gdb/solib-target.c

   1 /* Definitions for targets which report shared library events.
   2
   3    Copyright (C) 2007-2012 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 /* Private data for each loaded library.  */
  32 struct lm_info
  33 {
  34   /* The library's name.  The name is normally kept in the struct
  35      so_list; it is only here during XML parsing.  */
  36   char *name;
  37
  38   /* The target can either specify segment bases or section bases, not
  39      both.  */
  40
  41   /* The base addresses for each independently relocatable segment of
  42      this shared library.  */
  43   VEC(CORE_ADDR) *segment_bases;
  44
  45   /* The base addresses for each independently allocatable,
  46      relocatable section of this shared library.  */
  47   VEC(CORE_ADDR) *section_bases;
  48
  49   /* The cached offsets for each section of this shared library,
  50      determined from SEGMENT_BASES, or SECTION_BASES.  */
  51   struct section_offsets *offsets;
  52 };
  53
  54 typedef struct lm_info *lm_info_p;
  55 DEF_VEC_P(lm_info_p);
  56
  57 #if !defined(HAVE_LIBEXPAT)
  58
  59 static VEC(lm_info_p) *
  60 solib_target_parse_libraries (const char *library)
  61 {
  62   static int have_warned;
  63
  64   if (!have_warned)
  65     {
  66       have_warned = 1;
  67       warning (_("Can not parse XML library list; XML support was disabled "
  68                  "at compile time"));
  69     }
  70
  71   return NULL;
  72 }
  73
  74 #else /* HAVE_LIBEXPAT */
  75
  76 #include "xml-support.h"
  77
  78 /* Handle the start of a <segment> element.  */
  79
  80 static void
  81 library_list_start_segment (struct gdb_xml_parser *parser,
  82                             const struct gdb_xml_element *element,
  83                             void *user_data, VEC(gdb_xml_value_s) *attributes)
  84 {
  85   VEC(lm_info_p) **list = user_data;
  86   struct lm_info *last = VEC_last (lm_info_p, *list);
  87   ULONGEST *address_p = xml_find_attribute (attributes, "address")->value;
  88   CORE_ADDR address = (CORE_ADDR) *address_p;
  89
  90   if (last->section_bases != NULL)
  91     gdb_xml_error (parser,
  92                    _("Library list with both segments and sections"));
  93
  94   VEC_safe_push (CORE_ADDR, last->segment_bases, address);
  95 }
  96
  97 static void
  98 library_list_start_section (struct gdb_xml_parser *parser,
  99                             const struct gdb_xml_element *element,
 100                             void *user_data, VEC(gdb_xml_value_s) *attributes)
 101 {
 102   VEC(lm_info_p) **list = user_data;
 103   struct lm_info *last = VEC_last (lm_info_p, *list);
 104   ULONGEST *address_p = 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_p) **list = user_data;
 122   struct lm_info *item = XZALLOC (struct lm_info);
 123   const char *name = xml_find_attribute (attributes, "name")->value;
 124
 125   item->name = xstrdup (name);
 126   VEC_safe_push (lm_info_p, *list, item);
 127 }
 128
 129 static void
 130 library_list_end_library (struct gdb_xml_parser *parser,
 131                           const struct gdb_xml_element *element,
 132                           void *user_data, const char *body_text)
 133 {
 134   VEC(lm_info_p) **list = user_data;
 135   struct lm_info *lm_info = VEC_last (lm_info_p, *list);
 136
 137   if (lm_info->segment_bases == NULL
 138       && lm_info->section_bases == NULL)
 139     gdb_xml_error (parser,
 140                    _("No segment or section bases defined"));
 141 }
 142
 143
 144 /* Handle the start of a <library-list> element.  */
 145
 146 static void
 147 library_list_start_list (struct gdb_xml_parser *parser,
 148                          const struct gdb_xml_element *element,
 149                          void *user_data, VEC(gdb_xml_value_s) *attributes)
 150 {
 151   char *version = xml_find_attribute (attributes, "version")->value;
 152
 153   if (strcmp (version, "1.0") != 0)
 154     gdb_xml_error (parser,
 155                    _("Library list has unsupported version \"%s\""),
 156                    version);
 157 }
 158
 159 /* Discard the constructed library list.  */
 160
 161 static void
 162 solib_target_free_library_list (void *p)
 163 {
 164   VEC(lm_info_p) **result = p;
 165   struct lm_info *info;
 166   int ix;
 167
 168   for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
 169     {
 170       xfree (info->name);
 171       VEC_free (CORE_ADDR, info->segment_bases);
 172       VEC_free (CORE_ADDR, info->section_bases);
 173       xfree (info);
 174     }
 175   VEC_free (lm_info_p, *result);
 176   *result = NULL;
 177 }
 178
 179 /* The allowed elements and attributes for an XML library list.
