gdb/solib-target.c

   1 /* Definitions for targets which report shared library events.
   2
   3    Copyright (C) 2007-2015 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
  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 struct lm_info *lm_info_p;
  53 DEF_VEC_P(lm_info_p);
  54
  55 #if !defined(HAVE_LIBEXPAT)
  56
  57 static VEC(lm_info_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_p) **list = user_data;
  84   struct lm_info *last = VEC_last (lm_info_p, *list);
  85   ULONGEST *address_p = xml_find_attribute (attributes, "address")->value;
  86   CORE_ADDR address = (CORE_ADDR) *address_p;
  87
  88   if (last->section_bases != NULL)
  89     gdb_xml_error (parser,
  90                    _("Library list with both segments and sections"));
  91
  92   VEC_safe_push (CORE_ADDR, last->segment_bases, address);
  93 }
  94
  95 static void
  96 library_list_start_section (struct gdb_xml_parser *parser,
  97                             const struct gdb_xml_element *element,
  98                             void *user_data, VEC(gdb_xml_value_s) *attributes)
  99 {
 100   VEC(lm_info_p) **list = user_data;
 101   struct lm_info *last = VEC_last (lm_info_p, *list);
 102   ULONGEST *address_p = xml_find_attribute (attributes, "address")->value;
 103   CORE_ADDR address = (CORE_ADDR) *address_p;
 104
 105   if (last->segment_bases != NULL)
 106     gdb_xml_error (parser,
 107                    _("Library list with both segments and sections"));
 108
 109   VEC_safe_push (CORE_ADDR, last->section_bases, address);
 110 }
 111
 112 /* Handle the start of a <library> element.  */
 113
 114 static void
 115 library_list_start_library (struct gdb_xml_parser *parser,
 116                             const struct gdb_xml_element *element,
 117                             void *user_data, VEC(gdb_xml_value_s) *attributes)
 118 {
 119   VEC(lm_info_p) **list = user_data;
 120   struct lm_info *item = XCNEW (struct lm_info);
 121   const char *name = xml_find_attribute (attributes, "name")->value;
 122
 123   item->name = xstrdup (name);
 124   VEC_safe_push (lm_info_p, *list, item);
 125 }
 126
 127 static void
 128 library_list_end_library (struct gdb_xml_parser *parser,
 129                           const struct gdb_xml_element *element,
 130                           void *user_data, const char *body_text)
 131 {
 132   VEC(lm_info_p) **list = user_data;
 133   struct lm_info *lm_info = VEC_last (lm_info_p, *list);
 134
 135   if (lm_info->segment_bases == NULL
 136       && lm_info->section_bases == NULL)
 137     gdb_xml_error (parser,
 138                    _("No segment or section bases defined"));
 139 }
 140
 141
 142 /* Handle the start of a <library-list> element.  */
 143
 144 static void
 145 library_list_start_list (struct gdb_xml_parser *parser,
 146                          const struct gdb_xml_element *element,
 147                          void *user_data, VEC(gdb_xml_value_s) *attributes)
 148 {
 149   char *version = xml_find_attribute (attributes, "version")->value;
 150
 151   if (strcmp (version, "1.0") != 0)
 152     gdb_xml_error (parser,
 153                    _("Library list has unsupported version \"%s\""),
 154                    version);
 155 }
 156
 157 /* Discard the constructed library list.  */
 158
 159 static void
 160 solib_target_free_library_list (void *p)
 161 {
 162   VEC(lm_info_p) **result = p;
 163   struct lm_info *info;
 164   int ix;
 165
 166   for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
 167     {
 168       xfree (info->name);
 169       VEC_free (CORE_ADDR, info->segment_bases);
 170       VEC_free (CORE_ADDR, info->section_bases);
 171       xfree (info);
 172     }
 173   VEC_free (lm_info_p, *result);
 174   *result = NULL;
 175 }
 176
 177 /* The allowed elements and attributes for an XML library list.
