master
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1997-2000 Doug Rabson
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
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#define LINKER_FILE_MODULES 0x2 /* file has >0 modules at preload */
77 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */
78 char* filename; /* file which was loaded */
79 char* pathname; /* file name with full path */
80 int id; /* unique id */
81 caddr_t address; /* load address */
82 size_t size; /* size of file */
83 caddr_t ctors_addr; /* address of .ctors/.init_array */
84 size_t ctors_size; /* size of .ctors/.init_array */
85 enum {
86 LF_NONE = 0,
87 LF_CTORS,
88 LF_DTORS,
89 } ctors_invoked; /* have we run ctors yet? */
90 caddr_t dtors_addr; /* address of .dtors/.fini_array */
91 size_t dtors_size; /* size of .dtors/.fini_array */
92 int ndeps; /* number of dependencies */
93 linker_file_t* deps; /* list of dependencies */
94 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */
95 TAILQ_HEAD(, module) modules; /* modules in this file */
96 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */
97 int loadcnt; /* load counter value */
98
99 /*
100 * Function Boundary Tracing (FBT) or Statically Defined Tracing (SDT)
101 * fields.
102 */
103 int nenabled; /* number of enabled probes. */
104 int fbt_nentries; /* number of fbt entries created. */
105
106#ifdef __arm__
107 caddr_t exidx_addr; /* Unwind data index table start */
108 size_t exidx_size; /* Unwind data index table size */
109#endif
110};
111
112/*
113 * Object implementing a class of file (a.out, elf, etc.)
114 */
115typedef struct linker_class *linker_class_t;
116typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
117
118struct linker_class {
119 KOBJ_CLASS_FIELDS;
120 TAILQ_ENTRY(linker_class) link; /* list of all file classes */
121};
122
123/*
124 * Function type used when iterating over the list of linker files.
125 */
126typedef int linker_predicate_t(linker_file_t, void *);
127
128/*
129 * The "file" for the kernel.
130 */
131extern linker_file_t linker_kernel_file;
132
133/*
134 * Obtain a reference to a module, loading it if required.
135 */
136int linker_reference_module(const char* _modname, struct mod_depend *_verinfo,
137 linker_file_t* _result);
138
139/*
140 * Release a reference to a module, unloading it if there are no more
141 * references. Note that one should either provide a module name and
142 * optional version info or a linker file, but not both.
143 */
144int linker_release_module(const char *_modname, struct mod_depend *_verinfo,
145 linker_file_t _file);
146
147/*
148 * Iterate over all of the currently loaded linker files calling the
149 * predicate function while the function returns 0. Returns the value
150 * returned by the last predicate function.
151 */
152int linker_file_foreach(linker_predicate_t *_predicate, void *_context);
153
154/*
155 * Lookup a symbol in a file. If deps is TRUE, look in dependencies
156 * if not found in file.
157 */
158caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name,
159 int _deps);
160
161/*
162 * Lookup a linker set in a file. Return pointers to the first entry,
163 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {}
164 * void *start is really: "struct yoursetmember ***start;"
165 */
166int linker_file_lookup_set(linker_file_t _file, const char *_name,
167 void *_start, void *_stop, int *_count);
168
169/*
170 * List all functions in a file.
171 */
172int linker_file_function_listall(linker_file_t,
173 linker_function_nameval_callback_t, void *);
174
175/*
176 * Functions solely for use by the linker class handlers.
177 */
178int linker_add_class(linker_class_t _cls);
179int linker_file_unload(linker_file_t _file, int flags);
180int linker_load_dependencies(linker_file_t _lf);
181linker_file_t linker_make_file(const char* _filename, linker_class_t _cls);
182
183/*
184 * DDB Helpers, tuned specifically for ddb/db_kld.c
185 */
186int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
187int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
188 long *_diffp);
189int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
190int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
191 long *offset);
192
193/*
194 * stack(9) helper for situations where kernel locking is required.
195 */
196int linker_search_symbol_name_flags(caddr_t value, char *buf, u_int buflen,
197 long *offset, int flags);
198int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
199 long *offset);
200
201/* HWPMC helper */
202void *linker_hwpmc_list_objects(void);
203
204/* kldload/kldunload syscalls blocking */
205#define LINKER_UB_UNLOCK 0x0001 /* busy: unlock kld_sx locked on
206 return */
207#define LINKER_UB_LOCKED 0x0002 /* busy/unbusy: kld_sx locked on
208 entry */
209#define LINKER_UB_PCATCH 0x0004 /* busy: sleep interruptible */
210int linker_kldload_busy(int flags);
211void linker_kldload_unbusy(int flags);
212
213#endif /* _KERNEL */
214
215/*
216 * Module information subtypes
217 */
218#define MODINFO_END 0x0000 /* End of list */
219#define MODINFO_NAME 0x0001 /* Name of module (string) */
220#define MODINFO_TYPE 0x0002 /* Type of module (string) */
221#define MODINFO_ADDR 0x0003 /* Loaded address */
222#define MODINFO_SIZE 0x0004 /* Size of module */
223#define MODINFO_EMPTY 0x0005 /* Has been deleted */
224#define MODINFO_ARGS 0x0006 /* Parameters string */
225#define MODINFO_METADATA 0x8000 /* Module-specfic */
226
