gdb/solib-target.c

   1 /* Definitions for targets which report shared library events.
   2
   3    Copyright (C) 2007, 2008, 2009, 2010 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 #include "gdb_string.h"
  30
  31 DEF_VEC_O(CORE_ADDR);
  32
  33 /* Private data for each loaded library.  */
  34 struct lm_info
  35 {
  36   /* The library's name.  The name is normally kept in the struct
  37      so_list; it is only here during XML parsing.  */
  38   char *name;
  39
  40   /* The target can either specify segment bases or section bases, not
  41      both.  */
  42
  43   /* The base addresses for each independently relocatable segment of
  44      this shared library.  */
  45   VEC(CORE_ADDR) *segment_bases;
  46
  47   /* The base addresses for each independently allocatable,
  48      relocatable section of this shared library.  */
  49   VEC(CORE_ADDR) *section_bases;
  50
  51   /* The cached offsets for each section of this shared library,
  52      determined from SEGMENT_BASES, or SECTION_BASES.  */
  53   struct section_offsets *offsets;
  54 };
  55
  56 typedef struct lm_info *lm_info_p;
  57 DEF_VEC_P(lm_info_p);
  58
  59 #if !defined(HAVE_LIBEXPAT)
  60
  61 static VEC(lm_info_p) *
  62 solib_target_parse_libraries (const char *library)
  63 {
  64   static int have_warned;
  65
  66   if (!have_warned)
  67     {
  68       have_warned = 1;
  69       warning (_("Can not parse XML library list; XML support was disabled "
  70                  "at compile time"));
  71     }
  72
  73   return NULL;
  74 }
  75
  76 #else /* HAVE_LIBEXPAT */
  77
  78 #include "xml-support.h"
  79
  80 /* Handle the start of a <segment> element.  */
  81
  82 static void
  83 library_list_start_segment (struct gdb_xml_parser *parser,
  84                             const struct gdb_xml_element *element,
  85                             void *user_data, VEC(gdb_xml_value_s) *attributes)
  86 {
  87   VEC(lm_info_p) **list = user_data;
  88   struct lm_info *last = VEC_last (lm_info_p, *list);
  89   ULONGEST *address_p = VEC_index (gdb_xml_value_s, attributes, 0)->value;
  90   CORE_ADDR address = (CORE_ADDR) *address_p;
  91
  92   if (last->section_bases != NULL)
  93     gdb_xml_error (parser,
  94                    _("Library list with both segments and sections"));
  95
  96   VEC_safe_push (CORE_ADDR, last->segment_bases, &address);
  97 }
  98
  99 static void
 100 library_list_start_section (struct gdb_xml_parser *parser,
 101                             const struct gdb_xml_element *element,
 102                             void *user_data, VEC(gdb_xml_value_s) *attributes)
 103 {
 104   VEC(lm_info_p) **list = user_data;
 105   struct lm_info *last = VEC_last (lm_info_p, *list);
 106   ULONGEST *address_p = VEC_index (gdb_xml_value_s, attributes, 0)->value;
 107   CORE_ADDR address = (CORE_ADDR) *address_p;
 108
 109   if (last->segment_bases != NULL)
 110     gdb_xml_error (parser,
 111                    _("Library list with both segments and sections"));
 112
 113   VEC_safe_push (CORE_ADDR, last->section_bases, &address);
 114 }
 115
 116 /* Handle the start of a <library> element.  */
 117
 118 static void
 119 library_list_start_library (struct gdb_xml_parser *parser,
 120                             const struct gdb_xml_element *element,
 121                             void *user_data, VEC(gdb_xml_value_s) *attributes)
 122 {
 123   VEC(lm_info_p) **list = user_data;
 124   struct lm_info *item = XZALLOC (struct lm_info);
 125   const char *name = VEC_index (gdb_xml_value_s, attributes, 0)->value;
 126
 127   item->name = xstrdup (name);
 128   VEC_safe_push (lm_info_p, *list, item);
 129 }
 130
 131 static void
 132 library_list_end_library (struct gdb_xml_parser *parser,
 133                           const struct gdb_xml_element *element,
 134                           void *user_data, const char *body_text)
 135 {
 136   VEC(lm_info_p) **list = user_data;
 137   struct lm_info *lm_info = VEC_last (lm_info_p, *list);
 138
 139   if (lm_info->segment_bases == NULL
 140       && lm_info->section_bases == NULL)
 141     gdb_xml_error (parser,
 142                    _("No segment or section bases defined"));
 143 }
 144
 145
 146 /* Handle the start of a <library-list> element.  */
 147
 148 static void
 149 library_list_start_list (struct gdb_xml_parser *parser,
