| 1 | /* Handle FR-V (FDPIC) shared libraries for GDB, the GNU Debugger. |
| 2 | Copyright (C) 2004-2017 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "inferior.h" |
| 22 | #include "gdbcore.h" |
| 23 | #include "solib.h" |
| 24 | #include "solist.h" |
| 25 | #include "frv-tdep.h" |
| 26 | #include "objfiles.h" |
| 27 | #include "symtab.h" |
| 28 | #include "language.h" |
| 29 | #include "command.h" |
| 30 | #include "gdbcmd.h" |
| 31 | #include "elf/frv.h" |
| 32 | #include "gdb_bfd.h" |
| 33 | |
| 34 | /* Flag which indicates whether internal debug messages should be printed. */ |
| 35 | static unsigned int solib_frv_debug; |
| 36 | |
| 37 | /* FR-V pointers are four bytes wide. */ |
| 38 | enum { FRV_PTR_SIZE = 4 }; |
| 39 | |
| 40 | /* Representation of loadmap and related structs for the FR-V FDPIC ABI. */ |
| 41 | |
| 42 | /* External versions; the size and alignment of the fields should be |
| 43 | the same as those on the target. When loaded, the placement of |
| 44 | the bits in each field will be the same as on the target. */ |
| 45 | typedef gdb_byte ext_Elf32_Half[2]; |
| 46 | typedef gdb_byte ext_Elf32_Addr[4]; |
| 47 | typedef gdb_byte ext_Elf32_Word[4]; |
| 48 | |
| 49 | struct ext_elf32_fdpic_loadseg |
| 50 | { |
| 51 | /* Core address to which the segment is mapped. */ |
| 52 | ext_Elf32_Addr addr; |
| 53 | /* VMA recorded in the program header. */ |
| 54 | ext_Elf32_Addr p_vaddr; |
| 55 | /* Size of this segment in memory. */ |
| 56 | ext_Elf32_Word p_memsz; |
| 57 | }; |
| 58 | |
| 59 | struct ext_elf32_fdpic_loadmap { |
| 60 | /* Protocol version number, must be zero. */ |
| 61 | ext_Elf32_Half version; |
| 62 | /* Number of segments in this map. */ |
| 63 | ext_Elf32_Half nsegs; |
| 64 | /* The actual memory map. */ |
| 65 | struct ext_elf32_fdpic_loadseg segs[1 /* nsegs, actually */]; |
| 66 | }; |
| 67 | |
| 68 | /* Internal versions; the types are GDB types and the data in each |
| 69 | of the fields is (or will be) decoded from the external struct |
| 70 | for ease of consumption. */ |
| 71 | struct int_elf32_fdpic_loadseg |
| 72 | { |
| 73 | /* Core address to which the segment is mapped. */ |
| 74 | CORE_ADDR addr; |
| 75 | /* VMA recorded in the program header. */ |
| 76 | CORE_ADDR p_vaddr; |
| 77 | /* Size of this segment in memory. */ |
| 78 | long p_memsz; |
| 79 | }; |
| 80 | |
| 81 | struct int_elf32_fdpic_loadmap { |
| 82 | /* Protocol version number, must be zero. */ |
| 83 | int version; |
| 84 | /* Number of segments in this map. */ |
| 85 | int nsegs; |
| 86 | /* The actual memory map. */ |
| 87 | struct int_elf32_fdpic_loadseg segs[1 /* nsegs, actually */]; |
| 88 | }; |
| 89 | |
| 90 | /* Given address LDMADDR, fetch and decode the loadmap at that address. |
| 91 | Return NULL if there is a problem reading the target memory or if |
| 92 | there doesn't appear to be a loadmap at the given address. The |
| 93 | allocated space (representing the loadmap) returned by this |
| 94 | function may be freed via a single call to xfree(). */ |
| 95 | |
| 96 | static struct int_elf32_fdpic_loadmap * |
| 97 | fetch_loadmap (CORE_ADDR ldmaddr) |
| 98 | { |
| 99 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
| 100 | struct ext_elf32_fdpic_loadmap ext_ldmbuf_partial; |
| 101 | struct ext_elf32_fdpic_loadmap *ext_ldmbuf; |
| 102 | struct int_elf32_fdpic_loadmap *int_ldmbuf; |
| 103 | int ext_ldmbuf_size, int_ldmbuf_size; |
| 104 | int version, seg, nsegs; |
| 105 | |
| 106 | /* Fetch initial portion of the loadmap. */ |
| 107 | if (target_read_memory (ldmaddr, (gdb_byte *) &ext_ldmbuf_partial, |
| 108 | sizeof ext_ldmbuf_partial)) |
| 109 | { |
| 110 | /* Problem reading the target's memory. */ |
| 111 | return NULL; |
| 112 | } |
| 113 | |
| 114 | /* Extract the version. */ |
| 115 | version = extract_unsigned_integer (ext_ldmbuf_partial.version, |
| 116 | sizeof ext_ldmbuf_partial.version, |
| 117 | byte_order); |
| 118 | if (version != 0) |
| 119 | { |
| 120 | /* We only handle version 0. */ |
| 121 | return NULL; |
| 122 | } |
| 123 | |
| 124 | /* Extract the number of segments. */ |
| 125 | nsegs = extract_unsigned_integer (ext_ldmbuf_partial.nsegs, |
| 126 | sizeof ext_ldmbuf_partial.nsegs, |
| 127 | byte_order); |
| 128 | |
| 129 | if (nsegs <= 0) |
| 130 | return NULL; |
| 131 | |
| 132 | /* Allocate space for the complete (external) loadmap. */ |
| 133 | ext_ldmbuf_size = sizeof (struct ext_elf32_fdpic_loadmap) |
| 134 | + (nsegs - 1) * sizeof (struct ext_elf32_fdpic_loadseg); |
| 135 | ext_ldmbuf = (struct ext_elf32_fdpic_loadmap *) xmalloc (ext_ldmbuf_size); |
| 136 | |
| 137 | /* Copy over the portion of the loadmap that's already been read. */ |
| 138 | memcpy (ext_ldmbuf, &ext_ldmbuf_partial, sizeof ext_ldmbuf_partial); |
| 139 | |
| 140 | /* Read the rest of the loadmap from the target. */ |
| 141 | if (target_read_memory (ldmaddr + sizeof ext_ldmbuf_partial, |
| 142 | (gdb_byte *) ext_ldmbuf + sizeof ext_ldmbuf_partial, |
| 143 | ext_ldmbuf_size - sizeof ext_ldmbuf_partial)) |
| 144 | { |
| 145 | /* Couldn't read rest of the loadmap. */ |
| 146 | xfree (ext_ldmbuf); |
| 147 | return NULL; |
| 148 | } |
| 149 | |
| 150 | /* Allocate space into which to put information extract from the |
| 151 | external loadsegs. I.e, allocate the internal loadsegs. */ |
| 152 | int_ldmbuf_size = sizeof (struct int_elf32_fdpic_loadmap) |