 178    The root element is a <library-list>.  */
 179
 180 static const struct gdb_xml_attribute segment_attributes[] = {
 181   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 182   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 183 };
 184
 185 static const struct gdb_xml_attribute section_attributes[] = {
 186   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 187   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 188 };
 189
 190 static const struct gdb_xml_element library_children[] = {
 191   { "segment", segment_attributes, NULL,
 192     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 193     library_list_start_segment, NULL },
 194   { "section", section_attributes, NULL,
 195     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 196     library_list_start_section, NULL },
 197   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 198 };
 199
 200 static const struct gdb_xml_attribute library_attributes[] = {
 201   { "name", GDB_XML_AF_NONE, NULL, NULL },
 202   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 203 };
 204
 205 static const struct gdb_xml_element library_list_children[] = {
 206   { "library", library_attributes, library_children,
 207     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 208     library_list_start_library, library_list_end_library },
 209   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 210 };
 211
 212 static const struct gdb_xml_attribute library_list_attributes[] = {
 213   { "version", GDB_XML_AF_NONE, NULL, NULL },
 214   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 215 };
 216
 217 static const struct gdb_xml_element library_list_elements[] = {
 218   { "library-list", library_list_attributes, library_list_children,
 219     GDB_XML_EF_NONE, library_list_start_list, NULL },
 220   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 221 };
 222
 223 static VEC(lm_info_p) *
 224 solib_target_parse_libraries (const char *library)
 225 {
 226   VEC(lm_info_p) *result = NULL;
 227   struct cleanup *back_to = make_cleanup (solib_target_free_library_list,
 228                                           &result);
 229
 230   if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd",
 231                            library_list_elements, library, &result) == 0)
 232     {
 233       /* Parsed successfully, keep the result.  */
 234       discard_cleanups (back_to);
 235       return result;
 236     }
 237
 238   do_cleanups (back_to);
 239   return NULL;
 240 }
 241 #endif
 242
 243 static struct so_list *
 244 solib_target_current_sos (void)
 245 {
 246   struct so_list *new_solib, *start = NULL, *last = NULL;
 247   char *library_document;
 248   struct cleanup *old_chain;
 249   VEC(lm_info_p) *library_list;
 250   struct lm_info *info;
 251   int ix;
 252
 253   /* Fetch the list of shared libraries.  */
 254   library_document = target_read_stralloc (&current_target,
 255                                            TARGET_OBJECT_LIBRARIES,
 256                                            NULL);
 257   if (library_document == NULL)
 258     return NULL;
 259
 260   /* solib_target_parse_libraries may throw, so we use a cleanup.  */
 261   old_chain = make_cleanup (xfree, library_document);
 262
 263   /* Parse the list.  */
 264   library_list = solib_target_parse_libraries (library_document);
 265
 266   /* library_document string is not needed behind this point.  */
 267   do_cleanups (old_chain);
 268
 269   if (library_list == NULL)
 270     return NULL;
 271
 272   /* Build a struct so_list for each entry on the list.  */
 273   for (ix = 0; VEC_iterate (lm_info_p, library_list, ix, info); ix++)
 274     {
 275       new_solib = XCNEW (struct so_list);
 276       strncpy (new_solib->so_name, info->name, SO_NAME_MAX_PATH_SIZE - 1);
 277       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 278       strncpy (new_solib->so_original_name, info->name,
 279                SO_NAME_MAX_PATH_SIZE - 1);
 280       new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 281       new_solib->lm_info = info;
 282
 283       /* We no longer need this copy of the name.  */
 284       xfree (info->name);
 285       info->name = NULL;
 286
 287       /* Add it to the list.  */
 288       if (!start)
 289         last = start = new_solib;
 290       else
 291         {
 292           last->next = new_solib;
 293           last = new_solib;
 294         }
 295     }
 296
 297   /* Free the library list, but not its members.  */
 298   VEC_free (lm_info_p, library_list);
 299
 300   return start;
 301 }
 302
 303 static void
 304 solib_target_special_symbol_handling (void)
 305 {
 306   /* Nothing needed.  */
 307 }
 308
 309 static void
 310 solib_target_solib_create_inferior_hook (int from_tty)
 311 {
 312   /* Nothing needed.  */
 313 }
 314
 315 static void
 316 solib_target_clear_solib (void)
 317 {
 318   /* Nothing needed.  */
 319 }
 320
 321 static void
 322 solib_target_free_so (struct so_list *so)
 323 {
 324   gdb_assert (so->lm_info->name == NULL);
 325   xfree (so->lm_info->offsets);
 326   VEC_free (CORE_ADDR, so->lm_info->segment_bases);
 327   xfree (so->lm_info);
 328 }
 329
 330 static void
 331 solib_target_relocate_section_addresses (struct so_list *so,
 332                                          struct target_section *sec)
 333 {
 334   CORE_ADDR offset;
 335
 336   /* Build the offset table only once per object file.  We can not do
 337      it any earlier, since we need to open the file first.  */
 338   if (so->lm_info->offsets == NULL)
 339     {
 340       int num_sections = gdb_bfd_count_sections (so->abfd);
 341
 342       so->lm_info->offsets = xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections));
 343
 344       if (so->lm_info->section_bases)
 345         {
 346           int i;
 347           asection *sect;
 348           int num_section_bases
 349             = VEC_length (CORE_ADDR, so->lm_info->section_bases);
 350           int num_alloc_sections = 0;
 351
 352           for (i = 0, sect = so->abfd->sections;
 353                sect != NULL;
 354                i++, sect = sect->next)
 355             if ((bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 356               num_alloc_sections++;
 357
