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 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 #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 */ 115 typedef struct linker_class *linker_class_t; 116 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 117 118 struct 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 */ 126 typedef int linker_predicate_t(linker_file_t, void *); 127 128 /* 129 * The "file" for the kernel. 130 */ 131 extern linker_file_t linker_kernel_file; 132 133 /* 134 * Special symbol which will be replaced by a reference to the linker_file_t 135 * of the module it is used in. 136 */ 137 extern linker_file_t __this_linker_file; 138 139 /* 140 * Obtain a reference to a module, loading it if required. 141 */ 142 int linker_reference_module(const char* _modname, struct mod_depend *_verinfo, 143 linker_file_t* _result); 144 145 /* 146 * Release a reference to a module, unloading it if there are no more 147 * references. Note that one should either provide a module name and 148 * optional version info or a linker file, but not both. 149 */ 150 int linker_release_module(const char *_modname, struct mod_depend *_verinfo, 151 linker_file_t _file); 152 153 /* 154 * Iterate over all of the currently loaded linker files calling the 155 * predicate function while the function returns 0. Returns the value 156 * returned by the last predicate function. 157 */ 158 int linker_file_foreach(linker_predicate_t *_predicate, void *_context); 159 160 /* 161 * Lookup a symbol in a file. If deps is TRUE, look in dependencies 162 * if not found in file. 163 */ 164 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name, 165 int _deps); 166 167 /* 168 * Lookup a linker set in a file. Return pointers to the first entry, 169 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {} 170 * void *start is really: "struct yoursetmember ***start;" 171 */ 172 int linker_file_lookup_set(linker_file_t _file, const char *_name, 173 void *_start, void *_stop, int *_count); 174 175 /* 176 * List all functions in a file. 177 */ 178 int linker_file_function_listall(linker_file_t, 179 linker_function_nameval_callback_t, void *); 180 181 /* 182 * Functions solely for use by the linker class handlers. 183 */ 184 int linker_add_class(linker_class_t _cls); 185 int linker_file_unload(linker_file_t _file, int flags); 186 int linker_load_dependencies(linker_file_t _lf); 187 linker_file_t linker_make_file(const char* _filename, linker_class_t _cls); 188 189 /* 190 * DDB Helpers, tuned specifically for ddb/db_kld.c 191 */ 192 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 193 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 194 long *_diffp); 195 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 196 int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 197 long *offset); 198 199 /* 200 * stack(9) helper for situations where kernel locking is required. 201 */ 202 int linker_search_symbol_name_flags(caddr_t value, char *buf, u_int buflen, 203 long *offset, int flags); 204 int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 205 long *offset); 206 207 /* HWPMC helper */ 208 void *linker_hwpmc_list_objects(void); 209 210 /* kldload/kldunload syscalls blocking */ 211 #define LINKER_UB_UNLOCK 0x0001 /* busy: unlock kld_sx locked on 212 return */ 213 #define LINKER_UB_LOCKED 0x0002 /* busy/unbusy: kld_sx locked on 214 entry */ 215 #define LINKER_UB_PCATCH 0x0004 /* busy: sleep interruptible */ 216 int linker_kldload_busy(int flags); 217 void linker_kldload_unbusy(int flags); 218 219 #endif /* _KERNEL */ 220 221 /* 222 * Module information subtypes 223 */ 224 #define MODINFO_END 0x0000 /* End of list */ 225 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 226 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 227 #define MODINFO_ADDR 0x0003 /* Loaded address */ 228 #define MODINFO_SIZE 0x0004 /* Size of module */ 229 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 230 #define MODINFO_ARGS 0x0006 /* Parameters string */ 231 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 232 233 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 234 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 235 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 236 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 237 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 238 #define MODINFOMD_MB2HDR 0x0006 /* MB2 header info */ 239 /* These values are MD on PowerPC */ 240 #if !defined(__powerpc__) 241 #define MODINFOMD_ENVP 0x0006 /* envp[] */ 242 #define MODINFOMD_HOWTO 0x0007 /* boothowto */ 243 #define MODINFOMD_KERNEND 0x0008 /* kernend */ 244 #endif 245 #define MODINFOMD_SHDR 0x0009 /* section header table */ 246 #define MODINFOMD_CTORS_ADDR 0x000a /* address of .ctors */ 247 #define MODINFOMD_CTORS_SIZE 0x000b /* size of .ctors */ 248 #define MODINFOMD_FW_HANDLE 