2 * Copyright (c) 1997 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
26 * $FreeBSD: src/sys/sys/linker.h,v 1.17.2.1 2002/03/11 01:13:53 dd Exp $
29 #ifndef _SYS_LINKER_H_
30 #define _SYS_LINKER_H_
33 #include <sys/types.h>
36 #include <sys/param.h>
42 #include <sys/queue.h>
44 #include <machine/elf.h>
46 #include <sys/module.h>
49 MALLOC_DECLARE(M_LINKER);
53 * Object representing a file which has been loaded by the linker.
55 typedef struct linker_file* linker_file_t;
56 typedef TAILQ_HEAD(, linker_file) linker_file_list_t;
58 typedef caddr_t linker_sym_t; /* opaque symbol */
59 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */
62 * expanded out linker_sym_t
64 typedef struct linker_symval {
70 struct linker_file_ops {
72 * Lookup a symbol in the file's symbol table. If the symbol is
73 * not found then return ENOENT, otherwise zero. If the symbol
74 * found is a common symbol, return with *address set to zero and
75 * *size set to the size of the common space required. Otherwise
76 * set *address the value of the symbol.
78 int (*lookup_symbol)(linker_file_t, const char* name,
81 int (*symbol_values)(linker_file_t, c_linker_sym_t,
84 int (*search_symbol)(linker_file_t, caddr_t value,
85 c_linker_sym_t* sym, long* diffp);
88 * Completes the loading task started in preload_file.
90 int (*preload_finish)(linker_file_t);
93 * Unload a file, releasing dependancies and freeing storage.
95 void (*unload)(linker_file_t);
97 int (*lookup_set)(linker_file_t, const char *name,
98 void ***firstp, void ***lastp, int *countp);
101 struct common_symbol {
102 STAILQ_ENTRY(common_symbol) link;
108 int refs; /* reference count */
109 int userrefs; /* kldload(2) count */
111 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */
112 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */
113 char* filename; /* file which was loaded */
114 char* pathname; /* file name with full path */
115 int id; /* unique id */
116 caddr_t address; /* load address */
117 size_t size; /* size of file */
118 int ndeps; /* number of dependancies */
119 linker_file_t* deps; /* list of dependancies */
120 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */
121 TAILQ_HEAD(, module) modules; /* modules in this file */
122 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */
123 void* priv; /* implementation data */
125 struct linker_file_ops* ops;
129 * Object implementing a class of file (a.out, elf, etc.)
131 typedef struct linker_class *linker_class_t;
132 typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
134 struct linker_class_ops {
136 * Load a file, returning the new linker_file_t in *result. If
137 * the class does not recognise the file type, zero should be
138 * returned, without modifying *result. If the file is
139 * recognised, the file should be loaded, *result set to the new
140 * file and zero returned. If some other error is detected an
141 * appropriate errno should be returned.
143 int (*load_file)(const char *filename, linker_file_t *result);
145 * Same as load_file, but does not load dependencies. Necessary
146 * for tentatively loading (loader-)preloaded modules.
148 int (*preload_file)(const char *filename, linker_file_t *result);
151 struct linker_class {
152 TAILQ_ENTRY(linker_class) link; /* list of all file classes */
153 const char* desc; /* description (e.g. "a.out") */
154 void* priv; /* implementation data */
156 struct linker_class_ops *ops;
160 * Function type used when iterating over the list of linker files.
162 typedef int linker_predicate_t(linker_file_t, void *);
165 * The file which is currently loading. Used to register modules with
166 * the files which contain them.
168 extern linker_file_t linker_current_file;
171 * The "file" for the kernel.
173 extern linker_file_t linker_kernel_file;
176 * Add a new file class to the linker.
178 int linker_add_class(const char* _desc, void* _priv,
179 struct linker_class_ops* _ops);
182 * Load a file, trying each file class until one succeeds.
184 int linker_load_file(const char *_filename, linker_file_t *_result);
187 * Find a currently loaded file given its filename.
189 linker_file_t linker_find_file_by_name(const char* _filename);
192 * Find a currently loaded file given its file id.
194 linker_file_t linker_find_file_by_id(int _fileid);
197 * Called from a class handler when a file is laoded.
199 linker_file_t linker_make_file(const char* _filename, void* _priv,
200 struct linker_file_ops* _ops);
203 * Unload a file, freeing up memory.
205 int linker_file_unload(linker_file_t _file);
208 * Add a dependancy to a file.
210 void linker_file_add_dependancy(linker_file_t _file, linker_file_t _dep);
212 int linker_load_dependencies(linker_file_t lf);
215 * Iterate over all of the currently loaded linker files calling the
216 * predicate function while the function returns 0. Returns the value
217 * returned by the last predicate function.
