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   struct gdb_xml_value *version = xml_find_attribute (attributes, "version");
 150
 151   /* #FIXED attribute may be omitted, Expat returns NULL in such case.  */
 152   if (version != NULL)
 153     {
 154       const char *string = version->value;
 155
 156       if (strcmp (string, "1.0") != 0)
 157         gdb_xml_error (parser,
 158                        _("Library list has unsupported version \"%s\""),
 159                        version);
 160     }
 161 }
 162
 163 /* Discard the constructed library list.  */
 164
 165 static void
 166 solib_target_free_library_list (void *p)
 167 {
 168   VEC(lm_info_p) **result = p;
 169   struct lm_info *info;
 170   int ix;
 171
 172   for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
 173     {
 174       xfree (info->name);
 175       VEC_free (CORE_ADDR, info->segment_bases);
 176       VEC_free (CORE_ADDR, info->section_bases);
 177       xfree (info);
 178     }
 179   VEC_free (lm_info_p, *result);
 180   *result = NULL;
 181 }
 182
 183 /* The allowed elements and attributes for an XML library list.
 184    The root element is a <library-list>.  */
 185
 186 static const struct gdb_xml_attribute segment_attributes[] = {
 187   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 188   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 189 };
 190
 191 static const struct gdb_xml_attribute section_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_element library_children[] = {
 197   { "segment", segment_attributes, NULL,
 198     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 199     library_list_start_segment, NULL },
 200   { "section", section_attributes, NULL,
 201     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 202     library_list_start_section, NULL },
 203   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 204 };
 205
 206 static const struct gdb_xml_attribute library_attributes[] = {
 207   { "name", GDB_XML_AF_NONE, NULL, NULL },
 208   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 209 };
 210
 211 static const struct gdb_xml_element library_list_children[] = {
 212   { "library", library_attributes, library_children,
 213     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 214     library_list_start_library, library_list_end_library },
 215   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 216 };
 217
 218 static const struct gdb_xml_attribute library_list_attributes[] = {
 219   { "version", GDB_XML_AF_OPTIONAL, NULL, NULL },
 220   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 221 };
 222
 223 static const struct gdb_xml_element library_list_elements[] = {
 224   { "library-list", library_list_attributes, library_list_children,
 225     GDB_XML_EF_NONE, library_list_start_list, NULL },
 226   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 227 };
 228
 229 static VEC(lm_info_p) *
 230 solib_target_parse_libraries (const char *library)
 231 {
 232   VEC(lm_info_p) *result = NULL;
 233   struct cleanup *back_to = make_cleanup (solib_target_free_library_list,
 234                                           &result);
 235
 236   if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd",
 237                            library_list_elements, library, &result) == 0)
 238     {
 239       /* Parsed successfully, keep the result.  */
 240       discard_cleanups (back_to);
 241       return result;
 242     }
 243
 244   do_cleanups (back_to);
 245   return NULL;
 246 }
 247 #endif
 248
 249 static struct so_list *
 250 solib_target_current_sos (void)
 251 {
 252   struct so_list *new_solib, *start = NULL, *last = NULL;
 253   char *library_document;
 254   struct cleanup *old_chain;
 255   VEC(lm_info_p) *library_list;
 256   struct lm_info *info;
 257   int ix;
 258
 259   /* Fetch the list of shared libraries.  */
 260   library_document = target_read_stralloc (&current_target,
 261                                            TARGET_OBJECT_LIBRARIES,
 262                                            NULL);
 263   if (library_document == NULL)
 264     return NULL;
 265
 266   /* solib_target_parse_libraries may throw, so we use a cleanup.  */
 267   old_chain = make_cleanup (xfree, library_document);
 268
 269   /* Parse the list.  */
 270   library_list = solib_target_parse_libraries (library_document);
 271
 272   /* library_document string is not needed behind this point.  */
 273   do_cleanups (old_chain);
 274
 275   if (library_list == NULL)
 276     return NULL;
 277
 278   /* Build a struct so_list for each entry on the list.  */
 279   for (ix = 0; VEC_iterate (lm_info_p, library_list, ix, info); ix++)
 280     {
 281       new_solib = XCNEW (struct so_list);
 282       strncpy (new_solib->so_name, info->name, SO_NAME_MAX_PATH_SIZE - 1);
 283       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 284       strncpy (new_solib->so_original_name, info->name,
 285                SO_NAME_MAX_PATH_SIZE - 1);
 286       new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 287       new_solib->lm_info = info;
 288
 289       /* We no longer need this copy of the name.  */
 290       xfree (info->name);
 291       info->name = NULL;
 292
 293       /* Add it to the list.  */
 294       if (!start)
 295         last = start = new_solib;
 296       else
 297         {
 298           last->next = new_solib;
 299           last = new_solib;
 300         }
 301     }
 302
