| 1 | /* Handle Darwin shared libraries for GDB, the GNU Debugger. |
| 2 | |
| 3 | Copyright (C) 2009, 2010 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | |
| 22 | #include "symtab.h" |
| 23 | #include "bfd.h" |
| 24 | #include "symfile.h" |
| 25 | #include "objfiles.h" |
| 26 | #include "gdbcore.h" |
| 27 | #include "target.h" |
| 28 | #include "inferior.h" |
| 29 | #include "regcache.h" |
| 30 | #include "gdbthread.h" |
| 31 | |
| 32 | #include "gdb_assert.h" |
| 33 | |
| 34 | #include "solist.h" |
| 35 | #include "solib.h" |
| 36 | #include "solib-svr4.h" |
| 37 | |
| 38 | #include "bfd-target.h" |
| 39 | #include "elf-bfd.h" |
| 40 | #include "exec.h" |
| 41 | #include "auxv.h" |
| 42 | #include "exceptions.h" |
| 43 | #include "mach-o.h" |
| 44 | |
| 45 | struct gdb_dyld_image_info |
| 46 | { |
| 47 | /* Base address (which corresponds to the Mach-O header). */ |
| 48 | CORE_ADDR mach_header; |
| 49 | /* Image file path. */ |
| 50 | CORE_ADDR file_path; |
| 51 | /* st.m_time of image file. */ |
| 52 | unsigned long mtime; |
| 53 | }; |
| 54 | |
| 55 | /* Content of inferior dyld_all_image_infos structure. |
| 56 | See /usr/include/mach-o/dyld_images.h for the documentation. */ |
| 57 | struct gdb_dyld_all_image_infos |
| 58 | { |
| 59 | /* Version (1). */ |
| 60 | unsigned int version; |
| 61 | /* Number of images. */ |
| 62 | unsigned int count; |
| 63 | /* Image description. */ |
| 64 | CORE_ADDR info; |
| 65 | /* Notifier (function called when a library is added or removed). */ |
| 66 | CORE_ADDR notifier; |
| 67 | }; |
| 68 | |
| 69 | /* Current all_image_infos version. */ |
| 70 | #define DYLD_VERSION_MIN 1 |
| 71 | #define DYLD_VERSION_MAX 7 |
| 72 | |
| 73 | /* Address of structure dyld_all_image_infos in inferior. */ |
| 74 | static CORE_ADDR dyld_all_image_addr; |
| 75 | |
| 76 | /* Gdb copy of dyld_all_info_infos. */ |
| 77 | static struct gdb_dyld_all_image_infos dyld_all_image; |
| 78 | |
| 79 | /* Return non-zero if the version in dyld_all_image is known. */ |
| 80 | |
| 81 | static int |
| 82 | darwin_dyld_version_ok (void) |
| 83 | { |
| 84 | return dyld_all_image.version >= DYLD_VERSION_MIN |
| 85 | && dyld_all_image.version <= DYLD_VERSION_MAX; |
| 86 | } |
| 87 | |
| 88 | /* Read dyld_all_image from inferior. */ |
| 89 | |
| 90 | static void |
| 91 | darwin_load_image_infos (void) |
| 92 | { |
| 93 | gdb_byte buf[24]; |
| 94 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch); |
| 95 | struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr; |
| 96 | int len; |
| 97 | |
| 98 | /* If the structure address is not known, don't continue. */ |
| 99 | if (dyld_all_image_addr == 0) |
| 100 | return; |
| 101 | |
| 102 | /* The structure has 4 fields: version (4 bytes), count (4 bytes), |
| 103 | info (pointer) and notifier (pointer). */ |
| 104 | len = 4 + 4 + 2 * ptr_type->length; |
| 105 | gdb_assert (len <= sizeof (buf)); |
| 106 | memset (&dyld_all_image, 0, sizeof (dyld_all_image)); |
| 107 | |
| 108 | /* Read structure raw bytes from target. */ |
| 109 | if (target_read_memory (dyld_all_image_addr, buf, len)) |
| 110 | return; |
| 111 | |
| 112 | /* Extract the fields. */ |
| 113 | dyld_all_image.version = extract_unsigned_integer (buf, 4, byte_order); |
| 114 | if (!darwin_dyld_version_ok ()) |
| 115 | return; |
| 116 | |
| 117 | dyld_all_image.count = extract_unsigned_integer (buf + 4, 4, byte_order); |
| 118 | dyld_all_image.info = extract_typed_address (buf + 8, ptr_type); |
| 119 | dyld_all_image.notifier = extract_typed_address |
| 120 | (buf + 8 + ptr_type->length, ptr_type); |
