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   if (lm_info->segment_bases == NULL
 139       && lm_info->section_bases == NULL)
 140     gdb_xml_error (parser,
 141                    _("No segment or section bases defined"));
 142 }
 143
 144
 145 /* Handle the start of a <library-list> element.  */
 146
 147 static void
 148 library_list_start_list (struct gdb_xml_parser *parser,
 149                          const struct gdb_xml_element *element,
 150                          void *user_data, VEC(gdb_xml_value_s) *attributes)
 151 {
 152   char *version = VEC_index (gdb_xml_value_s, attributes, 0)->value;
 153
 154   if (strcmp (version, "1.0") != 0)
 155     gdb_xml_error (parser,
 156                    _("Library list has unsupported version \"%s\""),
 157                    version);
 158 }
 159
 160 /* Discard the constructed library list.  */
 161
 162 static void
 163 solib_target_free_library_list (void *p)
 164 {
 165   VEC(lm_info_p) **result = p;
 166   struct lm_info *info;
 167   int ix;
 168
 169   for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
 170     {
 171       xfree (info->name);
 172       VEC_free (CORE_ADDR, info->segment_bases);
 173       VEC_free (CORE_ADDR, info->section_bases);
 174       xfree (info);
 175     }
 176   VEC_free (lm_info_p, *result);
 177   *result = NULL;
 178 }
 179
 180 /* The allowed elements and attributes for an XML library list.
 181    The root element is a <library-list>.  */
 182
 183 const struct gdb_xml_attribute segment_attributes[] = {
 184   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 185   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 186 };
 187
 188 const struct gdb_xml_attribute section_attributes[] = {
 189   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 190   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 191 };
 192
 193 const struct gdb_xml_element library_children[] = {
 194   { "segment", segment_attributes, NULL,
 195     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 196     library_list_start_segment, NULL },
 197   { "section", section_attributes, NULL,
 198     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 199     library_list_start_section, NULL },
 200   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 201 };
 202
 203 const struct gdb_xml_attribute library_attributes[] = {
 204   { "name", GDB_XML_AF_NONE, NULL, NULL },
 205   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 206 };
 207
 208 const struct gdb_xml_element library_list_children[] = {
 209   { "library", library_attributes, library_children,
 210     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 211     library_list_start_library, library_list_end_library },
 212   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 213 };
 214
 215 const struct gdb_xml_attribute library_list_attributes[] = {
 216   { "version", GDB_XML_AF_NONE, NULL, NULL },
 217   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 218 };
 219
 220 const struct gdb_xml_element library_list_elements[] = {
 221   { "library-list", library_list_attributes, library_list_children,
 222     GDB_XML_EF_NONE, library_list_start_list, NULL },
 223   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 224 };
 225
 226 static VEC(lm_info_p) *
 227 solib_target_parse_libraries (const char *library)
 228 {
 229   struct gdb_xml_parser *parser;
 230   VEC(lm_info_p) *result = NULL;
 231   struct cleanup *before_deleting_result, *back_to;
 232
 233   back_to = make_cleanup (null_cleanup, NULL);
 234   parser = gdb_xml_create_parser_and_cleanup (_("target library list"),
 235                                               library_list_elements, &result);
 236   gdb_xml_use_dtd (parser, "library-list.dtd");
 237
 238   before_deleting_result = make_cleanup (solib_target_free_library_list,
 239                                          &result);
 240
 241   if (gdb_xml_parse (parser, library) == 0)
 242     /* Parsed successfully, don't need to delete the result.  */
 243     discard_cleanups (before_deleting_result);
 244
 245   do_cleanups (back_to);
 246   return result;
 247 }
 248 #endif
 249
 250 static struct so_list *
 251 solib_target_current_sos (void)
 252 {
 253   struct so_list *new_solib, *start = NULL, *last = NULL;
 254   const char *library_document;
 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   /* Parse the list.  */
 267   library_list = solib_target_parse_libraries (library_document);
 268   if (library_list == NULL)
 269     return NULL;
 270
 271   /* Build a struct so_list for each entry on the list.  */
 272   for (ix = 0; VEC_iterate (lm_info_p, library_list, ix, info); ix++)
 273     {
 274       new_solib = XZALLOC (struct so_list);
 275       strncpy (new_solib->so_name, info->name, SO_NAME_MAX_PATH_SIZE - 1);
 276       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 277       strncpy (new_solib->so_original_name, info->name,
 278                SO_NAME_MAX_PATH_SIZE - 1);
 279       new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 280       new_solib->lm_info = info;
 281
 282       /* We no longer need this copy of the name.  */
 283       xfree (info->name);
 284       info->name = NULL;
 285
 286       /* Add it to the list.  */
 287       if (!start)
 288         last = start = new_solib;
 289       else
 290         {
 291           last->next = new_solib;
 292           last = new_solib;
 293         }
 294     }
 295
 296   /* Free the library list, but not its members.  */
