gdb/solib-target.c

   1 /* Definitions for targets which report shared library events.
   2
   3    Copyright (C) 2007-2017 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "objfiles.h"
  22 #include "solist.h"
  23 #include "symtab.h"
  24 #include "symfile.h"
  25 #include "target.h"
  26 #include "vec.h"
  27 #include "solib-target.h"
  28
  29 /* Private data for each loaded library.  */
  30 struct lm_info_target : public lm_info_base
  31 {
  32   ~lm_info_target ()
  33   {
  34     VEC_free (CORE_ADDR, this->segment_bases);
  35     VEC_free (CORE_ADDR, this->section_bases);
  36   }
  37
  38   /* The library's name.  The name is normally kept in the struct
  39      so_list; it is only here during XML parsing.  */
  40   std::string name;
  41
  42   /* The target can either specify segment bases or section bases, not
  43      both.  */
  44
  45   /* The base addresses for each independently relocatable segment of
  46      this shared library.  */
  47   VEC(CORE_ADDR) *segment_bases = NULL;
  48
  49   /* The base addresses for each independently allocatable,
  50      relocatable section of this shared library.  */
  51   VEC(CORE_ADDR) *section_bases = NULL;
  52
  53   /* The cached offsets for each section of this shared library,
  54      determined from SEGMENT_BASES, or SECTION_BASES.  */
  55   section_offsets *offsets = NULL;
  56 };
  57
  58 typedef lm_info_target *lm_info_target_p;
  59 DEF_VEC_P(lm_info_target_p);
  60
  61 #if !defined(HAVE_LIBEXPAT)
  62
  63 static VEC(lm_info_target_p) *
  64 solib_target_parse_libraries (const char *library)
  65 {
  66   static int have_warned;
  67
  68   if (!have_warned)
  69     {
  70       have_warned = 1;
  71       warning (_("Can not parse XML library list; XML support was disabled "
  72                  "at compile time"));
  73     }
  74
  75   return NULL;
  76 }
  77
  78 #else /* HAVE_LIBEXPAT */
  79
  80 #include "xml-support.h"
  81
  82 /* Handle the start of a <segment> element.  */
  83
  84 static void
  85 library_list_start_segment (struct gdb_xml_parser *parser,
  86                             const struct gdb_xml_element *element,
  87                             void *user_data, VEC(gdb_xml_value_s) *attributes)
  88 {
  89   VEC(lm_info_target_p) **list = (VEC(lm_info_target_p) **) user_data;
  90   lm_info_target *last = VEC_last (lm_info_target_p, *list);
  91   ULONGEST *address_p
  92     = (ULONGEST *) xml_find_attribute (attributes, "address")->value;
  93   CORE_ADDR address = (CORE_ADDR) *address_p;
  94
  95   if (last->section_bases != NULL)
  96     gdb_xml_error (parser,
  97                    _("Library list with both segments and sections"));
  98
  99   VEC_safe_push (CORE_ADDR, last->segment_bases, address);
 100 }
 101
 102 static void
 103 library_list_start_section (struct gdb_xml_parser *parser,
 104                             const struct gdb_xml_element *element,
 105                             void *user_data, VEC(gdb_xml_value_s) *attributes)
 106 {
 107   VEC(lm_info_target_p) **list = (VEC(lm_info_target_p) **) user_data;
 108   lm_info_target *last = VEC_last (lm_info_target_p, *list);
 109   ULONGEST *address_p
 110     = (ULONGEST *) xml_find_attribute (attributes, "address")->value;
 111   CORE_ADDR address = (CORE_ADDR) *address_p;
 112
 113   if (last->segment_bases != NULL)
 114     gdb_xml_error (parser,
 115                    _("Library list with both segments and sections"));
 116
 117   VEC_safe_push (CORE_ADDR, last->section_bases, address);
 118 }
 119
 120 /* Handle the start of a <library> element.  */
 121
 122 static void
 123 library_list_start_library (struct gdb_xml_parser *parser,
 124                             const struct gdb_xml_element *element,
 125                             void *user_data, VEC(gdb_xml_value_s) *attributes)
 126 {
 127   VEC(lm_info_target_p) **list = (VEC(lm_info_target_p) **) user_data;
 128   lm_info_target *item = new lm_info_target;
 129   const char *name
 130     = (const char *) xml_find_attribute (attributes, "name")->value;
 131
 132   item->name = xstrdup (name);
 133   VEC_safe_push (lm_info_target_p, *list, item);
 134 }
 135
 136 static void
 137 library_list_end_library (struct gdb_xml_parser *parser,
 138                           const struct gdb_xml_element *element,
 139                           void *user_data, const char *body_text)
 140 {
 141   VEC(lm_info_target_p) **list = (VEC(lm_info_target_p) **) user_data;
 142   lm_info_target *lm_info = VEC_last (lm_info_target_p, *list);
 143
