| 1 | /* Handle SunOS and SVR4 shared libraries for GDB, the GNU Debugger. |
| 2 | Copyright 1990, 1991, 1992 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 2 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, write to the Free Software |
| 18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 19 | |
| 20 | |
| 21 | #include "defs.h" |
| 22 | |
| 23 | #include <sys/types.h> |
| 24 | #include <signal.h> |
| 25 | #include <string.h> |
| 26 | #include <link.h> |
| 27 | #include <sys/param.h> |
| 28 | #include <fcntl.h> |
| 29 | |
| 30 | #ifndef SVR4_SHARED_LIBS |
| 31 | /* SunOS shared libs need the nlist structure. */ |
| 32 | #include <a.out.h> |
| 33 | #endif |
| 34 | |
| 35 | #include "symtab.h" |
| 36 | #include "bfd.h" |
| 37 | #include "symfile.h" |
| 38 | #include "objfiles.h" |
| 39 | #include "gdbcore.h" |
| 40 | #include "command.h" |
| 41 | #include "target.h" |
| 42 | #include "frame.h" |
| 43 | #include "regex.h" |
| 44 | #include "inferior.h" |
| 45 | #include "language.h" |
| 46 | |
| 47 | #define MAX_PATH_SIZE 256 /* FIXME: Should be dynamic */ |
| 48 | |
| 49 | /* On SVR4 systems, for the initial implementation, use some runtime startup |
| 50 | symbol as the "startup mapping complete" breakpoint address. The models |
| 51 | for SunOS and SVR4 dynamic linking debugger support are different in that |
| 52 | SunOS hits one breakpoint when all mapping is complete while using the SVR4 |
| 53 | debugger support takes two breakpoint hits for each file mapped, and |
| 54 | there is no way to know when the "last" one is hit. Both these |
| 55 | mechanisms should be tied to a "breakpoint service routine" that |
| 56 | gets automatically executed whenever one of the breakpoints indicating |
| 57 | a change in mapping is hit. This is a future enhancement. (FIXME) */ |
| 58 | |
| 59 | #define BKPT_AT_SYMBOL 1 |
| 60 | |
| 61 | #if defined (BKPT_AT_SYMBOL) && defined (SVR4_SHARED_LIBS) |
| 62 | static char *bkpt_names[] = { |
| 63 | #ifdef SOLIB_BKPT_NAME |
| 64 | SOLIB_BKPT_NAME, /* Prefer configured name if it exists. */ |
| 65 | #endif |
| 66 | "_start", |
| 67 | "main", |
| 68 | NULL |
| 69 | }; |
| 70 | #endif |
| 71 | |
| 72 | /* local data declarations */ |
| 73 | |
| 74 | #ifndef SVR4_SHARED_LIBS |
| 75 | |
| 76 | #define DEBUG_BASE "_DYNAMIC" |
| 77 | #define LM_ADDR(so) ((so) -> lm.lm_addr) |
| 78 | #define LM_NEXT(so) ((so) -> lm.lm_next) |
| 79 | #define LM_NAME(so) ((so) -> lm.lm_name) |
| 80 | static struct link_dynamic dynamic_copy; |
| 81 | static struct link_dynamic_2 ld_2_copy; |
| 82 | static struct ld_debug debug_copy; |
| 83 | static CORE_ADDR debug_addr; |
| 84 | static CORE_ADDR flag_addr; |
| 85 | |
| 86 | #else /* SVR4_SHARED_LIBS */ |
| 87 | |
| 88 | #define DEBUG_BASE "_r_debug" |
| 89 | #define LM_ADDR(so) ((so) -> lm.l_addr) |
| 90 | #define LM_NEXT(so) ((so) -> lm.l_next) |
| 91 | #define LM_NAME(so) ((so) -> lm.l_name) |
| 92 | static struct r_debug debug_copy; |
| 93 | char shadow_contents[BREAKPOINT_MAX]; /* Stash old bkpt addr contents */ |
| 94 | |
| 95 | #endif /* !SVR4_SHARED_LIBS */ |
| 96 | |
| 97 | struct so_list { |
| 98 | struct so_list *next; /* next structure in linked list */ |
| 99 | struct link_map lm; /* copy of link map from inferior */ |
| 100 | struct link_map *lmaddr; /* addr in inferior lm was read from */ |
| 101 | CORE_ADDR lmend; /* upper addr bound of mapped object */ |
| 102 | char so_name[MAX_PATH_SIZE]; /* shared object lib name (FIXME) */ |
| 103 | char symbols_loaded; /* flag: symbols read in yet? */ |
| 104 | char from_tty; /* flag: print msgs? */ |
| 105 | struct objfile *objfile; /* objfile for loaded lib */ |
| 106 | struct section_table *sections; |
| 107 | struct section_table *sections_end; |
| 108 | struct section_table *textsection; |
| 109 | bfd *abfd; |
| 110 | }; |
| 111 | |
| 112 | static struct so_list *so_list_head; /* List of known shared objects */ |
| 113 | static CORE_ADDR debug_base; /* Base of dynamic linker structures */ |
| 114 | static CORE_ADDR breakpoint_addr; /* Address where end bkpt is set */ |
| 115 | |
| 116 | extern int |
| 117 | fdmatch PARAMS ((int, int)); /* In libiberty */ |
| 118 | |
| 119 | /* Local function prototypes */ |
| 120 | |
| 121 | static void |
| 122 | special_symbol_handling PARAMS ((struct so_list *)); |
| 123 | |
| 124 | static void |
| 125 | sharedlibrary_command PARAMS ((char *, int)); |
| 126 | |
| 127 | static int |
| 128 | enable_break PARAMS ((void)); |
| 129 | |
| 130 | static int |
| 131 | disable_break PARAMS ((void)); |
| 132 | |
| 133 | static void |
| 134 | info_sharedlibrary_command PARAMS ((char *, int)); |
| 135 | |
| 136 | static int |
| 137 | symbol_add_stub PARAMS ((char *)); |
| 138 | |
| 139 | static struct so_list * |
| 140 | find_solib PARAMS ((struct so_list *)); |
| 141 | |
| 142 | static struct link_map * |
| 143 | first_link_map_member PARAMS ((void)); |
| 144 | |
| 145 | static CORE_ADDR |
| 146 | locate_base PARAMS ((void)); |
| 147 | |
| 148 | static void |
| 149 | solib_map_sections PARAMS ((struct so_list *)); |
| 150 | |
| 151 | #ifdef SVR4_SHARED_LIBS |
| 152 | |
| 153 | static int |
| 154 | look_for_base PARAMS ((int, CORE_ADDR)); |
| 155 | |
| 156 | static CORE_ADDR |
| 157 | bfd_lookup_symbol PARAMS ((bfd *, char *)); |
| 158 | |
| 159 | #else |
| 160 | |
| 161 | static void |
| 162 | solib_add_common_symbols PARAMS ((struct rtc_symb *, struct objfile *)); |
| 163 | |
| 164 | #endif |
| 165 | |
| 166 | /* |
| 167 | |
| 168 | LOCAL FUNCTION |
| 169 | |
| 170 | solib_map_sections -- open bfd and build sections for shared lib |
| 171 | |
| 172 | SYNOPSIS |
| 173 | |
| 174 | static void solib_map_sections (struct so_list *so) |
| 175 | |
| 176 | DESCRIPTION |
| 177 | |
| 178 | Given a pointer to one of the shared objects in our list |
| 179 | of mapped objects, use the recorded name to open a bfd |
| 180 | descriptor for the object, build a section table, and then |
| 181 | relocate all the section addresses by the base address at |
| 182 | which the shared object was mapped. |
| 183 | |
| 184 | FIXMES |
| 185 | |
| 186 | In most (all?) cases the shared object file name recorded in the |