| 153 | + (nsegs - 1) * sizeof (struct int_elf32_fdpic_loadseg); |
| 154 | int_ldmbuf = (struct int_elf32_fdpic_loadmap *) xmalloc (int_ldmbuf_size); |
| 155 | |
| 156 | /* Place extracted information in internal structs. */ |
| 157 | int_ldmbuf->version = version; |
| 158 | int_ldmbuf->nsegs = nsegs; |
| 159 | for (seg = 0; seg < nsegs; seg++) |
| 160 | { |
| 161 | int_ldmbuf->segs[seg].addr |
| 162 | = extract_unsigned_integer (ext_ldmbuf->segs[seg].addr, |
| 163 | sizeof (ext_ldmbuf->segs[seg].addr), |
| 164 | byte_order); |
| 165 | int_ldmbuf->segs[seg].p_vaddr |
| 166 | = extract_unsigned_integer (ext_ldmbuf->segs[seg].p_vaddr, |
| 167 | sizeof (ext_ldmbuf->segs[seg].p_vaddr), |
| 168 | byte_order); |
| 169 | int_ldmbuf->segs[seg].p_memsz |
| 170 | = extract_unsigned_integer (ext_ldmbuf->segs[seg].p_memsz, |
| 171 | sizeof (ext_ldmbuf->segs[seg].p_memsz), |
| 172 | byte_order); |
| 173 | } |
| 174 | |
| 175 | xfree (ext_ldmbuf); |
| 176 | return int_ldmbuf; |
| 177 | } |
| 178 | |
| 179 | /* External link_map and elf32_fdpic_loadaddr struct definitions. */ |
| 180 | |
| 181 | typedef gdb_byte ext_ptr[4]; |
| 182 | |
| 183 | struct ext_elf32_fdpic_loadaddr |
| 184 | { |
| 185 | ext_ptr map; /* struct elf32_fdpic_loadmap *map; */ |
| 186 | ext_ptr got_value; /* void *got_value; */ |
| 187 | }; |
| 188 | |
| 189 | struct ext_link_map |
| 190 | { |
| 191 | struct ext_elf32_fdpic_loadaddr l_addr; |
| 192 | |
| 193 | /* Absolute file name object was found in. */ |
| 194 | ext_ptr l_name; /* char *l_name; */ |
| 195 | |
| 196 | /* Dynamic section of the shared object. */ |
| 197 | ext_ptr l_ld; /* ElfW(Dyn) *l_ld; */ |
| 198 | |
| 199 | /* Chain of loaded objects. */ |
| 200 | ext_ptr l_next, l_prev; /* struct link_map *l_next, *l_prev; */ |
| 201 | }; |
| 202 | |
| 203 | /* Link map info to include in an allocated so_list entry. */ |
| 204 | |
| 205 | struct lm_info_frv : public lm_info_base |
| 206 | { |
| 207 | ~lm_info_frv () |
| 208 | { |
| 209 | xfree (this->map); |
| 210 | xfree (this->dyn_syms); |
| 211 | xfree (this->dyn_relocs); |
| 212 | } |
| 213 | |
| 214 | /* The loadmap, digested into an easier to use form. */ |
| 215 | int_elf32_fdpic_loadmap *map = NULL; |
| 216 | /* The GOT address for this link map entry. */ |
| 217 | CORE_ADDR got_value = 0; |
| 218 | /* The link map address, needed for frv_fetch_objfile_link_map(). */ |
| 219 | CORE_ADDR lm_addr = 0; |
| 220 | |
| 221 | /* Cached dynamic symbol table and dynamic relocs initialized and |
| 222 | used only by find_canonical_descriptor_in_load_object(). |
| 223 | |
| 224 | Note: kevinb/2004-02-26: It appears that calls to |
| 225 | bfd_canonicalize_dynamic_reloc() will use the same symbols as |
| 226 | those supplied to the first call to this function. Therefore, |
| 227 | it's important to NOT free the asymbol ** data structure |
| 228 | supplied to the first call. Thus the caching of the dynamic |
| 229 | symbols (dyn_syms) is critical for correct operation. The |
| 230 | caching of the dynamic relocations could be dispensed with. */ |
| 231 | asymbol **dyn_syms = NULL; |
| 232 | arelent **dyn_relocs = NULL; |
| 233 | int dyn_reloc_count = 0; /* Number of dynamic relocs. */ |
| 234 | }; |
| 235 | |
| 236 | /* The load map, got value, etc. are not available from the chain |
| 237 | of loaded shared objects. ``main_executable_lm_info'' provides |
| 238 | a way to get at this information so that it doesn't need to be |
| 239 | frequently recomputed. Initialized by frv_relocate_main_executable(). */ |
| 240 | static lm_info_frv *main_executable_lm_info; |
| 241 | |
| 242 | static void frv_relocate_main_executable (void); |
| 243 | static CORE_ADDR main_got (void); |
| 244 | static int enable_break2 (void); |
| 245 | |
| 246 | /* Implement the "open_symbol_file_object" target_so_ops method. */ |
| 247 | |
| 248 | static int |
| 249 | open_symbol_file_object (void *from_ttyp) |
| 250 | { |
| 251 | /* Unimplemented. */ |
| 252 | return 0; |
| 253 | } |
| 254 | |
| 255 | /* Cached value for lm_base(), below. */ |
| 256 | static CORE_ADDR lm_base_cache = 0; |
| 257 | |
| 258 | /* Link map address for main module. */ |
| 259 | static CORE_ADDR main_lm_addr = 0; |
| 260 | |
| 261 | /* Return the address from which the link map chain may be found. On |
| 262 | the FR-V, this may be found in a number of ways. Assuming that the |
| 263 | main executable has already been relocated, the easiest way to find |
| 264 | this value is to look up the address of _GLOBAL_OFFSET_TABLE_. A |
| 265 | pointer to the start of the link map will be located at the word found |
| 266 | at _GLOBAL_OFFSET_TABLE_ + 8. (This is part of the dynamic linker |
| 267 | reserve area mandated by the ABI.) */ |
| 268 | |
| 269 | static CORE_ADDR |
| 270 | lm_base (void) |
| 271 | { |
| 272 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
| 273 | struct bound_minimal_symbol got_sym; |
| 274 | CORE_ADDR addr; |
| 275 | gdb_byte buf[FRV_PTR_SIZE]; |
| 276 | |
| 277 | /* One of our assumptions is that the main executable has been relocated. |
| 278 | Bail out if this has not happened. (Note that post_create_inferior() |
| 279 | in infcmd.c will call solib_add prior to solib_create_inferior_hook(). |
| 280 | If we allow this to happen, lm_base_cache will be initialized with |
| 281 | a bogus value. */ |
| 282 | if (main_executable_lm_info == 0) |