 144   if (lm_info->segment_bases == NULL
 145       && lm_info->section_bases == NULL)
 146     gdb_xml_error (parser,
 147                    _("No segment or section bases defined"));
 148 }
 149
 150
 151 /* Handle the start of a <library-list> element.  */
 152
 153 static void
 154 library_list_start_list (struct gdb_xml_parser *parser,
 155                          const struct gdb_xml_element *element,
 156                          void *user_data, VEC(gdb_xml_value_s) *attributes)
 157 {
 158   struct gdb_xml_value *version = xml_find_attribute (attributes, "version");
 159
 160   /* #FIXED attribute may be omitted, Expat returns NULL in such case.  */
 161   if (version != NULL)
 162     {
 163       const char *string = (const char *) version->value;
 164
 165       if (strcmp (string, "1.0") != 0)
 166         gdb_xml_error (parser,
 167                        _("Library list has unsupported version \"%s\""),
 168                        string);
 169     }
 170 }
 171
 172 /* Discard the constructed library list.  */
 173
 174 static void
 175 solib_target_free_library_list (void *p)
 176 {
 177   VEC(lm_info_target_p) **result = (VEC(lm_info_target_p) **) p;
 178   lm_info_target *info;
 179   int ix;
 180
 181   for (ix = 0; VEC_iterate (lm_info_target_p, *result, ix, info); ix++)
 182     delete info;
 183
 184   VEC_free (lm_info_target_p, *result);
 185   *result = NULL;
 186 }
 187
 188 /* The allowed elements and attributes for an XML library list.
 189    The root element is a <library-list>.  */
 190
 191 static const struct gdb_xml_attribute segment_attributes[] = {
 192   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 193   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 194 };
 195
 196 static const struct gdb_xml_attribute section_attributes[] = {
 197   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 198   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 199 };
 200
 201 static const struct gdb_xml_element library_children[] = {
 202   { "segment", segment_attributes, NULL,
 203     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 204     library_list_start_segment, NULL },
 205   { "section", section_attributes, NULL,
 206     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 207     library_list_start_section, NULL },
 208   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 209 };
 210
 211 static const struct gdb_xml_attribute library_attributes[] = {
 212   { "name", GDB_XML_AF_NONE, NULL, NULL },
 213   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 214 };
 215
 216 static const struct gdb_xml_element library_list_children[] = {
 217   { "library", library_attributes, library_children,
 218     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 219     library_list_start_library, library_list_end_library },
 220   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 221 };
 222
 223 static const struct gdb_xml_attribute library_list_attributes[] = {
 224   { "version", GDB_XML_AF_OPTIONAL, NULL, NULL },
 225   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 226 };
 227
 228 static const struct gdb_xml_element library_list_elements[] = {
 229   { "library-list", library_list_attributes, library_list_children,
 230     GDB_XML_EF_NONE, library_list_start_list, NULL },
 231   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 232 };
 233
 234 static VEC(lm_info_target_p) *
 235 solib_target_parse_libraries (const char *library)
 236 {
 237   VEC(lm_info_target_p) *result = NULL;
 238   struct cleanup *back_to = make_cleanup (solib_target_free_library_list,
 239                                           &result);
 240
 241   if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd",
 242                            library_list_elements, library, &result) == 0)
 243     {
 244       /* Parsed successfully, keep the result.  */
 245       discard_cleanups (back_to);
 246       return result;
 247     }
 248
 249   do_cleanups (back_to);
 250   return NULL;
 251 }
 252 #endif
 253
 254 static struct so_list *
 255 solib_target_current_sos (void)
 256 {
 257   struct so_list *new_solib, *start = NULL, *last = NULL;
 258   char *library_document;
 259   struct cleanup *old_chain;
 260   VEC(lm_info_target_p) *library_list;
 261   lm_info_target *info;
 262   int ix;
 263
 264   /* Fetch the list of shared libraries.  */
 265   library_document = target_read_stralloc (&current_target,
 266                                            TARGET_OBJECT_LIBRARIES,
 267                                            NULL);
 268   if (library_document == NULL)