 180    The root element is a <library-list>.  */
 181
 182 static const struct gdb_xml_attribute segment_attributes[] = {
 183   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 184   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 185 };
 186
 187 static const struct gdb_xml_attribute section_attributes[] = {
 188   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 189   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 190 };
 191
 192 static const struct gdb_xml_element library_children[] = {
 193   { "segment", segment_attributes, NULL,
 194     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 195     library_list_start_segment, NULL },
 196   { "section", section_attributes, NULL,
 197     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 198     library_list_start_section, NULL },
 199   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 200 };
 201
 202 static const struct gdb_xml_attribute library_attributes[] = {
 203   { "name", GDB_XML_AF_NONE, NULL, NULL },
 204   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 205 };
 206
 207 static const struct gdb_xml_element library_list_children[] = {
 208   { "library", library_attributes, library_children,
 209     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 210     library_list_start_library, library_list_end_library },
 211   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 212 };
 213
 214 static const struct gdb_xml_attribute library_list_attributes[] = {
 215   { "version", GDB_XML_AF_NONE, NULL, NULL },
 216   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 217 };
 218
 219 static const struct gdb_xml_element library_list_elements[] = {
 220   { "library-list", library_list_attributes, library_list_children,
 221     GDB_XML_EF_NONE, library_list_start_list, NULL },
 222   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 223 };
 224
 225 static VEC(lm_info_p) *
 226 solib_target_parse_libraries (const char *library)
 227 {
 228   VEC(lm_info_p) *result = NULL;
 229   struct cleanup *back_to = make_cleanup (solib_target_free_library_list,
 230                                           &result);
 231
 232   if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd",
 233                            library_list_elements, library, &result) == 0)
 234     {
 235       /* Parsed successfully, keep the result.  */
 236       discard_cleanups (back_to);
 237       return result;
 238     }
 239
 240   do_cleanups (back_to);
 241   return NULL;
 242 }
 243 #endif
 244
 245 static struct so_list *
 246 solib_target_current_sos (void)
 247 {
 248   struct so_list *new_solib, *start = NULL, *last = NULL;
 249   const char *library_document;
 250   VEC(lm_info_p) *library_list;
 251   struct lm_info *info;
 252   int ix;
 253
 254   /* Fetch the list of shared libraries.  */
 255   library_document = target_read_stralloc (&current_target,
 256                                            TARGET_OBJECT_LIBRARIES,
 257                                            NULL);
 258   if (library_document == NULL)
 259     return NULL;
 260
 261   /* Parse the list.  */
 262   library_list = solib_target_parse_libraries (library_document);
 263   if (library_list == NULL)
 264     return NULL;
 265
 266   /* Build a struct so_list for each entry on the list.  */
 267   for (ix = 0; VEC_iterate (lm_info_p, library_list, ix, info); ix++)
 268     {
 269       new_solib = XZALLOC (struct so_list);
 270       strncpy (new_solib->so_name, info->name, SO_NAME_MAX_PATH_SIZE - 1);
 271       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 272       strncpy (new_solib->so_original_name, info->name,
 273                SO_NAME_MAX_PATH_SIZE - 1);
 274       new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 275       new_solib->lm_info = info;
 276
 277       /* We no longer need this copy of the name.  */
 278       xfree (info->name);
 279       info->name = NULL;
 280
 281       /* Add it to the list.  */
 282       if (!start)
 283         last = start = new_solib;
 284       else
 285         {
