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 caddr_t dtors_addr; /* address of .dtors/.fini_array */ 86 size_t dtors_size; /* size of .dtors/.fini_array */ 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 */ 93 94 /* 95 * Function Boundary Tracing (FBT) or Statically Defined Tracing (SDT) 96 * fields. 97 */ 98 int nenabled; /* number of enabled probes. */ 99 int fbt_nentries; /* number of fbt entries created. */ 100 101 #ifdef __arm__ 102 caddr_t exidx_addr; /* Unwind data index table start */ 103 size_t exidx_size; /* Unwind data index table size */ 104 #endif 105 }; 106 107 /* 108 * Object implementing a class of file (a.out, elf, etc.) 109 */ 110 typedef struct linker_class *linker_class_t; 111 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 112 113 struct linker_class { 114 KOBJ_CLASS_FIELDS; 115 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 116 }; 117 118 /* 119 * Function type used when iterating over the list of linker files. 120 */ 121 typedef int linker_predicate_t(linker_file_t, void *); 122 123 /* 124 * The "file" for the kernel. 125 */ 126 extern linker_file_t linker_kernel_file; 127 128 /* 129 * Special symbol which will be replaced by a reference to the linker_file_t 130 * of the module it is used in. 131 */ 132 extern linker_file_t __this_linker_file; 133 134 /* 135 * Obtain a reference to a module, loading it if required. 136 */ 137 int linker_reference_module(const char* _modname, struct mod_depend *_verinfo, 138 linker_file_t* _result); 139 140 /* 141 * Release a reference to a module, unloading it if there are no more 142 * references. Note that one should either provide a module name and 143 * optional version info or a linker file, but not both. 144 */ 145 int linker_release_module(const char *_modname, struct mod_depend *_verinfo, 146 linker_file_t _file); 147 148 /* 149 * Iterate over all of the currently loaded linker files calling the 150 * predicate function while the function returns 0. Returns the value 151 * returned by the last predicate function. 152 */ 153 int linker_file_foreach(linker_predicate_t *_predicate, void *_context); 154 155 /* 156 * Lookup a symbol in a file. If deps is TRUE, look in dependencies 157 * if not found in file. 158 */ 159 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name, 160 int _deps); 161 162 /* 163 * Lookup a linker set in a file. Return pointers to the first entry, 164 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {} 165 * void *start is really: "struct yoursetmember ***start;" 166 */ 167 int linker_file_lookup_set(linker_file_t _file, const char *_name, 168 void *_start, void *_stop, int *_count); 169 170 /* 171 * List all functions in a file. 172 */ 173 int linker_file_function_listall(linker_file_t, 174 linker_function_nameval_callback_t, void *); 175 176 /* 177 * Functions solely for use by the linker class handlers. 178 */ 179 int linker_add_class(linker_class_t _cls); 180 int linker_file_unload(linker_file_t _file, int flags); 181 int linker_load_dependencies(linker_file_t _lf); 182 linker_file_t linker_make_file(const char* _filename, linker_class_t _cls); 183 184 /* 185 * DDB Helpers, tuned specifically for ddb/db_kld.c 186 */ 187 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 188 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 189 long *_diffp); 190 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 191 int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 192 long *offset); 193 194 /* 195 * stack(9) helper for situations where kernel locking is required. 196 */ 197 int linker_search_symbol_name_flags(caddr_t value, char *buf, u_int buflen, 198 long *offset, int flags); 199 int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 200 long *offset); 201 202 /* HWPMC helper */ 203 void *linker_hwpmc_list_objects(void); 204 205 /* kldload/kldunload syscalls blocking */ 206 #define LINKER_UB_UNLOCK 0x0001 /* busy: unlock kld_sx locked on 207 return */ 208 #define LINKER_UB_LOCKED 0x0002 /* busy/unbusy: kld_sx locked on 209 entry */ 210 #define LINKER_UB_PCATCH 0x0004 /* busy: sleep interruptible */ 211 int linker_kldload_busy(int flags); 212 void linker_kldload_unbusy(int flags); 213 214 #endif /* _KERNEL */ 215 216 /* 217 * Module information subtypes 218 */ 219 #define MODINFO_END 0x0000 /* End of list */ 220 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 221 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 222 #define MODINFO_ADDR 0x0003 /* Loaded address */ 223 #define MODINFO_SIZE 0x0004 /* Size of module */ 224 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 225 #define MODINFO_ARGS 0x0006 /* Parameters string */ 226 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 227 228 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 229 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 230 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 231 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 232 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 233 #define MODINFOMD_MB2HDR 0x0006 /* MB2 header info */ 234 /* These values are MD on PowerPC */ 235 #if !defined(__powerpc__) 236 #define MODINFOMD_ENVP 0x0006 /* envp[] */ 237 #define MODINFOMD_HOWTO 0x0007 /* boothowto */ 238 #define MODINFOMD_KERNEND 0x0008 /* kernend */ 239 #endif 240 #define MODINFOMD_SHDR 0x0009 /* section header table */ 241 #define MODINFOMD_CTORS_ADDR 0x000a /* address of .ctors */ 242 #define MODINFOMD_CTORS_SIZE 0x000b /* size of .ctors */ 243 #define MODINFOMD_FW_HANDLE 0x000c /* Firmware dependent handle */ 244 #define MODINFOMD_KEYBUF 0x000d /* Crypto key intake buffer */ 245 #define MODINFOMD_FONT 0x000e /* Console font */ 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 */ 266 extern vm_offset_t preload_addr_relocate; 267 extern caddr_t preload_metadata; 268 269 extern void * preload_fetch_addr(caddr_t _mod); 270 extern size_t preload_fetch_size(caddr_t _mod); 271 extern caddr_t preload_search_by_name(const char *_name); 272 extern caddr_t preload_search_by_type(const char *_type); 273 extern caddr_t preload_search_next_name(caddr_t _base); 274 extern caddr_t preload_search_info(caddr_t _mod, int _inf); 275 extern void preload_delete_name(const char *_name); 276 extern void preload_bootstrap_relocate(vm_offset_t _offset); 277 extern void preload_dump(void); 278 279 #ifdef KLD_DEBUG 280 281 extern 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 295 296 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *); 297 298 /* Support functions */ 299 bool elf_is_ifunc_reloc(Elf_Size r_info); 300 int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel, 301 int _type, elf_lookup_fn _lu); 302 int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel, 303 int _type, elf_lookup_fn _lu); 304 Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr); 305 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx); 306 const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx); 307 void link_elf_ireloc(caddr_t kmdp); 308 309 #if defined(__aarch64__) || defined(__amd64__) 310 int elf_reloc_late(linker_file_t _lf, Elf_Addr base, const void *_rel, 311 int _type, elf_lookup_fn _lu); 312 void link_elf_late_ireloc(void); 313 #endif 314 315 typedef 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; 326 327 int linker_ctf_get(linker_file_t, linker_ctf_t *); 328 329 int elf_cpu_load_file(linker_file_t); 330 int elf_cpu_unload_file(linker_file_t); 331 int 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 */ 341 struct 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 */ 350 351 struct 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 }; 360 361 struct 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 380 int kldload(const char* _file); 381 int kldunload(int _fileid); 382 int kldunloadf(int _fileid, int flags); 383 int kldfind(const char* _file); 384 int kldnext(int _fileid); 385 int kldstat(int _fileid, struct kld_file_stat* _stat); 386 int kldfirstmod(int _fileid); 387 int kldsym(int _fileid, int _cmd, void *_data); 388 __END_DECLS 389 390 #endif 391 392 #endif /* !_SYS_LINKER_H_ */ 393