| 1 | /* Cell SPU GNU/Linux support -- shared library handling. |
| 2 | Copyright (C) 2009 Free Software Foundation, Inc. |
| 3 | |
| 4 | Contributed by Ulrich Weigand <uweigand@de.ibm.com>. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 2 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 21 | Boston, MA 02111-1307, USA. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "gdbcore.h" |
| 25 | #include "gdb_string.h" |
| 26 | #include "gdb_assert.h" |
| 27 | #include "gdb_stat.h" |
| 28 | #include "arch-utils.h" |
| 29 | #include "bfd.h" |
| 30 | #include "symtab.h" |
| 31 | #include "solib.h" |
| 32 | #include "solib-svr4.h" |
| 33 | #include "solist.h" |
| 34 | #include "inferior.h" |
| 35 | #include "objfiles.h" |
| 36 | #include "observer.h" |
| 37 | #include "breakpoint.h" |
| 38 | #include "gdbthread.h" |
| 39 | |
| 40 | #include "spu-tdep.h" |
| 41 | |
| 42 | /* Highest SPE id (file handle) the inferior may have. */ |
| 43 | #define MAX_SPE_FD 1024 |
| 44 | |
| 45 | /* Stand-alone SPE executable? */ |
| 46 | #define spu_standalone_p() \ |
| 47 | (symfile_objfile && symfile_objfile->obfd \ |
| 48 | && bfd_get_arch (symfile_objfile->obfd) == bfd_arch_spu) |
| 49 | |
| 50 | |
| 51 | /* Relocate main SPE executable. */ |
| 52 | static void |
| 53 | spu_relocate_main_executable (int spufs_fd) |
| 54 | { |
| 55 | struct objfile *objfile; |
| 56 | struct cleanup *old_chain; |
| 57 | struct section_offsets *new_offsets; |
| 58 | int i; |
| 59 | |
| 60 | for (objfile = symfile_objfile; |
| 61 | objfile; |
| 62 | objfile = objfile->separate_debug_objfile) |
| 63 | { |
| 64 | new_offsets = xcalloc (objfile->num_sections, |
| 65 | sizeof (struct section_offsets)); |
| 66 | old_chain = make_cleanup (xfree, new_offsets); |
| 67 | |
| 68 | for (i = 0; i < objfile->num_sections; i++) |
| 69 | new_offsets->offsets[i] = SPUADDR (spufs_fd, 0); |
| 70 | |
| 71 | objfile_relocate (objfile, new_offsets); |
| 72 | do_cleanups (old_chain); |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | /* When running a stand-alone SPE executable, we may need to skip one more |
| 77 | exec event on startup, to get past the binfmt_misc loader. */ |
| 78 | static void |
| 79 | spu_skip_standalone_loader (void) |
| 80 | { |
| 81 | if (target_has_execution && !current_inferior ()->attach_flag) |
| 82 | { |
| 83 | struct target_waitstatus ws; |
| 84 | |
| 85 | /* Only some kernels report an extra SIGTRAP with the binfmt_misc |
| 86 | loader; others do not. In addition, if we have attached to an |
| 87 | already running inferior instead of starting a new one, we will |
| 88 | not see the extra SIGTRAP -- and we cannot readily distinguish |
| 89 | the two cases, in particular with the extended-remote target. |
| 90 | |
| 91 | Thus we issue a single-step here. If no extra SIGTRAP was pending, |
| 92 | this will step past the first instruction of the stand-alone SPE |
| 93 | executable loader, but we don't care about that. */ |
| 94 | |
| 95 | inferior_thread ()->in_infcall = 1; /* Suppress MI messages. */ |
| 96 | |
| 97 | target_resume (inferior_ptid, 1, TARGET_SIGNAL_0); |
| 98 | target_wait (minus_one_ptid, &ws, 0); |
| 99 | set_executing (minus_one_ptid, 0); |
| 100 | |
