2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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
31 #ifndef _SYS_LINKER_H_
32 #define _SYS_LINKER_H_
36 #include <machine/elf.h>
40 MALLOC_DECLARE(M_LINKER);
46 * Object representing a file which has been loaded by the linker.
48 typedef struct linker_file* linker_file_t;
49 typedef TAILQ_HEAD(, linker_file) linker_file_list_t;
51 typedef caddr_t linker_sym_t; /* opaque symbol */
52 typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */
53 typedef int (*linker_function_name_callback_t)(const char *, void *);
56 * expanded out linker_sym_t
58 typedef struct linker_symval {
64 typedef int (*linker_function_nameval_callback_t)(linker_file_t, int, linker_symval_t *, void *);
66 struct common_symbol {
67 STAILQ_ENTRY(common_symbol) link;
74 int refs; /* reference count */
75 int userrefs; /* kldload(2) count */
77 #define LINKER_FILE_LINKED 0x1 /* file has been fully linked */
78 #define LINKER_FILE_MODULES 0x2 /* file has >0 modules at preload */
79 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */
80 char* filename; /* file which was loaded */
81 char* pathname; /* file name with full path */
82 int id; /* unique id */
83 caddr_t address; /* load address */
84 size_t size; /* size of file */
85 caddr_t ctors_addr; /* address of .ctors */
86 size_t ctors_size; /* size of .ctors */
87 int ndeps; /* number of dependencies */
88 linker_file_t* deps; /* list of dependencies */
89 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */
90 TAILQ_HEAD(, module) modules; /* modules in this file */
91 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */
92 int loadcnt; /* load counter value */
95 * Function Boundary Tracing (FBT) or Statically Defined Tracing (SDT)
98 int nenabled; /* number of enabled probes. */
99 int fbt_nentries; /* number of fbt entries created. */
102 caddr_t exidx_addr; /* Unwind data index table start */
103 size_t exidx_size; /* Unwind data index table size */
108 * Object implementing a class of file (a.out, elf, etc.)
110 typedef struct linker_class *linker_class_t;
111 typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
113 struct linker_class {
115 TAILQ_ENTRY(linker_class) link; /* list of all file classes */
119 * Function type used when iterating over the list of linker files.
121 typedef int linker_predicate_t(linker_file_t, void *);
124 * The "file" for the kernel.
126 extern linker_file_t linker_kernel_file;
129 * Obtain a reference to a module, loading it if required.
131 int linker_reference_module(const char* _modname, struct mod_depend *_verinfo,
132 linker_file_t* _result);
135 * Release a reference to a module, unloading it if there are no more
136 * references. Note that one should either provide a module name and
137 * optional version info or a linker file, but not both.
139 int linker_release_module(const char *_modname, struct mod_depend *_verinfo,
140 linker_file_t _file);
143 * Iterate over all of the currently loaded linker files calling the
144 * predicate function while the function returns 0. Returns the value
145 * returned by the last predicate function.
147 int linker_file_foreach(linker_predicate_t *_predicate, void *_context);
150 * Lookup a symbol in a file. If deps is TRUE, look in dependencies
151 * if not found in file.
153 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name,
157 * Lookup a linker set in a file. Return pointers to the first entry,
158 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {}
159 * void *start is really: "struct yoursetmember ***start;"
161 int linker_file_lookup_set(linker_file_t _file, const char *_name,
162 void *_start, void *_stop, int *_count);
165 * List all functions in a file.
167 int linker_file_function_listall(linker_file_t,
168 linker_function_nameval_callback_t, void *);
171 * Functions solely for use by the linker class handlers.
173 int linker_add_class(linker_class_t _cls);
174 int linker_file_unload(linker_file_t _file, int flags);
175 int linker_load_dependencies(linker_file_t _lf);
176 linker_file_t linker_make_file(const char* _filename, linker_class_t _cls);
179 * DDB Helpers, tuned specifically for ddb/db_kld.c
181 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
182 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
184 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
185 int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
189 * stack(9) helper for situations where kernel locking is required.