| 187 | dynamic linkage tables will be a fully qualified pathname. For |
| 188 | cases where it isn't, do we really mimic the systems search |
| 189 | mechanism correctly in the below code (particularly the tilde |
| 190 | expansion stuff?). |
| 191 | */ |
| 192 | |
| 193 | static void |
| 194 | solib_map_sections (so) |
| 195 | struct so_list *so; |
| 196 | { |
| 197 | char *filename; |
| 198 | char *scratch_pathname; |
| 199 | int scratch_chan; |
| 200 | struct section_table *p; |
| 201 | struct cleanup *old_chain; |
| 202 | bfd *abfd; |
| 203 | |
| 204 | filename = tilde_expand (so -> so_name); |
| 205 | old_chain = make_cleanup (free, filename); |
| 206 | |
| 207 | scratch_chan = openp (getenv ("PATH"), 1, filename, O_RDONLY, 0, |
| 208 | &scratch_pathname); |
| 209 | if (scratch_chan < 0) |
| 210 | { |
| 211 | scratch_chan = openp (getenv ("LD_LIBRARY_PATH"), 1, filename, |
| 212 | O_RDONLY, 0, &scratch_pathname); |
| 213 | } |
| 214 | if (scratch_chan < 0) |
| 215 | { |
| 216 | perror_with_name (filename); |
| 217 | } |
| 218 | /* Leave scratch_pathname allocated. abfd->name will point to it. */ |
| 219 | |
| 220 | abfd = bfd_fdopenr (scratch_pathname, gnutarget, scratch_chan); |
| 221 | if (!abfd) |
| 222 | { |
| 223 | close (scratch_chan); |
| 224 | error ("Could not open `%s' as an executable file: %s", |
| 225 | scratch_pathname, bfd_errmsg (bfd_error)); |
| 226 | } |
| 227 | /* Leave bfd open, core_xfer_memory and "info files" need it. */ |
| 228 | so -> abfd = abfd; |
| 229 | abfd -> cacheable = true; |
| 230 | |
| 231 | if (!bfd_check_format (abfd, bfd_object)) |
| 232 | { |
| 233 | error ("\"%s\": not in executable format: %s.", |
| 234 | scratch_pathname, bfd_errmsg (bfd_error)); |
| 235 | } |
| 236 | if (build_section_table (abfd, &so -> sections, &so -> sections_end)) |
| 237 | { |
| 238 | error ("Can't find the file sections in `%s': %s", |
| 239 | bfd_get_filename (exec_bfd), bfd_errmsg (bfd_error)); |
| 240 | } |
| 241 | |
| 242 | for (p = so -> sections; p < so -> sections_end; p++) |
| 243 | { |
| 244 | /* Relocate the section binding addresses as recorded in the shared |
| 245 | object's file by the base address to which the object was actually |
| 246 | mapped. */ |
| 247 | p -> addr += (CORE_ADDR) LM_ADDR (so); |
| 248 | p -> endaddr += (CORE_ADDR) LM_ADDR (so); |
| 249 | so -> lmend = (CORE_ADDR) max (p -> endaddr, so -> lmend); |
| 250 | if (STREQ (p -> sec_ptr -> name, ".text")) |
| 251 | { |
| 252 | so -> textsection = p; |
| 253 | } |
| 254 | } |
| 255 | |
| 256 | /* Free the file names, close the file now. */ |
| 257 | do_cleanups (old_chain); |
| 258 | } |
| 259 | |
| 260 | /* Read all dynamically loaded common symbol definitions from the inferior |
| 261 | and add them to the minimal symbol table for the shared library objfile. */ |
| 262 | |
| 263 | #ifndef SVR4_SHARED_LIBS |
| 264 | |
| 265 | /* In GDB 4.9 this routine was a real performance hog. According to |
| 266 | some gprof data which mtranle@paris.IntelliCorp.COM (Minh Tran-Le) |
| 267 | sent, almost all the time spend in solib_add (up to 20 minutes with |
| 268 | 35 shared libraries) was spent here, with 5/6 in |
| 269 | lookup_minimal_symbol and 1/6 in read_memory. |
| 270 | |
| 271 | To fix this, we moved the call to special_symbol_handling out of the |
| 272 | loop in solib_add, so this only gets called once, rather than once |
| 273 | for every shared library, and also removed the call to lookup_minimal_symbol |
| 274 | in this routine. */ |
| 275 | |
| 276 | static void |
| 277 | solib_add_common_symbols (rtc_symp, objfile) |
| 278 | struct rtc_symb *rtc_symp; |
| 279 | struct objfile *objfile; |
| 280 | { |
| 281 | struct rtc_symb inferior_rtc_symb; |
| 282 | struct nlist inferior_rtc_nlist; |
| 283 | int len; |
| 284 | char *name; |
| 285 | char *origname; |
| 286 | |
| 287 | init_minimal_symbol_collection (); |
| 288 | make_cleanup (discard_minimal_symbols, 0); |
| 289 | |
| 290 | while (rtc_symp) |
| 291 | { |
| 292 | read_memory ((CORE_ADDR) rtc_symp, |
| 293 | (char *) &inferior_rtc_symb, |
| 294 | sizeof (inferior_rtc_symb)); |
| 295 | read_memory ((CORE_ADDR) inferior_rtc_symb.rtc_sp, |
| 296 | (char *) &inferior_rtc_nlist, |
| 297 | sizeof(inferior_rtc_nlist)); |
| 298 | if (inferior_rtc_nlist.n_type == N_COMM) |
| 299 | { |
| 300 | /* FIXME: The length of the symbol name is not available, but in the |
| 301 | current implementation the common symbol is allocated immediately |
| 302 | behind the name of the symbol. */ |
| 303 | len = inferior_rtc_nlist.n_value - inferior_rtc_nlist.n_un.n_strx; |
| 304 | |
| 305 | origname = name = xmalloc (len); |
| 306 | read_memory ((CORE_ADDR) inferior_rtc_nlist.n_un.n_name, name, len); |
| 307 | |
| 308 | /* Don't enter the symbol twice if the target is re-run. */ |
| 309 | |
| 310 | if (name[0] == bfd_get_symbol_leading_char (objfile->obfd)) |
| 311 | { |
| 312 | name++; |
| 313 | } |
| 314 | |
| 315 | #if 0 |
| 316 | /* I think this is unnecessary, GDB can probably deal with |
| 317 | duplicate minimal symbols, more or less. And the duplication |
| 318 | which used to happen because this was called for each shared |
| 319 | library is gone now that we are just called once. */ |
| 320 | /* FIXME: Do we really want to exclude symbols which happen |
| 321 | to match symbols for other locations in the inferior's |
| 322 | address space, even when they are in different linkage units? */ |
| 323 | if (lookup_minimal_symbol (name, (struct objfile *) NULL) == NULL) |
| 324 | #endif |
| 325 | { |
| 326 | name = obsavestring (name, strlen (name), |
| 327 | &objfile -> symbol_obstack); |
| 328 | prim_record_minimal_symbol (name, inferior_rtc_nlist.n_value, |
| 329 | mst_bss, objfile); |
| 330 | } |
| 331 | free (origname); |
| 332 | } |
| 333 | rtc_symp = inferior_rtc_symb.rtc_next; |
| 334 | } |
| 335 | |
| 336 | /* Install any minimal symbols that have been collected as the current |
| 337 | minimal symbols for this objfile. */ |
| 338 | |
| 339 | install_minimal_symbols (objfile); |
| 340 | } |
| 341 | |
| 342 | #endif /* SVR4_SHARED_LIBS */ |
| 343 | |
| 344 | #ifdef SVR4_SHARED_LIBS |
| 345 | |
| 346 | /* |
| 347 | |
