx);
251 const char *elf_get_symname(linker_file_t _lf, Elf_Word _symidx);
252
253 int elf_cpu_load_file(linker_file_t);
254 int elf_cpu_unload_file(linker_file_t);
255
256 /* values for type */
257 #define ELF_RELOC_REL 1
258 #define ELF_RELOC_RELA 2
259
260 #endif /* _KERNEL */
261
262 struct kld_file_stat {
263 int version; /* set to sizeof(linker_file_stat) */
264 char name[MAXPATHLEN];
265 int refs;
266 int id;
267 caddr_t address; /* load address */
268 size_t size; /* size in bytes */
269 };
270
271 struct kld_sym_lookup {
272 int version; /* set to sizeof(struct kld_sym_lookup) */
273 char *symname; /* Symbol name we are looking up */
274 u_long symvalue;
275 size_t symsize;
276 };
277 #define KLDSYM_LOOKUP 1
278
279 /*
280 * Flags for kldunloadf() and linker_file_unload()
281 */
282 #define LINKER_UNLOAD_NORMAL 0
283 #define LINKER_UNLOAD_FORCE 1
284
285 #ifndef _KERNEL
286
287 #include <sys/cdefs.h>
288
289 __BEGIN_DECLS
290 int kldload(const char* _file);
291 int kldunload(int _fileid);
292 int kldunloadf(int _fileid, int flags);
293 int kldfind(const char* _file);
294 int kldnext(int _fileid);
295 int kldstat(int _fileid, struct kld_file_stat* _stat);
296 int kldfirstmod(int _fileid);
297 int kldsym(int _fileid, int _cmd, void *_data);
298 __END_DECLS
299
300 #endif
301
302 #endif /* !_SYS_LINKER_H_ */
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