| 121 | } |
| 122 | |
| 123 | /* Link map info to include in an allocated so_list entry. */ |
| 124 | |
| 125 | struct lm_info |
| 126 | { |
| 127 | /* The target location of lm. */ |
| 128 | CORE_ADDR lm_addr; |
| 129 | }; |
| 130 | |
| 131 | struct darwin_so_list |
| 132 | { |
| 133 | /* Common field. */ |
| 134 | struct so_list sl; |
| 135 | /* Darwin specific data. */ |
| 136 | struct lm_info li; |
| 137 | }; |
| 138 | |
| 139 | /* Lookup the value for a specific symbol. */ |
| 140 | |
| 141 | static CORE_ADDR |
| 142 | lookup_symbol_from_bfd (bfd *abfd, char *symname) |
| 143 | { |
| 144 | long storage_needed; |
| 145 | asymbol **symbol_table; |
| 146 | unsigned int number_of_symbols; |
| 147 | unsigned int i; |
| 148 | CORE_ADDR symaddr = 0; |
| 149 | |
| 150 | storage_needed = bfd_get_symtab_upper_bound (abfd); |
| 151 | |
| 152 | if (storage_needed <= 0) |
| 153 | return 0; |
| 154 | |
| 155 | symbol_table = (asymbol **) xmalloc (storage_needed); |
| 156 | number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table); |
| 157 | |
| 158 | for (i = 0; i < number_of_symbols; i++) |
| 159 | { |
| 160 | asymbol *sym = symbol_table[i]; |
| 161 | if (strcmp (sym->name, symname) == 0 |
| 162 | && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0) |
| 163 | { |
| 164 | /* BFD symbols are section relative. */ |
| 165 | symaddr = sym->value + sym->section->vma; |
| 166 | break; |
| 167 | } |
| 168 | } |
| 169 | xfree (symbol_table); |
| 170 | |
| 171 | return symaddr; |
| 172 | } |
| 173 | |
| 174 | /* Return program interpreter string. */ |
| 175 | |
| 176 | static gdb_byte * |
| 177 | find_program_interpreter (void) |
| 178 | { |
| 179 | gdb_byte *buf = NULL; |
| 180 | |
| 181 | /* If we have an exec_bfd, get the interpreter from the load commands. */ |
| 182 | if (exec_bfd) |
| 183 | { |
| 184 | bfd_mach_o_load_command *cmd; |
| 185 | |
| 186 | if (bfd_mach_o_lookup_command (exec_bfd, |
| 187 | BFD_MACH_O_LC_LOAD_DYLINKER, &cmd) == 1) |
| 188 | return cmd->command.dylinker.name_str; |
| 189 | } |
| 190 | |
| 191 | /* If we didn't find it, read from memory. |
| 192 | FIXME: todo. */ |
| 193 | return buf; |
| 194 | } |
| 195 | |
| 196 | /* Not used. I don't see how the main symbol file can be found: the |
| 197 | interpreter name is needed and it is known from the executable file. |
| 198 | Note that darwin-nat.c implements pid_to_exec_file. */ |
| 199 | |
| 200 | static int |
| 201 | open_symbol_file_object (void *from_ttyp) |
| 202 | { |
| 203 | return 0; |
| 204 | } |
| 205 | |
| 206 | /* Build a list of currently loaded shared objects. See solib-svr4.c */ |
| 207 | |
| 208 | static struct so_list * |
| 209 | darwin_current_sos (void) |
| 210 | { |
| 211 | struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr; |
| 212 | int ptr_len = TYPE_LENGTH (ptr_type); |
| 213 | unsigned int image_info_size; |
| 214 | CORE_ADDR lm; |
| 215 | struct so_list *head = NULL; |
| 216 | struct so_list *tail = NULL; |
| 217 | int i; |
| 218 | |
| 219 | /* Be sure image infos are loaded. */ |
| 220 | darwin_load_image_infos (); |
| 221 | |
| 222 | if (!darwin_dyld_version_ok ()) |
| 223 | return NULL; |
| 224 | |
| 225 | image_info_size = ptr_len * 3; |
| 226 | |
| 227 | /* Read infos for each solib. |
| 228 | This first entry is ignored as this is the executable itself. */ |
| 229 | for (i = 1; i < dyld_all_image.count; i++) |
| 230 | { |
| 231 | CORE_ADDR info = dyld_all_image.info + i * image_info_size; |
| 232 | char buf[image_info_size]; |
| 233 | CORE_ADDR load_addr; |
| 234 | CORE_ADDR path_addr; |
