/* Definitions for targets which report shared library events. Copyright (C) 2007-2019 Free Software Foundation, Inc. This file is part of GDB. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "defs.h" #include "objfiles.h" #include "solist.h" #include "symtab.h" #include "symfile.h" #include "target.h" #include "solib-target.h" #include <vector> /* Private data for each loaded library. */ struct lm_info_target : public lm_info_base { /* The library's name. The name is normally kept in the struct so_list; it is only here during XML parsing. */ std::string name; /* The target can either specify segment bases or section bases, not both. */ /* The base addresses for each independently relocatable segment of this shared library. */ std::vector<CORE_ADDR> segment_bases; /* The base addresses for each independently allocatable, relocatable section of this shared library. */ std::vector<CORE_ADDR> section_bases; /* The cached offsets for each section of this shared library, determined from SEGMENT_BASES, or SECTION_BASES. */ section_offsets *offsets = NULL; }; typedef std::vector<std::unique_ptr<lm_info_target>> lm_info_vector; #if !defined(HAVE_LIBEXPAT) static lm_info_vector solib_target_parse_libraries (const char *library) { static int have_warned; if (!have_warned) { have_warned = 1; warning (_("Can not parse XML library list; XML support was disabled " "at compile time")); } return lm_info_vector (); } #else /* HAVE_LIBEXPAT */ #include "xml-support.h" /* Handle the start of a <segment> element. */ static void library_list_start_segment (struct gdb_xml_parser *parser, const struct gdb_xml_element *element, void *user_data, std::vector<gdb_xml_value> &attributes) { lm_info_vector *list = (lm_info_vector *) user_data; lm_info_target *last = list->back ().get (); ULONGEST *address_p = (ULONGEST *) xml_find_attribute (attributes, "address")->value.get (); CORE_ADDR address = (CORE_ADDR) *address_p; if (!last->section_bases.empty ()) gdb_xml_error (parser, _("Library list with both segments and sections")); last->segment_bases.push_back (address); } static void library_list_start_section (struct gdb_xml_parser *parser, const struct gdb_xml_element *element, void *user_data, std::vector<gdb_xml_value> &attributes) { lm_info_vector *list = (lm_info_vector *) user_data; lm_info_target *last = list->back ().get (); ULONGEST *address_p = (ULONGEST *) xml_find_attribute (attributes, "address")->value.get (); CORE_ADDR address = (CORE_ADDR) *address_p; if (!last->segment_bases.empty ()) gdb_xml_error (parser, _("Library list with both segments and sections")); last->section_bases.push_back (address); } /* Handle the start of a <library> element. */ static void library_list_start_library (struct gdb_xml_parser *parser, const struct gdb_xml_element *element, void *user_data, std::vector<gdb_xml_value> &attributes) { lm_info_vector *list = (lm_info_vector *) user_data; lm_info_target *item = new lm_info_target; item->name = (const char *) xml_find_attribute (attributes, "name")->value.get (); list->emplace_back (item); } static void library_list_end_library (struct gdb_xml_parser *parser, const struct gdb_xml_element *element, void *user_data, const char *body_text) { lm_info_vector *list = (lm_info_vector *) user_data; lm_info_target *lm_info = list->back ().get (); if (lm_info->segment_bases.empty () && lm_info->section_bases.empty ()) gdb_xml_error (parser, _("No segment or section bases defined")); } /* Handle the start of a <library-list> element. */ static void library_list_start_list (struct gdb_xml_parser *parser, const struct gdb_xml_element *element, void *user_data, std::vector<gdb_xml_value> &attributes) { struct gdb_xml_value *version = xml_find_attribute (attributes, "version"); /* #FIXED attribute may be omitted, Expat returns NULL in such case. */ if (version != NULL) { const char *string = (const char *) version->value.get (); if (strcmp (string, "1.0") != 0) gdb_xml_error (parser, _("Library list has unsupported version \"%s\""), string); } } /* The allowed elements and attributes for an XML library list. The root element is a <library-list>. */ static const struct gdb_xml_attribute segment_attributes[] = { { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL }, { NULL, GDB_XML_AF_NONE, NULL, NULL } }; static const struct gdb_xml_attribute section_attributes[] = { { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL }, { NULL, GDB_XML_AF_NONE, NULL, NULL } }; static const struct gdb_xml_element library_children[] = { { "segment", segment_attributes, NULL, GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL, library_list_start_segment, NULL }, { "section", section_attributes, NULL, GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL, library_list_start_section, NULL }, { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } }; static const struct gdb_xml_attribute library_attributes[] = { { "name", GDB_XML_AF_NONE, NULL, NULL }, { NULL, GDB_XML_AF_NONE, NULL, NULL } }; static const struct gdb_xml_element library_list_children[] = { { "library", library_attributes, library_children, GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL, library_list_start_library, library_list_end_library }, { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } }; static const struct gdb_xml_attribute library_list_attributes[] = { { "version", GDB_XML_AF_OPTIONAL, NULL, NULL }, { NULL, GDB_XML_AF_NONE, NULL, NULL } }; static const struct gdb_xml_element library_list_elements[] = { { "library-list", library_list_attributes, library_list_children, GDB_XML_EF_NONE, library_list_start_list, NULL }, { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } }; static lm_info_vector solib_target_parse_libraries (const char *library) { lm_info_vector result; if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd", library_list_elements, library, &result) == 