kernel: Add linker_file_foreach() (taken from FreeBSD).
[dragonfly.git] / sys / sys / linker.h
CommitLineData
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1/*-
2 * Copyright (c) 1997 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: src/sys/sys/linker.h,v 1.17.2.1 2002/03/11 01:13:53 dd Exp $
27 */
28
29#ifndef _SYS_LINKER_H_
30#define _SYS_LINKER_H_
31
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32#ifndef _SYS_TYPES_H_
33#include <sys/types.h>
34#endif
35#ifndef _SYS_PARAM_H_
36#include <sys/param.h>
37#endif
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38
39#ifdef _KERNEL
40
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41#ifndef _SYS_QUEUE_H_
42#include <sys/queue.h>
43#endif
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44#include <machine/elf.h>
45
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46#include <sys/module.h>
47
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48#ifdef MALLOC_DECLARE
49MALLOC_DECLARE(M_LINKER);
50#endif
51
52/*
53 * Object representing a file which has been loaded by the linker.
54 */
55typedef struct linker_file* linker_file_t;
56typedef TAILQ_HEAD(, linker_file) linker_file_list_t;
57
58typedef caddr_t linker_sym_t; /* opaque symbol */
59typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */
60
61/*
62 * expanded out linker_sym_t
63 */
64typedef struct linker_symval {
65 const char* name;
66 caddr_t value;
67 size_t size;
68} linker_symval_t;
69
70struct linker_file_ops {
71 /*
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.
77 */
78 int (*lookup_symbol)(linker_file_t, const char* name,
79 c_linker_sym_t* sym);
80
81 int (*symbol_values)(linker_file_t, c_linker_sym_t,
82 linker_symval_t*);
83
84 int (*search_symbol)(linker_file_t, caddr_t value,
85 c_linker_sym_t* sym, long* diffp);
86
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87 /*
88 * Completes the loading task started in preload_file.
89 */
90 int (*preload_finish)(linker_file_t);
91
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92 /*
93 * Unload a file, releasing dependancies and freeing storage.
94 */
95 void (*unload)(linker_file_t);
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96
97 int (*lookup_set)(linker_file_t, const char *name,
98 void ***firstp, void ***lastp, int *countp);
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99};
100
101struct common_symbol {
102 STAILQ_ENTRY(common_symbol) link;
103 char* name;
104 caddr_t address;
105};
106
107struct linker_file {
108 int refs; /* reference count */
109 int userrefs; /* kldload(2) count */
110 int flags;
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 int id; /* unique id */
115 caddr_t address; /* load address */
116 size_t size; /* size of file */
117 int ndeps; /* number of dependancies */
118 linker_file_t* deps; /* list of dependancies */
119 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */
120 TAILQ_HEAD(, module) modules; /* modules in this file */
1c0e3286 121 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */
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122 void* priv; /* implementation data */
123
124 struct linker_file_ops* ops;
125};
126
127/*
128 * Object implementing a class of file (a.out, elf, etc.)
129 */
130typedef struct linker_class *linker_class_t;
131typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
132
133struct linker_class_ops {
134 /*
135 * Load a file, returning the new linker_file_t in *result. If
136 * the class does not recognise the file type, zero should be
137 * returned, without modifying *result. If the file is
138 * recognised, the file should be loaded, *result set to the new
139 * file and zero returned. If some other error is detected an
140 * appropriate errno should be returned.
141 */
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142 int (*load_file)(const char *filename, linker_file_t *result);
143 /*
144 * Same as load_file, but does not load dependencies. Necessary
145 * for tentatively loading (loader-)preloaded modules.
146 */
147 int (*preload_file)(const char *filename, linker_file_t *result);
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148};
149
150struct linker_class {
151 TAILQ_ENTRY(linker_class) link; /* list of all file classes */
152 const char* desc; /* description (e.g. "a.out") */
153 void* priv; /* implementation data */
154
155 struct linker_class_ops *ops;
156};
157
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158/*
159 * Function type used when iterating over the list of linker files.
160 */
161typedef int linker_predicate_t(linker_file_t, void *);
162
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163/*
164 * The file which is currently loading. Used to register modules with
165 * the files which contain them.
166 */
167extern linker_file_t linker_current_file;
168
169/*
170 * The "file" for the kernel.
171 */
172extern linker_file_t linker_kernel_file;
173
174/*
175 * Add a new file class to the linker.
176 */
177int linker_add_class(const char* _desc, void* _priv,
178 struct linker_class_ops* _ops);
179
180/*
181 * Load a file, trying each file class until one succeeds.
182 */
1c0e3286 183int linker_load_file(const char *_filename, linker_file_t *_result);
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184
185/*
186 * Find a currently loaded file given its filename.
187 */
188linker_file_t linker_find_file_by_name(const char* _filename);
189
190/*
191 * Find a currently loaded file given its file id.
192 */
193linker_file_t linker_find_file_by_id(int _fileid);
194
195/*
196 * Called from a class handler when a file is laoded.
197 */
198linker_file_t linker_make_file(const char* _filename, void* _priv,
199 struct linker_file_ops* _ops);
200
201/*
202 * Unload a file, freeing up memory.
203 */
204int linker_file_unload(linker_file_t _file);
205
206/*
207 * Add a dependancy to a file.
208 */
addd2777 209void linker_file_add_dependancy(linker_file_t _file, linker_file_t _dep);
984263bc 210
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211int linker_load_dependencies(linker_file_t lf);
212
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213/*
214 * Iterate over all of the currently loaded linker files calling the
215 * predicate function while the function returns 0. Returns the value
216 * returned by the last predicate function.
