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