| 348 | LOCAL FUNCTION |
| 349 | |
| 350 | bfd_lookup_symbol -- lookup the value for a specific symbol |
| 351 | |
| 352 | SYNOPSIS |
| 353 | |
| 354 | CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname) |
| 355 | |
| 356 | DESCRIPTION |
| 357 | |
| 358 | An expensive way to lookup the value of a single symbol for |
| 359 | bfd's that are only temporary anyway. This is used by the |
| 360 | shared library support to find the address of the debugger |
| 361 | interface structures in the shared library. |
| 362 | |
| 363 | Note that 0 is specifically allowed as an error return (no |
| 364 | such symbol). |
| 365 | |
| 366 | FIXME: See if there is a less "expensive" way of doing this. |
| 367 | Also see if there is already another bfd or gdb function |
| 368 | that specifically does this, and if so, use it. |
| 369 | */ |
| 370 | |
| 371 | static CORE_ADDR |
| 372 | bfd_lookup_symbol (abfd, symname) |
| 373 | bfd *abfd; |
| 374 | char *symname; |
| 375 | { |
| 376 | unsigned int storage_needed; |
| 377 | asymbol *sym; |
| 378 | asymbol **symbol_table; |
| 379 | unsigned int number_of_symbols; |
| 380 | unsigned int i; |
| 381 | struct cleanup *back_to; |
| 382 | CORE_ADDR symaddr = 0; |
| 383 | |
| 384 | storage_needed = get_symtab_upper_bound (abfd); |
| 385 | |
| 386 | if (storage_needed > 0) |
| 387 | { |
| 388 | symbol_table = (asymbol **) xmalloc (storage_needed); |
| 389 | back_to = make_cleanup (free, (PTR)symbol_table); |
| 390 | number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table); |
| 391 | |
| 392 | for (i = 0; i < number_of_symbols; i++) |
| 393 | { |
| 394 | sym = *symbol_table++; |
| 395 | if (STREQ (sym -> name, symname)) |
| 396 | { |
| 397 | /* Bfd symbols are section relative. */ |
| 398 | symaddr = sym -> value + sym -> section -> vma; |
| 399 | break; |
| 400 | } |
| 401 | } |
| 402 | do_cleanups (back_to); |
| 403 | } |
| 404 | return (symaddr); |
| 405 | } |
| 406 | |
| 407 | /* |
| 408 | |
| 409 | LOCAL FUNCTION |
| 410 | |
| 411 | look_for_base -- examine file for each mapped address segment |
| 412 | |
| 413 | SYNOPSYS |
| 414 | |
| 415 | static int look_for_base (int fd, CORE_ADDR baseaddr) |
| 416 | |
| 417 | DESCRIPTION |
| 418 | |
| 419 | This function is passed to proc_iterate_over_mappings, which |
| 420 | causes it to get called once for each mapped address space, with |
| 421 | an open file descriptor for the file mapped to that space, and the |
| 422 | base address of that mapped space. |
| 423 | |
| 424 | Our job is to find the symbol DEBUG_BASE in the file that this |
| 425 | fd is open on, if it exists, and if so, initialize the dynamic |
| 426 | linker structure base address debug_base. |
| 427 | |
| 428 | Note that this is a computationally expensive proposition, since |
| 429 | we basically have to open a bfd on every call, so we specifically |
| 430 | avoid opening the exec file. |
| 431 | */ |
| 432 | |
| 433 | static int |
| 434 | look_for_base (fd, baseaddr) |
| 435 | int fd; |
| 436 | CORE_ADDR baseaddr; |
| 437 | { |
| 438 | bfd *interp_bfd; |
| 439 | CORE_ADDR address; |
| 440 | |
| 441 | /* If the fd is -1, then there is no file that corresponds to this |
| 442 | mapped memory segment, so skip it. Also, if the fd corresponds |
| 443 | to the exec file, skip it as well. */ |
| 444 | |
| 445 | if ((fd == -1) || fdmatch (fileno ((GDB_FILE *)(exec_bfd -> iostream)), fd)) |
| 446 | { |
| 447 | return (0); |
| 448 | } |
| 449 | |
| 450 | /* Try to open whatever random file this fd corresponds to. Note that |
| 451 | we have no way currently to find the filename. Don't gripe about |
| 452 | any problems we might have, just fail. */ |
| 453 | |
| 454 | if ((interp_bfd = bfd_fdopenr ("unnamed", gnutarget, fd)) == NULL) |
| 455 | { |
| 456 | return (0); |
| 457 | } |
| 458 | if (!bfd_check_format (interp_bfd, bfd_object)) |
| 459 | { |
| 460 | bfd_close (interp_bfd); |
| 461 | return (0); |
| 462 | } |
| 463 | |
| 464 | /* Now try to find our DEBUG_BASE symbol in this file, which we at |
| 465 | least know to be a valid ELF executable or shared library. */ |
| 466 | |
| 467 | if ((address = bfd_lookup_symbol (interp_bfd, DEBUG_BASE)) == 0) |
| 468 | { |
| 469 | bfd_close (interp_bfd); |
| 470 | return (0); |
| 471 | } |
| 472 | |
| 473 | /* Eureka! We found the symbol. But now we may need to relocate it |
| 474 | by the base address. If the symbol's value is less than the base |
| 475 | address of the shared library, then it hasn't yet been relocated |
| 476 | by the dynamic linker, and we have to do it ourself. FIXME: Note |
| 477 | that we make the assumption that the first segment that corresponds |
| 478 | to the shared library has the base address to which the library |
| 479 | was relocated. */ |
| 480 | |
| 481 | if (address < baseaddr) |
| 482 | { |
| 483 | address += baseaddr; |
| 484 | } |
| 485 | debug_base = address; |
| 486 | bfd_close (interp_bfd); |
| 487 | return (1); |
| 488 | } |
| 489 | |
| 490 | #endif |
| 491 | |
| 492 | /* |
| 493 | |
| 494 | LOCAL FUNCTION |
| 495 | |
| 496 | locate_base -- locate the base address of dynamic linker structs |
| 497 | |
| 498 | SYNOPSIS |
| 499 | |
| 500 | CORE_ADDR locate_base (void) |
| 501 | |
| 502 | DESCRIPTION |
| 503 | |
| 504 | For both the SunOS and SVR4 shared library implementations, if the |
| 505 | inferior executable has been linked dynamically, there is a single |
| 506 | address somewhere in the inferior's data space which is the key to |
| 507 | locating all of the dynamic linker's runtime structures. This |
| 508 | address is the value of the symbol defined by the macro DEBUG_BASE. |
| 509 | The job of this function is to find and return that address, or to |
| 510 | return 0 if there is no such address (the executable is statically |
| 511 | linked for example). |
| 512 | |
| 513 | For SunOS, the job is almost trivial, since the dynamic linker and |
| 514 | all of it's structures are statically linked to the executable at |
| 515 | link time. Thus the symbol for the address we are looking for has |
| 516 | already been added to the minimal symbol table for the executable's |
| 517 | objfile at the time the symbol file's symbols were read, and all we |
