gdb/solib-target.c

   1 /* Definitions for targets which report shared library events.
   2
   3    Copyright (C) 2007, 2008, 2009, 2010, 2011 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 = xml_find_attribute (attributes, "address")->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 = xml_find_attribute (attributes, "address")->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 = xml_find_attribute (attributes, "name")->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 = xml_find_attribute (attributes, "version")->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   VEC(lm_info_p) *result = NULL;
 231   struct cleanup *back_to = make_cleanup (solib_target_free_library_list,
 232                                           &result);
 233
 234   if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd",
 235                            library_list_elements, library, &result) == 0)
 236     {
 237       /* Parsed successfully, keep the result.  */
 238       discard_cleanups (back_to);
 239       return result;
 240     }
 241
 242   do_cleanups (back_to);
 243   return NULL;
 244 }
 245 #endif
 246
 247 static struct so_list *
 248 solib_target_current_sos (void)
 249 {
 250   struct so_list *new_solib, *start = NULL, *last = NULL;
 251   const char *library_document;
 252   VEC(lm_info_p) *library_list;
 253   struct lm_info *info;
 254   int ix;
 255
 256   /* Fetch the list of shared libraries.  */
 257   library_document = target_read_stralloc (&current_target,
 258                                            TARGET_OBJECT_LIBRARIES,
 259                                            NULL);
 260   if (library_document == NULL)
 261     return NULL;
 262
 263   /* Parse the list.  */
 264   library_list = solib_target_parse_libraries (library_document);
 265   if (library_list == NULL)
 266     return NULL;
 267
 268   /* Build a struct so_list for each entry on the list.  */
 269   for (ix = 0; VEC_iterate (lm_info_p, library_list, ix, info); ix++)
 270     {
 271       new_solib = XZALLOC (struct so_list);
 272       strncpy (new_solib->so_name, info->name, SO_NAME_MAX_PATH_SIZE - 1);
 273       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 274       strncpy (new_solib->so_original_name, info->name,
 275                SO_NAME_MAX_PATH_SIZE - 1);
 276       new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 277       new_solib->lm_info = info;
 278
 279       /* We no longer need this copy of the name.  */
 280       xfree (info->name);
 281       info->name = NULL;
 282
 283       /* Add it to the list.  */
 284       if (!start)
 285         last = start = new_solib;
 286       else
 287         {
 288           last->next = new_solib;
 289           last = new_solib;
 290         }
 291     }
 292
 293   /* Free the library list, but not its members.  */
 294   VEC_free (lm_info_p, library_list);
 295
 296   return start;
 297 }
 298
 299 static void
 300 solib_target_special_symbol_handling (void)
 301 {
 302   /* Nothing needed.  */
 303 }
 304
 305 static void
 306 solib_target_solib_create_inferior_hook (int from_tty)
 307 {
 308   /* Nothing needed.  */
 309 }
 310
 311 static void
 312 solib_target_clear_solib (void)
 313 {
 314   /* Nothing needed.  */
 315 }
 316
 317 static void
 318 solib_target_free_so (struct so_list *so)
 319 {
 320   gdb_assert (so->lm_info->name == NULL);
 321   xfree (so->lm_info->offsets);
 322   VEC_free (CORE_ADDR, so->lm_info->segment_bases);
 323   xfree (so->lm_info);
 324 }
 325
 326 static void
 327 solib_target_relocate_section_addresses (struct so_list *so,
 328                                          struct target_section *sec)
 329 {
 330   int flags = bfd_get_section_flags (sec->bfd, sec->the_bfd_section);
 331   CORE_ADDR offset;
 332
 333   /* Build the offset table only once per object file.  We can not do
 334      it any earlier, since we need to open the file first.  */
 335   if (so->lm_info->offsets == NULL)
 336     {
 337       int num_sections = bfd_count_sections (so->abfd);
 338
 339       so->lm_info->offsets = xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections));
 340
 341       if (so->lm_info->section_bases)
 342         {
 343           int i;
 344           asection *sect;
 345           int num_section_bases
 346             = VEC_length (CORE_ADDR, so->lm_info->section_bases);
 347           int num_alloc_sections = 0;
 348
 349           for (i = 0, sect = so->abfd->sections;
 350                sect != NULL;
 351                i++, sect = sect->next)
 352             if ((bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 353               num_alloc_sections++;
 354
 355           if (num_alloc_sections != num_section_bases)
 356             warning (_("\
 357 Could not relocate shared library \"%s\": wrong number of ALLOC sections"),
 358                      so->so_name);
 359           else
 360             {
 361               int bases_index = 0;
 362               int found_range = 0;
 363               CORE_ADDR *section_bases;
 364
 365               section_bases = VEC_address (CORE_ADDR,
 366                                            so->lm_info->section_bases);
 367
 368               so->addr_low = ~(CORE_ADDR) 0;
 369               so->addr_high = 0;
 370               for (i = 0, sect = so->abfd->sections;
 371                    sect != NULL;
 372                    i++, sect = sect->next)