| 283 | return 0; |
| 284 | |
| 285 | /* If we already have a cached value, return it. */ |
| 286 | if (lm_base_cache) |
| 287 | return lm_base_cache; |
| 288 | |
| 289 | got_sym = lookup_minimal_symbol ("_GLOBAL_OFFSET_TABLE_", NULL, |
| 290 | symfile_objfile); |
| 291 | if (got_sym.minsym == 0) |
| 292 | { |
| 293 | if (solib_frv_debug) |
| 294 | fprintf_unfiltered (gdb_stdlog, |
| 295 | "lm_base: _GLOBAL_OFFSET_TABLE_ not found.\n"); |
| 296 | return 0; |
| 297 | } |
| 298 | |
| 299 | addr = BMSYMBOL_VALUE_ADDRESS (got_sym) + 8; |
| 300 | |
| 301 | if (solib_frv_debug) |
| 302 | fprintf_unfiltered (gdb_stdlog, |
| 303 | "lm_base: _GLOBAL_OFFSET_TABLE_ + 8 = %s\n", |
| 304 | hex_string_custom (addr, 8)); |
| 305 | |
| 306 | if (target_read_memory (addr, buf, sizeof buf) != 0) |
| 307 | return 0; |
| 308 | lm_base_cache = extract_unsigned_integer (buf, sizeof buf, byte_order); |
| 309 | |
| 310 | if (solib_frv_debug) |
| 311 | fprintf_unfiltered (gdb_stdlog, |
| 312 | "lm_base: lm_base_cache = %s\n", |
| 313 | hex_string_custom (lm_base_cache, 8)); |
| 314 | |
| 315 | return lm_base_cache; |
| 316 | } |
| 317 | |
| 318 | |
| 319 | /* Implement the "current_sos" target_so_ops method. */ |
| 320 | |
| 321 | static struct so_list * |
| 322 | frv_current_sos (void) |
| 323 | { |
| 324 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
| 325 | CORE_ADDR lm_addr, mgot; |
| 326 | struct so_list *sos_head = NULL; |
| 327 | struct so_list **sos_next_ptr = &sos_head; |
| 328 | |
| 329 | /* Make sure that the main executable has been relocated. This is |
| 330 | required in order to find the address of the global offset table, |
| 331 | which in turn is used to find the link map info. (See lm_base() |
| 332 | for details.) |
| 333 | |
| 334 | Note that the relocation of the main executable is also performed |
| 335 | by solib_create_inferior_hook(), however, in the case of core |
| 336 | files, this hook is called too late in order to be of benefit to |
| 337 | solib_add. solib_add eventually calls this this function, |
| 338 | frv_current_sos, and also precedes the call to |
| 339 | solib_create_inferior_hook(). (See post_create_inferior() in |
| 340 | infcmd.c.) */ |
| 341 | if (main_executable_lm_info == 0 && core_bfd != NULL) |
| 342 | frv_relocate_main_executable (); |
| 343 | |
| 344 | /* Fetch the GOT corresponding to the main executable. */ |
| 345 | mgot = main_got (); |
| 346 | |
| 347 | /* Locate the address of the first link map struct. */ |
| 348 | lm_addr = lm_base (); |
| 349 | |
| 350 | /* We have at least one link map entry. Fetch the lot of them, |
| 351 | building the solist chain. */ |
| 352 | while (lm_addr) |
| 353 | { |
| 354 | struct ext_link_map lm_buf; |
| 355 | CORE_ADDR got_addr; |
| 356 | |
| 357 | if (solib_frv_debug) |
| 358 | fprintf_unfiltered (gdb_stdlog, |
| 359 | "current_sos: reading link_map entry at %s\n", |
| 360 | hex_string_custom (lm_addr, 8)); |
| 361 | |
| 362 | if (target_read_memory (lm_addr, (gdb_byte *) &lm_buf, |
| 363 | sizeof (lm_buf)) != 0) |
| 364 | { |
| 365 | warning (_("frv_current_sos: Unable to read link map entry. " |
| 366 | "Shared object chain may be incomplete.")); |
| 367 | break; |
| 368 | } |
| 369 | |
| 370 | got_addr |
| 371 | = extract_unsigned_integer (lm_buf.l_addr.got_value, |
| 372 | sizeof (lm_buf.l_addr.got_value), |
| 373 | byte_order); |
| 374 | /* If the got_addr is the same as mgotr, then we're looking at the |
| 375 | entry for the main executable. By convention, we don't include |
| 376 | this in the list of shared objects. */ |
| 377 | if (got_addr != mgot) |
| 378 | { |
| 379 | int errcode; |
| 380 | char *name_buf; |
| 381 | struct int_elf32_fdpic_loadmap *loadmap; |
| 382 | struct so_list *sop; |
| 383 | CORE_ADDR addr; |
| 384 | |
| 385 | /* Fetch the load map address. */ |
| 386 | addr = extract_unsigned_integer (lm_buf.l_addr.map, |
| 387 | sizeof lm_buf.l_addr.map, |
| 388 | byte_order); |
| 389 | loadmap = fetch_loadmap (addr); |
| 390 | if (loadmap == NULL) |
| 391 | { |
| 392 | warning (_("frv_current_sos: Unable to fetch load map. " |
| 393 | "Shared object chain may be incomplete.")); |
| 394 | break; |
| 395 | } |
| 396 | |
| 397 | sop = XCNEW (struct so_list); |
| 398 | lm_info_frv *li = new lm_info_frv; |
| 399 | sop->lm_info = li; |
| 400 | li->map = loadmap; |
| 401 | li->got_value = got_addr; |
| 402 | li->lm_addr = lm_addr; |
| 403 | /* Fetch the name. */ |
| 404 | addr = extract_unsigned_integer (lm_buf.l_name, |
| 405 | sizeof (lm_buf.l_name), |
| 406 | byte_order); |
| 407 | target_read_string (addr, &name_buf, SO_NAME_MAX_PATH_SIZE - 1, |
| 408 | &errcode); |
| 409 | |
| 410 | if (solib_frv_debug) |
| 411 | fprintf_unfiltered (gdb_stdlog, "current_sos: name = %s\n", |
| 412 | name_buf); |
| 413 | |
| 414 | if (errcode != 0) |
| 415 | warning (_("Can't read pathname for link map entry: %s."), |
| 416 | safe_strerror (errcode)); |
| 417 | else |
| 418 | { |
| 419 | strncpy (sop->so_name, name_buf, SO_NAME_MAX_PATH_SIZE - 1); |
| 420 | sop->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; |
| 421 | xfree (name_buf); |
| 422 | strcpy (sop->so_original_name, sop->so_name); |
| 423 | } |
| 424 | |
| 425 | *sos_next_ptr = sop; |
| 426 | sos_next_ptr = &sop->next; |
| 427 | } |
| 428 | else |
| 429 | { |
| 430 | main_lm_addr = lm_addr; |
| 431 | } |