| 518 | have to do is look it up there. Note that we explicitly do NOT want |
| 519 | to find the copies in the shared library. |
| 520 | |
| 521 | The SVR4 version is much more complicated because the dynamic linker |
| 522 | and it's structures are located in the shared C library, which gets |
| 523 | run as the executable's "interpreter" by the kernel. We have to go |
| 524 | to a lot more work to discover the address of DEBUG_BASE. Because |
| 525 | of this complexity, we cache the value we find and return that value |
| 526 | on subsequent invocations. Note there is no copy in the executable |
| 527 | symbol tables. |
| 528 | |
| 529 | Note that we can assume nothing about the process state at the time |
| 530 | we need to find this address. We may be stopped on the first instruc- |
| 531 | tion of the interpreter (C shared library), the first instruction of |
| 532 | the executable itself, or somewhere else entirely (if we attached |
| 533 | to the process for example). |
| 534 | |
| 535 | */ |
| 536 | |
| 537 | static CORE_ADDR |
| 538 | locate_base () |
| 539 | { |
| 540 | |
| 541 | #ifndef SVR4_SHARED_LIBS |
| 542 | |
| 543 | struct minimal_symbol *msymbol; |
| 544 | CORE_ADDR address = 0; |
| 545 | |
| 546 | /* For SunOS, we want to limit the search for DEBUG_BASE to the executable |
| 547 | being debugged, since there is a duplicate named symbol in the shared |
| 548 | library. We don't want the shared library versions. */ |
| 549 | |
| 550 | msymbol = lookup_minimal_symbol (DEBUG_BASE, symfile_objfile); |
| 551 | if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0)) |
| 552 | { |
| 553 | address = SYMBOL_VALUE_ADDRESS (msymbol); |
| 554 | } |
| 555 | return (address); |
| 556 | |
| 557 | #else /* SVR4_SHARED_LIBS */ |
| 558 | |
| 559 | /* Check to see if we have a currently valid address, and if so, avoid |
| 560 | doing all this work again and just return the cached address. If |
| 561 | we have no cached address, ask the /proc support interface to iterate |
| 562 | over the list of mapped address segments, calling look_for_base() for |
| 563 | each segment. When we are done, we will have either found the base |
| 564 | address or not. */ |
| 565 | |
| 566 | if (debug_base == 0) |
| 567 | { |
| 568 | proc_iterate_over_mappings (look_for_base); |
| 569 | } |
| 570 | return (debug_base); |
| 571 | |
| 572 | #endif /* !SVR4_SHARED_LIBS */ |
| 573 | |
| 574 | } |
| 575 | |
| 576 | /* |
| 577 | |
| 578 | LOCAL FUNCTION |
| 579 | |
| 580 | first_link_map_member -- locate first member in dynamic linker's map |
| 581 | |
| 582 | SYNOPSIS |
| 583 | |
| 584 | static struct link_map *first_link_map_member (void) |
| 585 | |
| 586 | DESCRIPTION |
| 587 | |
| 588 | Read in a copy of the first member in the inferior's dynamic |
| 589 | link map from the inferior's dynamic linker structures, and return |
| 590 | a pointer to the copy in our address space. |
| 591 | */ |
| 592 | |
| 593 | static struct link_map * |
| 594 | first_link_map_member () |
| 595 | { |
| 596 | struct link_map *lm = NULL; |
| 597 | |
| 598 | #ifndef SVR4_SHARED_LIBS |
| 599 | |
| 600 | read_memory (debug_base, (char *) &dynamic_copy, sizeof (dynamic_copy)); |
| 601 | if (dynamic_copy.ld_version >= 2) |
| 602 | { |
| 603 | /* It is a version that we can deal with, so read in the secondary |
| 604 | structure and find the address of the link map list from it. */ |
| 605 | read_memory ((CORE_ADDR) dynamic_copy.ld_un.ld_2, (char *) &ld_2_copy, |
| 606 | sizeof (struct link_dynamic_2)); |
| 607 | lm = ld_2_copy.ld_loaded; |
| 608 | } |
| 609 | |
| 610 | #else /* SVR4_SHARED_LIBS */ |
| 611 | |
| 612 | read_memory (debug_base, (char *) &debug_copy, sizeof (struct r_debug)); |
| 613 | /* FIXME: Perhaps we should validate the info somehow, perhaps by |
| 614 | checking r_version for a known version number, or r_state for |
| 615 | RT_CONSISTENT. */ |
| 616 | lm = debug_copy.r_map; |
| 617 | |
| 618 | #endif /* !SVR4_SHARED_LIBS */ |
| 619 | |
| 620 | return (lm); |
| 621 | } |
| 622 | |
| 623 | /* |
| 624 | |
| 625 | LOCAL FUNCTION |
| 626 | |
| 627 | find_solib -- step through list of shared objects |
| 628 | |
| 629 | SYNOPSIS |
| 630 | |
| 631 | struct so_list *find_solib (struct so_list *so_list_ptr) |
| 632 | |
| 633 | DESCRIPTION |
| 634 | |
| 635 | This module contains the routine which finds the names of any |
| 636 | loaded "images" in the current process. The argument in must be |
| 637 | NULL on the first call, and then the returned value must be passed |
| 638 | in on subsequent calls. This provides the capability to "step" down |
| 639 | the list of loaded objects. On the last object, a NULL value is |
| 640 | returned. |
| 641 | |
| 642 | The arg and return value are "struct link_map" pointers, as defined |
| 643 | in <link.h>. |
| 644 | */ |
| 645 | |
| 646 | static struct so_list * |
| 647 | find_solib (so_list_ptr) |
| 648 | struct so_list *so_list_ptr; /* Last lm or NULL for first one */ |
| 649 | { |
| 650 | struct so_list *so_list_next = NULL; |
| 651 | struct link_map *lm = NULL; |
| 652 | struct so_list *new; |
| 653 | |
| 654 | if (so_list_ptr == NULL) |
| 655 | { |
| 656 | /* We are setting up for a new scan through the loaded images. */ |
| 657 | if ((so_list_next = so_list_head) == NULL) |
| 658 | { |
| 659 | /* We have not already read in the dynamic linking structures |
| 660 | from the inferior, lookup the address of the base structure. */ |
| 661 | debug_base = locate_base (); |
| 662 | if (debug_base != 0) |
| 663 | { |
| 664 | /* Read the base structure in and find the address of the first |
| 665 | link map list member. */ |
| 666 | lm = first_link_map_member (); |
| 667 | } |
| 668 | } |
| 669 | } |
| 670 | else |
| 671 | { |
| 672 | /* We have been called before, and are in the process of walking |
| 673 | the shared library list. Advance to the next shared object. */ |
| 674 | if ((lm = LM_NEXT (so_list_ptr)) == NULL) |
| 675 | { |
| 676 | /* We have hit the end of the list, so check to see if any were |
| 677 | added, but be quiet if we can't read from the target any more. */ |
| 678 | int status = target_read_memory ((CORE_ADDR) so_list_ptr -> lmaddr, |
