1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 * $FreeBSD$ 29 */ 30 31 #ifndef _SYS_LINKER_H_ 32 #define _SYS_LINKER_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 caddr_t dtors_addr; /* address of .dtors/.fini_array */ 88 size_t dtors_size; /* size of .dtors/.fini_array */ 89 int ndeps; /* number of dependencies */ 90 linker_file_t* deps; /* list of dependencies */ 91 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 92 TAILQ_HEAD(, module) modules; /* modules in this file */ 93 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */ 94 int loadcnt; /* load counter value */ 95 96 /* 97 * Function Boundary Tracing (FBT) or Statically Defined Tracing (SDT) 98 * fields. 99 */ 100 int nenabled; /* number of enabled probes. */ 101 int fbt_nentries; /* number of fbt entries created. */ 102 103 #ifdef __arm__ 104 caddr_t exidx_addr; /* Unwind data index table start */ 105 size_t exidx_size; /* Unwind data index table size */ 106 #endif 107 }; 108 109 /* 110 * Object implementing a class of file (a.out, elf, etc.) 111 */ 112 typedef struct linker_class *linker_class_t; 113 typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 114 115 struct linker_class { 116 KOBJ_CLASS_FIELDS; 117 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 118 }; 119 120 /* 121 * Function type used when iterating over the list of linker files. 122 */ 123 typedef int linker_predicate_t(linker_file_t, void *); 124 125 /* 126 * The "file" for the kernel. 127 */ 128 extern linker_file_t linker_kernel_file; 129 130 /* 131 * Obtain a reference to a module, loading it if required. 132 */ 133 int linker_reference_module(const char* _modname, struct mod_depend *_verinfo, 134 linker_file_t* _result); 135 136 /* 137 * Release a reference to a module, unloading it if there are no more 138 * references. Note that one should either provide a module name and 139 * optional version info or a linker file, but not both. 140 */ 141 int linker_release_module(const char *_modname, struct mod_depend *_verinfo, 142 linker_file_t _file); 143 144 /* 145 * Iterate over all of the currently loaded linker files calling the 146 * predicate function while the function returns 0. Returns the value 147 * returned by the last predicate function. 148 */ 149 int linker_file_foreach(linker_predicate_t *_predicate, void *_context); 150 151 /* 152 * Lookup a symbol in a file. If deps is TRUE, look in dependencies 153 * if not found in file. 154 */ 155 caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name, 156 int _deps); 157 158 /* 159 * Lookup a linker set in a file. Return pointers to the first entry, 160 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {} 161 * void *start is really: "struct yoursetmember ***start;" 162 */ 163 int linker_file_lookup_set(linker_file_t _file, const char *_name, 164 void *_start, void *_stop, int *_count); 165 166 /* 167 * List all functions in a file. 168 */ 169 int linker_file_function_listall(linker_file_t, 170 linker_function_nameval_callback_t, void *); 171 172 /* 173 * Functions solely for use by the linker class handlers. 174 */ 175 int linker_add_class(linker_class_t _cls); 176 int linker_file_unload(linker_file_t _file, int flags); 177 int linker_load_dependencies(linker_file_t _lf); 178 linker_file_t linker_make_file(const char* _filename, linker_class_t _cls); 179 180 /* 181 * DDB Helpers, tuned specifically for ddb/db_kld.c 182 */ 183 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 184 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 185 long *_diffp); 186 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 187 int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 188 long *offset); 189 190 /* 191 * stack(9) helper for situations where kernel locking is required. 192 */ 193 int linker_search_symbol_name_flags(caddr_t value, char *buf, u_int buflen, 194 long *offset, int flags); 195 int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 196 long *offset); 197 198 /* HWPMC helper */ 199 void *linker_hwpmc_list_objects(void); 200 201 /* kldload/kldunload syscalls blocking */ 202 #define LINKER_UB_UNLOCK 0x0001 /* busy: unlock kld_sx locked on 203 return */ 204 #define LINKER_UB_LOCKED 0x0002 /* busy/unbusy: kld_sx locked on 205 entry */ 206 #define LINKER_UB_PCATCH 0x0004 /* busy: sleep interruptible */ 207 int linker_kldload_busy(int flags); 208 void linker_kldload_unbusy(int flags); 209 210 #endif /* _KERNEL */ 211 212 /* 213 * Module information subtypes 214 */ 215 #define MODINFO_END 0x0000 /* End of list */ 216 #define MODINFO_NAME 0x0001 /* Name of module (string) */ 217 #define MODINFO_TYPE 0x0002 /* Type of module (string) */ 218 #define MODINFO_ADDR 0x0003 /* Loaded address */ 219 #define MODINFO_SIZE 0x0004 /* Size of module */ 220 #define MODINFO_EMPTY 0x0005 /* Has been deleted */ 221 #define MODINFO_ARGS 0x0006 /* Parameters string */ 222 #define MODINFO_METADATA 0x8000 /* Module-specfic */ 223 224 #define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 225 #define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 226 #define MODINFOMD_SSYM 0x0003 /* start of symbols */ 227 #define MODINFOMD_ESYM 0x0004 /* end of symbols */ 228 #define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 