| 432 | |
| 433 | lm_addr = extract_unsigned_integer (lm_buf.l_next, |
| 434 | sizeof (lm_buf.l_next), byte_order); |
| 435 | } |
| 436 | |
| 437 | enable_break2 (); |
| 438 | |
| 439 | return sos_head; |
| 440 | } |
| 441 | |
| 442 | |
| 443 | /* Return 1 if PC lies in the dynamic symbol resolution code of the |
| 444 | run time loader. */ |
| 445 | |
| 446 | static CORE_ADDR interp_text_sect_low; |
| 447 | static CORE_ADDR interp_text_sect_high; |
| 448 | static CORE_ADDR interp_plt_sect_low; |
| 449 | static CORE_ADDR interp_plt_sect_high; |
| 450 | |
| 451 | static int |
| 452 | frv_in_dynsym_resolve_code (CORE_ADDR pc) |
| 453 | { |
| 454 | return ((pc >= interp_text_sect_low && pc < interp_text_sect_high) |
| 455 | || (pc >= interp_plt_sect_low && pc < interp_plt_sect_high) |
| 456 | || in_plt_section (pc)); |
| 457 | } |
| 458 | |
| 459 | /* Given a loadmap and an address, return the displacement needed |
| 460 | to relocate the address. */ |
| 461 | |
| 462 | static CORE_ADDR |
| 463 | displacement_from_map (struct int_elf32_fdpic_loadmap *map, |
| 464 | CORE_ADDR addr) |
| 465 | { |
| 466 | int seg; |
| 467 | |
| 468 | for (seg = 0; seg < map->nsegs; seg++) |
| 469 | { |
| 470 | if (map->segs[seg].p_vaddr <= addr |
| 471 | && addr < map->segs[seg].p_vaddr + map->segs[seg].p_memsz) |
| 472 | { |
| 473 | return map->segs[seg].addr - map->segs[seg].p_vaddr; |
| 474 | } |
| 475 | } |
| 476 | |
| 477 | return 0; |
| 478 | } |
| 479 | |
| 480 | /* Print a warning about being unable to set the dynamic linker |
| 481 | breakpoint. */ |
| 482 | |
| 483 | static void |
| 484 | enable_break_failure_warning (void) |
| 485 | { |
| 486 | warning (_("Unable to find dynamic linker breakpoint function.\n" |
| 487 | "GDB will be unable to debug shared library initializers\n" |
| 488 | "and track explicitly loaded dynamic code.")); |
| 489 | } |
| 490 | |
| 491 | /* Helper function for gdb_bfd_lookup_symbol. */ |
| 492 | |
| 493 | static int |
| 494 | cmp_name (const asymbol *sym, const void *data) |
| 495 | { |
| 496 | return (strcmp (sym->name, (const char *) data) == 0); |
| 497 | } |
| 498 | |
| 499 | /* Arrange for dynamic linker to hit breakpoint. |
| 500 | |
| 501 | The dynamic linkers has, as part of its debugger interface, support |
| 502 | for arranging for the inferior to hit a breakpoint after mapping in |
| 503 | the shared libraries. This function enables that breakpoint. |
| 504 | |
| 505 | On the FR-V, using the shared library (FDPIC) ABI, the symbol |
| 506 | _dl_debug_addr points to the r_debug struct which contains |
| 507 | a field called r_brk. r_brk is the address of the function |
| 508 | descriptor upon which a breakpoint must be placed. Being a |
| 509 | function descriptor, we must extract the entry point in order |
| 510 | to set the breakpoint. |
| 511 | |
| 512 | Our strategy will be to get the .interp section from the |
| 513 | executable. This section will provide us with the name of the |
| 514 | interpreter. We'll open the interpreter and then look up |
| 515 | the address of _dl_debug_addr. We then relocate this address |
| 516 | using the interpreter's loadmap. Once the relocated address |
| 517 | is known, we fetch the value (address) corresponding to r_brk |
| 518 | and then use that value to fetch the entry point of the function |
| 519 | we're interested in. */ |
| 520 | |
| 521 | static int enable_break2_done = 0; |
| 522 | |
| 523 | static int |
| 524 | enable_break2 (void) |
| 525 | { |
| 526 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
| 527 | asection *interp_sect; |
| 528 | |
| 529 | if (enable_break2_done) |
| 530 | return 1; |
| 531 | |
| 532 | interp_text_sect_low = interp_text_sect_high = 0; |
| 533 | interp_plt_sect_low = interp_plt_sect_high = 0; |
| 534 | |
| 535 | /* Find the .interp section; if not found, warn the user and drop |
| 536 | into the old breakpoint at symbol code. */ |
| 537 | interp_sect = bfd_get_section_by_name (exec_bfd, ".interp"); |
| 538 | if (interp_sect) |
| 539 | { |
| 540 | unsigned int interp_sect_size; |
| 541 | char *buf; |
| 542 | int status; |
| 543 | CORE_ADDR addr, interp_loadmap_addr; |
| 544 | gdb_byte addr_buf[FRV_PTR_SIZE]; |
| 545 | struct int_elf32_fdpic_loadmap *ldm; |
| 546 | |
| 547 | /* Read the contents of the .interp section into a local buffer; |
| 548 | the contents specify the dynamic linker this program uses. */ |
| 549 | interp_sect_size = bfd_section_size (exec_bfd, interp_sect); |
| 550 | buf = (char *) alloca (interp_sect_size); |
| 551 | bfd_get_section_contents (exec_bfd, interp_sect, |
| 552 | buf, 0, interp_sect_size); |
| 553 | |
| 554 | /* Now we need to figure out where the dynamic linker was |
| 555 | loaded so that we can load its symbols and place a breakpoint |
| 556 | in the dynamic linker itself. |
| 557 | |
| 558 | This address is stored on the stack. However, I've been unable |
| 559 | to find any magic formula to find it for Solaris (appears to |
| 560 | be trivial on GNU/Linux). Therefore, we have to try an alternate |
| 561 | mechanism to find the dynamic linker's base address. */ |
| 562 | |
| 563 | gdb_bfd_ref_ptr tmp_bfd; |
| 564 | TRY |
| 565 | { |
| 566 | tmp_bfd = solib_bfd_open (buf); |
| 567 | } |
| 568 | CATCH (ex, RETURN_MASK_ALL) |
| 569 | { |
| 570 | } |
| 571 | END_CATCH |
| 572 | |
| 573 | if (tmp_bfd == NULL) |
| 574 | { |
