xref: /illumos-gate/usr/src/boot/sys/sys/linker.h (revision 55fea89d)
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 typedef int (*linker_function_nameval_callback_t)(linker_file_t, int, linker_symval_t *, void *);
63 
64 struct common_symbol {
65     STAILQ_ENTRY(common_symbol) link;
66     char*		name;
67     caddr_t		address;
68 };
69 
70 struct linker_file {
71     KOBJ_FIELDS;
72     int			refs;		/* reference count */
73     int			userrefs;	/* kldload(2) count */
74     int			flags;
75 #define LINKER_FILE_LINKED	0x1	/* file has been fully linked */
76     TAILQ_ENTRY(linker_file) link;	/* list of all loaded files */
77     char*		filename;	/* file which was loaded */
78     char*		pathname;	/* file name with full path */
79     int			id;		/* unique id */
80     caddr_t		address;	/* load address */
81     size_t		size;		/* size of file */
82     caddr_t		ctors_addr;	/* address of .ctors */
83     size_t		ctors_size;	/* size of .ctors */
84     int			ndeps;		/* number of dependencies */
85     linker_file_t*	deps;		/* list of dependencies */
86     STAILQ_HEAD(, common_symbol) common; /* list of common symbols */
87     TAILQ_HEAD(, module) modules;	/* modules in this file */
88     TAILQ_ENTRY(linker_file) loaded;	/* preload dependency support */
89     int			loadcnt;	/* load counter value */
90 
91     /*
92      * Function Boundary Tracing (FBT) or Statically Defined Tracing (SDT)
93      * fields.
94      */
95     int			nenabled;	/* number of enabled probes. */
96     int			fbt_nentries;	/* number of fbt entries created. */
97 };
98 
99 /*
100  * Object implementing a class of file (a.out, elf, etc.)
101  */
102 typedef struct linker_class *linker_class_t;
103 typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
104 
105 struct linker_class {
106     KOBJ_CLASS_FIELDS;
107     TAILQ_ENTRY(linker_class) link;	/* list of all file classes */
108 };
109 
110 /*
111  * Function type used when iterating over the list of linker files.
112  */
113 typedef int linker_predicate_t(linker_file_t, void *);
114 
115 /*
116  * The "file" for the kernel.
117  */
118 extern linker_file_t	linker_kernel_file;
119 
120 /*
121  * Obtain a reference to a module, loading it if required.
122  */
123 int linker_reference_module(const char* _modname, struct mod_depend *_verinfo,
124 			    linker_file_t* _result);
125 
126 /*
127  * Release a reference to a module, unloading it if there are no more
128  * references.  Note that one should either provide a module name and
129  * optional version info or a linker file, but not both.
130  */
131 int linker_release_module(const char *_modname, struct mod_depend *_verinfo,
132 			  linker_file_t _file);
133 
134 /*
135  * Iterate over all of the currently loaded linker files calling the
136  * predicate function while the function returns 0.  Returns the value
137  * returned by the last predicate function.
138  */
139 int linker_file_foreach(linker_predicate_t *_predicate, void *_context);
140 
141 /*
142  * Lookup a symbol in a file.  If deps is TRUE, look in dependencies
143  * if not found in file.
144  */
145 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name,
146 				  int _deps);
147 
148 /*
149  * Lookup a linker set in a file.  Return pointers to the first entry,
150  * last + 1, and count of entries.  Use: for (p = start; p < stop; p++) {}
151  * void *start is really: "struct yoursetmember ***start;"
152  */
153 int linker_file_lookup_set(linker_file_t _file, const char *_name,
154 			   void *_start, void *_stop, int *_count);
155 
156 /*
157  * List all functions in a file.
158  */
159 int linker_file_function_listall(linker_file_t,
160 				 linker_function_nameval_callback_t, void *);
161 
162 /*
163  * Functions soley for use by the linker class handlers.
164  */
165 int linker_add_class(linker_class_t _cls);
166 int linker_file_unload(linker_file_t _file, int flags);
167 int linker_load_dependencies(linker_file_t _lf);
168 linker_file_t linker_make_file(const char* _filename, linker_class_t _cls);
169 
170 /*
171  * DDB Helpers, tuned specifically for ddb/db_kld.c
172  */
173 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
174 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
175 			     long *_diffp);
176 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
177 int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
178 				  long *offset);
179 
180 /*
181  * stack(9) helper for situations where kernel locking is required.