 286           last->next = new_solib;
 287           last = new_solib;
 288         }
 289     }
 290
 291   /* Free the library list, but not its members.  */
 292   VEC_free (lm_info_p, library_list);
 293
 294   return start;
 295 }
 296
 297 static void
 298 solib_target_special_symbol_handling (void)
 299 {
 300   /* Nothing needed.  */
 301 }
 302
 303 static void
 304 solib_target_solib_create_inferior_hook (int from_tty)
 305 {
 306   /* Nothing needed.  */
 307 }
 308
 309 static void
 310 solib_target_clear_solib (void)
 311 {
 312   /* Nothing needed.  */
 313 }
 314
 315 static void
 316 solib_target_free_so (struct so_list *so)
 317 {
 318   gdb_assert (so->lm_info->name == NULL);
 319   xfree (so->lm_info->offsets);
 320   VEC_free (CORE_ADDR, so->lm_info->segment_bases);
 321   xfree (so->lm_info);
 322 }
 323
 324 static void
 325 solib_target_relocate_section_addresses (struct so_list *so,
 326                                          struct target_section *sec)
 327 {
 328   int flags = bfd_get_section_flags (sec->bfd, sec->the_bfd_section);
 329   CORE_ADDR offset;
 330
 331   /* Build the offset table only once per object file.  We can not do
 332      it any earlier, since we need to open the file first.  */
 333   if (so->lm_info->offsets == NULL)
 334     {
 335       int num_sections = bfd_count_sections (so->abfd);
 336
 337       so->lm_info->offsets = xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections));
 338
 339       if (so->lm_info->section_bases)
 340         {
 341           int i;
 342           asection *sect;
 343           int num_section_bases
 344             = VEC_length (CORE_ADDR, so->lm_info->section_bases);
 345           int num_alloc_sections = 0;
 346
 347           for (i = 0, sect = so->abfd->sections;
 348                sect != NULL;
 349                i++, sect = sect->next)
 350             if ((bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 351               num_alloc_sections++;
 352
 353           if (num_alloc_sections != num_section_bases)
 354             warning (_("\
 355 Could not relocate shared library \"%s\": wrong number of ALLOC sections"),
 356                      so->so_name);
 357           else
 358             {
 359               int bases_index = 0;
 360               int found_range = 0;
 361               CORE_ADDR *section_bases;
 362
 363               section_bases = VEC_address (CORE_ADDR,
 364                                            so->lm_info->section_bases);
 365
 366               so->addr_low = ~(CORE_ADDR) 0;
 367               so->addr_high = 0;
 368               for (i = 0, sect = so->abfd->sections;
 369                    sect != NULL;
 370                    i++, sect = sect->next)
 371                 {
 372                   if (!(bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 373                     continue;
 374                   if (bfd_section_size (so->abfd, sect) > 0)
 375                     {
 376                       CORE_ADDR low, high;
 377
 378                       low = section_bases[i];
 379                       high = low + bfd_section_size (so->abfd, sect) - 1;
 380
 381                       if (low < so->addr_low)
 382                         so->addr_low = low;
 383                       if (high > so->addr_high)
 384                         so->addr_high = high;
 385                       gdb_assert (so->addr_low <= so->addr_high);
 386                       found_range = 1;
 387                     }
 388                   so->lm_info->offsets->offsets[i]
 389                     = section_bases[bases_index];
 390                   bases_index++;
 391                 }
 392               if (!found_range)
 393                 so->addr_low = so->addr_high = 0;
 394               gdb_assert (so->addr_low <= so->addr_high);
 395             }
 396         }
 397       else if (so->lm_info->segment_bases)
 398         {
 399           struct symfile_segment_data *data;
 400
 401           data = get_symfile_segment_data (so->abfd);
 402           if (data == NULL)