| 575 | enable_break_failure_warning (); |
| 576 | return 0; |
| 577 | } |
| 578 | |
| 579 | status = frv_fdpic_loadmap_addresses (target_gdbarch (), |
| 580 | &interp_loadmap_addr, 0); |
| 581 | if (status < 0) |
| 582 | { |
| 583 | warning (_("Unable to determine dynamic linker loadmap address.")); |
| 584 | enable_break_failure_warning (); |
| 585 | return 0; |
| 586 | } |
| 587 | |
| 588 | if (solib_frv_debug) |
| 589 | fprintf_unfiltered (gdb_stdlog, |
| 590 | "enable_break: interp_loadmap_addr = %s\n", |
| 591 | hex_string_custom (interp_loadmap_addr, 8)); |
| 592 | |
| 593 | ldm = fetch_loadmap (interp_loadmap_addr); |
| 594 | if (ldm == NULL) |
| 595 | { |
| 596 | warning (_("Unable to load dynamic linker loadmap at address %s."), |
| 597 | hex_string_custom (interp_loadmap_addr, 8)); |
| 598 | enable_break_failure_warning (); |
| 599 | return 0; |
| 600 | } |
| 601 | |
| 602 | /* Record the relocated start and end address of the dynamic linker |
| 603 | text and plt section for svr4_in_dynsym_resolve_code. */ |
| 604 | interp_sect = bfd_get_section_by_name (tmp_bfd.get (), ".text"); |
| 605 | if (interp_sect) |
| 606 | { |
| 607 | interp_text_sect_low |
| 608 | = bfd_section_vma (tmp_bfd.get (), interp_sect); |
| 609 | interp_text_sect_low |
| 610 | += displacement_from_map (ldm, interp_text_sect_low); |
| 611 | interp_text_sect_high |
| 612 | = interp_text_sect_low + bfd_section_size (tmp_bfd.get (), |
| 613 | interp_sect); |
| 614 | } |
| 615 | interp_sect = bfd_get_section_by_name (tmp_bfd.get (), ".plt"); |
| 616 | if (interp_sect) |
| 617 | { |
| 618 | interp_plt_sect_low = |
| 619 | bfd_section_vma (tmp_bfd.get (), interp_sect); |
| 620 | interp_plt_sect_low |
| 621 | += displacement_from_map (ldm, interp_plt_sect_low); |
| 622 | interp_plt_sect_high = |
| 623 | interp_plt_sect_low + bfd_section_size (tmp_bfd.get (), |
| 624 | interp_sect); |
| 625 | } |
| 626 | |
| 627 | addr = gdb_bfd_lookup_symbol (tmp_bfd.get (), cmp_name, "_dl_debug_addr"); |
| 628 | |
| 629 | if (addr == 0) |
| 630 | { |
| 631 | warning (_("Could not find symbol _dl_debug_addr " |
| 632 | "in dynamic linker")); |
| 633 | enable_break_failure_warning (); |
| 634 | return 0; |
| 635 | } |
| 636 | |
| 637 | if (solib_frv_debug) |
| 638 | fprintf_unfiltered (gdb_stdlog, |
| 639 | "enable_break: _dl_debug_addr " |
| 640 | "(prior to relocation) = %s\n", |
| 641 | hex_string_custom (addr, 8)); |
| 642 | |
| 643 | addr += displacement_from_map (ldm, addr); |
| 644 | |
| 645 | if (solib_frv_debug) |
| 646 | fprintf_unfiltered (gdb_stdlog, |
| 647 | "enable_break: _dl_debug_addr " |
| 648 | "(after relocation) = %s\n", |
| 649 | hex_string_custom (addr, 8)); |
| 650 | |
| 651 | /* Fetch the address of the r_debug struct. */ |
| 652 | if (target_read_memory (addr, addr_buf, sizeof addr_buf) != 0) |
| 653 | { |
| 654 | warning (_("Unable to fetch contents of _dl_debug_addr " |
| 655 | "(at address %s) from dynamic linker"), |
| 656 | hex_string_custom (addr, 8)); |
| 657 | } |
| 658 | addr = extract_unsigned_integer (addr_buf, sizeof addr_buf, byte_order); |
| 659 | |
| 660 | if (solib_frv_debug) |
| 661 | fprintf_unfiltered (gdb_stdlog, |
| 662 | "enable_break: _dl_debug_addr[0..3] = %s\n", |
| 663 | hex_string_custom (addr, 8)); |
| 664 | |
| 665 | /* If it's zero, then the ldso hasn't initialized yet, and so |
| 666 | there are no shared libs yet loaded. */ |
| 667 | if (addr == 0) |
| 668 | { |
| 669 | if (solib_frv_debug) |
| 670 | fprintf_unfiltered (gdb_stdlog, |
| 671 | "enable_break: ldso not yet initialized\n"); |
| 672 | /* Do not warn, but mark to run again. */ |
| 673 | return 0; |
| 674 | } |
| 675 | |
| 676 | /* Fetch the r_brk field. It's 8 bytes from the start of |
| 677 | _dl_debug_addr. */ |
| 678 | if (target_read_memory (addr + 8, addr_buf, sizeof addr_buf) != 0) |
| 679 | { |
| 680 | warning (_("Unable to fetch _dl_debug_addr->r_brk " |
| 681 | "(at address %s) from dynamic linker"), |
| 682 | hex_string_custom (addr + 8, 8)); |
| 683 | enable_break_failure_warning (); |
| 684 | return 0; |
| 685 | } |
| 686 | addr = extract_unsigned_integer (addr_buf, sizeof addr_buf, byte_order); |
| 687 | |
| 688 | /* Now fetch the function entry point. */ |
| 689 | if (target_read_memory (addr, addr_buf, sizeof addr_buf) != 0) |
| 690 | { |
| 691 | warning (_("Unable to fetch _dl_debug_addr->.r_brk entry point " |
| 692 | "(at address %s) from dynamic linker"), |
| 693 | hex_string_custom (addr, 8)); |
| 694 | enable_break_failure_warning (); |
| 695 | return 0; |
| 696 | } |
| 697 | addr = extract_unsigned_integer (addr_buf, sizeof addr_buf, byte_order); |
| 698 | |
| 699 | /* We're done with the loadmap. */ |
| 700 | xfree (ldm); |
| 701 | |
| 702 | /* Remove all the solib event breakpoints. Their addresses |
| 703 | may have changed since the last time we ran the program. */ |
| 704 | remove_solib_event_breakpoints (); |
| 705 | |
| 706 | /* Now (finally!) create the solib breakpoint. */ |
| 707 | create_solib_event_breakpoint (target_gdbarch (), addr); |
| 708 | |
| 709 | enable_break2_done = 1; |
| 710 | |
| 711 | return 1; |
| 712 | } |
| 713 | |
| 714 | /* Tell the user we couldn't set a dynamic linker breakpoint. */ |
| 715 | enable_break_failure_warning (); |
| 716 | |
| 717 | /* Failure return. */ |
| 718 | return 0; |
| 719 | } |
| 720 | |
| 721 | static int |