| 101 | inferior_thread ()->in_infcall = 0; |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | /* Build a list of `struct so_list' objects describing the shared |
| 106 | objects currently loaded in the inferior. */ |
| 107 | static struct so_list * |
| 108 | spu_current_sos (void) |
| 109 | { |
| 110 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch); |
| 111 | struct so_list *head; |
| 112 | struct so_list **link_ptr; |
| 113 | |
| 114 | char buf[MAX_SPE_FD * 4]; |
| 115 | int i, size; |
| 116 | |
| 117 | /* First, retrieve the SVR4 shared library list. */ |
| 118 | head = svr4_so_ops.current_sos (); |
| 119 | |
| 120 | /* Append our libraries to the end of the list. */ |
| 121 | for (link_ptr = &head; *link_ptr; link_ptr = &(*link_ptr)->next) |
| 122 | ; |
| 123 | |
| 124 | /* Determine list of SPU ids. */ |
| 125 | size = target_read (¤t_target, TARGET_OBJECT_SPU, NULL, |
| 126 | buf, 0, sizeof buf); |
| 127 | |
| 128 | /* Do not add stand-alone SPE executable context as shared library, |
| 129 | but relocate main SPE executable objfile. */ |
| 130 | if (spu_standalone_p ()) |
| 131 | { |
| 132 | if (size == 4) |
| 133 | { |
| 134 | int fd = extract_unsigned_integer (buf, 4, byte_order); |
| 135 | spu_relocate_main_executable (fd); |
| 136 | |
| 137 | /* Re-enable breakpoints after main SPU context was established; |
| 138 | see also comments in spu_solib_create_inferior_hook. */ |
| 139 | enable_breakpoints_after_startup (); |
| 140 | } |
| 141 | |
| 142 | return head; |
| 143 | } |
| 144 | |
| 145 | /* Create an so_list entry for each SPU id. */ |
| 146 | for (i = 0; i < size; i += 4) |
| 147 | { |
| 148 | int fd = extract_unsigned_integer (buf + i, 4, byte_order); |
| 149 | struct so_list *new; |
| 150 | |
| 151 | unsigned long long addr; |
| 152 | char annex[32], id[100]; |
| 153 | int len; |
| 154 | |
| 155 | /* Read object ID. There's a race window where the inferior may have |
| 156 | already created the SPE context, but not installed the object-id |
| 157 | yet. Skip such entries; we'll be back for them later. */ |
| 158 | xsnprintf (annex, sizeof annex, "%d/object-id", fd); |
| 159 | len = target_read (¤t_target, TARGET_OBJECT_SPU, annex, |
| 160 | id, 0, sizeof id); |
| 161 | if (len <= 0 || len >= sizeof id) |
| 162 | continue; |
| 163 | id[len] = 0; |
| 164 | if (sscanf (id, "0x%llx", &addr) != 1 || !addr) |
| 165 | continue; |
| 166 | |
| 167 | /* Allocate so_list structure. */ |
| 168 | new = XZALLOC (struct so_list); |
| 169 | |
| 170 | /* Encode FD and object ID in path name. Choose the name so as not |
| 171 | to conflict with any (normal) SVR4 library path name. */ |
| 172 | xsnprintf (new->so_name, sizeof new->so_name, "@0x%llx <%d>", addr, fd); |
| 173 | strcpy (new->so_original_name, new->so_name); |
| 174 | |
| 175 | *link_ptr = new; |
| 176 | link_ptr = &new->next; |
| 177 | } |
| 178 | |
| 179 | return head; |
| 180 | } |
| 181 | |
| 182 | /* Free so_list information. */ |
| 183 | static void |
| 184 | spu_free_so (struct so_list *so) |
| 185 | { |
| 186 | if (so->so_original_name[0] != '@') |
| 187 | svr4_so_ops.free_so (so); |
| 188 | } |
| 189 | |
| 190 | /* Relocate section addresses. */ |
| 191 | static void |
