FreeBSD/Linux Kernel Cross Reference
sys/sys/linker.h
1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1997-2000 Doug Rabson
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31 #ifndef _SYS_LINKER_H_
32 #define _SYS_LINKER_H_
33
34 #ifdef _KERNEL
35
36 #include <machine/elf.h>
37 #include <sys/kobj.h>
38
39 #ifdef MALLOC_DECLARE
40 MALLOC_DECLARE(M_LINKER);
41 #endif
42
43 struct mod_depend;
44
45 /*
46 * Object representing a file which has been loaded by the linker.
47 */
48 typedef struct linker_file* linker_file_t;
49 typedef TAILQ_HEAD(, linker_file) linker_file_list_t;
50
51 typedef caddr_t linker_sym_t; /* opaque symbol */
52 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */
53 typedef int (*linker_function_name_callback_t)(const char *, void *);
54
55 /*
56 * expanded out linker_sym_t
57 */
58 typedef struct linker_symval {
59 const char* name;
60 caddr_t value;
61 size_t size;
62 } linker_symval_t;
63
64 typedef int (*linker_function_nameval_callback_t)(linker_file_t, int, linker_symval_t *, void *);
65
66 struct common_symbol {
67 STAILQ_ENTRY(common_symbol) link;
68 char* name;
69 caddr_t address;
70 };
71
72 struct linker_file {
73 KOBJ_FIELDS;
74 int refs; /* reference count */
75 int userrefs; /* kldload(2) count */
76 int flags;
77 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */
78 #define LINKER_FILE_MODULES 0x2 /* file has >0 modules at preload */
79 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */
80 char* filename; /* file which was loaded */
81 char* pathname; /* file name with full path */
82 int id; /* unique id */
83 caddr_t address; /* load address */
84 size_t size; /* size of file */
85 caddr_t ctors_addr; /* address of .ctors/.init_array */
86 size_t ctors_size; /* size of .ctors/.init_array */
87 caddr_t dtors_addr; /* address of .dtors/.fini_array */
88 size_t dtors_size; /* size of .dtors/.fini_array */
89 int ndeps; /* number of dependencies */
90 linker_file_t* deps; /* list of dependencies */
91 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */
92 TAILQ_HEAD(, module) modules; /* modules in this file */
93 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */
94 int loadcnt; /* load counter value */
95
96 /*
97 * Function Boundary Tracing (FBT) or Statically Defined Tracing (SDT)
98 * fields.
99 */
100 int nenabled; /* number of enabled probes. */
101 int fbt_nentries; /* number of fbt entries created. */
102
103 #ifdef __arm__
104 caddr_t exidx_addr; /* Unwind data index table start */
105 size_t exidx_size; /* Unwind data index table size */
106 #endif
107 };
108
109 /*
110 * Object implementing a class of file (a.out, elf, etc.)
111 */
112 typedef struct linker_class *linker_class_t;
113 typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
114
115 struct linker_class {
116 KOBJ_CLASS_FIELDS;
117 TAILQ_ENTRY(linker_class) link; /* list of all file classes */
118 };
119
120 /*
121 * Function type used when iterating over the list of linker files.
122 */
123 typedef int linker_predicate_t(linker_file_t, void *);
124
125 /*
126 * The "file" for the kernel.
127 */
128 extern linker_file_t linker_kernel_file;
129
130 /*
131 * Obtain a reference to a module, loading it if required.
132 */
133 int linker_reference_module(const char* _modname, struct mod_depend *_verinfo,
134 linker_file_t* _result);
135
136 /*
137 * Release a reference to a module, unloading it if there are no more
138 * references. Note that one should either provide a module name and
139 * optional version info or a linker file, but not both.
140 */
141 int linker_release_module(const char *_modname, struct mod_depend *_verinfo,
142 linker_file_t _file);
143
144 /*
145 * Iterate over all of the currently loaded linker files calling the
146 * predicate function while the function returns 0. Returns the value
147 * returned by the last predicate function.
148 */
149 int linker_file_foreach(linker_predicate_t *_predicate, void *_context);
150
151 /*
152 * Lookup a symbol in a file. If deps is TRUE, look in dependencies
153 * if not found in file.