 373                 {
 374                   if (!(bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 375                     continue;
 376                   if (bfd_section_size (so->abfd, sect) > 0)
 377                     {
 378                       CORE_ADDR low, high;
 379
 380                       low = section_bases[i];
 381                       high = low + bfd_section_size (so->abfd, sect) - 1;
 382
 383                       if (low < so->addr_low)
 384                         so->addr_low = low;
 385                       if (high > so->addr_high)
 386                         so->addr_high = high;
 387                       gdb_assert (so->addr_low <= so->addr_high);
 388                       found_range = 1;
 389                     }
 390                   so->lm_info->offsets->offsets[i]
 391                     = section_bases[bases_index];
 392                   bases_index++;
 393                 }
 394               if (!found_range)
 395                 so->addr_low = so->addr_high = 0;
 396               gdb_assert (so->addr_low <= so->addr_high);
 397             }
 398         }
 399       else if (so->lm_info->segment_bases)
 400         {
 401           struct symfile_segment_data *data;
 402
 403           data = get_symfile_segment_data (so->abfd);
 404           if (data == NULL)
 405             warning (_("\
 406 Could not relocate shared library \"%s\": no segments"), so->so_name);
 407           else
 408             {
 409               ULONGEST orig_delta;
 410               int i;
 411               int num_bases;
 412               CORE_ADDR *segment_bases;
 413
 414               num_bases = VEC_length (CORE_ADDR, so->lm_info->segment_bases);
 415               segment_bases = VEC_address (CORE_ADDR,
 416                                            so->lm_info->segment_bases);
 417
 418               if (!symfile_map_offsets_to_segments (so->abfd, data,
 419                                                     so->lm_info->offsets,
 420                                                     num_bases, segment_bases))
 421                 warning (_("\
 422 Could not relocate shared library \"%s\": bad offsets"), so->so_name);
 423
 424               /* Find the range of addresses to report for this library in
 425                  "info sharedlibrary".  Report any consecutive segments
 426                  which were relocated as a single unit.  */
 427               gdb_assert (num_bases > 0);
 428               orig_delta = segment_bases[0] - data->segment_bases[0];
 429
 430               for (i = 1; i < data->num_segments; i++)
 431                 {
 432                   /* If we have run out of offsets, assume all
 433                      remaining segments have the same offset.  */
 434                   if (i >= num_bases)
 435                     continue;
 436
 437                   /* If this segment does not have the same offset, do
 438                      not include it in the library's range.  */
 439                   if (segment_bases[i] - data->segment_bases[i] != orig_delta)
 440                     break;
 441                 }
 442
 443               so->addr_low = segment_bases[0];
 444               so->addr_high = (data->segment_bases[i - 1]
 445                                + data->segment_sizes[i - 1]
 446                                + orig_delta);
 447               gdb_assert (so->addr_low <= so->addr_high);
 448
 449               free_symfile_segment_data (data);
 450             }
 451         }
 452     }
 453
 454   offset = so->lm_info->offsets->offsets[sec->the_bfd_section->index];
 455   sec->addr += offset;
 456   sec->endaddr += offset;
 457 }
 458
 459 static int
 460 solib_target_open_symbol_file_object (void *from_ttyp)
 461 {
 462   /* We can't locate the main symbol file based on the target's
 463      knowledge; the user has to specify it.  */
 464   return 0;
 465 }
 466
 467 static int
 468 solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
 469 {
 470   /* We don't have a range of addresses for the dynamic linker; there
 471      may not be one in the program's address space.  So only report
 472      PLT entries (which may be import stubs).  */
 473   return in_plt_section (pc, NULL);
 474 }
 475
 476 struct target_so_ops solib_target_so_ops;
 477
 478 /* -Wmissing-prototypes */
 479 extern initialize_file_ftype _initialize_solib_target;
 480
 481 void
 482 _initialize_solib_target (void)
 483 {
 484   solib_target_so_ops.relocate_section_addresses
 485     = solib_target_relocate_section_addresses;
 486   solib_target_so_ops.free_so = solib_target_free_so;
 487   solib_target_so_ops.clear_solib = solib_target_clear_solib;
 488   solib_target_so_ops.solib_create_inferior_hook
 489     = solib_target_solib_create_inferior_hook;
 490   solib_target_so_ops.special_symbol_handling
 491     = solib_target_special_symbol_handling;
 492   solib_target_so_ops.current_sos = solib_target_current_sos;
 493   solib_target_so_ops.open_symbol_file_object
 494     = solib_target_open_symbol_file_object;
 495   solib_target_so_ops.in_dynsym_resolve_code
 496     = solib_target_in_dynsym_resolve_code;
 497   solib_target_so_ops.bfd_open = solib_bfd_open;
 498
 499   /* Set current_target_so_ops to solib_target_so_ops if not already
 500      set.  */
 501   if (current_target_so_ops == 0)
 502     current_target_so_ops = &solib_target_so_ops;
 503 }