| 192 | spu_relocate_section_addresses (struct so_list *so, |
| 193 | struct target_section *sec) |
| 194 | { |
| 195 | if (so->so_original_name[0] != '@') |
| 196 | svr4_so_ops.relocate_section_addresses (so, sec); |
| 197 | else |
| 198 | { |
| 199 | unsigned long long addr; |
| 200 | int fd; |
| 201 | |
| 202 | /* Set addr_low/high to just LS offset for display. */ |
| 203 | if (so->addr_low == 0 && so->addr_high == 0 |
| 204 | && strcmp (sec->the_bfd_section->name, ".text") == 0) |
| 205 | { |
| 206 | so->addr_low = sec->addr; |
| 207 | so->addr_high = sec->endaddr; |
| 208 | } |
| 209 | |
| 210 | /* Decode object ID. */ |
| 211 | if (sscanf (so->so_original_name, "@0x%llx <%d>", &addr, &fd) != 2) |
| 212 | internal_error (__FILE__, __LINE__, "bad object ID"); |
| 213 | |
| 214 | sec->addr = SPUADDR (fd, sec->addr); |
| 215 | sec->endaddr = SPUADDR (fd, sec->endaddr); |
| 216 | } |
| 217 | } |
| 218 | |
| 219 | |
| 220 | /* Inferior memory should contain an SPE executable image at location ADDR. |
| 221 | Allocate a BFD representing that executable. Return NULL on error. */ |
| 222 | |
| 223 | static void * |
| 224 | spu_bfd_iovec_open (bfd *nbfd, void *open_closure) |
| 225 | { |
| 226 | return open_closure; |
| 227 | } |
| 228 | |
| 229 | static int |
| 230 | spu_bfd_iovec_close (bfd *nbfd, void *stream) |
| 231 | { |
| 232 | xfree (stream); |
| 233 | return 1; |
| 234 | } |
| 235 | |
| 236 | static file_ptr |
| 237 | spu_bfd_iovec_pread (bfd *abfd, void *stream, void *buf, |
| 238 | file_ptr nbytes, file_ptr offset) |
| 239 | { |
| 240 | CORE_ADDR addr = *(CORE_ADDR *)stream; |
| 241 | int ret; |
| 242 | |
| 243 | ret = target_read_memory (addr + offset, buf, nbytes); |
| 244 | if (ret != 0) |
| 245 | { |
| 246 | bfd_set_error (bfd_error_invalid_operation); |
| 247 | return -1; |
| 248 | } |
| 249 | |
| 250 | return nbytes; |
| 251 | } |
| 252 | |
| 253 | static int |
| 254 | spu_bfd_iovec_stat (bfd *abfd, void *stream, struct stat *sb) |
| 255 | { |
| 256 | /* We don't have an easy way of finding the size of embedded spu |
| 257 | images. We could parse the in-memory ELF header and section |
| 258 | table to find the extent of the last section but that seems |
| 259 | pointless when the size is needed only for checks of other |
| 260 | parsed values in dbxread.c. */ |
| 261 | sb->st_size = INT_MAX; |
| 262 | return 0; |
| 263 | } |
| 264 | |
| 265 | static bfd * |
| 266 | spu_bfd_fopen (char *name, CORE_ADDR addr) |
| 267 | { |
| 268 | bfd *nbfd; |
| 269 | |
| 270 | CORE_ADDR *open_closure = xmalloc (sizeof (CORE_ADDR)); |
| 271 | *open_closure = addr; |
| 272 | |
| 273 | nbfd = bfd_openr_iovec (xstrdup (name), "elf32-spu", |
| 274 | spu_bfd_iovec_open, open_closure, |
| 275 | spu_bfd_iovec_pread, spu_bfd_iovec_close, |
| 276 | spu_bfd_iovec_stat); |
| 277 | if (!nbfd) |
| 278 | return NULL; |
| 279 | |
| 280 | if (!bfd_check_format (nbfd, bfd_object)) |
| 281 | { |
| 282 | bfd_close (nbfd); |
| 283 | return NULL; |
| 284 | } |
| 285 | |
| 286 | return nbfd; |
| 287 | } |
| 288 | |
| 289 | /* Open shared library BFD. */ |
| 290 | static bfd * |
| 291 | spu_bfd_open (char *pathname) |
| 292 | { |
| 293 | char *original_name = strrchr (pathname, '@'); |
