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 #include <sys/param.h> 33 34 #ifdef _KERNEL 35 36 #include <machine/elf.h> 37 #include <sys/kobj.h> 38 39 #ifdef MALLOC_DECLARE 40 MALLOC_DECLARE(M_LINKER); 41 #endif 42 43 struct mod_depend; 44 45 /* 46 * Object representing a file which has been loaded by the linker. 47 */ 48 typedef struct linker_file* linker_file_t; 49 typedef TAILQ_HEAD(, linker_file) linker_file_list_t; 50 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 *); 54 55 /* 56 * expanded out linker_sym_t 57 */ 58 typedef struct linker_symval { 59 const char* name; 60 caddr_t value; 61 size_t size; 62 } linker_symval_t; 63 64 typedef int (*linker_function_nameval_callback_t)(linker_file_t, int, linker_symval_t *, void *); 65 66 struct common_symbol { 67 STAILQ_ENTRY(common_symbol) link; 68 char* name; 69 caddr_t address; 70 }; 71 72 struct linker_file { 73 KOBJ_FIELDS; 74 int refs; /* reference count */ 75 int userrefs; /* kldload(2) count */ 76 int flags; 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/.init_array */ 86 size_t ctors_size; /* size of .ctors/.init_array */ 87 enum { 88 LF_NONE = 0, 89 LF_CTORS, 90 LF_DTORS, 91 } ctors_invoked; /* have we run ctors yet? */ 92 caddr_t dtors_addr; /* address of .dtors/.fini_array */ 93 size_t dtors_size; /* size of .dtors/.fini_array */ 94 int ndeps; /* number of dependencies */ 95 linker_file_t* deps; /* list of dependencies */ 96 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 97 TAILQ_HEAD(, module) modules; /* modules in this file */ 98 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */ 99 int loadcnt; /* load counter value */ 100 101 /* 102 * Function Boundary Tracing (FBT) or Statically Defined Tracing (SDT) 103 * fields. 104 */ 105 int nenabled; /* number of enabled probes. */ 106 int fbt_nentries; /* number of fbt entries created. */ 107 108 #ifdef __arm__ 109 caddr_t exidx_addr; /* Unwind data index table start */ 110 size_t exidx_size; /* Unwind data index table size */ 111 #endif 112 }; 113 114 /* 115 * Object implementing a class of file (a.out, elf, etc.) 116 */ 117 typedef struct linker_class *linker_class_t; 118 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 119 120 struct linker_class { 121 KOBJ_CLASS_FIELDS; 122 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 123 }; 124 125 /* 126 * Function type used when iterating over the list of linker files. 127 */ 128 typedef int linker_predicate_t(linker_file_t, void *); 129 130 /* 131 * The "file" for the kernel. 132 */ 133 extern linker_file_t linker_kernel_file; 134 135 /* 136 * Special symbol which will be replaced by a reference to the linker_file_t 137 * of the module it is used in. 138 */ 139 extern linker_file_t __this_linker_file; 140 141 /* 142 * Obtain a reference to a module, loading it if required. 143 */ 144 int linker_reference_module(const char* _modname, struct mod_depend *_verinfo, 145 linker_file_t* _result); 146 147 /* 148 * Release a reference to a module, unloading it if there are no more 149 * references. Note that one should either provide a module name and 150 * optional version info or a linker file, but not both. 151 */ 152 int linker_release_module(const char *_modname, struct mod_depend *_verinfo, 153 linker_file_t _file); 154 155 /* 156 * Iterate over all of the currently loaded linker files calling the 157 * predicate function while the function returns 0. Returns the value 158 * returned by the last predicate function. 159 */ 160 int linker_file_foreach(linker_predicate_t *_predicate, void *_context); 161 162 /* 163 * Lookup a symbol in a file. If deps is TRUE, look in dependencies 164 * if not found in file. 165 */ 166 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name, 167 int _deps); 168 169 /* 170 * Lookup a linker set in a file. Return pointers to the first entry, 171 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {} 172 * void *start is really: "struct yoursetmember ***start;" 173 */ 174 int linker_file_lookup_set(linker_file_t _file, const char *_name, 175 void *_start, void *_stop, int *_count); 176 177 /* 178 * List all functions in a file. 179 */ 180 int linker_file_function_listall(linker_file_t, 181 linker_function_nameval_callback_t, void *); 182 183 /* 184 * Functions solely for use by the linker class handlers. 