linker.h revision 329099
1/*- 2 * Copyright (c) 1997-2000 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: stable/11/sys/sys/linker.h 329099 2018-02-10 04:37:44Z kevans $ 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 38MALLOC_DECLARE(M_LINKER); 39#endif 40 41struct mod_depend; 42 43/* 44 * Object representing a file which has been loaded by the linker. 45 */ 46typedef struct linker_file* linker_file_t; 47typedef TAILQ_HEAD(, linker_file) linker_file_list_t; 48 49typedef caddr_t linker_sym_t; /* opaque symbol */ 50typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */ 51typedef int (*linker_function_name_callback_t)(const char *, void *); 52 53/* 54 * expanded out linker_sym_t 55 */ 56typedef struct linker_symval { 57 const char* name; 58 caddr_t value; 59 size_t size; 60} linker_symval_t; 61 62typedef int (*linker_function_nameval_callback_t)(linker_file_t, int, linker_symval_t *, void *); 63 64struct common_symbol { 65 STAILQ_ENTRY(common_symbol) link; 66 char* name; 67 caddr_t address; 68}; 69 70struct 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 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */ 77 char* filename; /* file which was loaded */ 78 char* pathname; /* file name with full path */ 79 int id; /* unique id */ 80 caddr_t address; /* load address */ 81 size_t size; /* size of file */ 82 caddr_t ctors_addr; /* address of .ctors */ 83 size_t ctors_size; /* size of .ctors */ 84 int ndeps; /* number of dependencies */ 85 linker_file_t* deps; /* list of dependencies */ 86 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 87 TAILQ_HEAD(, module) modules; /* modules in this file */ 88 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */ 89 int loadcnt; /* load counter value */ 90 91 /* 92 * Function Boundary Tracing (FBT) or Statically Defined Tracing (SDT) 93 * fields. 94 */ 95 int nenabled; /* number of enabled probes. */ 96 int fbt_nentries; /* number of fbt entries created. */ 97}; 98 99/* 100 * Object implementing a class of file (a.out, elf, etc.) 101 */ 102typedef struct linker_class *linker_class_t; 103typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 104 105struct linker_class { 106 KOBJ_CLASS_FIELDS; 107 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 108}; 109 110/* 111 * Function type used when iterating over the list of linker files. 112 */ 113typedef int linker_predicate_t(linker_file_t, void *); 114 115/* 116 * The "file" for the kernel. 117 */ 118extern linker_file_t linker_kernel_file; 119 120/* 121 * Obtain a reference to a module, loading it if required. 122 */ 123int linker_reference_module(const char* _modname, struct mod_depend *_verinfo, 124 linker_file_t* _result); 125 126/* 127 * Release a reference to a module, unloading it if there are no more 128 * references. Note that one should either provide a module name and 129 * optional version info or a linker file, but not both. 130 */ 131int linker_release_module(const char *_modname, struct mod_depend *_verinfo, 132 linker_file_t _file); 133 134/* 135 * Iterate over all of the currently loaded linker files calling the 136 * predicate function while the function returns 0. Returns the value 137 * returned by the last predicate function. 138 */ 139int linker_file_foreach(linker_predicate_t *_predicate, void *_context); 140 141/* 142 * Lookup a symbol in a file. If deps is TRUE, look in dependencies 143 * if not found in file. 144 */ 145caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name, 146 int _deps); 147 148/* 149 * Lookup a linker set in a file. Return pointers to the first entry, 150 * last + 1, and count of entries. Use: for (p = start; p < stop; p++) {} 151 * void *start is really: "struct yoursetmember ***start;" 152 */ 153int linker_file_lookup_set(linker_file_t _file, const char *_name, 154 void *_start, void *_stop, int *_count); 155 156/* 157 * List all functions in a file. 158 */ 159int linker_file_function_listall(linker_file_t, 160 linker_function_nameval_callback_t, void *); 161 162/* 163 * Functions solely for use by the linker class handlers. 164 */ 165int linker_add_class(linker_class_t _cls); 166int linker_file_unload(linker_file_t _file, int flags); 167int linker_load_dependencies(linker_file_t _lf); 168linker_file_t linker_make_file(const char* _filename, linker_class_t _cls); 169 170/* 171 * DDB Helpers, tuned specifically for ddb/db_kld.c 172 */ 173int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 174int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 175 long *_diffp); 176int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 177int linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 178 long *offset); 179 180/* 181 * stack(9) helper for situations where kernel locking is required. 