 150                          const struct gdb_xml_element *element,
 151                          void *user_data, VEC(gdb_xml_value_s) *attributes)
 152 {
 153   char *version = VEC_index (gdb_xml_value_s, attributes, 0)->value;
 154
 155   if (strcmp (version, "1.0") != 0)
 156     gdb_xml_error (parser,
 157                    _("Library list has unsupported version \"%s\""),
 158                    version);
 159 }
 160
 161 /* Discard the constructed library list.  */
 162
 163 static void
 164 solib_target_free_library_list (void *p)
 165 {
 166   VEC(lm_info_p) **result = p;
 167   struct lm_info *info;
 168   int ix;
 169
 170   for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
 171     {
 172       xfree (info->name);
 173       VEC_free (CORE_ADDR, info->segment_bases);
 174       VEC_free (CORE_ADDR, info->section_bases);
 175       xfree (info);
 176     }
 177   VEC_free (lm_info_p, *result);
 178   *result = NULL;
 179 }
 180
 181 /* The allowed elements and attributes for an XML library list.
 182    The root element is a <library-list>.  */
 183
 184 const struct gdb_xml_attribute segment_attributes[] = {
 185   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 186   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 187 };
 188
 189 const struct gdb_xml_attribute section_attributes[] = {
 190   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 191   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 192 };
 193
 194 const struct gdb_xml_element library_children[] = {
 195   { "segment", segment_attributes, NULL,
 196     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 197     library_list_start_segment, NULL },
 198   { "section", section_attributes, NULL,
 199     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 200     library_list_start_section, NULL },
 201   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 202 };
 203
 204 const struct gdb_xml_attribute library_attributes[] = {
 205   { "name", GDB_XML_AF_NONE, NULL, NULL },
 206   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 207 };
 208
 209 const struct gdb_xml_element library_list_children[] = {
 210   { "library", library_attributes, library_children,
 211     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 212     library_list_start_library, library_list_end_library },
 213   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 214 };
 215
 216 const struct gdb_xml_attribute library_list_attributes[] = {
 217   { "version", GDB_XML_AF_NONE, NULL, NULL },
 218   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 219 };
 220
 221 const struct gdb_xml_element library_list_elements[] = {
 222   { "library-list", library_list_attributes, library_list_children,
 223     GDB_XML_EF_NONE, library_list_start_list, NULL },
 224   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 225 };
 226
 227 static VEC(lm_info_p) *
 228 solib_target_parse_libraries (const char *library)
 229 {
 230   struct gdb_xml_parser *parser;
 231   VEC(lm_info_p) *result = NULL;
 232   struct cleanup *before_deleting_result, *back_to;
 233
 234   back_to = make_cleanup (null_cleanup, NULL);
 235   parser = gdb_xml_create_parser_and_cleanup (_("target library list"),
 236                                               library_list_elements, &result);
 237   gdb_xml_use_dtd (parser, "library-list.dtd");
 238
 239   before_deleting_result = make_cleanup (solib_target_free_library_list,
 240                                          &result);
 241
 242   if (gdb_xml_parse (parser, library) == 0)
 243     /* Parsed successfully, don't need to delete the result.  */
 244     discard_cleanups (before_deleting_result);
 245
 246   do_cleanups (back_to);
 247   return result;
 248 }
 249 #endif
 250
 251 static struct so_list *
 252 solib_target_current_sos (void)
 253 {
 254   struct so_list *new_solib, *start = NULL, *last = NULL;
 255   const char *library_document;
 256   VEC(lm_info_p) *library_list;
 257   struct lm_info *info;
 258   int ix;
 259
 260   /* Fetch the list of shared libraries.  */
 261   library_document = target_read_stralloc (&current_target,
 262                                            TARGET_OBJECT_LIBRARIES,
 263                                            NULL);
 264   if (library_document == NULL)
 265     return NULL;
 266
 267   /* Parse the list.  */
 268   library_list = solib_target_parse_libraries (library_document);