227#define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */
228#define MODINFOMD_ELFHDR 0x0002 /* ELF header */
229#define MODINFOMD_SSYM 0x0003 /* start of symbols */
230#define MODINFOMD_ESYM 0x0004 /* end of symbols */
231#define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */
232#define MODINFOMD_MB2HDR 0x0006 /* MB2 header info */
233/* These values are MD on PowerPC */
234#if !defined(__powerpc__)
235#define MODINFOMD_ENVP 0x0006 /* envp[] */
236#define MODINFOMD_HOWTO 0x0007 /* boothowto */
237#define MODINFOMD_KERNEND 0x0008 /* kernend */
238#endif
239#define MODINFOMD_SHDR 0x0009 /* section header table */
240#define MODINFOMD_CTORS_ADDR 0x000a /* address of .ctors */
241#define MODINFOMD_CTORS_SIZE 0x000b /* size of .ctors */
242#define MODINFOMD_FW_HANDLE 0x000c /* Firmware dependent handle */
243#define MODINFOMD_KEYBUF 0x000d /* Crypto key intake buffer */
244#define MODINFOMD_FONT 0x000e /* Console font */
245#define MODINFOMD_SPLASH 0x000f /* Console splash screen */
246#define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */
247
248#define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */
249
250#ifdef _KERNEL
251#define MD_FETCH(mdp, info, type) ({ \
252 type *__p; \
253 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \
254 __p ? *__p : 0; \
255})
256#endif
257
258#define LINKER_HINTS_VERSION 1 /* linker.hints file version */
259#define LINKER_HINTS_MAX (1 << 20) /* Allow at most 1MB for linker.hints */
260
261#ifdef _KERNEL
262
263/*
264 * Module lookup
265 */
266extern vm_offset_t preload_addr_relocate;
267extern caddr_t preload_metadata;
268
269extern void * preload_fetch_addr(caddr_t _mod);
270extern size_t preload_fetch_size(caddr_t _mod);
271extern caddr_t preload_search_by_name(const char *_name);
272extern caddr_t preload_search_by_type(const char *_type);
273extern caddr_t preload_search_next_name(caddr_t _base);
274extern caddr_t preload_search_info(caddr_t _mod, int _inf);
275extern void preload_delete_name(const char *_name);
276extern void preload_bootstrap_relocate(vm_offset_t _offset);
277extern void preload_dump(void);
278
279#ifdef KLD_DEBUG
280
281extern int kld_debug;
282#define KLD_DEBUG_FILE 1 /* file load/unload */
283#define KLD_DEBUG_SYM 2 /* symbol lookup */
284
285#define KLD_DPF(cat, args) \
286 do { \
287 if (kld_debug & KLD_DEBUG_##cat) printf args; \
288 } while (0)
289
290#else
291
292#define KLD_DPF(cat, args)
293
294#endif
295
296typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *);
297
298/* Support functions */
299bool elf_is_ifunc_reloc(Elf_Size r_info);
300int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel,
301 int _type, elf_lookup_fn _lu);
302int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel,
303 int _type, elf_lookup_fn _lu);
304Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr);
305const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx);
306const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx);
307void link_elf_ireloc(caddr_t kmdp);
308
309#if defined(__aarch64__) || defined(__amd64__)
310int elf_reloc_late(linker_file_t _lf, Elf_Addr base, const void *_rel,
311 int _type, elf_lookup_fn _lu);
312void link_elf_late_ireloc(void);
313#endif
314
315typedef struct linker_ctf {
316 const uint8_t *ctftab; /* Decompressed CTF data. */
317 int ctfcnt; /* Number of CTF data bytes. */
318 const Elf_Sym *symtab; /* Ptr to the symbol table. */
319 int nsym; /* Number of symbols. */
320 const char *strtab; /* Ptr to the string table. */
321 int strcnt; /* Number of string bytes. */
322 uint32_t **ctfoffp; /* Ptr to array of obj/fnc offsets. */
323 uint32_t **typoffp; /* Ptr to array of type offsets. */
324 long *typlenp; /* Ptr to number of type data entries. */
325} linker_ctf_t;
326
327int linker_ctf_get(linker_file_t, linker_ctf_t *);
328
329int elf_cpu_load_file(linker_file_t);
330int elf_cpu_unload_file(linker_file_t);
331int elf_cpu_parse_dynamic(caddr_t, Elf_Dyn *);
332
333/* values for type */
334#define ELF_RELOC_REL 1
335#define ELF_RELOC_RELA 2
336
337/*
338 * This is version 1 of the KLD file status structure. It is identified
339 * by its _size_ in the version field.
340 */
341struct kld_file_stat_1 {
342 int version; /* set to sizeof(struct kld_file_stat_1) */
343 char name[MAXPATHLEN];
344 int refs;
345 int id;
346 caddr_t address; /* load address */
347 size_t size; /* size in bytes */
348};
349#endif /* _KERNEL */
350
351struct kld_file_stat {
352 int version; /* set to sizeof(struct kld_file_stat) */
353 char name[MAXPATHLEN];
354 int refs;
355 int id;
356 caddr_t address; /* load address */
357 size_t size; /* size in bytes */
358 char pathname[MAXPATHLEN];
359};
360
361struct kld_sym_lookup {
362 int version; /* set to sizeof(struct kld_sym_lookup) */
363 char *symname; /* Symbol name we are looking up */
364 u_long symvalue;
365 size_t symsize;
366};
367#define KLDSYM_LOOKUP 1
368
369/*
370 * Flags for kldunloadf() and linker_file_unload()
371 */
372#define LINKER_UNLOAD_NORMAL 0
373#define LINKER_UNLOAD_FORCE 1
374
375#ifndef _KERNEL
376
377#include <sys/cdefs.h>
378
379__BEGIN_DECLS
380int kldload(const char* _file);
381int kldunload(int _fileid);
382int kldunloadf(int _fileid, int flags);
383int kldfind(const char* _file);
384int kldnext(int _fileid);
385int kldstat(int _fileid, struct kld_file_stat* _stat);
386int kldfirstmod(int _fileid);
387int kldsym(int _fileid, int _cmd, void *_data);
388__END_DECLS
389
390#endif
391
392#endif /* !_SYS_LINKER_H_ */