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