| 679 | (char *) &(so_list_ptr -> lm), |
| 680 | sizeof (struct link_map)); |
| 681 | if (status == 0) |
| 682 | { |
| 683 | lm = LM_NEXT (so_list_ptr); |
| 684 | } |
| 685 | else |
| 686 | { |
| 687 | lm = NULL; |
| 688 | } |
| 689 | } |
| 690 | so_list_next = so_list_ptr -> next; |
| 691 | } |
| 692 | if ((so_list_next == NULL) && (lm != NULL)) |
| 693 | { |
| 694 | /* Get next link map structure from inferior image and build a local |
| 695 | abbreviated load_map structure */ |
| 696 | new = (struct so_list *) xmalloc (sizeof (struct so_list)); |
| 697 | memset ((char *) new, 0, sizeof (struct so_list)); |
| 698 | new -> lmaddr = lm; |
| 699 | /* Add the new node as the next node in the list, or as the root |
| 700 | node if this is the first one. */ |
| 701 | if (so_list_ptr != NULL) |
| 702 | { |
| 703 | so_list_ptr -> next = new; |
| 704 | } |
| 705 | else |
| 706 | { |
| 707 | so_list_head = new; |
| 708 | } |
| 709 | so_list_next = new; |
| 710 | read_memory ((CORE_ADDR) lm, (char *) &(new -> lm), |
| 711 | sizeof (struct link_map)); |
| 712 | /* For the SVR4 version, there is one entry that has no name |
| 713 | (for the inferior executable) since it is not a shared object. */ |
| 714 | if (LM_NAME (new) != 0) |
| 715 | { |
| 716 | if (!target_read_string((CORE_ADDR) LM_NAME (new), new -> so_name, |
| 717 | MAX_PATH_SIZE - 1)) |
| 718 | error ("find_solib: Can't read pathname for load map\n"); |
| 719 | new -> so_name[MAX_PATH_SIZE - 1] = 0; |
| 720 | solib_map_sections (new); |
| 721 | } |
| 722 | } |
| 723 | return (so_list_next); |
| 724 | } |
| 725 | |
| 726 | /* A small stub to get us past the arg-passing pinhole of catch_errors. */ |
| 727 | |
| 728 | static int |
| 729 | symbol_add_stub (arg) |
| 730 | char *arg; |
| 731 | { |
| 732 | register struct so_list *so = (struct so_list *) arg; /* catch_errs bogon */ |
| 733 | |
| 734 | so -> objfile = symbol_file_add (so -> so_name, so -> from_tty, |
| 735 | (unsigned int) so -> textsection -> addr, |
| 736 | 0, 0, 0); |
| 737 | return (1); |
| 738 | } |
| 739 | |
| 740 | /* |
| 741 | |
| 742 | GLOBAL FUNCTION |
| 743 | |
| 744 | solib_add -- add a shared library file to the symtab and section list |
| 745 | |
| 746 | SYNOPSIS |
| 747 | |
| 748 | void solib_add (char *arg_string, int from_tty, |
| 749 | struct target_ops *target) |
| 750 | |
| 751 | DESCRIPTION |
| 752 | |
| 753 | */ |
| 754 | |
| 755 | void |
| 756 | solib_add (arg_string, from_tty, target) |
| 757 | char *arg_string; |
| 758 | int from_tty; |
| 759 | struct target_ops *target; |
| 760 | { |
| 761 | register struct so_list *so = NULL; /* link map state variable */ |
| 762 | |
| 763 | /* Last shared library that we read. */ |
| 764 | struct so_list *so_last = NULL; |
| 765 | |
| 766 | char *re_err; |
| 767 | int count; |
| 768 | int old; |
| 769 | |
| 770 | if ((re_err = re_comp (arg_string ? arg_string : ".")) != NULL) |
| 771 | { |
| 772 | error ("Invalid regexp: %s", re_err); |
| 773 | } |
| 774 | |
| 775 | /* Getting new symbols may change our opinion about what is |
| 776 | frameless. */ |
| 777 | reinit_frame_cache (); |
| 778 | |
| 779 | while ((so = find_solib (so)) != NULL) |
| 780 | { |
| 781 | if (so -> so_name[0] && re_exec (so -> so_name)) |
| 782 | { |
| 783 | so -> from_tty = from_tty; |
| 784 | if (so -> symbols_loaded) |
| 785 | { |
| 786 | if (from_tty) |
| 787 | { |
| 788 | printf_unfiltered ("Symbols already loaded for %s\n", so -> so_name); |
| 789 | } |
| 790 | } |
| 791 | else if (catch_errors |
| 792 | (symbol_add_stub, (char *) so, |
| 793 | "Error while reading shared library symbols:\n", |
| 794 | RETURN_MASK_ALL)) |
| 795 | { |
| 796 | so_last = so; |
| 797 | so -> symbols_loaded = 1; |
| 798 | } |
| 799 | } |
| 800 | } |
| 801 | |
| 802 | /* Now add the shared library sections to the section table of the |
| 803 | specified target, if any. */ |
| 804 | if (target) |
| 805 | { |
| 806 | /* Count how many new section_table entries there are. */ |
| 807 | so = NULL; |
| 808 | count = 0; |
| 809 | while ((so = find_solib (so)) != NULL) |
| 810 | { |
| 811 | if (so -> so_name[0]) |
| 812 | { |
| 813 | count += so -> sections_end - so -> sections; |
| 814 | } |
| 815 | } |
| 816 | |
| 817 | if (count) |
| 818 | { |
| 819 | /* Reallocate the target's section table including the new size. */ |
| 820 | if (target -> to_sections) |
| 821 | { |
| 822 | old = target -> to_sections_end - target -> to_sections; |
| 823 | target -> to_sections = (struct section_table *) |
| 824 | xrealloc ((char *)target -> to_sections, |
| 825 | (sizeof (struct section_table)) * (count + old)); |
| 826 | } |
| 827 | else |
| 828 | { |
| 829 | old = 0; |
| 830 | target -> to_sections = (struct section_table *) |
| 831 | xmalloc ((sizeof (struct section_table)) * count); |
| 832 | } |
| 833 | target -> to_sections_end = target -> to_sections + (count + old); |
| 834 | |
| 835 | /* Add these section table entries to the target's table. */ |
| 836 | while ((so = find_solib (so)) != NULL) |
| 837 | { |
| 838 | if (so -> so_name[0]) |
| 839 | { |
| 840 | count = so -> sections_end - so -> sections; |
| 841 | memcpy ((char *) (target -> to_sections + old), |
| 842 | so -> sections, |
| 843 | (sizeof (struct section_table)) * count); |
| 844 | old += count; |
| 845 | } |
| 846 | } |
| 847 | } |
| 848 | } |
| 849 | |
| 850 | /* Calling this once at the end means that we put all the minimal |
| 851 | symbols for commons into the objfile for the last shared library. |
| 852 | Since they are in common, this should not be a problem. If we |
| 853 | delete the objfile with the minimal symbols, we can put all the |
| 854 | symbols into a new objfile (and will on the next call to solib_add). |
| 855 | |
| 856 | An alternate approach would be to create an objfile just for |
| 857 | common minsyms, thus not needing any objfile argument to |
| 858 | solib_add_common_symbols. */ |
| 859 | |
| 860 | if (so_last) |
| 861 | special_symbol_handling (so_last); |
| 862 | } |
| 863 | |
| 864 | /* |
| 865 | |
| 866 | LOCAL FUNCTION |
| 867 | |
| 868 | info_sharedlibrary_command -- code for "info sharedlibrary" |
| 869 | |