 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 = XZALLOC (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   int flags = bfd_get_section_flags (sec->bfd, sec->the_bfd_section);
 335   CORE_ADDR offset;
 336
 337   /* Build the offset table only once per object file.  We can not do
 338      it any earlier, since we need to open the file first.  */
 339   if (so->lm_info->offsets == NULL)
 340     {
 341       int num_sections = bfd_count_sections (so->abfd);
 342
 343       so->lm_info->offsets = xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections));
 344
 345       if (so->lm_info->section_bases)
 346         {
 347           int i;
 348           asection *sect;
 349           int num_section_bases
 350             = VEC_length (CORE_ADDR, so->lm_info->section_bases);
 351           int num_alloc_sections = 0;
 352
 353           for (i = 0, sect = so->abfd->sections;
 354                sect != NULL;
 355                i++, sect = sect->next)
 356             if ((bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 357               num_alloc_sections++;
 358
 359           if (num_alloc_sections != num_section_bases)
 360             warning (_("\
 361 Could not relocate shared library \"%s\": wrong number of ALLOC sections"),
 362                      so->so_name);
 363           else
 364             {
 365               int bases_index = 0;
 366               int found_range = 0;
 367               CORE_ADDR *section_bases;
 368
 369               section_bases = VEC_address (CORE_ADDR,
 370                                            so->lm_info->section_bases);
 371
 372               so->addr_low = ~(CORE_ADDR) 0;
 373               so->addr_high = 0;
 374               for (i = 0, sect = so->abfd->sections;
 375                    sect != NULL;
 376                    i++, sect = sect->next)
 377                 {
 378                   if (!(bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 379                     continue;
 380                   if (bfd_section_size (so->abfd, sect) > 0)
 381                     {
 382                       CORE_ADDR low, high;
 383
 384                       low = section_bases[i];
 385                       high = low + bfd_section_size (so->abfd, sect) - 1;
 386
 387                       if (low < so->addr_low)
 388                         so->addr_low = low;
 389                       if (high > so->addr_high)
 390                         so->addr_high = high;
 391                       gdb_assert (so->addr_low <= so->addr_high);
 392                       found_range = 1;
 393                     }
 394                   so->lm_info->offsets->offsets[i] = 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[sec->the_bfd_section->index];
 458   sec->addr += offset;
 459   sec->endaddr += offset;
 460 }
 461
 462 static int
 463 solib_target_open_symbol_file_object (void *from_ttyp)
 464 {
 465   /* We can't locate the main symbol file based on the target's
 466      knowledge; the user has to specify it.  */
 467   return 0;
 468 }
 469
 470 static int
 471 solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
 472 {
 473   /* We don't have a range of addresses for the dynamic linker; there
 474      may not be one in the program's address space.  So only report
 475      PLT entries (which may be import stubs).  */
 476   return in_plt_section (pc, NULL);
 477 }
 478
 479 struct target_so_ops solib_target_so_ops;
 480
 481 extern initialize_file_ftype _initialize_solib_target; /* -Wmissing-prototypes */
 482
 483 void
 484 _initialize_solib_target (void)
 485 {
 486   solib_target_so_ops.relocate_section_addresses
 487     = solib_target_relocate_section_addresses;
 488   solib_target_so_ops.free_so = solib_target_free_so;
 489   solib_target_so_ops.clear_solib = solib_target_clear_solib;
 490   solib_target_so_ops.solib_create_inferior_hook
 491     = solib_target_solib_create_inferior_hook;
 492   solib_target_so_ops.special_symbol_handling
 493     = solib_target_special_symbol_handling;
 494   solib_target_so_ops.current_sos = solib_target_current_sos;
 495   solib_target_so_ops.open_symbol_file_object
 496     = solib_target_open_symbol_file_object;
 497   solib_target_so_ops.in_dynsym_resolve_code
 498     = solib_target_in_dynsym_resolve_code;
 499   solib_target_so_ops.bfd_open = solib_bfd_open;
 500 }