 269     return NULL;
 270
 271   /* solib_target_parse_libraries may throw, so we use a cleanup.  */
 272   old_chain = make_cleanup (xfree, library_document);
 273
 274   /* Parse the list.  */
 275   library_list = solib_target_parse_libraries (library_document);
 276
 277   /* library_document string is not needed behind this point.  */
 278   do_cleanups (old_chain);
 279
 280   if (library_list == NULL)
 281     return NULL;
 282
 283   /* Build a struct so_list for each entry on the list.  */
 284   for (ix = 0; VEC_iterate (lm_info_target_p, library_list, ix, info); ix++)
 285     {
 286       new_solib = XCNEW (struct so_list);
 287       strncpy (new_solib->so_name, info->name.c_str (),
 288                SO_NAME_MAX_PATH_SIZE - 1);
 289       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 290       strncpy (new_solib->so_original_name, info->name.c_str (),
 291                SO_NAME_MAX_PATH_SIZE - 1);
 292       new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 293       new_solib->lm_info = info;
 294
 295       /* We no longer need this copy of the name.  */
 296       info->name.clear ();
 297
 298       /* Add it to the list.  */
 299       if (!start)
 300         last = start = new_solib;
 301       else
 302         {
 303           last->next = new_solib;
 304           last = new_solib;
 305         }
 306     }
 307
 308   /* Free the library list, but not its members.  */
 309   VEC_free (lm_info_target_p, library_list);
 310
 311   return start;
 312 }
 313
 314 static void
 315 solib_target_solib_create_inferior_hook (int from_tty)
 316 {
 317   /* Nothing needed.  */
 318 }
 319
 320 static void
 321 solib_target_clear_solib (void)
 322 {
 323   /* Nothing needed.  */
 324 }
 325
 326 static void
 327 solib_target_free_so (struct so_list *so)
 328 {
 329   lm_info_target *li = (lm_info_target *) so->lm_info;
 330
 331   gdb_assert (li->name.empty ());
 332
 333   delete li;
 334 }
 335
 336 static void
 337 solib_target_relocate_section_addresses (struct so_list *so,
 338                                          struct target_section *sec)
 339 {
 340   CORE_ADDR offset;
 341   lm_info_target *li = (lm_info_target *) so->lm_info;
 342
 343   /* Build the offset table only once per object file.  We can not do
 344      it any earlier, since we need to open the file first.  */
 345   if (li->offsets == NULL)
 346     {
 347       int num_sections = gdb_bfd_count_sections (so->abfd);
 348
 349       li->offsets
 350         = ((struct section_offsets *)
 351            xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections)));
 352
 353       if (li->section_bases)
 354         {
 355           int i;
 356           asection *sect;
 357           int num_section_bases
 358             = VEC_length (CORE_ADDR, li->section_bases);
 359           int num_alloc_sections = 0;
 360
 361           for (i = 0, sect = so->abfd->sections;
 362                sect != NULL;
 363                i++, sect = sect->next)
 364             if ((bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 365               num_alloc_sections++;
 366
 367           if (num_alloc_sections != num_section_bases)
 368             warning (_("\
 369 Could not relocate shared library \"%s\": wrong number of ALLOC sections"),
 370                      so->so_name);
 371           else
 372             {
 373               int bases_index = 0;
 374               int found_range = 0;
 375               CORE_ADDR *section_bases;
 376
 377               section_bases = VEC_address (CORE_ADDR,
 378                                            li->section_bases);
 379
 380               so->addr_low = ~(CORE_ADDR) 0;
 381               so->addr_high = 0;
 382               for (i = 0, sect = so->abfd->sections;
 383                    sect != NULL;
 384                    i++, sect = sect->next)
 385                 {
 386                   if (!(bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 387                     continue;
 388                   if (bfd_section_size (so->abfd, sect) > 0)
 389                     {
 390                       CORE_ADDR low, high;
 391
 392                       low = section_bases[i];
 393                       high = low + bfd_section_size (so->abfd, sect) - 1;
 394
 395                       if (low < so->addr_low)
 396                         so->addr_low = low;
 397                       if (high > so->addr_high)
 398                         so->addr_high = high;
 399                       gdb_assert (so->addr_low <= so->addr_high);