| 722 | enable_break (void) |
| 723 | { |
| 724 | asection *interp_sect; |
| 725 | CORE_ADDR entry_point; |
| 726 | |
| 727 | if (symfile_objfile == NULL) |
| 728 | { |
| 729 | if (solib_frv_debug) |
| 730 | fprintf_unfiltered (gdb_stdlog, |
| 731 | "enable_break: No symbol file found.\n"); |
| 732 | return 0; |
| 733 | } |
| 734 | |
| 735 | if (!entry_point_address_query (&entry_point)) |
| 736 | { |
| 737 | if (solib_frv_debug) |
| 738 | fprintf_unfiltered (gdb_stdlog, |
| 739 | "enable_break: Symbol file has no entry point.\n"); |
| 740 | return 0; |
| 741 | } |
| 742 | |
| 743 | /* Check for the presence of a .interp section. If there is no |
| 744 | such section, the executable is statically linked. */ |
| 745 | |
| 746 | interp_sect = bfd_get_section_by_name (exec_bfd, ".interp"); |
| 747 | |
| 748 | if (interp_sect == NULL) |
| 749 | { |
| 750 | if (solib_frv_debug) |
| 751 | fprintf_unfiltered (gdb_stdlog, |
| 752 | "enable_break: No .interp section found.\n"); |
| 753 | return 0; |
| 754 | } |
| 755 | |
| 756 | create_solib_event_breakpoint (target_gdbarch (), entry_point); |
| 757 | |
| 758 | if (solib_frv_debug) |
| 759 | fprintf_unfiltered (gdb_stdlog, |
| 760 | "enable_break: solib event breakpoint " |
| 761 | "placed at entry point: %s\n", |
| 762 | hex_string_custom (entry_point, 8)); |
| 763 | return 1; |
| 764 | } |
| 765 | |
| 766 | static void |
| 767 | frv_relocate_main_executable (void) |
| 768 | { |
| 769 | int status; |
| 770 | CORE_ADDR exec_addr, interp_addr; |
| 771 | struct int_elf32_fdpic_loadmap *ldm; |
| 772 | struct cleanup *old_chain; |
| 773 | struct section_offsets *new_offsets; |
| 774 | int changed; |
| 775 | struct obj_section *osect; |
| 776 | |
| 777 | status = frv_fdpic_loadmap_addresses (target_gdbarch (), |
| 778 | &interp_addr, &exec_addr); |
| 779 | |
| 780 | if (status < 0 || (exec_addr == 0 && interp_addr == 0)) |
| 781 | { |
| 782 | /* Not using FDPIC ABI, so do nothing. */ |
| 783 | return; |
| 784 | } |
| 785 | |
| 786 | /* Fetch the loadmap located at ``exec_addr''. */ |
| 787 | ldm = fetch_loadmap (exec_addr); |
| 788 | if (ldm == NULL) |
| 789 | error (_("Unable to load the executable's loadmap.")); |
| 790 | |
| 791 | delete main_executable_lm_info; |
| 792 | main_executable_lm_info = new lm_info_frv; |
| 793 | main_executable_lm_info->map = ldm; |
| 794 | |
| 795 | new_offsets = XCNEWVEC (struct section_offsets, |
| 796 | symfile_objfile->num_sections); |
| 797 | old_chain = make_cleanup (xfree, new_offsets); |
| 798 | changed = 0; |
| 799 | |
| 800 | ALL_OBJFILE_OSECTIONS (symfile_objfile, osect) |
| 801 | { |
| 802 | CORE_ADDR orig_addr, addr, offset; |
| 803 | int osect_idx; |
| 804 | int seg; |
| 805 | |
| 806 | osect_idx = osect - symfile_objfile->sections; |
| 807 | |
| 808 | /* Current address of section. */ |
| 809 | addr = obj_section_addr (osect); |
| 810 | /* Offset from where this section started. */ |
| 811 | offset = ANOFFSET (symfile_objfile->section_offsets, osect_idx); |
| 812 | /* Original address prior to any past relocations. */ |
| 813 | orig_addr = addr - offset; |
| 814 | |
| 815 | for (seg = 0; seg < ldm->nsegs; seg++) |
| 816 | { |
| 817 | if (ldm->segs[seg].p_vaddr <= orig_addr |
| 818 | && orig_addr < ldm->segs[seg].p_vaddr + ldm->segs[seg].p_memsz) |
| 819 | { |
| 820 | new_offsets->offsets[osect_idx] |
| 821 | = ldm->segs[seg].addr - ldm->segs[seg].p_vaddr; |
| 822 | |
| 823 | if (new_offsets->offsets[osect_idx] != offset) |
| 824 | changed = 1; |
| 825 | break; |
| 826 | } |
| 827 | } |
| 828 | } |
| 829 | |
| 830 | if (changed) |
| 831 | objfile_relocate (symfile_objfile, new_offsets); |
| 832 | |
| 833 | do_cleanups (old_chain); |
| 834 | |
| 835 | /* Now that symfile_objfile has been relocated, we can compute the |
| 836 | GOT value and stash it away. */ |
| 837 | main_executable_lm_info->got_value = main_got (); |
| 838 | } |
| 839 | |
| 840 | /* Implement the "create_inferior_hook" target_solib_ops method. |
| 841 | |
| 842 | For the FR-V shared library ABI (FDPIC), the main executable needs |
| 843 | to be relocated. The shared library breakpoints also need to be |
| 844 | enabled. */ |
| 845 | |
| 846 | static void |
| 847 | frv_solib_create_inferior_hook (int from_tty) |
| 848 | { |
| 849 | /* Relocate main executable. */ |
| 850 | frv_relocate_main_executable (); |
| 851 | |
| 852 | /* Enable shared library breakpoints. */ |
| 853 | if (!enable_break ()) |
| 854 | { |
| 855 | warning (_("shared library handler failed to enable breakpoint")); |
| 856 | return; |
| 857 | } |
| 858 | } |
| 859 | |
| 860 | static void |
| 861 | frv_clear_solib (void) |
| 862 | { |
| 863 | lm_base_cache = 0; |
| 864 | enable_break2_done = 0; |
| 865 | main_lm_addr = 0; |
| 866 | |
| 867 | delete main_executable_lm_info; |
| 868 | main_executable_lm_info = NULL; |
| 869 | } |
| 870 | |
| 871 | static void |
| 872 | frv_free_so (struct so_list *so) |
| 873 | { |
| 874 | lm_info_frv *li = (lm_info_frv *) so->lm_info; |
| 875 | |
| 876 | delete li; |
| 877 | } |
| 878 | |
| 879 | static void |
| 880 | frv_relocate_section_addresses (struct so_list *so, |
| 881 | struct target_section *sec) |
| 882 | { |
| 883 | int seg; |
| 884 | lm_info_frv *li = (lm_info_frv *) so->lm_info; |
| 885 | int_elf32_fdpic_loadmap *map = li->map; |
| 886 | |
| 887 | for (seg = 0; seg < map->nsegs; seg++) |
| 888 | { |