229 #define MODINFOMD_MB2HDR 0x0006 /* MB2 header info */ 230 /* These values are MD on PowerPC */ 231 #if !defined(__powerpc__) 232 #define MODINFOMD_ENVP 0x0006 /* envp[] */ 233 #define MODINFOMD_HOWTO 0x0007 /* boothowto */ 234 #define MODINFOMD_KERNEND 0x0008 /* kernend */ 235 #endif 236 #define MODINFOMD_SHDR 0x0009 /* section header table */ 237 #define MODINFOMD_CTORS_ADDR 0x000a /* address of .ctors */ 238 #define MODINFOMD_CTORS_SIZE 0x000b /* size of .ctors */ 239 #define MODINFOMD_FW_HANDLE 0x000c /* Firmware dependent handle */ 240 #define MODINFOMD_KEYBUF 0x000d /* Crypto key intake buffer */ 241 #define MODINFOMD_FONT 0x000e /* Console font */ 242 #define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 243 244 #define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 245 246 #ifdef _KERNEL 247 #define MD_FETCH(mdp, info, type) ({ \ 248 type *__p; \ 249 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \ 250 __p ? *__p : 0; \ 251 }) 252 #endif 253 254 #define LINKER_HINTS_VERSION 1 /* linker.hints file version */ 255 #define LINKER_HINTS_MAX (1 << 20) /* Allow at most 1MB for linker.hints */ 256 257 #ifdef _KERNEL 258 259 /* 260 * Module lookup 261 */ 262 extern vm_offset_t preload_addr_relocate; 263 extern caddr_t preload_metadata; 264 265 extern void * preload_fetch_addr(caddr_t _mod); 266 extern size_t preload_fetch_size(caddr_t _mod); 267 extern caddr_t preload_search_by_name(const char *_name); 268 extern caddr_t preload_search_by_type(const char *_type); 269 extern caddr_t preload_search_next_name(caddr_t _base); 270 extern caddr_t preload_search_info(caddr_t _mod, int _inf); 271 extern void preload_delete_name(const char *_name); 272 extern void preload_bootstrap_relocate(vm_offset_t _offset); 273 extern void preload_dump(void); 274 275 #ifdef KLD_DEBUG 276 277 extern int kld_debug; 278 #define KLD_DEBUG_FILE 1 /* file load/unload */ 279 #define KLD_DEBUG_SYM 2 /* symbol lookup */ 280 281 #define KLD_DPF(cat, args) \ 282 do { \ 283 if (kld_debug & KLD_DEBUG_##cat) printf args; \ 284 } while (0) 285 286 #else 287 288 #define KLD_DPF(cat, args) 289 290 #endif 291 292 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *); 293 294 /* Support functions */ 295 bool elf_is_ifunc_reloc(Elf_Size r_info); 296 int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel, 297 int _type, elf_lookup_fn _lu); 298 int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel, 299 int _type, elf_lookup_fn _lu); 300 Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr); 301 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx); 302 const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx); 303 void link_elf_ireloc(caddr_t kmdp); 304 305 #if defined(__aarch64__) || defined(__amd64__) 306 int elf_reloc_late(linker_file_t _lf, Elf_Addr base, const void *_rel, 307 int _type, elf_lookup_fn _lu); 308 void link_elf_late_ireloc(void); 309 #endif 310 311 typedef struct linker_ctf { 312 const uint8_t *ctftab; /* Decompressed CTF data. */ 313 int ctfcnt; /* Number of CTF data bytes. */ 314 const Elf_Sym *symtab; /* Ptr to the symbol table. */ 315 int nsym; /* Number of symbols. */ 316 const char *strtab; /* Ptr to the string table. */ 317 int strcnt; /* Number of string bytes. */ 318 uint32_t **ctfoffp; /* Ptr to array of obj/fnc offsets. */ 319 uint32_t **typoffp; /* Ptr to array of type offsets. */ 320 long *typlenp; /* Ptr to number of type data entries. */ 321 } linker_ctf_t; 322 323 int linker_ctf_get(linker_file_t, linker_ctf_t *); 324 325 int elf_cpu_load_file(linker_file_t); 326 int elf_cpu_unload_file(linker_file_t); 327 int elf_cpu_parse_dynamic(caddr_t, Elf_Dyn *); 328 329 /* values for type */ 330 #define ELF_RELOC_REL 1 331 #define ELF_RELOC_RELA 2 332 333 /* 334 * This is version 1 of the KLD file status structure. It is identified 335 * by its _size_ in the version field. 336 */ 337 struct kld_file_stat_1 { 338 int version; /* set to sizeof(struct kld_file_stat_1) */ 339 char name[MAXPATHLEN]; 340 int refs; 341 int id; 342 caddr_t address; /* load address */ 343 size_t size; /* size in bytes */ 344 }; 345 #endif /* _KERNEL */ 346 347 struct kld_file_stat { 348 int version; /* set to sizeof(struct kld_file_stat) */ 349 char name[MAXPATHLEN]; 350 int refs; 351 int id; 352 caddr_t address; /* load address */ 353 size_t size; /* size in bytes */ 354 char pathname[MAXPATHLEN]; 355 }; 356 357 struct kld_sym_lookup { 358 int version; /* set to sizeof(struct kld_sym_lookup) */ 359 char *symname; /* Symbol name we are looking up */ 360 u_long symvalue; 361 size_t symsize; 362 }; 363 #define KLDSYM_LOOKUP 1 364 365 /* 366 * Flags for kldunloadf() and linker_file_unload() 367 */ 368 #define LINKER_UNLOAD_NORMAL 0 369 #define LINKER_UNLOAD_FORCE 1 370 371 #ifndef _KERNEL 372 373 #include <sys/cdefs.h> 374 375 __BEGIN_DECLS 376 int kldload(const char* _file); 377 int kldunload(int _fileid); 378 int kldunloadf(int _fileid, int flags); 379 int kldfind(const char* _file); 380 int kldnext(int _fileid); 381 int kldstat(int _fileid, struct kld_file_stat* _stat); 382 int kldfirstmod(int _fileid); 383 int kldsym(int _fileid, int _cmd, void *_data); 384 __END_DECLS 385 386 #endif 387 388 #endif /* !_SYS_LINKER_H_ */ 389