154 */
155 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name,
156 int _deps);
157
158 /*
159 * Lookup a linker set in a file. Return pointers to the first entry,
160 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {}
161 * void *start is really: "struct yoursetmember ***start;"
162 */
163 int linker_file_lookup_set(linker_file_t _file, const char *_name,
164 void *_start, void *_stop, int *_count);
165
166 /*
167 * List all functions in a file.
168 */
169 int linker_file_function_listall(linker_file_t,
170 linker_function_nameval_callback_t, void *);
171
172 /*
173 * Functions solely for use by the linker class handlers.
174 */
175 int linker_add_class(linker_class_t _cls);
176 int linker_file_unload(linker_file_t _file, int flags);
177 int linker_load_dependencies(linker_file_t _lf);
178 linker_file_t linker_make_file(const char* _filename, linker_class_t _cls);
179
180 /*
181 * DDB Helpers, tuned specifically for ddb/db_kld.c
182 */
183 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
184 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
185 long *_diffp);
186 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
187 int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
188 long *offset);
189
190 /*
191 * stack(9) helper for situations where kernel locking is required.
192 */
193 int linker_search_symbol_name_flags(caddr_t value, char *buf, u_int buflen,
194 long *offset, int flags);
195 int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
196 long *offset);
197
198 /* HWPMC helper */
199 void *linker_hwpmc_list_objects(void);
200
201 /* kldload/kldunload syscalls blocking */
202 #define LINKER_UB_UNLOCK 0x0001 /* busy: unlock kld_sx locked on
203 return */
204 #define LINKER_UB_LOCKED 0x0002 /* busy/unbusy: kld_sx locked on
205 entry */
206 #define LINKER_UB_PCATCH 0x0004 /* busy: sleep interruptible */
207 int linker_kldload_busy(int flags);
208 void linker_kldload_unbusy(int flags);
209
210 #endif /* _KERNEL */
211
212 /*
213 * Module information subtypes
214 */
215 #define MODINFO_END 0x0000 /* End of list */
216 #define MODINFO_NAME 0x0001 /* Name of module (string) */
217 #define MODINFO_TYPE 0x0002 /* Type of module (string) */
218 #define MODINFO_ADDR 0x0003 /* Loaded address */
219 #define MODINFO_SIZE 0x0004 /* Size of module */
220 #define MODINFO_EMPTY 0x0005 /* Has been deleted */
221 #define MODINFO_ARGS 0x0006 /* Parameters string */
222 #define MODINFO_METADATA 0x8000 /* Module-specfic */
223
224 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */
225 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */
226 #define MODINFOMD_SSYM 0x0003 /* start of symbols */
227 #define MODINFOMD_ESYM 0x0004 /* end of symbols */
228 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */
229 #define MODINFOMD_MB2HDR 0x0006 /* MB2 header info */
230 /* These values are MD on PowerPC */
231 #if !defined(__powerpc__)
232 #define MODINFOMD_ENVP 0x0006 /* envp[] */
233 #define MODINFOMD_HOWTO 0x0007 /* boothowto */
234 #define MODINFOMD_KERNEND 0x0008 /* kernend */
235 #endif
236 #define MODINFOMD_SHDR 0x0009 /* section header table */
237 #define MODINFOMD_CTORS_ADDR 0x000a /* address of .ctors */
238 #define MODINFOMD_CTORS_SIZE 0x000b /* size of .ctors */
239 #define MODINFOMD_FW_HANDLE 0x000c /* Firmware dependent handle */
240 #define MODINFOMD_KEYBUF 0x000d /* Crypto key intake buffer */
241 #define MODINFOMD_FONT 0x000e /* Console font */
242 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */
243
244 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */
245
246 #ifdef _KERNEL
247 #define MD_FETCH(mdp, info, type) ({ \
248 type *__p; \
249 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \
250 __p ? *__p : 0; \
251 })
252 #endif
253
254 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */
255 #define LINKER_HINTS_MAX (1 << 20) /* Allow at most 1MB for linker.hints */
256
257 #ifdef _KERNEL
258
259 /*
260 * Module lookup
261 */
262 extern vm_offset_t preload_addr_relocate;
