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
38MALLOC_DECLARE(M_LINKER);
39#endif
40
41struct mod_depend;
42
43/*
44 * Object representing a file which has been loaded by the linker.
45 */
46typedef struct linker_file* linker_file_t;
47typedef TAILQ_HEAD(, linker_file) linker_file_list_t;
48
49typedef caddr_t linker_sym_t;		/* opaque symbol */
50typedef c_caddr_t c_linker_sym_t;	/* const opaque symbol */
51typedef int (*linker_function_name_callback_t)(const char *, void *);
52
53/*
54 * expanded out linker_sym_t
55 */
56typedef struct linker_symval {
57    const char*		name;
58    caddr_t		value;
59    size_t		size;
60} linker_symval_t;
61
62typedef int (*linker_function_nameval_callback_t)(linker_file_t, int, linker_symval_t *, void *);
63
64struct common_symbol {
65    STAILQ_ENTRY(common_symbol) link;
66    char*		name;
67    caddr_t		address;
68};
69
70struct 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 */
102typedef struct linker_class *linker_class_t;
103typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
104
105struct 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 */
113typedef int linker_predicate_t(linker_file_t, void *);
114
115/*
116 * The "file" for the kernel.
117 */
118extern linker_file_t	linker_kernel_file;
119
120/*
121 * Obtain a reference to a module, loading it if required.
122 */
123int 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 */
131int 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 */
139int 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 */
145caddr_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 */
153int 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 */
159int 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 */
165int linker_add_class(linker_class_t _cls);
166int linker_file_unload(linker_file_t _file, int flags);
167int linker_load_dependencies(linker_file_t _lf);
168linker_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 */
173int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
174int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
175			     long *_diffp);
176int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
177int 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 */
183int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
184    long *offset);
185
186
187/* HWPMC helper */
188void *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 */
239extern vm_offset_t	preload_addr_relocate;
240extern caddr_t		preload_metadata;
241
242extern void *		preload_fetch_addr(caddr_t _mod);
243extern size_t		preload_fetch_size(caddr_t _mod);
244extern caddr_t		preload_search_by_name(const char *_name);
245extern caddr_t		preload_search_by_type(const char *_type);
246extern caddr_t		preload_search_next_name(caddr_t _base);
247extern caddr_t		preload_search_info(caddr_t _mod, int _inf);
248extern void		preload_delete_name(const char *_name);
249extern void		preload_bootstrap_relocate(vm_offset_t _offset);
250
251#ifdef KLD_DEBUG
252
253extern 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
268typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *);
269
270/* Support functions */
271int	elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu);
272int	elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu);
273Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr);
274const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx);
275const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx);
276
277typedef 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
289int	linker_ctf_get(linker_file_t, linker_ctf_t *);
290
291int elf_cpu_load_file(linker_file_t);
292int 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 */
302struct 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
312struct 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
322struct 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
341int	kldload(const char* _file);
342int	kldunload(int _fileid);
343int	kldunloadf(int _fileid, int flags);
344int	kldfind(const char* _file);
345int	kldnext(int _fileid);
346int	kldstat(int _fileid, struct kld_file_stat* _stat);
347int	kldfirstmod(int _fileid);
348int	kldsym(int _fileid, int _cmd, void *_data);
349__END_DECLS
350
351#endif
352
353#endif /* !_SYS_LINKER_H_ */
354