0) { /* Parsed successfully. */ return result; } result.clear (); return result; } #endif static struct so_list * solib_target_current_sos (void) { struct so_list *new_solib, *start = NULL, *last = NULL; /* Fetch the list of shared libraries. */ gdb::optional<gdb::char_vector> library_document = target_read_stralloc (current_top_target (), TARGET_OBJECT_LIBRARIES, NULL); if (!library_document) return NULL; /* Parse the list. */ lm_info_vector library_list = solib_target_parse_libraries (library_document->data ()); if (library_list.empty ()) return NULL; /* Build a struct so_list for each entry on the list. */ for (auto &&info : library_list) { new_solib = XCNEW (struct so_list); strncpy (new_solib->so_name, info->name.c_str (), SO_NAME_MAX_PATH_SIZE - 1); new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; strncpy (new_solib->so_original_name, info->name.c_str (), SO_NAME_MAX_PATH_SIZE - 1); new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; /* We no longer need this copy of the name. */ info->name.clear (); new_solib->lm_info = info.release (); /* Add it to the list. */ if (!start) last = start = new_solib; else { last->next = new_solib; last = new_solib; } } return start; } static void solib_target_solib_create_inferior_hook (int from_tty) { /* Nothing needed. */ } static void solib_target_clear_solib (void) { /* Nothing needed. */ } static void solib_target_free_so (struct so_list *so) { lm_info_target *li = (lm_info_target *) so->lm_info; gdb_assert (li->name.empty ()); delete li; } static void solib_target_relocate_section_addresses (struct so_list *so, struct target_section *sec) { CORE_ADDR offset; lm_info_target *li = (lm_info_target *) so->lm_info; /* Build the offset table only once per object file. We can not do it any earlier, since we need to open the file first. */ if (li->offsets == NULL) { int num_sections = gdb_bfd_count_sections (so->abfd); li->offsets = ((struct section_offsets *) xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections))); if (!li->section_bases.empty ()) { int i; asection *sect; int num_alloc_sections = 0; for (i = 0, sect = so->abfd->sections; sect != NULL; i++, sect = sect->next) if ((bfd_section_flags (sect) & SEC_ALLOC)) num_alloc_sections++; if (num_alloc_sections != li->section_bases.size ()) warning (_("\ Could not relocate shared library \"%s\": wrong number of ALLOC sections"), so->so_name); else { int bases_index = 0; int found_range = 0; so->addr_low = ~(CORE_ADDR) 0; so->addr_high = 0; for (i = 0, sect = so->abfd->sections; sect != NULL; i++, sect = sect->next) { if (!(bfd_section_flags (sect) & SEC_ALLOC)) continue; if (bfd_section_size (sect) > 0) { CORE_ADDR low, high; low = li->section_bases[i]; high = low + bfd_section_size (sect) - 1; if (low < so->addr_low) so->addr_low = low; if (high > so->addr_high) so->addr_high = high; gdb_assert (so->addr_low <= so->addr_high); found_range = 1; } li->offsets->offsets[i] = li->section_bases[bases_index]; bases_index++; } if (!found_range) so->addr_low = so->addr_high = 0; gdb_assert (so->addr_low <= so->addr_high); } } else if (!li->segment_bases.empty ()) { struct symfile_segment_data *data; data = get_symfile_segment_data (so->abfd); if (data == NULL) warning (_("\ Could not relocate shared library \"%s\": no segments"), so->so_name); else { ULONGEST orig_delta; int i; if (!symfile_map_offsets_to_segments (so->abfd, data, li->offsets, li->segment_bases.size (), li->segment_bases.data ())) warning (_("\ Could not relocate shared library \"%s\": bad offsets"), so->so_name); /* Find the range of addresses to report for this library in "info sharedlibrary". Report any consecutive segments which were relocated as a single unit. */ gdb_assert (li->segment_bases.size () > 0); orig_delta = li->segment_bases[0] - data->segment_bases[0]; for (i = 1; i < data->num_segments; i++) { /* If we have run out of offsets, assume all remaining segments have the same offset. */ if (i >= li->segment_bases.size ()) continue; /* If this segment does not have the same offset, do not include it in the library's range. */ if (li->segment_bases[i] - data->segment_bases[i] != orig_delta) break; } so->addr_low = li->segment_bases[0]; so->addr_high = (data->segment_bases[i - 1] + data->segment_sizes[i - 1] + orig_delta); gdb_assert (so->addr_low <= so->addr_high); free_symfile_segment_data (data); } } } offset = li->offsets->offsets[gdb_bfd_section_index (sec->the_bfd_section->owner, sec->the_bfd_section)]; sec->addr += offset; sec->endaddr += offset; } static int solib_target_open_symbol_file_object (int from_tty) { /* We can't locate the main symbol file based on the target's knowledge; the user has to specify it. */ return 0; } static int solib_target_in_dynsym_resolve_code (CORE_ADDR pc) { /* We don't have a range of addresses for the dynamic linker; there may not be one in the program's address space. So only report PLT entries (which may be import stubs). */ return in_plt_section (pc); } struct target_so_ops solib_target_so_ops; void _initialize_solib_target (void) { solib_target_so_ops.relocate_section_addresses = solib_target_relocate_section_addresses; solib_target_so_ops.free_so = solib_target_free_so; solib_target_so_ops.clear_solib = solib_target_clear_solib; solib_target_so_ops.solib_create_inferior_hook = solib_target_solib_create_inferior_hook; solib_target_so_ops.current_sos = solib_target_current_sos; solib_target_so_ops.open_symbol_file_object = solib_target_open_symbol_file_object; solib_target_so_ops.in_dynsym_resolve_code = solib_target_in_dynsym_resolve_code; solib_target_so_ops.bfd_open = solib_bfd_open; /* Set current_target_so_ops to solib_target_so_ops if not already set. */ if (current_target_so_ops == 0) current_target_so_ops = &solib_target_so_ops; }