263 extern caddr_t preload_metadata;
264
265 extern void * preload_fetch_addr(caddr_t _mod);
266 extern size_t preload_fetch_size(caddr_t _mod);
267 extern caddr_t preload_search_by_name(const char *_name);
268 extern caddr_t preload_search_by_type(const char *_type);
269 extern caddr_t preload_search_next_name(caddr_t _base);
270 extern caddr_t preload_search_info(caddr_t _mod, int _inf);
271 extern void preload_delete_name(const char *_name);
272 extern void preload_bootstrap_relocate(vm_offset_t _offset);
273 extern void preload_dump(void);
274
275 #ifdef KLD_DEBUG
276
277 extern int kld_debug;
278 #define KLD_DEBUG_FILE 1 /* file load/unload */
279 #define KLD_DEBUG_SYM 2 /* symbol lookup */
280
281 #define KLD_DPF(cat, args) \
282 do { \
283 if (kld_debug & KLD_DEBUG_##cat) printf args; \
284 } while (0)
285
286 #else
287
288 #define KLD_DPF(cat, args)
289
290 #endif
291
292 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *);
293
294 /* Support functions */
295 bool elf_is_ifunc_reloc(Elf_Size r_info);
296 int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel,
297 int _type, elf_lookup_fn _lu);
298 int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel,
299 int _type, elf_lookup_fn _lu);
300 Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr);
301 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx);
302 const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx);
303 void link_elf_ireloc(caddr_t kmdp);
304
305 #if defined(__aarch64__) || defined(__amd64__)
306 int elf_reloc_late(linker_file_t _lf, Elf_Addr base, const void *_rel,
307 int _type, elf_lookup_fn _lu);
308 void link_elf_late_ireloc(void);
309 #endif
310
311 typedef struct linker_ctf {
312 const uint8_t *ctftab; /* Decompressed CTF data. */
313 int ctfcnt; /* Number of CTF data bytes. */
314 const Elf_Sym *symtab; /* Ptr to the symbol table. */
315 int nsym; /* Number of symbols. */
316 const char *strtab; /* Ptr to the string table. */
317 int strcnt; /* Number of string bytes. */
318 uint32_t **ctfoffp; /* Ptr to array of obj/fnc offsets. */
319 uint32_t **typoffp; /* Ptr to array of type offsets. */
320 long *typlenp; /* Ptr to number of type data entries. */
321 } linker_ctf_t;
322
323 int linker_ctf_get(linker_file_t, linker_ctf_t *);
324
325 int elf_cpu_load_file(linker_file_t);
326 int elf_cpu_unload_file(linker_file_t);
327 int elf_cpu_parse_dynamic(caddr_t, Elf_Dyn *);
328
329 /* values for type */
330 #define ELF_RELOC_REL 1
331 #define ELF_RELOC_RELA 2
332
333 /*
334 * This is version 1 of the KLD file status structure. It is identified
335 * by its _size_ in the version field.
336 */
337 struct kld_file_stat_1 {
338 int version; /* set to sizeof(struct kld_file_stat_1) */
339 char name[MAXPATHLEN];
340 int refs;
341 int id;
342 caddr_t address; /* load address */
343 size_t size; /* size in bytes */
344 };
345 #endif /* _KERNEL */
346
347 struct kld_file_stat {
348 int version; /* set to sizeof(struct kld_file_stat) */
349 char name[MAXPATHLEN];
350 int refs;
351 int id;
352 caddr_t address; /* load address */
353 size_t size; /* size in bytes */
354 char pathname[MAXPATHLEN];
355 };
356
357 struct kld_sym_lookup {
358 int version; /* set to sizeof(struct kld_sym_lookup) */
359 char *symname; /* Symbol name we are looking up */
360 u_long symvalue;
361 size_t symsize;
362 };
363 #define KLDSYM_LOOKUP 1
364
365 /*
366 * Flags for kldunloadf() and linker_file_unload()
367 */
368 #define LINKER_UNLOAD_NORMAL 0
369 #define LINKER_UNLOAD_FORCE 1
370
371 #ifndef _KERNEL
372
373 #include <sys/cdefs.h>
374
375 __BEGIN_DECLS
376 int kldload(const char* _file);
377 int kldunload(int _fileid);
378 int kldunloadf(int _fileid, int flags);
379 int kldfind(const char* _file);
380 int kldnext(int _fileid);
381 int kldstat(int _fileid, struct kld_file_stat* _stat);
382 int kldfirstmod(int _fileid);
383 int kldsym(int _fileid, int _cmd, void *_data);
384 __END_DECLS
385
386 #endif
387
388 #endif /* !_SYS_LINKER_H_ */
Cache object: 2ef73e4139eb1e7d17c5e778c435dacd
|