185 */ 186 int linker_add_class(linker_class_t _cls); 187 int linker_file_unload(linker_file_t _file, int flags); 188 int linker_load_dependencies(linker_file_t _lf); 189 linker_file_t linker_make_file(const char* _filename, linker_class_t _cls); 190 191 /* 192 * DDB Helpers, tuned specifically for ddb/db_kld.c 193 */ 194 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 195 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 196 long *_diffp); 197 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 198 int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 199 long *offset); 200 201 /* 202 * stack(9) helper for situations where kernel locking is required. 203 */ 204 int linker_search_symbol_name_flags(caddr_t value, char *buf, u_int buflen, 205 long *offset, int flags); 206 int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 207 long *offset); 208 209 /* HWPMC helper */ 210 void *linker_hwpmc_list_objects(void); 211 212 /* kldload/kldunload syscalls blocking */ 213 #define LINKER_UB_UNLOCK 0x0001 /* busy: unlock kld_sx locked on 214 return */ 215 #define LINKER_UB_LOCKED 0x0002 /* busy/unbusy: kld_sx locked on 216 entry */ 217 #define LINKER_UB_PCATCH 0x0004 /* busy: sleep interruptible */ 218 int linker_kldload_busy(int flags); 219 void linker_kldload_unbusy(int flags); 220 221 #endif /* _KERNEL */ 222 223 /* 224 * ELF file types 225 */ 226 #define KERNTYPE_MB "elf multiboot kernel" 227 #define KERNTYPE "elf kernel" 228 #define MODTYPE_OBJ "elf obj module" 229 #define MODTYPE "elf module" 230 231 /* 232 * Module information subtypes 233 */ 234 #define MODINFO_END 0x0000 /* End of list */ 235 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 236 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 237 #define MODINFO_ADDR 0x0003 /* Loaded address */ 238 #define MODINFO_SIZE 0x0004 /* Size of module */ 239 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 240 #define MODINFO_ARGS 0x0006 /* Parameters string */ 241 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 242 243 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 244 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 245 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 246 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 247 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 248 #define MODINFOMD_MB2HDR 0x0006 /* MB2 header info */ 249 /* These values are MD on PowerPC */ 250 #if !defined(__powerpc__) 251 #define MODINFOMD_ENVP 0x0006 /* envp[] */ 252 #define MODINFOMD_HOWTO 0x0007 /* boothowto */ 253 #define MODINFOMD_KERNEND 0x0008 /* kernend */ 254 #endif 255 #define MODINFOMD_SHDR 0x0009 /* section header table */ 256 #define MODINFOMD_CTORS_ADDR 0x000a /* address of .ctors */ 257 #define MODINFOMD_CTORS_SIZE 0x000b /* size of .ctors */ 258 #define MODINFOMD_FW_HANDLE 0x000c /* Firmware dependent handle */ 259 #define MODINFOMD_KEYBUF 0x000d /* Crypto key intake buffer */ 260 #define MODINFOMD_FONT 0x000e /* Console font */ 261 #define MODINFOMD_SPLASH 0x000f /* Console splash screen */ 262 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 263 264 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 265 266 #ifdef _KERNEL 267 #define MD_FETCH(mdp, info, type) ({ \ 268 type *__p; \ 269 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \ 270 __p ? *__p : 0; \ 271 }) 272 #endif 273 274 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */ 275 #define LINKER_HINTS_MAX (1 << 20) /* Allow at most 1MB for linker.hints */ 276 277 #ifdef _KERNEL 278 279 /* 280 * Module lookup 281 */ 282 extern vm_offset_t preload_addr_relocate; 283 extern caddr_t preload_metadata, preload_kmdp; 284 extern const char preload_modtype[]; 285 extern const char preload_kerntype[]; 286 extern const char preload_modtype_obj[]; 287 288 extern void * preload_fetch_addr(caddr_t _mod); 289 extern size_t