usr/src/boot/sys/sys/linker.h

   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  * $FreeBSD$
  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     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  */
 102 typedef struct linker_class *linker_class_t;
 103 typedef TAILQ_HEAD(, linker_class) linker_class_list_t;
 104
 105 struct 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  */
 113 typedef int linker_predicate_t(linker_file_t, void *);
 114
 115 /*
 116  * The "file" for the kernel.
 117  */
 118 extern linker_file_t    linker_kernel_file;
 119
 120 /*
 121  * Obtain a reference to a module, loading it if required.
 122  */
 123 int 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  */
 131 int 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  */
 139 int 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  */
 145 caddr_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  */
 153 int 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  */
 159 int linker_file_function_listall(linker_file_t,
 160                                  linker_function_nameval_callback_t, void *);
 161
 162 /*
 163  * Functions soley for use by the linker class handlers.
 164  */
 165 int linker_add_class(linker_class_t _cls);
 166 int linker_file_unload(linker_file_t _file, int flags);
 167 int linker_load_dependencies(linker_file_t _lf);
 168 linker_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  */
 173 int linker_ddb_lookup(const char *_symstr, c_linker_sym_t *_sym);
 174 int linker_ddb_search_symbol(caddr_t _value, c_linker_sym_t *_sym,
 175                              long *_diffp);
 176 int linker_ddb_symbol_values(c_linker_sym_t _sym, linker_symval_t *_symval);
 177 int 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  */
 183 int linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
 184     long *offset);
 185
 186
 187 /* HWPMC helper */
 188 void *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_NOCOPY        0x8000          /* don't copy this metadata to the kernel */
 220
 221 #define MODINFOMD_DEPLIST       (0x4001 | MODINFOMD_NOCOPY)     /* depends on */
 222
 223 #ifdef _KERNEL
 224 #define MD_FETCH(mdp, info, type) ({ \
 225         type *__p; \
 226         __p = (type *)preload_search_info((mdp), MODINFO_METADATA | (info)); \
 227         __p ? *__p : 0; \
 228 })
 229 #endif
 230
 231 #define LINKER_HINTS_VERSION    1               /* linker.hints file version */
 232 #define LINKER_HINTS_MAX        (1 << 20)       /* Allow at most 1MB for linker.hints */
 233
 234 #ifdef _KERNEL
 235
 236 /*
 237  * Module lookup
 238  */
 239 extern vm_offset_t      preload_addr_relocate;
 240 extern caddr_t          preload_metadata;
 241
 242 extern void *           preload_fetch_addr(caddr_t _mod);
 243 extern size_t           preload_fetch_size(caddr_t _mod);
 244 extern caddr_t          preload_search_by_name(const char *_name);
 245 extern caddr_t          preload_search_by_type(const char *_type);
 246 extern caddr_t          preload_search_next_name(caddr_t _base);
 247 extern caddr_t          preload_search_info(caddr_t _mod, int _inf);
 248 extern void             preload_delete_name(const char *_name);
 249 extern void             preload_bootstrap_relocate(vm_offset_t _offset);
 250
 251 #ifdef KLD_DEBUG
 252
 253 extern int kld_debug;
 254 #define KLD_DEBUG_FILE  1       /* file load/unload */
 255 #define KLD_DEBUG_SYM   2       /* symbol lookup */
 256
 257 #define KLD_DPF(cat, args)                                      \
 258         do {                                                    \
 259                 if (kld_debug & KLD_DEBUG_##cat) printf args;   \
 260         } while (0)
 261
 262 #else
 263
 264 #define KLD_DPF(cat, args)
 265
 266 #endif
 267
 268 typedef int elf_lookup_fn(linker_file_t, Elf_Size, int, Elf_Addr *);
 269
 270 /* Support functions */
 271 int     elf_reloc(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu);
 272 int     elf_reloc_local(linker_file_t _lf, Elf_Addr base, const void *_rel, int _type, elf_lookup_fn _lu);
 273 Elf_Addr elf_relocaddr(linker_file_t _lf, Elf_Addr addr);
 274 const Elf_Sym *elf_get_sym(linker_file_t _lf, Elf_Size _symidx);
 275 const char *elf_get_symname(linker_file_t _lf, Elf_Size _symidx);
 276
 277 typedef struct linker_ctf {
 278         const uint8_t   *ctftab;        /* Decompressed CTF data. */
 279         int             ctfcnt;         /* Number of CTF data bytes. */
 280         const Elf_Sym   *symtab;        /* Ptr to the symbol table. */
 281         int             nsym;           /* Number of symbols. */
 282         const char      *strtab;        /* Ptr to the string table. */
 283         int             strcnt;         /* Number of string bytes. */
 284         uint32_t        **ctfoffp;      /* Ptr to array of obj/fnc offsets. */
 285         uint32_t        **typoffp;      /* Ptr to array of type offsets. */
 286         long            *typlenp;       /* Ptr to number of type data entries. */
 287 } linker_ctf_t;
 288
 289 int     linker_ctf_get(linker_file_t, linker_ctf_t *);
 290
 291 int elf_cpu_load_file(linker_file_t);
 292 int elf_cpu_unload_file(linker_file_t);
 293
 294 /* values for type */
 295 #define ELF_RELOC_REL   1
 296 #define ELF_RELOC_RELA  2
 297
 298 /*
 299  * This is version 1 of the KLD file status structure. It is identified
 300  * by its _size_ in the version field.
 301  */
 302 struct kld_file_stat_1 {
 303     int         version;        /* set to sizeof(struct kld_file_stat_1) */
 304     char        name[MAXPATHLEN];
 305     int         refs;
 306     int         id;
 307     caddr_t     address;        /* load address */
 308     size_t      size;           /* size in bytes */
 309 };
 310 #endif /* _KERNEL */
 311
 312 struct kld_file_stat {
 313     int         version;        /* set to sizeof(struct kld_file_stat) */
 314     char        name[MAXPATHLEN];
 315     int         refs;
 316     int         id;
 317     caddr_t     address;        /* load address */
 318     size_t      size;           /* size in bytes */
 319     char        pathname[MAXPATHLEN];
 320 };
 321
 322 struct kld_sym_lookup {
 323     int         version;        /* set to sizeof(struct kld_sym_lookup) */
 324     char        *symname;       /* Symbol name we are looking up */
 325     u_long      symvalue;
 326     size_t      symsize;
 327 };
 328 #define KLDSYM_LOOKUP   1
 329
 330 /*
 331  * Flags for kldunloadf() and linker_file_unload()
 332  */
 333 #define LINKER_UNLOAD_NORMAL    0
 334 #define LINKER_UNLOAD_FORCE     1
 335
 336 #ifndef _KERNEL
 337
 338 #include <sys/cdefs.h>
 339
 340 __BEGIN_DECLS
 341 int     kldload(const char* _file);
 342 int     kldunload(int _fileid);
 343 int     kldunloadf(int _fileid, int flags);
 344 int     kldfind(const char* _file);
 345 int     kldnext(int _fileid);
 346 int     kldstat(int _fileid, struct kld_file_stat* _stat);
 347 int     kldfirstmod(int _fileid);
 348 int     kldsym(int _fileid, int _cmd, void *_data);
 349 __END_DECLS
 350
 351 #endif
 352
 353 #endif /* !_SYS_LINKER_H_ */