| 870 | SYNOPSIS |
| 871 | |
| 872 | static void info_sharedlibrary_command () |
| 873 | |
| 874 | DESCRIPTION |
| 875 | |
| 876 | Walk through the shared library list and print information |
| 877 | about each attached library. |
| 878 | */ |
| 879 | |
| 880 | static void |
| 881 | info_sharedlibrary_command (ignore, from_tty) |
| 882 | char *ignore; |
| 883 | int from_tty; |
| 884 | { |
| 885 | register struct so_list *so = NULL; /* link map state variable */ |
| 886 | int header_done = 0; |
| 887 | |
| 888 | if (exec_bfd == NULL) |
| 889 | { |
| 890 | printf_unfiltered ("No exec file.\n"); |
| 891 | return; |
| 892 | } |
| 893 | while ((so = find_solib (so)) != NULL) |
| 894 | { |
| 895 | if (so -> so_name[0]) |
| 896 | { |
| 897 | if (!header_done) |
| 898 | { |
| 899 | printf_unfiltered("%-12s%-12s%-12s%s\n", "From", "To", "Syms Read", |
| 900 | "Shared Object Library"); |
| 901 | header_done++; |
| 902 | } |
| 903 | printf_unfiltered ("%-12s", |
| 904 | local_hex_string_custom ((unsigned long) LM_ADDR (so), |
| 905 | "08l")); |
| 906 | printf_unfiltered ("%-12s", |
| 907 | local_hex_string_custom ((unsigned long) so -> lmend, |
| 908 | "08l")); |
| 909 | printf_unfiltered ("%-12s", so -> symbols_loaded ? "Yes" : "No"); |
| 910 | printf_unfiltered ("%s\n", so -> so_name); |
| 911 | } |
| 912 | } |
| 913 | if (so_list_head == NULL) |
| 914 | { |
| 915 | printf_unfiltered ("No shared libraries loaded at this time.\n"); |
| 916 | } |
| 917 | } |
| 918 | |
| 919 | /* |
| 920 | |
| 921 | GLOBAL FUNCTION |
| 922 | |
| 923 | solib_address -- check to see if an address is in a shared lib |
| 924 | |
| 925 | SYNOPSIS |
| 926 | |
| 927 | int solib_address (CORE_ADDR address) |
| 928 | |
| 929 | DESCRIPTION |
| 930 | |
| 931 | Provides a hook for other gdb routines to discover whether or |
| 932 | not a particular address is within the mapped address space of |
| 933 | a shared library. Any address between the base mapping address |
| 934 | and the first address beyond the end of the last mapping, is |
| 935 | considered to be within the shared library address space, for |
| 936 | our purposes. |
| 937 | |
| 938 | For example, this routine is called at one point to disable |
| 939 | breakpoints which are in shared libraries that are not currently |
| 940 | mapped in. |
| 941 | */ |
| 942 | |
| 943 | int |
| 944 | solib_address (address) |
| 945 | CORE_ADDR address; |
| 946 | { |
| 947 | register struct so_list *so = 0; /* link map state variable */ |
| 948 | |
| 949 | while ((so = find_solib (so)) != NULL) |
| 950 | { |
| 951 | if (so -> so_name[0]) |
| 952 | { |
| 953 | if ((address >= (CORE_ADDR) LM_ADDR (so)) && |
| 954 | (address < (CORE_ADDR) so -> lmend)) |
| 955 | { |
| 956 | return (1); |
| 957 | } |
| 958 | } |
| 959 | } |
| 960 | return (0); |
| 961 | } |
| 962 | |
| 963 | /* Called by free_all_symtabs */ |
| 964 | |
| 965 | void |
| 966 | clear_solib() |
| 967 | { |
| 968 | struct so_list *next; |
| 969 | char *bfd_filename; |
| 970 | |
| 971 | while (so_list_head) |
| 972 | { |
| 973 | if (so_list_head -> sections) |
| 974 | { |
| 975 | free ((PTR)so_list_head -> sections); |
| 976 | } |
| 977 | if (so_list_head -> abfd) |
| 978 | { |
| 979 | bfd_filename = bfd_get_filename (so_list_head -> abfd); |
| 980 | bfd_close (so_list_head -> abfd); |
| 981 | } |
| 982 | else |
| 983 | /* This happens for the executable on SVR4. */ |
| 984 | bfd_filename = NULL; |
| 985 | |
| 986 | next = so_list_head -> next; |
| 987 | if (bfd_filename) |
| 988 | free ((PTR)bfd_filename); |
| 989 | free ((PTR)so_list_head); |
| 990 | so_list_head = next; |
| 991 | } |
| 992 | debug_base = 0; |
| 993 | } |
| 994 | |
| 995 | /* |
| 996 | |
| 997 | LOCAL FUNCTION |
| 998 | |
| 999 | disable_break -- remove the "mapping changed" breakpoint |
| 1000 | |
| 1001 | SYNOPSIS |
| 1002 | |
| 1003 | static int disable_break () |
| 1004 | |
| 1005 | DESCRIPTION |
| 1006 | |
| 1007 | Removes the breakpoint that gets hit when the dynamic linker |
| 1008 | completes a mapping change. |
| 1009 | |
| 1010 | */ |
| 1011 | |
| 1012 | static int |
| 1013 | disable_break () |
| 1014 | { |
| 1015 | int status = 1; |
| 1016 | |
| 1017 | #ifndef SVR4_SHARED_LIBS |
| 1018 | |
| 1019 | int in_debugger = 0; |
| 1020 | |
| 1021 | /* Read the debugger structure from the inferior to retrieve the |
| 1022 | address of the breakpoint and the original contents of the |
| 1023 | breakpoint address. Remove the breakpoint by writing the original |
| 1024 | contents back. */ |
| 1025 | |
| 1026 | read_memory (debug_addr, (char *) &debug_copy, sizeof (debug_copy)); |
| 1027 | |
| 1028 | /* Set `in_debugger' to zero now. */ |
| 1029 | |
| 1030 | write_memory (flag_addr, (char *) &in_debugger, sizeof (in_debugger)); |
| 1031 | |
| 1032 | breakpoint_addr = (CORE_ADDR) debug_copy.ldd_bp_addr; |
| 1033 | write_memory (breakpoint_addr, (char *) &debug_copy.ldd_bp_inst, |
| 1034 | sizeof (debug_copy.ldd_bp_inst)); |
| 1035 | |
| 1036 | #else /* SVR4_SHARED_LIBS */ |
| 1037 | |
| 1038 | /* Note that breakpoint address and original contents are in our address |
| 1039 | space, so we just need to write the original contents back. */ |
| 1040 | |
| 1041 | if (memory_remove_breakpoint (breakpoint_addr, shadow_contents) != 0) |
| 1042 | { |
| 1043 | status = 0; |
| 1044 | } |
| 1045 | |
| 1046 | #endif /* !SVR4_SHARED_LIBS */ |
| 1047 | |
| 1048 | /* For the SVR4 version, we always know the breakpoint address. For the |
| 1049 | SunOS version we don't know it until the above code is executed. |
| 1050 | Grumble if we are stopped anywhere besides the breakpoint address. */ |
| 1051 | |
| 1052 | if (stop_pc != breakpoint_addr) |
| 1053 | { |
| 1054 | warning ("stopped at unknown breakpoint while handling shared libraries"); |
| 1055 | } |
| 1056 | |
| 1057 | return (status); |
| 1058 | } |
| 1059 | |
| 1060 | /* |
| 1061 | |
| 1062 | LOCAL FUNCTION |
| 1063 | |
| 1064 | enable_break -- arrange for dynamic linker to hit breakpoint |
| 1065 | |
| 1066 | SYNOPSIS |
| 1067 | |
| 1068 | int enable_break (void) |
| 1069 | |
| 1070 | DESCRIPTION |
| 1071 | |
| 1072 | Both the SunOS and the SVR4 dynamic linkers have, as part of their |