217 */
218int linker_file_foreach(linker_predicate_t *_predicate, void *_context);
219
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220/*
221 * Lookup a symbol in a file. If deps is TRUE, look in dependancies
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222 * if not found in file. The symbol's value is returned in the
223 * caddr_t. An error is returned, 0 if no error occured.
984263bc 224 */
d1786c1b 225int linker_file_lookup_symbol(linker_file_t _file, const char* _name,
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226 int _deps, caddr_t *);
227
228
229/*
230 * Lookup a linker set in a file. Return pointers to the first entry,
231 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {}
232 * void *start is really: "struct yoursetmember ***start;"
233 */
234int linker_file_lookup_set(linker_file_t _file, const char *_name,
235 void *_start, void *_stop, int *_count);
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236
237/*
238 * Search the linker path for the module. Return the full pathname in
239 * a malloc'ed buffer.
240 */
241char *linker_search_path(const char *_filename);
242
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243int linker_reference_module(const char *modname, struct mod_depend *verinfo,
244 linker_file_t *retult);
245int linker_release_module(const char *modname, struct mod_depend *verinfo,
246 linker_file_t lf);
247
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248/*
249 * DDB Helpers, tuned specifically for ddb/db_kld.c
250 */
251int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
252int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
253 long *_diffp);
254int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
255
256
257#endif /* _KERNEL */
258
259/*
260 * Module information subtypes
261 */
262#define MODINFO_END 0x0000 /* End of list */
263#define MODINFO_NAME 0x0001 /* Name of module (string) */
264#define MODINFO_TYPE 0x0002 /* Type of module (string) */
265#define MODINFO_ADDR 0x0003 /* Loaded address */
266#define MODINFO_SIZE 0x0004 /* Size of module */
267#define MODINFO_EMPTY 0x0005 /* Has been deleted */
268#define MODINFO_ARGS 0x0006 /* Parameters string */
269#define MODINFO_METADATA 0x8000 /* Module-specfic */
270
271#define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */
272#define MODINFOMD_ELFHDR 0x0002 /* ELF header */
273#define MODINFOMD_SSYM 0x0003 /* start of symbols */
274#define MODINFOMD_ESYM 0x0004 /* end of symbols */
275#define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */
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276#define MODINFOMD_ENVP 0x0006 /* (from 5.x) envp[] */
277#define MODINFOMD_HOWTO 0x0007 /* (from 5.x) boothowto */
278#define MODINFOMD_KERNEND 0x0008 /* (from 5.x) kernend */
1c0e3286 279#define MODINFOMD_SHDR 0x0009 /* section header table */
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280#define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */
281
282#define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */
283
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284#ifdef _KERNEL
285#define MD_FETCH(mdp, info, type) ({ \
286 type *__p; \
287 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \
288 __p ? *__p : 0; \
289})
290#endif
291
292#define LINKER_HINTS_VERSION 1 /* linker.hints file version */
293
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294#ifdef _KERNEL
295
296/*
297 * Module lookup
298 */
299extern caddr_t preload_metadata;
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300extern caddr_t preload_search_by_name(const char *);
301extern caddr_t preload_search_by_type(const char *);
302extern caddr_t preload_search_next_name(caddr_t);
303extern caddr_t preload_search_info(caddr_t, int);
304extern void preload_delete_name(const char *);
305extern void preload_bootstrap_relocate(vm_offset_t);
306extern struct mod_metadata *find_mod_metadata(const char *);
32832096 307
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308#ifdef KLD_DEBUG
309
310extern int kld_debug;
311#define KLD_DEBUG_FILE 1 /* file load/unload */
312#define KLD_DEBUG_SYM 2 /* symbol lookup */
313
314#define KLD_DPF(cat, args) \
315 do { \
26be20a0 316 if (kld_debug & KLD_DEBUG_##cat) kprintf args; \
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317 } while (0)
318
319#else
320
321#define KLD_DPF(cat, args)
322
323#endif
324
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325typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *);
326
984263bc 327/* Support functions */
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328int elf_reloc(linker_file_t, Elf_Addr, const void *, int, elf_lookup_fn);
329int elf_reloc_local(linker_file_t, Elf_Addr, const void *, int, elf_lookup_fn);
330Elf_Addr elf_relocaddr(linker_file_t, Elf_Addr);
005f09fe 331
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332/* values for type */
333#define ELF_RELOC_REL 1
334#define ELF_RELOC_RELA 2
335
336#endif /* _KERNEL */
337
338struct kld_file_stat {
339 int version; /* set to sizeof(linker_file_stat) */
340 char name[MAXPATHLEN];
341 int refs;
342 int id;
343 caddr_t address; /* load address */
344 size_t size; /* size in bytes */
345};
346
347struct kld_sym_lookup {
348 int version; /* set to sizeof(struct kld_sym_lookup) */
e7f74efc 349 const char *symname; /* Symbol name we are looking up */
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350 u_long symvalue;
351 size_t symsize;
352};
03d6a592 353
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354#define KLDSYM_LOOKUP 1
355
356#ifndef _KERNEL
357
03d6a592 358#ifndef _SYS_CDEFS_H_
984263bc 359#include <sys/cdefs.h>
03d6a592 360#endif
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361
362__BEGIN_DECLS
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363int kldload(const char *);
364int kldunload(int);
365int kldfind(const char *);
366int kldnext(int);
367int kldstat(int, struct kld_file_stat *);
368int kldfirstmod(int);
369int kldsym(int, int, void *);
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370__END_DECLS
371
372#endif
373
374#endif /* !_SYS_LINKER_H_ */