219 int linker_file_foreach(linker_predicate_t *_predicate, void *_context);
222 * Lookup a symbol in a file. If deps is TRUE, look in dependancies
223 * if not found in file. The symbol's value is returned in the
224 * caddr_t. An error is returned, 0 if no error occured.
226 int linker_file_lookup_symbol(linker_file_t _file, const char* _name,
227 int _deps, caddr_t *);
231 * Lookup a linker set in a file. Return pointers to the first entry,
232 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {}
233 * void *start is really: "struct yoursetmember ***start;"
235 int linker_file_lookup_set(linker_file_t _file, const char *_name,
236 void *_start, void *_stop, int *_count);
239 * Search the linker path for the module. Return the full pathname in
240 * a malloc'ed buffer.
242 char *linker_search_path(const char *_filename);
244 int linker_reference_module(const char *modname, struct mod_depend *verinfo,
245 linker_file_t *retult);
246 int linker_release_module(const char *modname, struct mod_depend *verinfo,
250 * DDB Helpers, tuned specifically for ddb/db_kld.c
252 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
253 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
255 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
261 * Module information subtypes
263 #define MODINFO_END 0x0000 /* End of list */
264 #define MODINFO_NAME 0x0001 /* Full path name of module (string) */
265 #define MODINFO_TYPE 0x0002 /* Type of module (string) */
266 #define MODINFO_ADDR 0x0003 /* Loaded address */
267 #define MODINFO_SIZE 0x0004 /* Size of module */
268 #define MODINFO_EMPTY 0x0005 /* Has been deleted */
269 #define MODINFO_ARGS 0x0006 /* Parameters string */
270 #define MODINFO_METADATA 0x8000 /* Module-specfic */
272 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */
273 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */
274 #define MODINFOMD_SSYM 0x0003 /* start of symbols */
275 #define MODINFOMD_ESYM 0x0004 /* end of symbols */
276 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */
277 #define MODINFOMD_ENVP 0x0006 /* (from 5.x) envp[] */
278 #define MODINFOMD_HOWTO 0x0007 /* (from 5.x) boothowto */
279 #define MODINFOMD_KERNEND 0x0008 /* (from 5.x) kernend */
280 #define MODINFOMD_SHDR 0x0009 /* section header table */
281 #define MODINFOMD_FW_HANDLE 0x000a /* Firmware dependent handle */
282 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */
284 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */
287 #define MD_FETCH(mdp, info, type) ({ \
289 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \
294 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */
301 extern caddr_t preload_metadata;
302 caddr_t preload_search_by_name(const char *);
303 caddr_t preload_search_by_type(const char *);
304 caddr_t preload_search_next_name(caddr_t);
305 caddr_t preload_search_info(caddr_t, int);
306 void preload_delete_name(const char *);
307 void preload_bootstrap_relocate(vm_offset_t);
308 extern struct mod_metadata *find_mod_metadata(const char *);
312 extern int kld_debug;
313 #define KLD_DEBUG_FILE 1 /* file load/unload */
314 #define KLD_DEBUG_SYM 2 /* symbol lookup */
316 #define KLD_DPF(cat, args) \
318 if (kld_debug & KLD_DEBUG_##cat) kprintf args; \
323 #define KLD_DPF(cat, args)
327 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *);
329 /* Support functions */
330 int elf_reloc(linker_file_t, Elf_Addr, const void *, int, elf_lookup_fn);
331 int elf_reloc_local(linker_file_t, Elf_Addr, const void *, int, elf_lookup_fn);
332 Elf_Addr elf_relocaddr(linker_file_t, Elf_Addr);
334 /* values for type */
335 #define ELF_RELOC_REL 1
336 #define ELF_RELOC_RELA 2
340 struct kld_file_stat {
341 int version; /* set to sizeof(linker_file_stat) */
342 char name[MAXPATHLEN];
343 char pathname[MAXPATHLEN];
346 caddr_t address; /* load address */
347 size_t size; /* size in bytes */
350 struct kld_sym_lookup {
351 int version; /* set to sizeof(struct kld_sym_lookup) */
352 const char *symname; /* Symbol name we are looking up */
357 #define KLDSYM_LOOKUP 1
361 #ifndef _SYS_CDEFS_H_
362 #include <sys/cdefs.h>
366 int kldload(const char *);
368 int kldfind(const char *);
370 int kldstat(int, struct kld_file_stat *);
371 int kldfirstmod(int);
372 int kldsym(int, int, void *);
377 #endif /* !_SYS_LINKER_H_ */