| 294 | bfd *abfd; |
| 295 | asection *spu_name; |
| 296 | unsigned long long addr; |
| 297 | int fd; |
| 298 | |
| 299 | /* Handle regular SVR4 libraries. */ |
| 300 | if (!original_name) |
| 301 | return svr4_so_ops.bfd_open (pathname); |
| 302 | |
| 303 | /* Decode object ID. */ |
| 304 | if (sscanf (original_name, "@0x%llx <%d>", &addr, &fd) != 2) |
| 305 | internal_error (__FILE__, __LINE__, "bad object ID"); |
| 306 | |
| 307 | /* Open BFD representing SPE executable. */ |
| 308 | abfd = spu_bfd_fopen (original_name, (CORE_ADDR) addr); |
| 309 | if (!abfd) |
| 310 | error (_("Cannot read SPE executable at %s"), original_name); |
| 311 | |
| 312 | /* Retrieve SPU name note. */ |
| 313 | spu_name = bfd_get_section_by_name (abfd, ".note.spu_name"); |
| 314 | if (spu_name) |
| 315 | { |
| 316 | int sect_size = bfd_section_size (abfd, spu_name); |
| 317 | if (sect_size > 20) |
| 318 | { |
| 319 | char *buf = alloca (sect_size - 20 + strlen (original_name) + 1); |
| 320 | bfd_get_section_contents (abfd, spu_name, buf, 20, sect_size - 20); |
| 321 | buf[sect_size - 20] = '\0'; |
| 322 | |
| 323 | strcat (buf, original_name); |
| 324 | |
| 325 | xfree ((char *)abfd->filename); |
| 326 | abfd->filename = xstrdup (buf); |
| 327 | } |
| 328 | } |
| 329 | |
| 330 | return abfd; |
| 331 | } |
| 332 | |
| 333 | /* Lookup global symbol in a SPE executable. */ |
| 334 | static struct symbol * |
| 335 | spu_lookup_lib_symbol (const struct objfile *objfile, |
| 336 | const char *name, |
| 337 | const char *linkage_name, |
| 338 | const domain_enum domain) |
| 339 | { |
| 340 | if (bfd_get_arch (objfile->obfd) == bfd_arch_spu) |
| 341 | return lookup_global_symbol_from_objfile (objfile, name, linkage_name, |
| 342 | domain); |
| 343 | |
| 344 | if (svr4_so_ops.lookup_lib_global_symbol != NULL) |
| 345 | return svr4_so_ops.lookup_lib_global_symbol (objfile, name, linkage_name, |
| 346 | domain); |
| 347 | return NULL; |
| 348 | } |
| 349 | |
| 350 | /* Enable shared library breakpoint. */ |
| 351 | static int |
| 352 | spu_enable_break (struct objfile *objfile) |
| 353 | { |
| 354 | struct minimal_symbol *spe_event_sym = NULL; |
| 355 | |
| 356 | /* The libspe library will call __spe_context_update_event whenever any |
| 357 | SPE context is allocated or destroyed. */ |
| 358 | spe_event_sym = lookup_minimal_symbol ("__spe_context_update_event", |
| 359 | NULL, objfile); |
| 360 | |
| 361 | /* Place a solib_event breakpoint on the symbol. */ |
| 362 | if (spe_event_sym) |
| 363 | { |
| 364 | CORE_ADDR addr = SYMBOL_VALUE_ADDRESS (spe_event_sym); |
| 365 | addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch, addr, |
| 366 | ¤t_target); |
| 367 | create_solib_event_breakpoint (target_gdbarch, addr); |
| 368 | return 1; |
| 369 | } |
| 370 | |
| 371 | return 0; |
| 372 | } |
| 373 | |
| 374 | /* Create inferior hook. */ |
| 375 | static void |
| 376 | spu_solib_create_inferior_hook (void) |
| 377 | { |
| 378 | /* Remove all previously installed solib breakpoints. Both the SVR4 |
| 379 | code and us will re-install all required breakpoints. */ |
| 380 | remove_solib_event_breakpoints (); |
| 381 | |
| 382 | /* Handle SPE stand-alone executables. */ |
