gdb/solib-target.c - gdb

Global variables defined

Data types defined

Functions defined

Source code

  1. /* Definitions for targets which report shared library events.

  3.    Copyright (C) 2007-2015 Free Software Foundation, Inc.

  5.    This file is part of GDB.

  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.

  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.

  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/>.  */

  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"

  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;

  36.   /* The target can either specify segment bases or section bases, not
  37.      both.  */

  39.   /* The base addresses for each independently relocatable segment of
  40.      this shared library.  */
  41.   VEC(CORE_ADDR) *segment_bases;

  43.   /* The base addresses for each independently allocatable,
  44.      relocatable section of this shared library.  */
  45.   VEC(CORE_ADDR) *section_bases;

  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. };

  52. ‌typedef struct lm_info *lm_info_p;
  53. ‌DEF_VEC_P(lm_info_p);

  55. #if !defined(HAVE_LIBEXPAT)

  57. ‌static VEC(lm_info_p) *
  58. solib_target_parse_libraries (const char *library)
  59. {
  60.   static int have_warned;

  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.     }

  69.   return NULL;
  70. }

  72. #else /* HAVE_LIBEXPAT */

  74. #include "xml-support.h"

  76. /* Handle the start of a <segment> element.  */

  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;

  88.   if (last->section_bases != NULL)
  89.     gdb_xml_error (parser,
  90.                    _("Library list with both segments and sections"));

  92.   VEC_safe_push (CORE_ADDR, last->segment_bases, address);
  93. }

  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;

  105.   if (last->segment_bases != NULL)
  106.     gdb_xml_error (parser,
  107.                    _("Library list with both segments and sections"));

  109.   VEC_safe_push (CORE_ADDR, last->section_bases, address);
  110. }

  112. /* Handle the start of a <library> element.  */

  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;

  123.   item->name = xstrdup (name);
  124.   VEC_safe_push (lm_info_p, *list, item);
  125. }

  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);

  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. }


  142. /* Handle the start of a <library-list> element.  */

  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.   char *version = xml_find_attribute (attributes, "version")->value;

  151.   if (strcmp (version, "1.0") != 0)
  152.     gdb_xml_error (parser,
  153.                    _("Library list has unsupported version \"%s\""),
  154.                    version);
  155. }

  157. /* Discard the constructed library list.  */

  159. static void
  160. ‌solib_target_free_library_list (void *p)
  161. {
  162.   VEC(lm_info_p) **result = p;
  163.   struct lm_info *info;
  164.   int ix;

  166.   for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
  167.     {
  168.       xfree (info->name);
  169.       VEC_free (CORE_ADDR, info->segment_bases);
  170.       VEC_free (CORE_ADDR, info->section_bases);
  171.       xfree (info);
  172.     }
  173.   VEC_free (lm_info_p, *result);
  174.   *result = NULL;
  175. }

  177. /* The allowed elements and attributes for an XML library list.
  178.    The root element is a <library-list>.  */

  180. ‌static const struct gdb_xml_attribute segment_attributes[] = {
  181.   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
  182.   { NULL, GDB_XML_AF_NONE, NULL, NULL }
  183. };

  185. ‌static const struct gdb_xml_attribute section_attributes[] = {
  186.   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
  187.   { NULL, GDB_XML_AF_NONE, NULL, NULL }
  188. };

  190. ‌static const struct gdb_xml_element library_children[] = {
  191.   { "segment", segment_attributes, NULL,
  192.     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
  193.     library_list_start_segment, NULL },
  194.   { "section", section_attributes, NULL,
  195.     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
  196.     library_list_start_section, NULL },
  197.   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
  198. };

  200. ‌static const struct gdb_xml_attribute library_attributes[] = {
  201.   { "name", GDB_XML_AF_NONE, NULL, NULL },
  202.   { NULL, GDB_XML_AF_NONE, NULL, NULL }
  203. };

  205. ‌static const struct gdb_xml_element library_list_children[] = {
  206.   { "library", library_attributes, library_children,
  207.     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
  208.     library_list_start_library, library_list_end_library },
  209.   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
  210. };

  212. ‌static const struct gdb_xml_attribute library_list_attributes[] = {
  213.   { "version", GDB_XML_AF_NONE, NULL, NULL },
  214.   { NULL, GDB_XML_AF_NONE, NULL, NULL }
  215. };

  217. ‌static const struct gdb_xml_element library_list_elements[] = {
  218.   { "library-list", library_list_attributes, library_list_children,
  219.     GDB_XML_EF_NONE, library_list_start_list, NULL },
  220.   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
  221. };

  223. ‌static VEC(lm_info_p) *
  224. solib_target_parse_libraries (const char *library)
  225. {
  226.   VEC(lm_info_p) *result = NULL;
  227.   struct cleanup *back_to = make_cleanup (solib_target_free_library_list,
  228.                                           &result);

  230.   if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd",
  231.                            library_list_elements, library, &result) == 0)
  232.     {
  233.       /* Parsed successfully, keep the result.  */
  234.       discard_cleanups (back_to);
  235.       return result;
  236.     }

  238.   do_cleanups (back_to);
  239.   return NULL;
  240. }
  241. #endif

  243. static struct so_list *
  244. ‌solib_target_current_sos (void)
  245. {
  246.   struct so_list *new_solib, *start = NULL, *last = NULL;
  247.   char *library_document;
  248.   struct cleanup *old_chain;
  249.   VEC(lm_info_p) *library_list;
  250.   struct lm_info *info;
  251.   int ix;