| 1073 | debugger interface, support for arranging for the inferior to hit |
| 1074 | a breakpoint after mapping in the shared libraries. This function |
| 1075 | enables that breakpoint. |
| 1076 | |
| 1077 | For SunOS, there is a special flag location (in_debugger) which we |
| 1078 | set to 1. When the dynamic linker sees this flag set, it will set |
| 1079 | a breakpoint at a location known only to itself, after saving the |
| 1080 | original contents of that place and the breakpoint address itself, |
| 1081 | in it's own internal structures. When we resume the inferior, it |
| 1082 | will eventually take a SIGTRAP when it runs into the breakpoint. |
| 1083 | We handle this (in a different place) by restoring the contents of |
| 1084 | the breakpointed location (which is only known after it stops), |
| 1085 | chasing around to locate the shared libraries that have been |
| 1086 | loaded, then resuming. |
| 1087 | |
| 1088 | For SVR4, the debugger interface structure contains a member (r_brk) |
| 1089 | which is statically initialized at the time the shared library is |
| 1090 | built, to the offset of a function (_r_debug_state) which is guaran- |
| 1091 | teed to be called once before mapping in a library, and again when |
| 1092 | the mapping is complete. At the time we are examining this member, |
| 1093 | it contains only the unrelocated offset of the function, so we have |
| 1094 | to do our own relocation. Later, when the dynamic linker actually |
| 1095 | runs, it relocates r_brk to be the actual address of _r_debug_state(). |
| 1096 | |
| 1097 | The debugger interface structure also contains an enumeration which |
| 1098 | is set to either RT_ADD or RT_DELETE prior to changing the mapping, |
| 1099 | depending upon whether or not the library is being mapped or unmapped, |
| 1100 | and then set to RT_CONSISTENT after the library is mapped/unmapped. |
| 1101 | */ |
| 1102 | |
| 1103 | static int |
| 1104 | enable_break () |
| 1105 | { |
| 1106 | int success = 0; |
| 1107 | |
| 1108 | #ifndef SVR4_SHARED_LIBS |
| 1109 | |
| 1110 | int j; |
| 1111 | int in_debugger; |
| 1112 | |
| 1113 | /* Get link_dynamic structure */ |
| 1114 | |
| 1115 | j = target_read_memory (debug_base, (char *) &dynamic_copy, |
| 1116 | sizeof (dynamic_copy)); |
| 1117 | if (j) |
| 1118 | { |
| 1119 | /* unreadable */ |
| 1120 | return (0); |
| 1121 | } |
| 1122 | |
| 1123 | /* Calc address of debugger interface structure */ |
| 1124 | |
| 1125 | debug_addr = (CORE_ADDR) dynamic_copy.ldd; |
| 1126 | |
| 1127 | /* Calc address of `in_debugger' member of debugger interface structure */ |
| 1128 | |
| 1129 | flag_addr = debug_addr + (CORE_ADDR) ((char *) &debug_copy.ldd_in_debugger - |
| 1130 | (char *) &debug_copy); |
| 1131 | |
| 1132 | /* Write a value of 1 to this member. */ |
| 1133 | |
| 1134 | in_debugger = 1; |
| 1135 | write_memory (flag_addr, (char *) &in_debugger, sizeof (in_debugger)); |
| 1136 | success = 1; |
| 1137 | |
| 1138 | #else /* SVR4_SHARED_LIBS */ |
| 1139 | |
| 1140 | #ifdef BKPT_AT_SYMBOL |
| 1141 | |
| 1142 | struct minimal_symbol *msymbol; |
| 1143 | char **bkpt_namep; |
| 1144 | CORE_ADDR bkpt_addr; |
| 1145 | |
| 1146 | /* Scan through the list of symbols, trying to look up the symbol and |
| 1147 | set a breakpoint there. Terminate loop when we/if we succeed. */ |
| 1148 | |
| 1149 | breakpoint_addr = 0; |
| 1150 | for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++) |
| 1151 | { |
| 1152 | msymbol = lookup_minimal_symbol (*bkpt_namep, symfile_objfile); |
| 1153 | if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0)) |
| 1154 | { |
| 1155 | bkpt_addr = SYMBOL_VALUE_ADDRESS (msymbol); |
| 1156 | if (target_insert_breakpoint (bkpt_addr, shadow_contents) == 0) |
| 1157 | { |
| 1158 | breakpoint_addr = bkpt_addr; |
| 1159 | success = 1; |
| 1160 | break; |
| 1161 | } |
| 1162 | } |
| 1163 | } |
| 1164 | |
| 1165 | #else /* !BKPT_AT_SYMBOL */ |
| 1166 | |
| 1167 | struct symtab_and_line sal; |
| 1168 | |
| 1169 | /* Read the debugger interface structure directly. */ |
| 1170 | |
| 1171 | read_memory (debug_base, (char *) &debug_copy, sizeof (debug_copy)); |
| 1172 | |
| 1173 | /* Set breakpoint at the debugger interface stub routine that will |
| 1174 | be called just prior to each mapping change and again after the |
| 1175 | mapping change is complete. Set up the (nonexistent) handler to |
| 1176 | deal with hitting these breakpoints. (FIXME). */ |
| 1177 | |
| 1178 | warning ("'%s': line %d: missing SVR4 support code", __FILE__, __LINE__); |
| 1179 | success = 1; |
| 1180 | |
| 1181 | #endif /* BKPT_AT_SYMBOL */ |
| 1182 | |
| 1183 | #endif /* !SVR4_SHARED_LIBS */ |
| 1184 | |
| 1185 | return (success); |
| 1186 | } |
| 1187 | |
| 1188 | /* |
| 1189 | |
| 1190 | GLOBAL FUNCTION |
| 1191 | |
| 1192 | solib_create_inferior_hook -- shared library startup support |
| 1193 | |
| 1194 | SYNOPSIS |
| 1195 | |
| 1196 | void solib_create_inferior_hook() |
| 1197 | |
| 1198 | DESCRIPTION |
| 1199 | |
| 1200 | When gdb starts up the inferior, it nurses it along (through the |
| 1201 | shell) until it is ready to execute it's first instruction. At this |
| 1202 | point, this function gets called via expansion of the macro |
| 1203 | SOLIB_CREATE_INFERIOR_HOOK. |
| 1204 | |
| 1205 | For SunOS executables, this first instruction is typically the |
| 1206 | one at "_start", or a similar text label, regardless of whether |
| 1207 | the executable is statically or dynamically linked. The runtime |
| 1208 | startup code takes care of dynamically linking in any shared |
| 1209 | libraries, once gdb allows the inferior to continue. |
| 1210 | |
| 1211 | For SVR4 executables, this first instruction is either the first |
| 1212 | instruction in the dynamic linker (for dynamically linked |
| 1213 | executables) or the instruction at "start" for statically linked |
| 1214 | executables. For dynamically linked executables, the system |
| 1215 | first exec's /lib/libc.so.N, which contains the dynamic linker, |
| 1216 | and starts it running. The dynamic linker maps in any needed |
| 1217 | shared libraries, maps in the actual user executable, and then |
