2 * SPDX-License-Identifier: BSD-2-Clause
4 * Copyright (c) 1997-2000 Doug Rabson
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
29 #ifndef _SYS_LINKER_H_
30 #define _SYS_LINKER_H_
34 #include <machine/elf.h>
38 MALLOC_DECLARE(M_LINKER);
44 * Object representing a file which has been loaded by the linker.
46 typedef struct linker_file* linker_file_t;
47 typedef TAILQ_HEAD(, linker_file) linker_file_list_t;
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 *);
54 * expanded out linker_sym_t
56 typedef struct linker_symval {
62 typedef int (*linker_function_nameval_callback_t)(linker_file_t, int, linker_symval_t *, void *);
64 struct common_symbol {
65 STAILQ_ENTRY(common_symbol) link;
72 int refs; /* reference count */
73 int userrefs; /* kldload(2) count */
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 */
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 */
100 * Function Boundary Tracing (FBT) or Statically Defined Tracing (SDT)
103 int nenabled; /* number of enabled probes. */
104 int fbt_nentries; /* number of fbt entries created. */
107 caddr_t exidx_addr; /* Unwind data index table start */
108 size_t exidx_size; /* Unwind data index table size */
113 * Object implementing a class of file (a.out, elf, etc.)
115 typedef struct linker_class *linker_class_t;
116 typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
118 struct linker_class {
120 TAILQ_ENTRY(linker_class) link; /* list of all file classes */
124 * Function type used when iterating over the list of linker files.
126 typedef int linker_predicate_t(linker_file_t, void *);
129 * The "file" for the kernel.
131 extern linker_file_t linker_kernel_file;
134 * Obtain a reference to a module, loading it if required.
136 int linker_reference_module(const char* _modname, struct mod_depend *_verinfo,
137 linker_file_t* _result);
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.
144 int linker_release_module(const char *_modname, struct mod_depend *_verinfo,
145 linker_file_t _file);
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.
152 int linker_file_foreach(linker_predicate_t *_predicate, void *_context);
155 * Lookup a symbol in a file. If deps is TRUE, look in dependencies
156 * if not found in file.
158 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name,
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;"
166 int linker_file_lookup_set(linker_file_t _file, const char *_name,
167 void *_start, void *_stop, int *_count);
170 * List all functions in a file.
172 int linker_file_function_listall(linker_file_t,
173 linker_function_nameval_callback_t, void *);
176 * Functions solely for use by the linker class handlers.
178 int linker_add_class(linker_class_t _cls);
179 int linker_file_unload(linker_file_t _file, int flags);
180 int linker_load_dependencies(linker_file_t _lf);
181 linker_file_t linker_make_file(const char* _filename, linker_class_t _cls);
184 * DDB Helpers, tuned specifically for ddb/db_kld.c
186 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
187 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
189 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
190 int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
194 * stack(9) helper for situations where kernel locking is required.