| 383 | if (spu_standalone_p ()) |
| 384 | { |
| 385 | /* After an SPE stand-alone executable was loaded, we'll receive |
| 386 | an additional trap due to the binfmt_misc handler. Make sure |
| 387 | to skip that trap. */ |
| 388 | spu_skip_standalone_loader (); |
| 389 | |
| 390 | /* If the user established breakpoints before starting the inferior, GDB |
| 391 | would attempt to insert those now. This would fail because the SPU |
| 392 | context has not yet been created and the SPU executable has not yet |
| 393 | been loaded. To prevent such failures, we disable all user-created |
| 394 | breakpoints now; they will be re-enabled in spu_current_sos once the |
| 395 | main SPU context has been detected. */ |
| 396 | disable_breakpoints_before_startup (); |
| 397 | |
| 398 | /* A special case arises when re-starting an executable, because at |
| 399 | this point it still resides at the relocated address range that was |
| 400 | determined during its last execution. We need to undo the relocation |
| 401 | so that that multi-architecture target recognizes the stand-alone |
| 402 | initialization special case. */ |
| 403 | spu_relocate_main_executable (-1); |
| 404 | } |
| 405 | |
| 406 | /* Call SVR4 hook -- this will re-insert the SVR4 solib breakpoints. */ |
| 407 | svr4_so_ops.solib_create_inferior_hook (); |
| 408 | |
| 409 | /* If the inferior is statically linked against libspe, we need to install |
| 410 | our own solib breakpoint right now. Otherwise, it will be installed by |
| 411 | the solib_loaded observer below as soon as libspe is loaded. */ |
| 412 | spu_enable_break (NULL); |
| 413 | } |
| 414 | |
| 415 | /* Install SPE "shared library" handling. This is called by -tdep code |
| 416 | that wants to support SPU as a secondary architecture. */ |
| 417 | void |
| 418 | set_spu_solib_ops (struct gdbarch *gdbarch) |
| 419 | { |
| 420 | static struct target_so_ops spu_so_ops; |
| 421 | |
| 422 | /* Initialize this lazily, to avoid an initialization order |
| 423 | dependency on solib-svr4.c's _initialize routine. */ |
| 424 | if (spu_so_ops.current_sos == NULL) |
| 425 | { |
| 426 | spu_so_ops = svr4_so_ops; |
| 427 | spu_so_ops.solib_create_inferior_hook = spu_solib_create_inferior_hook; |
| 428 | spu_so_ops.relocate_section_addresses = spu_relocate_section_addresses; |
| 429 | spu_so_ops.free_so = spu_free_so; |
| 430 | spu_so_ops.current_sos = spu_current_sos; |
| 431 | spu_so_ops.bfd_open = spu_bfd_open; |
| 432 | spu_so_ops.lookup_lib_global_symbol = spu_lookup_lib_symbol; |
| 433 | } |
| 434 | |
| 435 | set_solib_ops (gdbarch, &spu_so_ops); |
| 436 | } |
| 437 | |
| 438 | /* Observer for the solib_loaded event. Used to install our breakpoint |
| 439 | if libspe is a shared library. */ |
| 440 | static void |
| 441 | spu_solib_loaded (struct so_list *so) |
| 442 | { |
| 443 | if (strstr (so->so_original_name, "/libspe") != NULL) |
| 444 | { |
| 445 | solib_read_symbols (so, so->from_tty ? SYMFILE_VERBOSE : 0); |
| 446 | spu_enable_break (so->objfile); |
| 447 | } |
| 448 | } |
| 449 | |
| 450 | void |
| 451 | _initialize_spu_solib (void) |
| 452 | { |
| 453 | observer_attach_solib_loaded (spu_solib_loaded); |
| 454 | } |
| 455 | |