| 889 | if (map->segs[seg].p_vaddr <= sec->addr |
| 890 | && sec->addr < map->segs[seg].p_vaddr + map->segs[seg].p_memsz) |
| 891 | { |
| 892 | CORE_ADDR displ = map->segs[seg].addr - map->segs[seg].p_vaddr; |
| 893 | |
| 894 | sec->addr += displ; |
| 895 | sec->endaddr += displ; |
| 896 | break; |
| 897 | } |
| 898 | } |
| 899 | } |
| 900 | |
| 901 | /* Return the GOT address associated with the main executable. Return |
| 902 | 0 if it can't be found. */ |
| 903 | |
| 904 | static CORE_ADDR |
| 905 | main_got (void) |
| 906 | { |
| 907 | struct bound_minimal_symbol got_sym; |
| 908 | |
| 909 | got_sym = lookup_minimal_symbol ("_GLOBAL_OFFSET_TABLE_", |
| 910 | NULL, symfile_objfile); |
| 911 | if (got_sym.minsym == 0) |
| 912 | return 0; |
| 913 | |
| 914 | return BMSYMBOL_VALUE_ADDRESS (got_sym); |
| 915 | } |
| 916 | |
| 917 | /* Find the global pointer for the given function address ADDR. */ |
| 918 | |
| 919 | CORE_ADDR |
| 920 | frv_fdpic_find_global_pointer (CORE_ADDR addr) |
| 921 | { |
| 922 | struct so_list *so; |
| 923 | |
| 924 | so = master_so_list (); |
| 925 | while (so) |
| 926 | { |
| 927 | int seg; |
| 928 | lm_info_frv *li = (lm_info_frv *) so->lm_info; |
| 929 | int_elf32_fdpic_loadmap *map = li->map; |
| 930 | |
| 931 | for (seg = 0; seg < map->nsegs; seg++) |
| 932 | { |
| 933 | if (map->segs[seg].addr <= addr |
| 934 | && addr < map->segs[seg].addr + map->segs[seg].p_memsz) |
| 935 | return li->got_value; |
| 936 | } |
| 937 | |
| 938 | so = so->next; |
| 939 | } |
| 940 | |
| 941 | /* Didn't find it in any of the shared objects. So assume it's in the |
| 942 | main executable. */ |
| 943 | return main_got (); |
| 944 | } |
| 945 | |
| 946 | /* Forward declarations for frv_fdpic_find_canonical_descriptor(). */ |
| 947 | static CORE_ADDR find_canonical_descriptor_in_load_object |
| 948 | (CORE_ADDR, CORE_ADDR, const char *, bfd *, lm_info_frv *); |
| 949 | |
| 950 | /* Given a function entry point, attempt to find the canonical descriptor |
| 951 | associated with that entry point. Return 0 if no canonical descriptor |
| 952 | could be found. */ |
| 953 | |
| 954 | CORE_ADDR |
| 955 | frv_fdpic_find_canonical_descriptor (CORE_ADDR entry_point) |
| 956 | { |
| 957 | const char *name; |
| 958 | CORE_ADDR addr; |
| 959 | CORE_ADDR got_value; |
| 960 | struct symbol *sym; |
| 961 | |
| 962 | /* Fetch the corresponding global pointer for the entry point. */ |
| 963 | got_value = frv_fdpic_find_global_pointer (entry_point); |
| 964 | |
| 965 | /* Attempt to find the name of the function. If the name is available, |
| 966 | it'll be used as an aid in finding matching functions in the dynamic |
| 967 | symbol table. */ |
| 968 | sym = find_pc_function (entry_point); |
| 969 | if (sym == 0) |
| 970 | name = 0; |
| 971 | else |
| 972 | name = SYMBOL_LINKAGE_NAME (sym); |
| 973 | |
| 974 | /* Check the main executable. */ |
| 975 | addr = find_canonical_descriptor_in_load_object |
| 976 | (entry_point, got_value, name, symfile_objfile->obfd, |
| 977 | main_executable_lm_info); |
| 978 | |
| 979 | /* If descriptor not found via main executable, check each load object |
| 980 | in list of shared objects. */ |
| 981 | if (addr == 0) |
| 982 | { |
| 983 | struct so_list *so; |
| 984 | |
| 985 | so = master_so_list (); |
| 986 | while (so) |
| 987 | { |
| 988 | lm_info_frv *li = (lm_info_frv *) so->lm_info; |
| 989 | |
| 990 | addr = find_canonical_descriptor_in_load_object |
| 991 | (entry_point, got_value, name, so->abfd, li); |
| 992 | |
| 993 | if (addr != 0) |
| 994 | break; |
| 995 | |
| 996 | so = so->next; |
| 997 | } |
| 998 | } |
| 999 | |
| 1000 | return addr; |
| 1001 | } |
| 1002 | |
| 1003 | static CORE_ADDR |
| 1004 | find_canonical_descriptor_in_load_object |
| 1005 | (CORE_ADDR entry_point, CORE_ADDR got_value, const char *name, bfd *abfd, |
| 1006 | lm_info_frv *lm) |
| 1007 | { |
| 1008 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
| 1009 | arelent *rel; |
| 1010 | unsigned int i; |
| 1011 | CORE_ADDR addr = 0; |
| 1012 | |
| 1013 | /* Nothing to do if no bfd. */ |
| 1014 | if (abfd == 0) |
| 1015 | return 0; |
| 1016 | |
| 1017 | /* Nothing to do if no link map. */ |
| 1018 | if (lm == 0) |
| 1019 | return 0; |
| 1020 | |
| 1021 | /* We want to scan the dynamic relocs for R_FRV_FUNCDESC relocations. |
| 1022 | (More about this later.) But in order to fetch the relocs, we |
| 1023 | need to first fetch the dynamic symbols. These symbols need to |
| 1024 | be cached due to the way that bfd_canonicalize_dynamic_reloc() |
| 1025 | works. (See the comments in the declaration of struct lm_info |
| 1026 | for more information.) */ |
| 1027 | if (lm->dyn_syms == NULL) |
| 1028 | { |
| 1029 | long storage_needed; |
| 1030 | unsigned int number_of_symbols; |
| 1031 | |
| 1032 | /* Determine amount of space needed to hold the dynamic symbol table. */ |
| 1033 | storage_needed = bfd_get_dynamic_symtab_upper_bound (abfd); |
| 1034 | |
| 1035 | /* If there are no dynamic symbols, there's nothing to do. */ |
| 1036 | if (storage_needed <= 0) |
| 1037 | return 0; |
| 1038 | |
| 1039 | /* Allocate space for the dynamic symbol table. */ |
| 1040 | lm->dyn_syms = (asymbol **) xmalloc (storage_needed); |
| 1041 | |
| 1042 | /* Fetch the dynamic symbol table. */ |
| 1043 | number_of_symbols = bfd_canonicalize_dynamic_symtab (abfd, lm->dyn_syms); |
| 1044 | |