 400                       found_range = 1;
 401                     }
 402                   li->offsets->offsets[i]
 403                     = section_bases[bases_index];
 404                   bases_index++;
 405                 }
 406               if (!found_range)
 407                 so->addr_low = so->addr_high = 0;
 408               gdb_assert (so->addr_low <= so->addr_high);
 409             }
 410         }
 411       else if (li->segment_bases)
 412         {
 413           struct symfile_segment_data *data;
 414
 415           data = get_symfile_segment_data (so->abfd);
 416           if (data == NULL)
 417             warning (_("\
 418 Could not relocate shared library \"%s\": no segments"), so->so_name);
 419           else
 420             {
 421               ULONGEST orig_delta;
 422               int i;
 423               int num_bases;
 424               CORE_ADDR *segment_bases;
 425
 426               num_bases = VEC_length (CORE_ADDR, li->segment_bases);
 427               segment_bases = VEC_address (CORE_ADDR, li->segment_bases);
 428
 429               if (!symfile_map_offsets_to_segments (so->abfd, data, li->offsets,
 430                                                     num_bases, segment_bases))
 431                 warning (_("\
 432 Could not relocate shared library \"%s\": bad offsets"), so->so_name);
 433
 434               /* Find the range of addresses to report for this library in
 435                  "info sharedlibrary".  Report any consecutive segments
 436                  which were relocated as a single unit.  */
 437               gdb_assert (num_bases > 0);
 438               orig_delta = segment_bases[0] - data->segment_bases[0];
 439
 440               for (i = 1; i < data->num_segments; i++)
 441                 {
 442                   /* If we have run out of offsets, assume all
 443                      remaining segments have the same offset.  */
 444                   if (i >= num_bases)
 445                     continue;
 446
 447                   /* If this segment does not have the same offset, do
 448                      not include it in the library's range.  */
 449                   if (segment_bases[i] - data->segment_bases[i] != orig_delta)
 450                     break;
 451                 }
 452
 453               so->addr_low = segment_bases[0];
 454               so->addr_high = (data->segment_bases[i - 1]
 455                                + data->segment_sizes[i - 1]
 456                                + orig_delta);
 457               gdb_assert (so->addr_low <= so->addr_high);
 458
 459               free_symfile_segment_data (data);
 460             }
 461         }
 462     }
 463
 464   offset = li->offsets->offsets[gdb_bfd_section_index
 465                                 (sec->the_bfd_section->owner,
 466                                  sec->the_bfd_section)];
 467   sec->addr += offset;
 468   sec->endaddr += offset;
 469 }
 470
 471 static int
 472 solib_target_open_symbol_file_object (void *from_ttyp)
 473 {
 474   /* We can't locate the main symbol file based on the target's
 475      knowledge; the user has to specify it.  */
 476   return 0;
 477 }
 478
 479 static int
 480 solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
 481 {
 482   /* We don't have a range of addresses for the dynamic linker; there
 483      may not be one in the program's address space.  So only report
 484      PLT entries (which may be import stubs).  */
 485   return in_plt_section (pc);
 486 }
 487
 488 struct target_so_ops solib_target_so_ops;
 489
 490 /* -Wmissing-prototypes */
 491 extern initialize_file_ftype _initialize_solib_target;
 492
 493 void
 494 _initialize_solib_target (void)
 495 {
 496   solib_target_so_ops.relocate_section_addresses
 497     = solib_target_relocate_section_addresses;
 498   solib_target_so_ops.free_so = solib_target_free_so;
 499   solib_target_so_ops.clear_solib = solib_target_clear_solib;
 500   solib_target_so_ops.solib_create_inferior_hook
 501     = solib_target_solib_create_inferior_hook;
 502   solib_target_so_ops.current_sos = solib_target_current_sos;
 503   solib_target_so_ops.open_symbol_file_object
 504     = solib_target_open_symbol_file_object;
 505   solib_target_so_ops.in_dynsym_resolve_code
 506     = solib_target_in_dynsym_resolve_code;
 507   solib_target_so_ops.bfd_open = solib_bfd_open;
 508
 509   /* Set current_target_so_ops to solib_target_so_ops if not already
 510      set.  */
 511   if (current_target_so_ops == 0)
 512     current_target_so_ops = &solib_target_so_ops;
 513 }