182 */ 183int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 184 long *offset); 185 186 187/* HWPMC helper */ 188void *linker_hwpmc_list_objects(void); 189 190#endif /* _KERNEL */ 191 192/* 193 * Module information subtypes 194 */ 195#define MODINFO_END 0x0000 /* End of list */ 196#define MODINFO_NAME 0x0001 /* Name of module (string) */ 197#define MODINFO_TYPE 0x0002 /* Type of module (string) */ 198#define MODINFO_ADDR 0x0003 /* Loaded address */ 199#define MODINFO_SIZE 0x0004 /* Size of module */ 200#define MODINFO_EMPTY 0x0005 /* Has been deleted */ 201#define MODINFO_ARGS 0x0006 /* Parameters string */ 202#define MODINFO_METADATA 0x8000 /* Module-specfic */ 203 204#define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 205#define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 206#define MODINFOMD_SSYM 0x0003 /* start of symbols */ 207#define MODINFOMD_ESYM 0x0004 /* end of symbols */ 208#define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 209/* These values are MD on these two platforms */ 210#if !defined(__sparc64__) && !defined(__powerpc__) 211#define MODINFOMD_ENVP 0x0006 /* envp[] */ 212#define MODINFOMD_HOWTO 0x0007 /* boothowto */ 213#define MODINFOMD_KERNEND 0x0008 /* kernend */ 214#endif 215#define MODINFOMD_SHDR 0x0009 /* section header table */ 216#define MODINFOMD_CTORS_ADDR 0x000a /* address of .ctors */ 217#define MODINFOMD_CTORS_SIZE 0x000b /* size of .ctors */ 218#define MODINFOMD_FW_HANDLE 0x000c /* Firmware dependent handle */ 219#define MODINFOMD_KEYBUF 0x000d /* Crypto key intake buffer */ 220#define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 221 222#define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 223 224#ifdef _KERNEL 225#define MD_FETCH(mdp, info, type) ({ \ 226 type *__p; \ 227 __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \ 228 __p ? *__p : 0; \ 229}) 230#endif 231 232#define LINKER_HINTS_VERSION 1 /* linker.hints file version */ 233#define LINKER_HINTS_MAX (1 << 20) /* Allow at most 1MB for linker.hints */ 234 235#ifdef _KERNEL 236 237/* 238 * Module lookup 239 */ 240extern vm_offset_t preload_addr_relocate; 241extern caddr_t preload_metadata; 242 243extern void * preload_fetch_addr(caddr_t _mod); 244extern size_t preload_fetch_size(caddr_t _mod); 245extern caddr_t preload_search_by_name(const char *_name); 246extern caddr_t preload_search_by_type(const char *_type); 247extern caddr_t preload_search_next_name(caddr_t _base); 248extern caddr_t preload_search_info(caddr_t _mod, int _inf); 249extern void preload_delete_name(const char *_name); 250extern void preload_bootstrap_relocate(vm_offset_t _offset); 251 252#ifdef KLD_DEBUG 253 254extern int kld_debug; 255#define KLD_DEBUG_FILE 1 /* file load/unload */ 256#define KLD_DEBUG_SYM 2 /* symbol lookup */ 257 258#define KLD_DPF(cat, args) \ 259 do { \ 260 if (kld_debug & KLD_DEBUG_##cat) printf args; \ 261 } while (0) 262 263#else 264 265#define KLD_DPF(cat, args) 266 267#endif 268 269typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *); 270 271/* Support functions */ 272int elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu); 273int elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu); 274Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr); 275const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx); 276const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx); 277 278typedef struct linker_ctf { 279 const uint8_t *ctftab; /* Decompressed CTF data. */ 280 int ctfcnt; /* Number of CTF data bytes. */ 281 const Elf_Sym *symtab; /* Ptr to the symbol table. */ 282 int nsym; /* Number of symbols. */ 283 const char *strtab; /* Ptr to the string table. */ 284 int strcnt; /* Number of string bytes. */ 285 uint32_t **ctfoffp; /* Ptr to array of obj/fnc offsets. */ 286 uint32_t **typoffp; /* Ptr to array of type offsets. */ 287 long *typlenp; /* Ptr to number of type data entries. */ 288} linker_ctf_t; 289 290int linker_ctf_get(linker_file_t, linker_ctf_t *); 291 292int elf_cpu_load_file(linker_file_t); 293int elf_cpu_unload_file(linker_file_t); 294 295/* values for type */ 296#define ELF_RELOC_REL 1 297#define ELF_RELOC_RELA 2 298 299/* 300 * This is version 1 of the KLD file status structure. It is identified 301 * by its _size_ in the version field. 302 */ 303struct kld_file_stat_1 { 304 int version; /* set to sizeof(struct kld_file_stat_1) */ 305 char name[MAXPATHLEN]; 306 int refs; 307 int id; 308 caddr_t address; /* load address */ 309 size_t size; /* size in bytes */ 310}; 311#endif /* _KERNEL */ 312 313struct kld_file_stat { 314 int version; /* set to sizeof(struct kld_file_stat) */ 315 char name[MAXPATHLEN]; 316 int refs; 317 int id; 318 caddr_t address; /* load address */ 319 size_t size; /* size in bytes */ 320 char pathname[MAXPATHLEN]; 321}; 322 323struct kld_sym_lookup { 324 int version; /* set to sizeof(struct kld_sym_lookup) */ 325 char *symname; /* Symbol name we are looking up */ 326 u_long symvalue; 327 size_t symsize; 328}; 329#define KLDSYM_LOOKUP 1 330 331/* 332 * Flags for kldunloadf() and linker_file_unload() 333 */ 334#define LINKER_UNLOAD_NORMAL 0 335#define LINKER_UNLOAD_FORCE 1 336 337#ifndef _KERNEL 338 339#include <sys/cdefs.h> 340 341__BEGIN_DECLS 342int kldload(const char* _file); 343int kldunload(int _fileid); 344int kldunloadf(int _fileid, int flags); 345int kldfind(const char* _file); 346int kldnext(int _fileid); 347int kldstat(int _fileid, struct kld_file_stat* _stat); 348int kldfirstmod(int _fileid); 349int kldsym(int _fileid, int _cmd, void *_data); 350__END_DECLS 351 352#endif 353 354#endif /* !_SYS_LINKER_H_ */ 355