196 int linker_search_symbol_name_flags(caddr_t value, char *buf, u_int buflen,
197 long *offset, int flags);
198 int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
202 void *linker_hwpmc_list_objects(void);
204 /* kldload/kldunload syscalls blocking */
205 #define LINKER_UB_UNLOCK 0x0001 /* busy: unlock kld_sx locked on
207 #define LINKER_UB_LOCKED 0x0002 /* busy/unbusy: kld_sx locked on
209 #define LINKER_UB_PCATCH 0x0004 /* busy: sleep interruptible */
210 int linker_kldload_busy(int flags);
211 void linker_kldload_unbusy(int flags);
216 * Module information subtypes
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 */
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 */
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_NOCOPY 0x8000 /* don't copy this metadata to the kernel */
247 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */
250 #define MD_FETCH(mdp, info, type) ({ \
252 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \
257 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */
258 #define LINKER_HINTS_MAX (1 << 20) /* Allow at most 1MB for linker.hints */
265 extern vm_offset_t preload_addr_relocate;
266 extern caddr_t preload_metadata;
268 extern void * preload_fetch_addr(caddr_t _mod);
269 extern size_t preload_fetch_size(caddr_t _mod);
270 extern caddr_t preload_search_by_name(const char *_name);
271 extern caddr_t preload_search_by_type(const char *_type);
272 extern caddr_t preload_search_next_name(caddr_t _base);
273 extern caddr_t preload_search_info(caddr_t _mod, int _inf);
274 extern void preload_delete_name(const char *_name);
275 extern void preload_bootstrap_relocate(vm_offset_t _offset);
276 extern void preload_dump(void);
280 extern int kld_debug;
281 #define KLD_DEBUG_FILE 1 /* file load/unload */
282 #define KLD_DEBUG_SYM 2 /* symbol lookup */
284 #define KLD_DPF(cat, args) \
286 if (kld_debug & KLD_DEBUG_##cat) printf args; \
291 #define KLD_DPF(cat, args)
295 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *);
297 /* Support functions */
298 bool elf_is_ifunc_reloc(Elf_Size r_info);
299 int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel,
300 int _type, elf_lookup_fn _lu);
301 int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel,
302 int _type, elf_lookup_fn _lu);
303 Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr);
304 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx);
305 const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx);
306 void link_elf_ireloc(caddr_t kmdp);
308 #if defined(__aarch64__) || defined(__amd64__)
309 int elf_reloc_late(linker_file_t _lf, Elf_Addr base, const void *_rel,
310 int _type, elf_lookup_fn _lu);
311 void link_elf_late_ireloc(void);
314 typedef struct linker_ctf {
315 const uint8_t *ctftab; /* Decompressed CTF data. */
316 int ctfcnt; /* Number of CTF data bytes. */
317 const Elf_Sym *symtab; /* Ptr to the symbol table. */
318 int nsym; /* Number of symbols. */
319 const char *strtab; /* Ptr to the string table. */
320 int strcnt; /* Number of string bytes. */
321 uint32_t **ctfoffp; /* Ptr to array of obj/fnc offsets. */
322 uint32_t **typoffp; /* Ptr to array of type offsets. */
323 long *typlenp; /* Ptr to number of type data entries. */
326 int linker_ctf_get(linker_file_t, linker_ctf_t *);
327 int linker_ctf_lookup_sym_ddb(const char *symname, c_linker_sym_t *sym,
329 int linker_ctf_lookup_typename_ddb(linker_ctf_t *lc, const char *typename);
331 int elf_cpu_load_file(linker_file_t);
332 int elf_cpu_unload_file(linker_file_t);
333 int elf_cpu_parse_dynamic(caddr_t, Elf_Dyn *);
335 /* values for type */
336 #define ELF_RELOC_REL 1
337 #define ELF_RELOC_RELA 2
340 * This is version 1 of the KLD file status structure. It is identified
341 * by its _size_ in the version field.
343 struct kld_file_stat_1 {
344 int version; /* set to sizeof(struct kld_file_stat_1) */
345 char name[MAXPATHLEN];
348 caddr_t address; /* load address */
349 size_t size; /* size in bytes */
353 struct kld_file_stat {
354 int version; /* set to sizeof(struct kld_file_stat) */
355 char name[MAXPATHLEN];
358 caddr_t address; /* load address */
359 size_t size; /* size in bytes */
360 char pathname[MAXPATHLEN];
363 struct kld_sym_lookup {
364 int version; /* set to sizeof(struct kld_sym_lookup) */
365 char *symname; /* Symbol name we are looking up */
369 #define KLDSYM_LOOKUP 1
372 * Flags for kldunloadf() and linker_file_unload()
374 #define LINKER_UNLOAD_NORMAL 0
375 #define LINKER_UNLOAD_FORCE 1
379 #include <sys/cdefs.h>
382 int kldload(const char* _file);
383 int kldunload(int _fileid);
384 int kldunloadf(int _fileid, int flags);
385 int kldfind(const char* _file);
386 int kldnext(int _fileid);
387 int kldstat(int _fileid, struct kld_file_stat* _stat);
388 int kldfirstmod(int _fileid);
389 int kldsym(int _fileid, int _cmd, void *_data);
394 #endif /* !_SYS_LINKER_H_ */