191 int linker_search_symbol_name_flags(caddr_t value, char *buf, u_int buflen,
192 long *offset, int flags);
193 int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
197 void *linker_hwpmc_list_objects(void);
202 * Module information subtypes
204 #define MODINFO_END 0x0000 /* End of list */
205 #define MODINFO_NAME 0x0001 /* Name of module (string) */
206 #define MODINFO_TYPE 0x0002 /* Type of module (string) */
207 #define MODINFO_ADDR 0x0003 /* Loaded address */
208 #define MODINFO_SIZE 0x0004 /* Size of module */
209 #define MODINFO_EMPTY 0x0005 /* Has been deleted */
210 #define MODINFO_ARGS 0x0006 /* Parameters string */
211 #define MODINFO_METADATA 0x8000 /* Module-specfic */
213 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */
214 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */
215 #define MODINFOMD_SSYM 0x0003 /* start of symbols */
216 #define MODINFOMD_ESYM 0x0004 /* end of symbols */
217 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */
218 /* These values are MD on PowerPC */
219 #if !defined(__powerpc__)
220 #define MODINFOMD_ENVP 0x0006 /* envp[] */
221 #define MODINFOMD_HOWTO 0x0007 /* boothowto */
222 #define MODINFOMD_KERNEND 0x0008 /* kernend */
224 #define MODINFOMD_SHDR 0x0009 /* section header table */
225 #define MODINFOMD_CTORS_ADDR 0x000a /* address of .ctors */
226 #define MODINFOMD_CTORS_SIZE 0x000b /* size of .ctors */
227 #define MODINFOMD_FW_HANDLE 0x000c /* Firmware dependent handle */
228 #define MODINFOMD_KEYBUF 0x000d /* Crypto key intake buffer */
229 #define MODINFOMD_FONT 0x000e /* Console font */
230 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */
232 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */
235 #define MD_FETCH(mdp, info, type) ({ \
237 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \
242 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */
243 #define LINKER_HINTS_MAX (1 << 20) /* Allow at most 1MB for linker.hints */
250 extern vm_offset_t preload_addr_relocate;
251 extern caddr_t preload_metadata;
253 extern void * preload_fetch_addr(caddr_t _mod);
254 extern size_t preload_fetch_size(caddr_t _mod);
255 extern caddr_t preload_search_by_name(const char *_name);
256 extern caddr_t preload_search_by_type(const char *_type);
257 extern caddr_t preload_search_next_name(caddr_t _base);
258 extern caddr_t preload_search_info(caddr_t _mod, int _inf);
259 extern void preload_delete_name(const char *_name);
260 extern void preload_bootstrap_relocate(vm_offset_t _offset);
261 extern void preload_dump(void);
265 extern int kld_debug;
266 #define KLD_DEBUG_FILE 1 /* file load/unload */
267 #define KLD_DEBUG_SYM 2 /* symbol lookup */
269 #define KLD_DPF(cat, args) \
271 if (kld_debug & KLD_DEBUG_##cat) printf args; \
276 #define KLD_DPF(cat, args)
280 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *);
282 /* Support functions */
283 bool elf_is_ifunc_reloc(Elf_Size r_info);
284 int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel,
285 int _type, elf_lookup_fn _lu);
286 int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel,
287 int _type, elf_lookup_fn _lu);
288 Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr);
289 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx);
290 const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx);
291 void link_elf_ireloc(caddr_t kmdp);
293 #if defined(__aarch64__) || defined(__amd64__)
294 int elf_reloc_late(linker_file_t _lf, Elf_Addr base, const void *_rel,
295 int _type, elf_lookup_fn _lu);
296 void link_elf_late_ireloc(void);
299 typedef struct linker_ctf {
300 const uint8_t *ctftab; /* Decompressed CTF data. */
301 int ctfcnt; /* Number of CTF data bytes. */
302 const Elf_Sym *symtab; /* Ptr to the symbol table. */
303 int nsym; /* Number of symbols. */
304 const char *strtab; /* Ptr to the string table. */
305 int strcnt; /* Number of string bytes. */
306 uint32_t **ctfoffp; /* Ptr to array of obj/fnc offsets. */
307 uint32_t **typoffp; /* Ptr to array of type offsets. */
308 long *typlenp; /* Ptr to number of type data entries. */
311 int linker_ctf_get(linker_file_t, linker_ctf_t *);
313 int elf_cpu_load_file(linker_file_t);
314 int elf_cpu_unload_file(linker_file_t);
315 int elf_cpu_parse_dynamic(caddr_t, Elf_Dyn *);
317 /* values for type */
318 #define ELF_RELOC_REL 1
319 #define ELF_RELOC_RELA 2
322 * This is version 1 of the KLD file status structure. It is identified
323 * by its _size_ in the version field.
325 struct kld_file_stat_1 {
326 int version; /* set to sizeof(struct kld_file_stat_1) */
327 char name[MAXPATHLEN];
330 caddr_t address; /* load address */
331 size_t size; /* size in bytes */
335 struct kld_file_stat {
336 int version; /* set to sizeof(struct kld_file_stat) */
337 char name[MAXPATHLEN];
340 caddr_t address; /* load address */
341 size_t size; /* size in bytes */
342 char pathname[MAXPATHLEN];
345 struct kld_sym_lookup {
346 int version; /* set to sizeof(struct kld_sym_lookup) */
347 char *symname; /* Symbol name we are looking up */
351 #define KLDSYM_LOOKUP 1
354 * Flags for kldunloadf() and linker_file_unload()
356 #define LINKER_UNLOAD_NORMAL 0
357 #define LINKER_UNLOAD_FORCE 1
361 #include <sys/cdefs.h>
364 int kldload(const char* _file);
365 int kldunload(int _fileid);
366 int kldunloadf(int _fileid, int flags);
367 int kldfind(const char* _file);
368 int kldnext(int _fileid);
369 int kldstat(int _fileid, struct kld_file_stat* _stat);
370 int kldfirstmod(int _fileid);
371 int kldsym(int _fileid, int _cmd, void *_data);
376 #endif /* !_SYS_LINKER_H_ */