182  */
183 int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
184     long *offset);
185 
186 
187 /* HWPMC helper */
188 void *linker_hwpmc_list_objects(void);
189 
190 #endif	/* _KERNEL */
191 
192 /*
193  * Module information subtypes
194  */
195 #define MODINFO_END		0x0000		/* End of list */
196 #define MODINFO_NAME		0x0001		/* Name of module (string) */
197 #define MODINFO_TYPE		0x0002		/* Type of module (string) */
198 #define MODINFO_ADDR		0x0003		/* Loaded address */
199 #define MODINFO_SIZE		0x0004		/* Size of module */
200 #define MODINFO_EMPTY		0x0005		/* Has been deleted */
201 #define MODINFO_ARGS		0x0006		/* Parameters string */
202 #define MODINFO_METADATA	0x8000		/* Module-specfic */
203 
204 #define MODINFOMD_AOUTEXEC	0x0001		/* a.out exec header */
205 #define MODINFOMD_ELFHDR	0x0002		/* ELF header */
206 #define MODINFOMD_SSYM		0x0003		/* start of symbols */
207 #define MODINFOMD_ESYM		0x0004		/* end of symbols */
208 #define MODINFOMD_DYNAMIC	0x0005		/* _DYNAMIC pointer */
209 /* These values are MD on these two platforms */
210 #if !defined(__sparc64__) && !defined(__powerpc__)
211 #define MODINFOMD_ENVP		0x0006		/* envp[] */
212 #define MODINFOMD_HOWTO		0x0007		/* boothowto */
213 #define MODINFOMD_KERNEND	0x0008		/* kernend */
214 #endif
215 #define MODINFOMD_SHDR		0x0009		/* section header table */
216 #define MODINFOMD_CTORS_ADDR	0x000a		/* address of .ctors */
217 #define MODINFOMD_CTORS_SIZE	0x000b		/* size of .ctors */
218 #define MODINFOMD_FW_HANDLE	0x000c		/* Firmware dependent handle */
219 #define MODINFOMD_NOCOPY	0x8000		/* don't copy this metadata to the kernel */
220 
221 #define MODINFOMD_DEPLIST	(0x4001 | MODINFOMD_NOCOPY)	/* depends on */
222 
223 #ifdef _KERNEL
224 #define MD_FETCH(mdp, info, type) ({ \
225 	type *__p; \
226 	__p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \
227 	__p ? *__p : 0; \
228 })
229 #endif
230 
231 #define	LINKER_HINTS_VERSION	1		/* linker.hints file version */
232 #define	LINKER_HINTS_MAX	(1 << 20)	/* Allow at most 1MB for linker.hints */
233 
234 #ifdef _KERNEL
235 
236 /*
237  * Module lookup
238  */
239 extern vm_offset_t	preload_addr_relocate;
240 extern caddr_t		preload_metadata;
241 
242 extern void *		preload_fetch_addr(caddr_t _mod);
243 extern size_t		preload_fetch_size(caddr_t _mod);
244 extern caddr_t		preload_search_by_name(const char *_name);
245 extern caddr_t		preload_search_by_type(const char *_type);
246 extern caddr_t		preload_search_next_name(caddr_t _base);
247 extern caddr_t		preload_search_info(caddr_t _mod, int _inf);
248 extern void		preload_delete_name(const char *_name);
249 extern void		preload_bootstrap_relocate(vm_offset_t _offset);
250 
251 #ifdef KLD_DEBUG
252 
253 extern int kld_debug;
254 #define KLD_DEBUG_FILE	1	/* file load/unload */
255 #define KLD_DEBUG_SYM	2	/* symbol lookup */
256 
257 #define KLD_DPF(cat, args)					\
258 	do {							\
259 		if (kld_debug & KLD_DEBUG_##cat) printf args;	\
260 	} while (0)
261 
262 #else
263 
264 #define KLD_DPF(cat, args)
265 
266 #endif
267 
268 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *);
269 
270 /* Support functions */
271 int	elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu);
272 int	elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu);
273 Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr);
274 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx);
275 const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx);
276 
277 typedef struct linker_ctf {
278 	const uint8_t 	*ctftab;	/* Decompressed CTF data. */
279 	int 		ctfcnt;		/* Number of CTF data bytes. */
280 	const Elf_Sym	*symtab;	/* Ptr to the symbol table. */
281 	int		nsym;		/* Number of symbols. */
282 	const char	*strtab;	/* Ptr to the string table. */
283 	int 		strcnt;		/* Number of string bytes. */
284 	uint32_t	**ctfoffp;	/* Ptr to array of obj/fnc offsets. */
285 	uint32_t	**typoffp;	/* Ptr to array of type offsets. */
286 	long		*typlenp;	/* Ptr to number of type data entries. */
287 } linker_ctf_t;
288 
289 int	linker_ctf_get(linker_file_t, linker_ctf_t *);
290 
291 int elf_cpu_load_file(linker_file_t);
292 int elf_cpu_unload_file(linker_file_t);
293 
294 /* values for type */
295 #define ELF_RELOC_REL	1
296 #define ELF_RELOC_RELA	2
297 
298 /*
299  * This is version 1 of the KLD file status structure. It is identified
300  * by its _size_ in the version field.
301  */
302 struct kld_file_stat_1 {
303     int		version;	/* set to sizeof(struct kld_file_stat_1) */
304     char        name[MAXPATHLEN];
305     int		refs;
306     int		id;
307     caddr_t	address;	/* load address */
308     size_t	size;		/* size in bytes */
309 };
310 #endif /* _KERNEL */
311 
312 struct kld_file_stat {
313     int		version;	/* set to sizeof(struct kld_file_stat) */
314     char        name[MAXPATHLEN];
315     int		refs;
316     int		id;
317     caddr_t	address;	/* load address */
318     size_t	size;		/* size in bytes */
319     char        pathname[MAXPATHLEN];
320 };
321 
322 struct kld_sym_lookup {
323     int		version;	/* set to sizeof(struct kld_sym_lookup) */
324     char	*symname;	/* Symbol name we are looking up */
325     u_long	symvalue;
326     size_t	symsize;
327 };
328 #define KLDSYM_LOOKUP	1
329 
330 /*
331  * Flags for kldunloadf() and linker_file_unload()
332  */
333 #define LINKER_UNLOAD_NORMAL	0
334 #define LINKER_UNLOAD_FORCE	1
335 
336 #ifndef _KERNEL
337 
338 #include <sys/cdefs.h>
339 
340 __BEGIN_DECLS
341 int	kldload(const char* _file);
342 int	kldunload(int _fileid);
343 int	kldunloadf(int _fileid, int flags);
344 int	kldfind(const char* _file);
345 int	kldnext(int _fileid);
346 int	kldstat(int _fileid, struct kld_file_stat* _stat);
347 int	kldfirstmod(int _fileid);
348 int	kldsym(int _fileid, int _cmd, void *_data);
349 __END_DECLS
350 
351 #endif
352 
353 #endif /* !_SYS_LINKER_H_ */
354