preload_fetch_size(caddr_t _mod); 290 extern caddr_t preload_search_by_name(const char *_name); 291 extern caddr_t preload_search_by_type(const char *_type); 292 extern caddr_t preload_search_next_name(caddr_t _base); 293 extern caddr_t preload_search_info(caddr_t _mod, int _inf); 294 extern void preload_initkmdp(bool _fatal); 295 extern void preload_delete_name(const char *_name); 296 extern void preload_bootstrap_relocate(vm_offset_t _offset); 297 extern void preload_dump(void); 298 299 #ifdef KLD_DEBUG 300 301 extern int kld_debug; 302 #define KLD_DEBUG_FILE 1 /* file load/unload */ 303 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 304 305 #define KLD_DPF(cat, args) \ 306 do { \ 307 if (kld_debug & KLD_DEBUG_##cat) printf args; \ 308 } while (0) 309 310 #else 311 312 #define KLD_DPF(cat, args) 313 314 #endif 315 316 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *); 317 318 /* Support functions */ 319 bool elf_is_ifunc_reloc(Elf_Size r_info); 320 int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel, 321 int _type, elf_lookup_fn _lu); 322 int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel, 323 int _type, elf_lookup_fn _lu); 324 Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr); 325 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx); 326 const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx); 327 void link_elf_ireloc(void); 328 329 #if defined(__aarch64__) || defined(__amd64__) 330 int elf_reloc_late(linker_file_t _lf, Elf_Addr base, const void *_rel, 331 int _type, elf_lookup_fn _lu); 332 void link_elf_late_ireloc(void); 333 #endif 334 335 typedef struct linker_ctf { 336 const uint8_t *ctftab; /* Decompressed CTF data. */ 337 int ctfcnt; /* Number of CTF data bytes. */ 338 const Elf_Sym *symtab; /* Ptr to the symbol table. */ 339 int nsym; /* Number of symbols. */ 340 const char *strtab; /* Ptr to the string table. */ 341 int strcnt; /* Number of string bytes. */ 342 uint32_t **ctfoffp; /* Ptr to array of obj/fnc offsets. */ 343 uint32_t **typoffp; /* Ptr to array of type offsets. */ 344 long *typlenp; /* Ptr to number of type data entries. */ 345 } linker_ctf_t; 346 347 int linker_ctf_get(linker_file_t, linker_ctf_t *); 348 int linker_ctf_lookup_sym_ddb(const char *symname, c_linker_sym_t *sym, 349 linker_ctf_t *lc); 350 int linker_ctf_lookup_typename_ddb(linker_ctf_t *lc, const char *typename); 351 352 int elf_cpu_load_file(linker_file_t); 353 int elf_cpu_unload_file(linker_file_t); 354 int elf_cpu_parse_dynamic(caddr_t, Elf_Dyn *); 355 356 /* values for type */ 357 #define ELF_RELOC_REL 1 358 #define ELF_RELOC_RELA 2 359 360 /* 361 * This is version 1 of the KLD file status structure. It is identified 362 * by its _size_ in the version field. 363 */ 364 struct kld_file_stat_1 { 365 int version; /* set to sizeof(struct kld_file_stat_1) */ 366 char name[MAXPATHLEN]; 367 int refs; 368 int id; 369 caddr_t address; /* load address */ 370 size_t size; /* size in bytes */ 371 }; 372 #endif /* _KERNEL */ 373 374 struct kld_file_stat { 375 int version; /* set to sizeof(struct kld_file_stat) */ 376 char name[MAXPATHLEN]; 377 int refs; 378 int id; 379 caddr_t address; /* load address */ 380 size_t size; /* size in bytes */ 381 char pathname[MAXPATHLEN]; 382 }; 383 384 struct kld_sym_lookup { 385 int version; /* set to sizeof(struct kld_sym_lookup) */ 386 char *symname; /* Symbol name we are looking up */ 387 u_long symvalue; 388 size_t symsize; 389 }; 390 #define KLDSYM_LOOKUP 1 391 392 /* 393 * Flags for kldunloadf() and linker_file_unload() 394 */ 395 #define LINKER_UNLOAD_NORMAL 0 396 #define LINKER_UNLOAD_FORCE 1 397 398 #ifndef _KERNEL 399 400 #include <sys/cdefs.h> 401 402 __BEGIN_DECLS 403 int kldload(const char* _file); 404 int kldunload(int _fileid); 405 int kldunloadf(int _fileid, int flags); 406 int kldfind(const char* _file); 407 int kldnext(int _fileid); 408 int kldstat(int _fileid, struct kld_file_stat* _stat); 409 int kldfirstmod(int _fileid); 410 int kldsym(int _fileid, int _cmd, void *_data); 411 __END_DECLS 412 413 #endif 414 415 #endif /* !_SYS_LINKER_H_ */ 416