 403             warning (_("\
 404 Could not relocate shared library \"%s\": no segments"), so->so_name);
 405           else
 406             {
 407               ULONGEST orig_delta;
 408               int i;
 409               int num_bases;
 410               CORE_ADDR *segment_bases;
 411
 412               num_bases = VEC_length (CORE_ADDR, so->lm_info->segment_bases);
 413               segment_bases = VEC_address (CORE_ADDR,
 414                                            so->lm_info->segment_bases);
 415
 416               if (!symfile_map_offsets_to_segments (so->abfd, data,
 417                                                     so->lm_info->offsets,
 418                                                     num_bases, segment_bases))
 419                 warning (_("\
 420 Could not relocate shared library \"%s\": bad offsets"), so->so_name);
 421
 422               /* Find the range of addresses to report for this library in
 423                  "info sharedlibrary".  Report any consecutive segments
 424                  which were relocated as a single unit.  */
 425               gdb_assert (num_bases > 0);
 426               orig_delta = segment_bases[0] - data->segment_bases[0];
 427
 428               for (i = 1; i < data->num_segments; i++)
 429                 {
 430                   /* If we have run out of offsets, assume all
 431                      remaining segments have the same offset.  */
 432                   if (i >= num_bases)
 433                     continue;
 434
 435                   /* If this segment does not have the same offset, do
 436                      not include it in the library's range.  */
 437                   if (segment_bases[i] - data->segment_bases[i] != orig_delta)
 438                     break;
 439                 }
 440
 441               so->addr_low = segment_bases[0];
 442               so->addr_high = (data->segment_bases[i - 1]
 443                                + data->segment_sizes[i - 1]
 444                                + orig_delta);
 445               gdb_assert (so->addr_low <= so->addr_high);
 446
 447               free_symfile_segment_data (data);
 448             }
 449         }
 450     }
 451
 452   offset = so->lm_info->offsets->offsets[sec->the_bfd_section->index];
 453   sec->addr += offset;
 454   sec->endaddr += offset;
 455 }
 456
 457 static int
 458 solib_target_open_symbol_file_object (void *from_ttyp)
 459 {
 460   /* We can't locate the main symbol file based on the target's
 461      knowledge; the user has to specify it.  */
 462   return 0;
 463 }
 464
 465 static int
 466 solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
 467 {
 468   /* We don't have a range of addresses for the dynamic linker; there
 469      may not be one in the program's address space.  So only report
 470      PLT entries (which may be import stubs).  */
 471   return in_plt_section (pc, NULL);
 472 }
 473
 474 struct target_so_ops solib_target_so_ops;
 475
 476 /* -Wmissing-prototypes */
 477 extern initialize_file_ftype _initialize_solib_target;
 478
 479 void
 480 _initialize_solib_target (void)
 481 {
 482   solib_target_so_ops.relocate_section_addresses
 483     = solib_target_relocate_section_addresses;
 484   solib_target_so_ops.free_so = solib_target_free_so;
 485   solib_target_so_ops.clear_solib = solib_target_clear_solib;
 486   solib_target_so_ops.solib_create_inferior_hook
 487     = solib_target_solib_create_inferior_hook;
 488   solib_target_so_ops.special_symbol_handling
 489     = solib_target_special_symbol_handling;
 490   solib_target_so_ops.current_sos = solib_target_current_sos;
 491   solib_target_so_ops.open_symbol_file_object
 492     = solib_target_open_symbol_file_object;
 493   solib_target_so_ops.in_dynsym_resolve_code
 494     = solib_target_in_dynsym_resolve_code;
 495   solib_target_so_ops.bfd_open = solib_bfd_open;
 496
 497   /* Set current_target_so_ops to solib_target_so_ops if not already
 498      set.  */
 499   if (current_target_so_ops == 0)
 500     current_target_so_ops = &solib_target_so_ops;
 501 }