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 $
27 * $DragonFly: src/sys/sys/linker.h,v 1.2 2003/06/17 04:28:58 dillon Exp $
30 #ifndef _SYS_LINKER_H_
31 #define _SYS_LINKER_H_
35 #include <machine/elf.h>
38 MALLOC_DECLARE(M_LINKER);
42 * Object representing a file which has been loaded by the linker.
44 typedef struct linker_file* linker_file_t;
45 typedef TAILQ_HEAD(, linker_file) linker_file_list_t;
47 typedef caddr_t linker_sym_t; /* opaque symbol */
48 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */
51 * expanded out linker_sym_t
53 typedef struct linker_symval {
59 struct linker_file_ops {
61 * Lookup a symbol in the file's symbol table. If the symbol is
62 * not found then return ENOENT, otherwise zero. If the symbol
63 * found is a common symbol, return with *address set to zero and
64 * *size set to the size of the common space required. Otherwise
65 * set *address the value of the symbol.
67 int (*lookup_symbol)(linker_file_t, const char* name,
70 int (*symbol_values)(linker_file_t, c_linker_sym_t,
73 int (*search_symbol)(linker_file_t, caddr_t value,
74 c_linker_sym_t* sym, long* diffp);
77 * Unload a file, releasing dependancies and freeing storage.
79 void (*unload)(linker_file_t);
82 struct common_symbol {
83 STAILQ_ENTRY(common_symbol) link;
89 int refs; /* reference count */
90 int userrefs; /* kldload(2) count */
92 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */
93 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */
94 char* filename; /* file which was loaded */
95 int id; /* unique id */
96 caddr_t address; /* load address */
97 size_t size; /* size of file */
98 int ndeps; /* number of dependancies */
99 linker_file_t* deps; /* list of dependancies */
100 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */
101 TAILQ_HEAD(, module) modules; /* modules in this file */
102 void* priv; /* implementation data */
104 struct linker_file_ops* ops;
108 * Object implementing a class of file (a.out, elf, etc.)
110 typedef struct linker_class *linker_class_t;
111 typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
113 struct linker_class_ops {
115 * Load a file, returning the new linker_file_t in *result. If
116 * the class does not recognise the file type, zero should be
117 * returned, without modifying *result. If the file is
118 * recognised, the file should be loaded, *result set to the new
119 * file and zero returned. If some other error is detected an
120 * appropriate errno should be returned.
122 int (*load_file)(const char* filename, linker_file_t* result);
125 struct linker_class {
126 TAILQ_ENTRY(linker_class) link; /* list of all file classes */
127 const char* desc; /* description (e.g. "a.out") */
128 void* priv; /* implementation data */
130 struct linker_class_ops *ops;
134 * The file which is currently loading. Used to register modules with
135 * the files which contain them.
137 extern linker_file_t linker_current_file;
140 * The "file" for the kernel.
142 extern linker_file_t linker_kernel_file;
145 * Add a new file class to the linker.
147 int linker_add_class(const char* _desc, void* _priv,
148 struct linker_class_ops* _ops);
151 * Load a file, trying each file class until one succeeds.
153 int linker_load_file(const char* _filename, linker_file_t* _result);
156 * Find a currently loaded file given its filename.
158 linker_file_t linker_find_file_by_name(const char* _filename);
161 * Find a currently loaded file given its file id.
163 linker_file_t linker_find_file_by_id(int _fileid);
166 * Called from a class handler when a file is laoded.
168 linker_file_t linker_make_file(const char* _filename, void* _priv,
169 struct linker_file_ops* _ops);
172 * Unload a file, freeing up memory.
174 int linker_file_unload(linker_file_t _file);
177 * Add a dependancy to a file.
179 int linker_file_add_dependancy(linker_file_t _file, linker_file_t _dep);
182 * Lookup a symbol in a file. If deps is TRUE, look in dependancies
183 * if not found in file.
185 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name,
189 * Search the linker path for the module. Return the full pathname in
190 * a malloc'ed buffer.
192 char *linker_search_path(const char *_filename);
195 * DDB Helpers, tuned specifically for ddb/db_kld.c
197 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
198 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
200 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
206 * Module information subtypes
208 #define MODINFO_END 0x0000 /* End of list */
209 #define MODINFO_NAME 0x0001 /* Name of module (string) */
210 #define MODINFO_TYPE 0x0002 /* Type of module (string) */
211 #define MODINFO_ADDR 0x0003 /* Loaded address */
212 #define MODINFO_SIZE 0x0004 /* Size of module */
213 #define MODINFO_EMPTY 0x0005 /* Has been deleted */
214 #define MODINFO_ARGS 0x0006 /* Parameters string */
215 #define MODINFO_METADATA 0x8000 /* Module-specfic */
217 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */
218 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */
219 #define MODINFOMD_SSYM 0x0003 /* start of symbols */
220 #define MODINFOMD_ESYM 0x0004 /* end of symbols */
221 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */
222 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */
224 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */
231 extern caddr_t preload_metadata;
232 extern caddr_t preload_search_by_name(const char *_name);
233 extern caddr_t preload_search_by_type(const char *_type);
234 extern caddr_t preload_search_next_name(caddr_t _base);
235 extern caddr_t preload_search_info(caddr_t _mod, int _inf);
236 extern void preload_delete_name(const char *_name);
237 extern void preload_bootstrap_relocate(vm_offset_t _offset);
241 extern int kld_debug;
242 #define KLD_DEBUG_FILE 1 /* file load/unload */
243 #define KLD_DEBUG_SYM 2 /* symbol lookup */
245 #define KLD_DPF(cat, args) \
247 if (kld_debug & KLD_DEBUG_##cat) printf args; \
252 #define KLD_DPF(cat, args)
256 /* Support functions */
257 int elf_reloc(linker_file_t _lf, const void *_rel, int _type,
259 /* values for type */
260 #define ELF_RELOC_REL 1
261 #define ELF_RELOC_RELA 2
265 struct kld_file_stat {
266 int version; /* set to sizeof(linker_file_stat) */
267 char name[MAXPATHLEN];
270 caddr_t address; /* load address */
271 size_t size; /* size in bytes */
274 struct kld_sym_lookup {
275 int version; /* set to sizeof(struct kld_sym_lookup) */
276 char *symname; /* Symbol name we are looking up */
280 #define KLDSYM_LOOKUP 1
284 #include <sys/cdefs.h>
287 int kldload(const char* _file);
288 int kldunload(int _fileid);
289 int kldfind(const char* _file);
290 int kldnext(int _fileid);
291 int kldstat(int _fileid, struct kld_file_stat* _stat);
292 int kldfirstmod(int _fileid);
293 int kldsym(int _fileid, int _cmd, void *_data);
298 #endif /* !_SYS_LINKER_H_ */