 358           if (num_alloc_sections != num_section_bases)
 359             warning (_("\
 360 Could not relocate shared library \"%s\": wrong number of ALLOC sections"),
 361                      so->so_name);
 362           else
 363             {
 364               int bases_index = 0;
 365               int found_range = 0;
 366               CORE_ADDR *section_bases;
 367
 368               section_bases = VEC_address (CORE_ADDR,
 369                                            so->lm_info->section_bases);
 370
 371               so->addr_low = ~(CORE_ADDR) 0;
 372               so->addr_high = 0;
 373               for (i = 0, sect = so->abfd->sections;
 374                    sect != NULL;
 375                    i++, sect = sect->next)
 376                 {
 377                   if (!(bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 378                     continue;
 379                   if (bfd_section_size (so->abfd, sect) > 0)
 380                     {
 381                       CORE_ADDR low, high;
 382
 383                       low = section_bases[i];
 384                       high = low + bfd_section_size (so->abfd, sect) - 1;
 385
 386                       if (low < so->addr_low)
 387                         so->addr_low = low;
 388                       if (high > so->addr_high)
 389                         so->addr_high = high;
 390                       gdb_assert (so->addr_low <= so->addr_high);
 391                       found_range = 1;
 392                     }
 393                   so->lm_info->offsets->offsets[i]
 394                     = section_bases[bases_index];
 395                   bases_index++;
 396                 }
 397               if (!found_range)
 398                 so->addr_low = so->addr_high = 0;
 399               gdb_assert (so->addr_low <= so->addr_high);
 400             }
 401         }
 402       else if (so->lm_info->segment_bases)
 403         {
 404           struct symfile_segment_data *data;
 405
 406           data = get_symfile_segment_data (so->abfd);
 407           if (data == NULL)
 408             warning (_("\
 409 Could not relocate shared library \"%s\": no segments"), so->so_name);
 410           else
 411             {
 412               ULONGEST orig_delta;
 413               int i;
 414               int num_bases;
 415               CORE_ADDR *segment_bases;
 416
 417               num_bases = VEC_length (CORE_ADDR, so->lm_info->segment_bases);
 418               segment_bases = VEC_address (CORE_ADDR,
 419                                            so->lm_info->segment_bases);
 420
 421               if (!symfile_map_offsets_to_segments (so->abfd, data,
 422                                                     so->lm_info->offsets,
 423                                                     num_bases, segment_bases))
 424                 warning (_("\
 425 Could not relocate shared library \"%s\": bad offsets"), so->so_name);
 426
 427               /* Find the range of addresses to report for this library in
 428                  "info sharedlibrary".  Report any consecutive segments
 429                  which were relocated as a single unit.  */
 430               gdb_assert (num_bases > 0);
 431               orig_delta = segment_bases[0] - data->segment_bases[0];
 432
 433               for (i = 1; i < data->num_segments; i++)
 434                 {
 435                   /* If we have run out of offsets, assume all
 436                      remaining segments have the same offset.  */
 437                   if (i >= num_bases)
 438                     continue;
 439
 440                   /* If this segment does not have the same offset, do
 441                      not include it in the library's range.  */
 442                   if (segment_bases[i] - data->segment_bases[i] != orig_delta)
 443                     break;
 444                 }
 445
 446               so->addr_low = segment_bases[0];
 447               so->addr_high = (data->segment_bases[i - 1]
 448                                + data->segment_sizes[i - 1]
 449                                + orig_delta);
 450               gdb_assert (so->addr_low <= so->addr_high);
 451
 452               free_symfile_segment_data (data);
 453             }
 454         }
 455     }
 456
 457   offset = so->lm_info->offsets->offsets[gdb_bfd_section_index
 458                                          (sec->the_bfd_section->owner,
 459                                           sec->the_bfd_section)];
 460   sec->addr += offset;
 461   sec->endaddr += offset;
 462 }
 463
 464 static int
 465 solib_target_open_symbol_file_object (void *from_ttyp)
 466 {
 467   /* We can't locate the main symbol file based on the target's
 468      knowledge; the user has to specify it.  */
 469   return 0;
 470 }
 471
 472 static int
 473 solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
 474 {
 475   /* We don't have a range of addresses for the dynamic linker; there
 476      may not be one in the program's address space.  So only report
 477      PLT entries (which may be import stubs).  */
 478   return in_plt_section (pc);
 479 }
 480
 481 struct target_so_ops solib_target_so_ops;
 482
 483 /* -Wmissing-prototypes */
 484 extern initialize_file_ftype _initialize_solib_target;
 485
 486 void
 487 _initialize_solib_target (void)
 488 {
 489   solib_target_so_ops.relocate_section_addresses
 490     = solib_target_relocate_section_addresses;
 491   solib_target_so_ops.free_so = solib_target_free_so;
 492   solib_target_so_ops.clear_solib = solib_target_clear_solib;
 493   solib_target_so_ops.solib_create_inferior_hook
 494     = solib_target_solib_create_inferior_hook;
 495   solib_target_so_ops.special_symbol_handling
 496     = solib_target_special_symbol_handling;
 497   solib_target_so_ops.current_sos = solib_target_current_sos;
 498   solib_target_so_ops.open_symbol_file_object
 499     = solib_target_open_symbol_file_object;
 500   solib_target_so_ops.in_dynsym_resolve_code
 501     = solib_target_in_dynsym_resolve_code;
 502   solib_target_so_ops.bfd_open = solib_bfd_open;
 503
 504   /* Set current_target_so_ops to solib_target_so_ops if not already
 505      set.  */
 506   if (current_target_so_ops == 0)
 507     current_target_so_ops = &solib_target_so_ops;
 508 }