| 1045 | if (number_of_symbols == 0) |
| 1046 | return 0; |
| 1047 | } |
| 1048 | |
| 1049 | /* Fetch the dynamic relocations if not already cached. */ |
| 1050 | if (lm->dyn_relocs == NULL) |
| 1051 | { |
| 1052 | long storage_needed; |
| 1053 | |
| 1054 | /* Determine amount of space needed to hold the dynamic relocs. */ |
| 1055 | storage_needed = bfd_get_dynamic_reloc_upper_bound (abfd); |
| 1056 | |
| 1057 | /* Bail out if there are no dynamic relocs. */ |
| 1058 | if (storage_needed <= 0) |
| 1059 | return 0; |
| 1060 | |
| 1061 | /* Allocate space for the relocs. */ |
| 1062 | lm->dyn_relocs = (arelent **) xmalloc (storage_needed); |
| 1063 | |
| 1064 | /* Fetch the dynamic relocs. */ |
| 1065 | lm->dyn_reloc_count |
| 1066 | = bfd_canonicalize_dynamic_reloc (abfd, lm->dyn_relocs, lm->dyn_syms); |
| 1067 | } |
| 1068 | |
| 1069 | /* Search the dynamic relocs. */ |
| 1070 | for (i = 0; i < lm->dyn_reloc_count; i++) |
| 1071 | { |
| 1072 | rel = lm->dyn_relocs[i]; |
| 1073 | |
| 1074 | /* Relocs of interest are those which meet the following |
| 1075 | criteria: |
| 1076 | |
| 1077 | - the names match (assuming the caller could provide |
| 1078 | a name which matches ``entry_point''). |
| 1079 | - the relocation type must be R_FRV_FUNCDESC. Relocs |
| 1080 | of this type are used (by the dynamic linker) to |
| 1081 | look up the address of a canonical descriptor (allocating |
| 1082 | it if need be) and initializing the GOT entry referred |
| 1083 | to by the offset to the address of the descriptor. |
| 1084 | |
| 1085 | These relocs of interest may be used to obtain a |
| 1086 | candidate descriptor by first adjusting the reloc's |
| 1087 | address according to the link map and then dereferencing |
| 1088 | this address (which is a GOT entry) to obtain a descriptor |
| 1089 | address. */ |
| 1090 | if ((name == 0 || strcmp (name, (*rel->sym_ptr_ptr)->name) == 0) |
| 1091 | && rel->howto->type == R_FRV_FUNCDESC) |
| 1092 | { |
| 1093 | gdb_byte buf [FRV_PTR_SIZE]; |
| 1094 | |
| 1095 | /* Compute address of address of candidate descriptor. */ |
| 1096 | addr = rel->address + displacement_from_map (lm->map, rel->address); |
| 1097 | |
| 1098 | /* Fetch address of candidate descriptor. */ |
| 1099 | if (target_read_memory (addr, buf, sizeof buf) != 0) |
| 1100 | continue; |
| 1101 | addr = extract_unsigned_integer (buf, sizeof buf, byte_order); |
| 1102 | |
| 1103 | /* Check for matching entry point. */ |
| 1104 | if (target_read_memory (addr, buf, sizeof buf) != 0) |
| 1105 | continue; |
| 1106 | if (extract_unsigned_integer (buf, sizeof buf, byte_order) |
| 1107 | != entry_point) |
| 1108 | continue; |
| 1109 | |
| 1110 | /* Check for matching got value. */ |
| 1111 | if (target_read_memory (addr + 4, buf, sizeof buf) != 0) |
| 1112 | continue; |
| 1113 | if (extract_unsigned_integer (buf, sizeof buf, byte_order) |
| 1114 | != got_value) |
| 1115 | continue; |
| 1116 | |
| 1117 | /* Match was successful! Exit loop. */ |
| 1118 | break; |
| 1119 | } |
| 1120 | } |
| 1121 | |
| 1122 | return addr; |
| 1123 | } |
| 1124 | |
| 1125 | /* Given an objfile, return the address of its link map. This value is |
| 1126 | needed for TLS support. */ |
| 1127 | CORE_ADDR |
| 1128 | frv_fetch_objfile_link_map (struct objfile *objfile) |
| 1129 | { |
| 1130 | struct so_list *so; |
| 1131 | |
| 1132 | /* Cause frv_current_sos() to be run if it hasn't been already. */ |
| 1133 | if (main_lm_addr == 0) |
| 1134 | solib_add (0, 0, 1); |
| 1135 | |
| 1136 | /* frv_current_sos() will set main_lm_addr for the main executable. */ |
| 1137 | if (objfile == symfile_objfile) |
| 1138 | return main_lm_addr; |
| 1139 | |
| 1140 | /* The other link map addresses may be found by examining the list |
| 1141 | of shared libraries. */ |
| 1142 | for (so = master_so_list (); so; so = so->next) |
| 1143 | { |
| 1144 | lm_info_frv *li = (lm_info_frv *) so->lm_info; |
| 1145 | |
| 1146 | if (so->objfile == objfile) |
| 1147 | return li->lm_addr; |
| 1148 | } |
| 1149 | |
| 1150 | /* Not found! */ |
| 1151 | return 0; |
| 1152 | } |
| 1153 | |
| 1154 | struct target_so_ops frv_so_ops; |
| 1155 | |
| 1156 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 1157 | extern initialize_file_ftype _initialize_frv_solib; |
| 1158 | |
| 1159 | void |
| 1160 | _initialize_frv_solib (void) |
| 1161 | { |
| 1162 | frv_so_ops.relocate_section_addresses = frv_relocate_section_addresses; |
| 1163 | frv_so_ops.free_so = frv_free_so; |
| 1164 | frv_so_ops.clear_solib = frv_clear_solib; |
| 1165 | frv_so_ops.solib_create_inferior_hook = frv_solib_create_inferior_hook; |
| 1166 | frv_so_ops.current_sos = frv_current_sos; |
| 1167 | frv_so_ops.open_symbol_file_object = open_symbol_file_object; |
| 1168 | frv_so_ops.in_dynsym_resolve_code = frv_in_dynsym_resolve_code; |
| 1169 | frv_so_ops.bfd_open = solib_bfd_open; |
| 1170 | |
| 1171 | /* Debug this file's internals. */ |
| 1172 | add_setshow_zuinteger_cmd ("solib-frv", class_maintenance, |
| 1173 | &solib_frv_debug, _("\ |
| 1174 | Set internal debugging of shared library code for FR-V."), _("\ |
| 1175 | Show internal debugging of shared library code for FR-V."), _("\ |
| 1176 | When non-zero, FR-V solib specific internal debugging is enabled."), |
| 1177 | NULL, |
| 1178 | NULL, /* FIXME: i18n: */ |
| 1179 | &setdebuglist, &showdebuglist); |
| 1180 | } |