linker.h revision 63858
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: head/sys/sys/linker.h 63858 2000-07-25 22:58:52Z jhb $ 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 41/* 42 * Object representing a file which has been loaded by the linker. 43 */ 44typedef struct linker_file* linker_file_t; 45typedef TAILQ_HEAD(, linker_file) linker_file_list_t; 46 47typedef caddr_t linker_sym_t; /* opaque symbol */ 48typedef c_caddr_t c_linker_sym_t; /* const opaque symbol */ 49 50/* 51 * expanded out linker_sym_t 52 */ 53typedef struct linker_symval { 54 const char* name; 55 caddr_t value; 56 size_t size; 57} linker_symval_t; 58 59struct common_symbol { 60 STAILQ_ENTRY(common_symbol) link; 61 char* name; 62 caddr_t address; 63}; 64 65struct linker_file { 66 KOBJ_FIELDS; 67 int refs; /* reference count */ 68 int userrefs; /* kldload(2) count */ 69 int flags; 70#define LINKER_FILE_LINKED 0x1 /* file has been fully linked */ 71 TAILQ_ENTRY(linker_file) link; /* list of all loaded files */ 72 char* filename; /* file which was loaded */ 73 int id; /* unique id */ 74 caddr_t address; /* load address */ 75 size_t size; /* size of file */ 76 int ndeps; /* number of dependancies */ 77 linker_file_t* deps; /* list of dependancies */ 78 STAILQ_HEAD(, common_symbol) common; /* list of common symbols */ 79 TAILQ_HEAD(, module) modules; /* modules in this file */ 80 TAILQ_ENTRY(linker_file) loaded; /* preload dependency support */ 81}; 82 83/* 84 * Object implementing a class of file (a.out, elf, etc.) 85 */ 86typedef struct linker_class *linker_class_t; 87typedef TAILQ_HEAD(, linker_class) linker_class_list_t; 88 89struct linker_class { 90 KOBJ_CLASS_FIELDS; 91 TAILQ_ENTRY(linker_class) link; /* list of all file classes */ 92}; 93 94/* 95 * The "file" for the kernel. 96 */ 97extern linker_file_t linker_kernel_file; 98 99/* 100 * Add a new file class to the linker. 101 */ 102int linker_add_class(linker_class_t _cls); 103 104/* 105 * Load a file, trying each file class until one succeeds. 106 */ 107int linker_load_file(const char* _filename, linker_file_t* _result); 108 109/* 110 * Find a currently loaded file given its filename. 111 */ 112linker_file_t linker_find_file_by_name(const char* _filename); 113 114/* 115 * Find a currently loaded file given its file id. 116 */ 117linker_file_t linker_find_file_by_id(int _fileid); 118 119/* 120 * Called from a class handler when a file is laoded. 121 */ 122linker_file_t linker_make_file(const char* _filename, linker_class_t _cls); 123 124/* 125 * Unload a file, freeing up memory. 126 */ 127int linker_file_unload(linker_file_t _file); 128 129/* 130 * Add a dependancy to a file. 131 */ 132int linker_file_add_dependancy(linker_file_t _file, linker_file_t _dep); 133 134/* 135 * Lookup a symbol in a file. If deps is TRUE, look in dependancies 136 * if not found in file. 137 */ 138caddr_t linker_file_lookup_symbol(linker_file_t _file, const char* _name, 139 int _deps); 140 141/* 142 * This routine is responsible for finding dependencies of userland 143 * initiated kldload(2)'s of files. 144 */ 145int linker_load_dependancies(linker_file_t _lf); 146 147/* 148 * DDB Helpers, tuned specifically for ddb/db_kld.c 149 */ 150int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym); 151int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym, 152 long *_diffp); 153int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval); 154 155 156#endif /* _KERNEL */ 157 158/* 159 * Module information subtypes 160 */ 161#define MODINFO_END 0x0000 /* End of list */ 162#define MODINFO_NAME 0x0001 /* Name of module (string) */ 163#define MODINFO_TYPE 0x0002 /* Type of module (string) */ 164#define MODINFO_ADDR 0x0003 /* Loaded address */ 165#define MODINFO_SIZE 0x0004 /* Size of module */ 166#define MODINFO_EMPTY 0x0005 /* Has been deleted */ 167#define MODINFO_ARGS 0x0006 /* Parameters string */ 168#define MODINFO_METADATA 0x8000 /* Module-specfic */ 169 170#define MODINFOMD_AOUTEXEC 0x0001 /* a.out exec header */ 171#define MODINFOMD_ELFHDR 0x0002 /* ELF header */ 172#define MODINFOMD_SSYM 0x0003 /* start of symbols */ 173#define MODINFOMD_ESYM 0x0004 /* end of symbols */ 174#define MODINFOMD_DYNAMIC 0x0005 /* _DYNAMIC pointer */ 175#define MODINFOMD_NOCOPY 0x8000 /* don't copy this metadata to the kernel */ 176 177#define MODINFOMD_DEPLIST (0x4001 | MODINFOMD_NOCOPY) /* depends on */ 178 179#ifdef _KERNEL 180 181/* 182 * Module lookup 183 */ 184extern caddr_t preload_metadata; 185extern caddr_t preload_search_by_name(const char *_name); 186extern caddr_t preload_search_by_type(const char *_type); 187extern caddr_t preload_search_next_name(caddr_t _base); 188extern caddr_t preload_search_info(caddr_t _mod, int _inf); 189extern void preload_delete_name(const char *_name); 190extern void preload_bootstrap_relocate(vm_offset_t _offset); 191 192#ifdef DDB 193extern void r_debug_state(void); 194#endif 195 196#ifdef KLD_DEBUG 197 198extern int kld_debug; 199#define KLD_DEBUG_FILE 1 /* file load/unload */ 200#define KLD_DEBUG_SYM 2 /* symbol lookup */ 201 202#define KLD_DPF(cat, args) \ 203 do { \ 204 if (kld_debug & KLD_DEBUG_##cat) printf args; \ 205 } while (0) 206 207#else 208 209#define KLD_DPF(cat, args) 210 211#endif 212 213/* Support functions */ 214int elf_reloc(linker_file_t _lf, const void *_rel, int _type, 215 const char *_sym); 216/* values for type */ 217#define ELF_RELOC_REL 1 218#define ELF_RELOC_RELA 2 219 220#endif /* _KERNEL */ 221 222struct kld_file_stat { 223 int version; /* set to sizeof(linker_file_stat) */ 224 char name[MAXPATHLEN]; 225 int refs; 226 int id; 227 caddr_t address; /* load address */ 228 size_t size; /* size in bytes */ 229}; 230 231struct kld_sym_lookup { 232 int version; /* set to sizeof(struct kld_sym_lookup) */ 233 char *symname; /* Symbol name we are looking up */ 234 u_long symvalue; 235 size_t symsize; 236}; 237#define KLDSYM_LOOKUP 1 238 239#ifndef _KERNEL 240 241#include <sys/cdefs.h> 242 243__BEGIN_DECLS 244int kldload(const char* _file); 245int kldunload(int _fileid); 246int kldfind(const char* _file); 247int kldnext(int _fileid); 248int kldstat(int _fileid, struct kld_file_stat* _stat); 249int kldfirstmod(int _fileid); 250int kldsym(int _fileid, int _cmd, void *_data); 251__END_DECLS 252 253#endif 254 255#endif /* !_SYS_LINKER_H_ */ 256