| 235 | char *file_path; |
| 236 | int errcode; |
| 237 | struct darwin_so_list *dnew; |
| 238 | struct so_list *new; |
| 239 | struct cleanup *old_chain; |
| 240 | |
| 241 | /* Read image info from inferior. */ |
| 242 | if (target_read_memory (info, buf, image_info_size)) |
| 243 | break; |
| 244 | |
| 245 | load_addr = extract_typed_address (buf, ptr_type); |
| 246 | path_addr = extract_typed_address (buf + ptr_len, ptr_type); |
| 247 | |
| 248 | target_read_string (path_addr, &file_path, |
| 249 | SO_NAME_MAX_PATH_SIZE - 1, &errcode); |
| 250 | if (errcode) |
| 251 | break; |
| 252 | |
| 253 | /* Create and fill the new so_list element. */ |
| 254 | dnew = XZALLOC (struct darwin_so_list); |
| 255 | new = &dnew->sl; |
| 256 | old_chain = make_cleanup (xfree, dnew); |
| 257 | |
| 258 | new->lm_info = &dnew->li; |
| 259 | |
| 260 | strncpy (new->so_name, file_path, SO_NAME_MAX_PATH_SIZE - 1); |
| 261 | new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; |
| 262 | strcpy (new->so_original_name, new->so_name); |
| 263 | xfree (file_path); |
| 264 | new->lm_info->lm_addr = load_addr; |
| 265 | |
| 266 | if (head == NULL) |
| 267 | head = new; |
| 268 | else |
| 269 | tail->next = new; |
| 270 | tail = new; |
| 271 | |
| 272 | discard_cleanups (old_chain); |
| 273 | } |
| 274 | |
| 275 | return head; |
| 276 | } |
| 277 | |
| 278 | /* Return 1 if PC lies in the dynamic symbol resolution code of the |
| 279 | run time loader. */ |
| 280 | |
| 281 | int |
| 282 | darwin_in_dynsym_resolve_code (CORE_ADDR pc) |
| 283 | { |
| 284 | return 0; |
| 285 | } |
| 286 | |
| 287 | |
| 288 | /* No special symbol handling. */ |
| 289 | |
| 290 | static void |
| 291 | darwin_special_symbol_handling (void) |
| 292 | { |
| 293 | } |
| 294 | |
| 295 | /* Shared library startup support. See documentation in solib-svr4.c */ |
| 296 | |
| 297 | static void |
| 298 | darwin_solib_create_inferior_hook (int from_tty) |
| 299 | { |
| 300 | struct minimal_symbol *msymbol; |
| 301 | char **bkpt_namep; |
| 302 | asection *interp_sect; |
| 303 | gdb_byte *interp_name; |
| 304 | CORE_ADDR sym_addr; |
| 305 | CORE_ADDR load_addr = 0; |
| 306 | int load_addr_found = 0; |
| 307 | int loader_found_in_list = 0; |
| 308 | struct so_list *so; |
| 309 | bfd *dyld_bfd = NULL; |
| 310 | struct inferior *inf = current_inferior (); |
| 311 | |
| 312 | /* Find the program interpreter. */ |
| 313 | interp_name = find_program_interpreter (); |
| 314 | if (!interp_name) |
| 315 | return; |
| 316 | |
| 317 | /* Create a bfd for the interpreter. */ |
| 318 | sym_addr = 0; |
| 319 | dyld_bfd = bfd_openr (interp_name, gnutarget); |
| 320 | if (dyld_bfd) |
| 321 | { |
| 322 | bfd *sub; |
| 323 | sub = bfd_mach_o_fat_extract (dyld_bfd, bfd_object, |
| 324 | gdbarch_bfd_arch_info (target_gdbarch)); |
| 325 | if (sub) |
| 326 | dyld_bfd = sub; |
| 327 | else |
| 328 | { |
| 329 | bfd_close (dyld_bfd); |
| 330 | dyld_bfd = NULL; |
| 331 | } |
| 332 | } |
| 333 | if (!dyld_bfd) |
| 334 | return; |
| 335 | |
| 336 | if (!inf->attach_flag) |
| 337 | { |
| 338 | /* We find the dynamic linker's base address by examining |
| 339 | the current pc (which should point at the entry point for the |
| 340 | dynamic linker) and subtracting the offset of the entry point. */ |
| 341 | load_addr = (regcache_read_pc (get_current_regcache ()) |
| 342 | - bfd_get_start_address (dyld_bfd)); |
| 343 | } |
| 344 | else |
| 345 | { |
| 346 | /* FIXME: todo. |
| 347 | Get address of __DATA.__dyld in exec_bfd, read address at offset 0. |
| 348 | */ |
| 349 | return; |
| 350 | } |