0x000c /* Firmware dependent handle */ 249 #define MODINFOMD_KEYBUF 0x000d /* Crypto key intake buffer */ 250 #define MODINFOMD_FONT 0x000e /* Console font */ 251 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 252 253 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 254 255 #ifdef _KERNEL 256 #define MD_FETCH(mdp, info, type) ({ \ 257 type *__p; \ 258 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \ 259 __p ? *__p : 0; \ 260 }) 261 #endif 262 263 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */ 264 #define LINKER_HINTS_MAX (1 << 20) /* Allow at most 1MB for linker.hints */ 265 266 #ifdef _KERNEL 267 268 /* 269 * Module lookup 270 */ 271 extern vm_offset_t preload_addr_relocate; 272 extern caddr_t preload_metadata; 273 274 extern void * preload_fetch_addr(caddr_t _mod); 275 extern size_t preload_fetch_size(caddr_t _mod); 276 extern caddr_t preload_search_by_name(const char *_name); 277 extern caddr_t preload_search_by_type(const char *_type); 278 extern caddr_t preload_search_next_name(caddr_t _base); 279 extern caddr_t preload_search_info(caddr_t _mod, int _inf); 280 extern void preload_delete_name(const char *_name); 281 extern void preload_bootstrap_relocate(vm_offset_t _offset); 282 extern void preload_dump(void); 283 284 #ifdef KLD_DEBUG 285 286 extern int kld_debug; 287 #define KLD_DEBUG_FILE 1 /* file load/unload */ 288 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 289 290 #define KLD_DPF(cat, args) \ 291 do { \ 292 if (kld_debug & KLD_DEBUG_##cat) printf args; \ 293 } while (0) 294 295 #else 296 297 #define KLD_DPF(cat, args) 298 299 #endif 300 301 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *); 302 303 /* Support functions */ 304 bool elf_is_ifunc_reloc(Elf_Size r_info); 305 int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel, 306 int _type, elf_lookup_fn _lu); 307 int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel, 308 int _type, elf_lookup_fn _lu); 309 Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr); 310 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx); 311 const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx); 312 void link_elf_ireloc(caddr_t kmdp); 313 314 #if defined(__aarch64__) || defined(__amd64__) 315 int elf_reloc_late(linker_file_t _lf, Elf_Addr base, const void *_rel, 316 int _type, elf_lookup_fn _lu); 317 void link_elf_late_ireloc(void); 318 #endif 319 320 typedef struct linker_ctf { 321 const uint8_t *ctftab; /* Decompressed CTF data. */ 322 int ctfcnt; /* Number of CTF data bytes. */ 323 const Elf_Sym *symtab; /* Ptr to the symbol table. */ 324 int nsym; /* Number of symbols. */ 325 const char *strtab; /* Ptr to the string table. */ 326 int strcnt; /* Number of string bytes. */ 327 uint32_t **ctfoffp; /* Ptr to array of obj/fnc offsets. */ 328 uint32_t **typoffp; /* Ptr to array of type offsets. */ 329 long *typlenp; /* Ptr to number of type data entries. */ 330 } linker_ctf_t; 331 332 int linker_ctf_get(linker_file_t, linker_ctf_t *); 333 int linker_ctf_lookup_sym_ddb(const char *symname, c_linker_sym_t *sym, 334 linker_ctf_t *lc); 335 int linker_ctf_lookup_typename_ddb(linker_ctf_t *lc, const char *typename); 336 337 int elf_cpu_load_file(linker_file_t); 338 int elf_cpu_unload_file(linker_file_t); 339 int elf_cpu_parse_dynamic(caddr_t, Elf_Dyn *); 340 341 /* values for type */ 342 #define ELF_RELOC_REL 1 343 #define ELF_RELOC_RELA 2 344 345 /* 346 * This is version 1 of the KLD file status structure. It is identified 347 * by its _size_ in the version field. 348 */ 349 struct kld_file_stat_1 { 350 int version; /* set to sizeof(struct kld_file_stat_1) */ 351 char name[MAXPATHLEN]; 352 int refs; 353 int id; 354 caddr_t address; /* load address */ 355 size_t size; /* size in bytes */ 356 }; 357 #endif /* _KERNEL */ 358 359 struct kld_file_stat { 360 int version; /* set to sizeof(struct kld_file_stat) */ 361 char name[MAXPATHLEN]; 362 int refs; 363 int id; 364 caddr_t address; /* load address */ 365 size_t size; /* size in bytes */ 366 char pathname[MAXPATHLEN]; 367 }; 368 369 struct kld_sym_lookup { 370 int version; /* set to sizeof(struct kld_sym_lookup) */ 371 char *symname; /* Symbol name we are looking up */ 372 u_long symvalue; 373 size_t symsize; 374 }; 375 #define KLDSYM_LOOKUP 1 376 377 /* 378 * Flags for kldunloadf() and linker_file_unload() 379 */ 380 #define LINKER_UNLOAD_NORMAL 0 381 #define LINKER_UNLOAD_FORCE 1 382 383 #ifndef _KERNEL 384 385 #include <sys/cdefs.h> 386 387 __BEGIN_DECLS 388 int kldload(const char* _file); 389 int kldunload(int _fileid); 390 int kldunloadf(int _fileid, int flags); 391 int kldfind(const char* _file); 392 int kldnext(int _fileid); 393 int kldstat(int _fileid, struct kld_file_stat* _stat); 394 int kldfirstmod(int _fileid); 395 int kldsym(int _fileid, int _cmd, void *_data); 396 __END_DECLS 397 398 #endif 399 400 #endif /* !_SYS_LINKER_H_ */ 401