 297   VEC_free (lm_info_p, library_list);
 298
 299   return start;
 300 }
 301
 302 static void
 303 solib_target_special_symbol_handling (void)
 304 {
 305   /* Nothing needed.  */
 306 }
 307
 308 static void
 309 solib_target_solib_create_inferior_hook (int from_tty)
 310 {
 311   /* Nothing needed.  */
 312 }
 313
 314 static void
 315 solib_target_clear_solib (void)
 316 {
 317   /* Nothing needed.  */
 318 }
 319
 320 static void
 321 solib_target_free_so (struct so_list *so)
 322 {
 323   gdb_assert (so->lm_info->name == NULL);
 324   xfree (so->lm_info->offsets);
 325   VEC_free (CORE_ADDR, so->lm_info->segment_bases);
 326   xfree (so->lm_info);
 327 }
 328
 329 static void
 330 solib_target_relocate_section_addresses (struct so_list *so,
 331                                          struct target_section *sec)
 332 {
 333   int flags = bfd_get_section_flags (sec->bfd, sec->the_bfd_section);
 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 = 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               section_bases = VEC_address (CORE_ADDR,
 368                                            so->lm_info->section_bases);
 369
 370               so->addr_low = ~(CORE_ADDR) 0;
 371               so->addr_high = 0;
 372               for (i = 0, sect = so->abfd->sections;
 373                    sect != NULL;
 374                    i++, sect = sect->next)
 375                 {
 376                   if (!(bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 377                     continue;
 378                   if (bfd_section_size (so->abfd, sect) > 0)
 379                     {
 380                       CORE_ADDR low, high;
 381                       low = section_bases[i];
 382                       high = low + bfd_section_size (so->abfd, sect) - 1;
 383
 384                       if (low < so->addr_low)
 385                         so->addr_low = low;
 386                       if (high > so->addr_high)
 387                         so->addr_high = high;
 388                       gdb_assert (so->addr_low <= so->addr_high);
 389                       found_range = 1;
 390                     }
 391                   so->lm_info->offsets->offsets[i] = 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           data = get_symfile_segment_data (so->abfd);
 403           if (data == NULL)
 404             warning (_("\
 405 Could not relocate shared library \"%s\": no segments"), so->so_name);
 406           else
 407             {
 408               ULONGEST orig_delta;
 409               int i;
 410               int num_bases;
 411               CORE_ADDR *segment_bases;
 412
 413               num_bases = VEC_length (CORE_ADDR, so->lm_info->segment_bases);
 414               segment_bases = VEC_address (CORE_ADDR,
 415                                            so->lm_info->segment_bases);
 416
 417               if (!symfile_map_offsets_to_segments (so->abfd, data,
 418                                                     so->lm_info->offsets,
 419                                                     num_bases, segment_bases))
 420                 warning (_("\
 421 Could not relocate shared library \"%s\": bad offsets"), so->so_name);
 422
 423               /* Find the range of addresses to report for this library in
 424                  "info sharedlibrary".  Report any consecutive segments
 425                  which were relocated as a single unit.  */
 426               gdb_assert (num_bases > 0);
 427               orig_delta = segment_bases[0] - data->segment_bases[0];
 428
 429               for (i = 1; i < data->num_segments; i++)
 430                 {
 431                   /* If we have run out of offsets, assume all
 432                      remaining segments have the same offset.  */
 433                   if (i >= num_bases)
 434                     continue;
 435
 436                   /* If this segment does not have the same offset, do
 437                      not include it in the library's range.  */
 438                   if (segment_bases[i] - data->segment_bases[i] != orig_delta)
 439                     break;
 440                 }
 441
 442               so->addr_low = segment_bases[0];
 443               so->addr_high = (data->segment_bases[i - 1]
 444                                + data->segment_sizes[i - 1]
 445                                + orig_delta);
 446               gdb_assert (so->addr_low <= so->addr_high);
 447
 448               free_symfile_segment_data (data);
 449             }
 450         }
 451     }
 452
 453   offset = so->lm_info->offsets->offsets[sec->the_bfd_section->index];
 454   sec->addr += offset;
 455   sec->endaddr += offset;
 456 }
 457
 458 static int
 459 solib_target_open_symbol_file_object (void *from_ttyp)
 460 {
 461   /* We can't locate the main symbol file based on the target's
 462      knowledge; the user has to specify it.  */
 463   return 0;
 464 }
 465
 466 static int
 467 solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
 468 {
 469   /* We don't have a range of addresses for the dynamic linker; there
 470      may not be one in the program's address space.  So only report
 471      PLT entries (which may be import stubs).  */
 472   return in_plt_section (pc, NULL);
 473 }
 474
 475 struct target_so_ops solib_target_so_ops;
 476
 477 extern initialize_file_ftype _initialize_solib_target; /* -Wmissing-prototypes */
 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 }