 303   /* Free the library list, but not its members.  */
 304   VEC_free (lm_info_p, library_list);
 305
 306   return start;
 307 }
 308
 309 static void
 310 solib_target_special_symbol_handling (void)
 311 {
 312   /* Nothing needed.  */
 313 }
 314
 315 static void
 316 solib_target_solib_create_inferior_hook (int from_tty)
 317 {
 318   /* Nothing needed.  */
 319 }
 320
 321 static void
 322 solib_target_clear_solib (void)
 323 {
 324   /* Nothing needed.  */
 325 }
 326
 327 static void
 328 solib_target_free_so (struct so_list *so)
 329 {
 330   gdb_assert (so->lm_info->name == NULL);
 331   xfree (so->lm_info->offsets);
 332   VEC_free (CORE_ADDR, so->lm_info->segment_bases);
 333   xfree (so->lm_info);
 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
 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 (so->lm_info->offsets == NULL)
 345     {
 346       int num_sections = gdb_bfd_count_sections (so->abfd);
 347
 348       so->lm_info->offsets
 349         = ((struct section_offsets *)
 350            xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections)));
 351
 352       if (so->lm_info->section_bases)
 353         {
 354           int i;
 355           asection *sect;
 356           int num_section_bases
 357             = VEC_length (CORE_ADDR, so->lm_info->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                                            so->lm_info->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                   so->lm_info->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 (so->lm_info->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, so->lm_info->segment_bases);
 426               segment_bases = VEC_address (CORE_ADDR,
 427                                            so->lm_info->segment_bases);
 428
 429               if (!symfile_map_offsets_to_segments (so->abfd, data,
 430                                                     so->lm_info->offsets,
 431                                                     num_bases, segment_bases))
 432                 warning (_("\
 433 Could not relocate shared library \"%s\": bad offsets"), so->so_name);
 434
 435               /* Find the range of addresses to report for this library in
 436                  "info sharedlibrary".  Report any consecutive segments
 437                  which were relocated as a single unit.  */
 438               gdb_assert (num_bases > 0);
 439               orig_delta = segment_bases[0] - data->segment_bases[0];
 440
 441               for (i = 1; i < data->num_segments; i++)
 442                 {
 443                   /* If we have run out of offsets, assume all
 444                      remaining segments have the same offset.  */
 445                   if (i >= num_bases)
 446                     continue;
 447
 448                   /* If this segment does not have the same offset, do
 449                      not include it in the library's range.  */
 450                   if (segment_bases[i] - data->segment_bases[i] != orig_delta)
 451                     break;
 452                 }
 453
 454               so->addr_low = segment_bases[0];
 455               so->addr_high = (data->segment_bases[i - 1]
 456                                + data->segment_sizes[i - 1]
 457                                + orig_delta);
 458               gdb_assert (so->addr_low <= so->addr_high);
 459
 460               free_symfile_segment_data (data);
 461             }
 462         }
 463     }
 464
 465   offset = so->lm_info->offsets->offsets[gdb_bfd_section_index
 466                                          (sec->the_bfd_section->owner,
 467                                           sec->the_bfd_section)];
 468   sec->addr += offset;
 469   sec->endaddr += offset;
 470 }
 471
 472 static int
 473 solib_target_open_symbol_file_object (void *from_ttyp)
 474 {
 475   /* We can't locate the main symbol file based on the target's
 476      knowledge; the user has to specify it.  */
 477   return 0;
 478 }
 479
 480 static int
 481 solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
 482 {
 483   /* We don't have a range of addresses for the dynamic linker; there
 484      may not be one in the program's address space.  So only report
 485      PLT entries (which may be import stubs).  */
 486   return in_plt_section (pc);
 487 }
 488
 489 struct target_so_ops solib_target_so_ops;
 490
 491 /* -Wmissing-prototypes */
 492 extern initialize_file_ftype _initialize_solib_target;
 493
 494 void
 495 _initialize_solib_target (void)
 496 {
 497   solib_target_so_ops.relocate_section_addresses
 498     = solib_target_relocate_section_addresses;
 499   solib_target_so_ops.free_so = solib_target_free_so;
 500   solib_target_so_ops.clear_solib = solib_target_clear_solib;
 501   solib_target_so_ops.solib_create_inferior_hook
 502     = solib_target_solib_create_inferior_hook;
 503   solib_target_so_ops.special_symbol_handling
 504     = solib_target_special_symbol_handling;
 505   solib_target_so_ops.current_sos = solib_target_current_sos;
 506   solib_target_so_ops.open_symbol_file_object
 507     = solib_target_open_symbol_file_object;
 508   solib_target_so_ops.in_dynsym_resolve_code
 509     = solib_target_in_dynsym_resolve_code;
 510   solib_target_so_ops.bfd_open = solib_bfd_open;
 511
 512   /* Set current_target_so_ops to solib_target_so_ops if not already
 513      set.  */
 514   if (current_target_so_ops == 0)
 515     current_target_so_ops = &solib_target_so_ops;
 516 }