| 351 | |
| 352 | /* Now try to set a breakpoint in the dynamic linker. */ |
| 353 | dyld_all_image_addr = |
| 354 | lookup_symbol_from_bfd (dyld_bfd, "_dyld_all_image_infos"); |
| 355 | |
| 356 | bfd_close (dyld_bfd); |
| 357 | |
| 358 | if (dyld_all_image_addr == 0) |
| 359 | return; |
| 360 | |
| 361 | dyld_all_image_addr += load_addr; |
| 362 | |
| 363 | darwin_load_image_infos (); |
| 364 | |
| 365 | if (darwin_dyld_version_ok ()) |
| 366 | create_solib_event_breakpoint (target_gdbarch, dyld_all_image.notifier); |
| 367 | } |
| 368 | |
| 369 | static void |
| 370 | darwin_clear_solib (void) |
| 371 | { |
| 372 | dyld_all_image_addr = 0; |
| 373 | dyld_all_image.version = 0; |
| 374 | } |
| 375 | |
| 376 | static void |
| 377 | darwin_free_so (struct so_list *so) |
| 378 | { |
| 379 | } |
| 380 | |
| 381 | /* The section table is built from bfd sections using bfd VMAs. |
| 382 | Relocate these VMAs according to solib info. */ |
| 383 | |
| 384 | static void |
| 385 | darwin_relocate_section_addresses (struct so_list *so, |
| 386 | struct target_section *sec) |
| 387 | { |
| 388 | sec->addr += so->lm_info->lm_addr; |
| 389 | sec->endaddr += so->lm_info->lm_addr; |
| 390 | |
| 391 | /* Best effort to set addr_high/addr_low. This is used only by |
| 392 | 'info sharedlibary'. */ |
| 393 | if (so->addr_high == 0) |
| 394 | { |
| 395 | so->addr_low = sec->addr; |
| 396 | so->addr_high = sec->endaddr; |
| 397 | } |
| 398 | if (sec->endaddr > so->addr_high) |
| 399 | so->addr_high = sec->endaddr; |
| 400 | if (sec->addr < so->addr_low) |
| 401 | so->addr_low = sec->addr; |
| 402 | } |
| 403 | \f |
| 404 | static struct symbol * |
| 405 | darwin_lookup_lib_symbol (const struct objfile *objfile, |
| 406 | const char *name, |
| 407 | const domain_enum domain) |
| 408 | { |
| 409 | return NULL; |
| 410 | } |
| 411 | |
| 412 | static bfd * |
| 413 | darwin_bfd_open (char *pathname) |
| 414 | { |
| 415 | char *found_pathname; |
| 416 | int found_file; |
| 417 | bfd *abfd; |
| 418 | bfd *res; |
| 419 | |
| 420 | /* Search for shared library file. */ |
| 421 | found_pathname = solib_find (pathname, &found_file); |
| 422 | if (found_pathname == NULL) |
| 423 | perror_with_name (pathname); |
| 424 | |
| 425 | /* Open bfd for shared library. */ |
| 426 | abfd = solib_bfd_fopen (found_pathname, found_file); |
| 427 | |
| 428 | res = bfd_mach_o_fat_extract (abfd, bfd_object, |
| 429 | gdbarch_bfd_arch_info (target_gdbarch)); |
| 430 | if (!res) |
| 431 | { |
| 432 | bfd_close (abfd); |
| 433 | make_cleanup (xfree, found_pathname); |
| 434 | error (_("`%s': not a shared-library: %s"), |
| 435 | found_pathname, bfd_errmsg (bfd_get_error ())); |
| 436 | } |
| 437 | return res; |
| 438 | } |
| 439 | |
| 440 | struct target_so_ops darwin_so_ops; |
| 441 | |
| 442 | void |
| 443 | _initialize_darwin_solib (void) |
| 444 | { |
| 445 | darwin_so_ops.relocate_section_addresses = darwin_relocate_section_addresses; |
| 446 | darwin_so_ops.free_so = darwin_free_so; |
| 447 | darwin_so_ops.clear_solib = darwin_clear_solib; |
| 448 | darwin_so_ops.solib_create_inferior_hook = darwin_solib_create_inferior_hook; |
| 449 | darwin_so_ops.special_symbol_handling = darwin_special_symbol_handling; |
| 450 | darwin_so_ops.current_sos = darwin_current_sos; |
| 451 | darwin_so_ops.open_symbol_file_object = open_symbol_file_object; |
| 452 | darwin_so_ops.in_dynsym_resolve_code = darwin_in_dynsym_resolve_code; |
| 453 | darwin_so_ops.lookup_lib_global_symbol = darwin_lookup_lib_symbol; |
| 454 | darwin_so_ops.bfd_open = darwin_bfd_open; |
| 455 | } |