  253.   /* Fetch the list of shared libraries.  */
  254.   library_document = target_read_stralloc (&current_target,
  255.                                            TARGET_OBJECT_LIBRARIES,
  256.                                            NULL);
  257.   if (library_document == NULL)
  258.     return NULL;

  260.   /* solib_target_parse_libraries may throw, so we use a cleanup.  */
  261.   old_chain = make_cleanup (xfree, library_document);

  263.   /* Parse the list.  */
  264.   library_list = solib_target_parse_libraries (library_document);

  266.   /* library_document string is not needed behind this point.  */
  267.   do_cleanups (old_chain);

  269.   if (library_list == NULL)
  270.     return NULL;

  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 = XCNEW (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;

  283.       /* We no longer need this copy of the name.  */
  284.       xfree (info->name);
  285.       info->name = NULL;

  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.     }

  297.   /* Free the library list, but not its members.  */
  298.   VEC_free (lm_info_p, library_list);

  300.   return start;
  301. }

  303. static void
  304. ‌solib_target_special_symbol_handling (void)
  305. {
  306.   /* Nothing needed.  */
  307. }

  309. static void
  310. ‌solib_target_solib_create_inferior_hook (int from_tty)
  311. {
  312.   /* Nothing needed.  */
  313. }

  315. static void
  316. ‌solib_target_clear_solib (void)
  317. {
  318.   /* Nothing needed.  */
  319. }

  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. }

  330. static void
  331. ‌solib_target_relocate_section_addresses (struct so_list *so,
  332.                                          struct target_section *sec)
  333. {
  334.   CORE_ADDR offset;

  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 = gdb_bfd_count_sections (so->abfd);

  342.       so->lm_info->offsets = xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections));

  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;

  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++;

  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;

  368.               section_bases = VEC_address (CORE_ADDR,
  369.                                            so->lm_info->section_bases);

  371.               so->addr_low = ~(CORE_ADDR) 0;
  372.               so->addr_high = 0;
  373.               for (i = 0, sect = so->abfd->sections;
  374.                    sect != NULL;
  375.                    i++, sect = sect->next)
  376.                 {
  377.                   if (!(bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
  378.                     continue;
  379.                   if (bfd_section_size (so->abfd, sect) > 0)
  380.                     {
  381.                       CORE_ADDR low, high;

  383.                       low = section_bases[i];
  384.                       high = low + bfd_section_size (so->abfd, sect) - 1;

  386.                       if (low < so->addr_low)
  387.                         so->addr_low = low;
  388.                       if (high > so->addr_high)
  389.                         so->addr_high = high;
  390.                       gdb_assert (so->addr_low <= so->addr_high);
  391.                       found_range = 1;
  392.                     }
  393.                   so->lm_info->offsets->offsets[i]
  394.                     = 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;

  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;

  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);

  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);

  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];

  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;

  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.                 }

  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);

  452.               free_symfile_segment_data (data);
  453.             }
  454.         }
  455.     }

  457.   offset = so->lm_info->offsets->offsets[gdb_bfd_section_index
  458.                                          (sec->the_bfd_section->owner,
  459.                                           sec->the_bfd_section)];
  460.   sec->addr += offset;
  461.   sec->endaddr += offset;
  462. }

  464. static int
  465. ‌solib_target_open_symbol_file_object (void *from_ttyp)
  466. {
  467.   /* We can't locate the main symbol file based on the target's
  468.      knowledge; the user has to specify it.  */
  469.   return 0;
  470. }

  472. static int
  473. ‌solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
  474. {
  475.   /* We don't have a range of addresses for the dynamic linker; there
  476.      may not be one in the program's address space.  So only report
  477.      PLT entries (which may be import stubs).  */
  478.   return in_plt_section (pc);
  479. }

  481. ‌struct target_so_ops solib_target_so_ops;

  483. /* -Wmissing-prototypes */
  484. extern initialize_file_ftype _initialize_solib_target;

  486. void
  487. ‌_initialize_solib_target (void)
  488. {
  489.   solib_target_so_ops.relocate_section_addresses
  490.     = solib_target_relocate_section_addresses;
  491.   solib_target_so_ops.free_so = solib_target_free_so;
  492.   solib_target_so_ops.clear_solib = solib_target_clear_solib;
  493.   solib_target_so_ops.solib_create_inferior_hook
  494.     = solib_target_solib_create_inferior_hook;
  495.   solib_target_so_ops.special_symbol_handling
  496.     = solib_target_special_symbol_handling;
  497.   solib_target_so_ops.current_sos = solib_target_current_sos;
  498.   solib_target_so_ops.open_symbol_file_object
  499.     = solib_target_open_symbol_file_object;
  500.   solib_target_so_ops.in_dynsym_resolve_code
  501.     = solib_target_in_dynsym_resolve_code;
  502.   solib_target_so_ops.bfd_open = solib_bfd_open;

  504.   /* Set current_target_so_ops to solib_target_so_ops if not already
  505.      set.  */
  506.   if (current_target_so_ops == 0)
  507.     current_target_so_ops = &solib_target_so_ops;
  508. }