| 1218 | jumps to "start" in the user executable. |
| 1219 | |
| 1220 | For both SunOS shared libraries, and SVR4 shared libraries, we |
| 1221 | can arrange to cooperate with the dynamic linker to discover the |
| 1222 | names of shared libraries that are dynamically linked, and the |
| 1223 | base addresses to which they are linked. |
| 1224 | |
| 1225 | This function is responsible for discovering those names and |
| 1226 | addresses, and saving sufficient information about them to allow |
| 1227 | their symbols to be read at a later time. |
| 1228 | |
| 1229 | FIXME |
| 1230 | |
| 1231 | Between enable_break() and disable_break(), this code does not |
| 1232 | properly handle hitting breakpoints which the user might have |
| 1233 | set in the startup code or in the dynamic linker itself. Proper |
| 1234 | handling will probably have to wait until the implementation is |
| 1235 | changed to use the "breakpoint handler function" method. |
| 1236 | |
| 1237 | Also, what if child has exit()ed? Must exit loop somehow. |
| 1238 | */ |
| 1239 | |
| 1240 | void |
| 1241 | solib_create_inferior_hook() |
| 1242 | { |
| 1243 | /* If we are using the BKPT_AT_SYMBOL code, then we don't need the base |
| 1244 | yet. In fact, in the case of a SunOS4 executable being run on |
| 1245 | Solaris, we can't get it yet. find_solib will get it when it needs |
| 1246 | it. */ |
| 1247 | #if !(defined (SVR4_SHARED_LIBS) && defined (BKPT_AT_SYMBOL)) |
| 1248 | if ((debug_base = locate_base ()) == 0) |
| 1249 | { |
| 1250 | /* Can't find the symbol or the executable is statically linked. */ |
| 1251 | return; |
| 1252 | } |
| 1253 | #endif |
| 1254 | |
| 1255 | if (!enable_break ()) |
| 1256 | { |
| 1257 | warning ("shared library handler failed to enable breakpoint"); |
| 1258 | return; |
| 1259 | } |
| 1260 | |
| 1261 | /* Now run the target. It will eventually hit the breakpoint, at |
| 1262 | which point all of the libraries will have been mapped in and we |
| 1263 | can go groveling around in the dynamic linker structures to find |
| 1264 | out what we need to know about them. */ |
| 1265 | |
| 1266 | clear_proceed_status (); |
| 1267 | stop_soon_quietly = 1; |
| 1268 | stop_signal = 0; |
| 1269 | do |
| 1270 | { |
| 1271 | target_resume (-1, 0, stop_signal); |
| 1272 | wait_for_inferior (); |
| 1273 | } |
| 1274 | while (stop_signal != SIGTRAP); |
| 1275 | stop_soon_quietly = 0; |
| 1276 | |
| 1277 | /* We are now either at the "mapping complete" breakpoint (or somewhere |
| 1278 | else, a condition we aren't prepared to deal with anyway), so adjust |
| 1279 | the PC as necessary after a breakpoint, disable the breakpoint, and |
| 1280 | add any shared libraries that were mapped in. */ |
| 1281 | |
| 1282 | if (DECR_PC_AFTER_BREAK) |
| 1283 | { |
| 1284 | stop_pc -= DECR_PC_AFTER_BREAK; |
| 1285 | write_register (PC_REGNUM, stop_pc); |
| 1286 | } |
| 1287 | |
| 1288 | if (!disable_break ()) |
| 1289 | { |
| 1290 | warning ("shared library handler failed to disable breakpoint"); |
| 1291 | } |
| 1292 | |
| 1293 | solib_add ((char *) 0, 0, (struct target_ops *) 0); |
| 1294 | } |
| 1295 | |
| 1296 | /* |
| 1297 | |
| 1298 | LOCAL FUNCTION |
| 1299 | |
| 1300 | special_symbol_handling -- additional shared library symbol handling |
| 1301 | |
| 1302 | SYNOPSIS |
| 1303 | |
| 1304 | void special_symbol_handling (struct so_list *so) |
| 1305 | |
| 1306 | DESCRIPTION |
| 1307 | |
| 1308 | Once the symbols from a shared object have been loaded in the usual |
| 1309 | way, we are called to do any system specific symbol handling that |
| 1310 | is needed. |
| 1311 | |
| 1312 | For Suns, this consists of grunging around in the dynamic linkers |
| 1313 | structures to find symbol definitions for "common" symbols and |
| 1314 | adding them to the minimal symbol table for the corresponding |
| 1315 | objfile. |
| 1316 | |
| 1317 | */ |
| 1318 | |
| 1319 | static void |
| 1320 | special_symbol_handling (so) |
| 1321 | struct so_list *so; |
| 1322 | { |
| 1323 | #ifndef SVR4_SHARED_LIBS |
| 1324 | int j; |
| 1325 | |
| 1326 | if (debug_addr == 0) |
| 1327 | { |
| 1328 | /* Get link_dynamic structure */ |
| 1329 | |
| 1330 | j = target_read_memory (debug_base, (char *) &dynamic_copy, |
| 1331 | sizeof (dynamic_copy)); |
| 1332 | if (j) |
| 1333 | { |
| 1334 | /* unreadable */ |
| 1335 | return; |
| 1336 | } |
| 1337 | |
| 1338 | /* Calc address of debugger interface structure */ |
| 1339 | /* FIXME, this needs work for cross-debugging of core files |
| 1340 | (byteorder, size, alignment, etc). */ |
| 1341 | |
| 1342 | debug_addr = (CORE_ADDR) dynamic_copy.ldd; |
| 1343 | } |
| 1344 | |
| 1345 | /* Read the debugger structure from the inferior, just to make sure |
| 1346 | we have a current copy. */ |
| 1347 | |
| 1348 | j = target_read_memory (debug_addr, (char *) &debug_copy, |
| 1349 | sizeof (debug_copy)); |
| 1350 | if (j) |
| 1351 | return; /* unreadable */ |
| 1352 | |
| 1353 | /* Get common symbol definitions for the loaded object. */ |
| 1354 | |
| 1355 | if (debug_copy.ldd_cp) |
| 1356 | { |
| 1357 | solib_add_common_symbols (debug_copy.ldd_cp, so -> objfile); |
| 1358 | } |
| 1359 | |
| 1360 | #endif /* !SVR4_SHARED_LIBS */ |
| 1361 | } |
| 1362 | |
| 1363 | |
| 1364 | /* |
| 1365 | |
| 1366 | LOCAL FUNCTION |
| 1367 | |
| 1368 | sharedlibrary_command -- handle command to explicitly add library |
| 1369 | |
| 1370 | SYNOPSIS |
| 1371 | |
| 1372 | static void sharedlibrary_command (char *args, int from_tty) |
| 1373 | |
| 1374 | DESCRIPTION |
| 1375 | |
| 1376 | */ |
| 1377 | |
| 1378 | static void |
| 1379 | sharedlibrary_command (args, from_tty) |
| 1380 | char *args; |
| 1381 | int from_tty; |
| 1382 | { |
| 1383 | dont_repeat (); |
| 1384 | solib_add (args, from_tty, (struct target_ops *) 0); |
| 1385 | } |
| 1386 | |
| 1387 | void |
| 1388 | _initialize_solib() |
| 1389 | { |
| 1390 | |
| 1391 | add_com ("sharedlibrary", class_files, sharedlibrary_command, |
| 1392 | "Load shared object library symbols for files matching REGEXP."); |
| 1393 | add_info ("sharedlibrary", info_sharedlibrary_command, |
| 1394 | "Status of loaded shared object libraries."); |
| 1395 | } |