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/* Definitions for targets which report shared library events.
Copyright (C) 2007-2024 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 "objfiles.h"
#include "solist.h"
#include "symtab.h"
#include "symfile.h"
#include "target.h"
#include "solib-target.h"
#include <vector>
#include "inferior.h"
/* Private data for each loaded library. */
struct lm_info_target final : public lm_info
{
/* 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;
};
using lm_info_target_up = std::unique_ptr<lm_info_target>;
#if !defined(HAVE_LIBEXPAT)
static std::vector<lm_info_target_up>
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 {};
}
#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)
{
auto *list = (std::vector<lm_info_target_up> *) 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)
{
auto *list = (std::vector<lm_info_target_up> *) 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)
{
auto *list = (std::vector<lm_info_target_up> *) 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)
{
auto *list = (std::vector<lm_info_target_up> *) 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 std::vector<lm_info_target_up>
solib_target_parse_libraries (const char *library)
{
std::vector<lm_info_target_up> 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 intrusive_list<solib>
solib_target_current_sos (void)
{
intrusive_list<solib> sos;
/* Fetch the list of shared libraries. */
std::optional<gdb::char_vector> library_document
= target_read_stralloc (current_inferior ()->top_target (),
TARGET_OBJECT_LIBRARIES, NULL);
if (!library_document)
return {};
/* Parse the list. */
std::vector<lm_info_target_up> library_list
= solib_target_parse_libraries (library_document->data ());
/* Build a struct solib for each entry on the list. */
for (lm_info_target_up &info : library_list)
{
solib *new_solib = new solib;
/* We don't need a copy of the name in INFO anymore. */
new_solib->so_name = std::move (info->name);
new_solib->so_original_name = new_solib->so_name;
new_solib->lm_info = std::move (info);
/* Add it to the list. */
sos.push_back (*new_solib);
}
return sos;
}
static void
solib_target_solib_create_inferior_hook (int from_tty)
{
/* Nothing needed. */
}
static void
solib_target_relocate_section_addresses (solib &so, target_section *sec)
{
CORE_ADDR offset;
auto *li = gdb::checked_static_cast<lm_info_target *> (so.lm_info.get ());
/* 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.empty ())
{
int num_sections = gdb_bfd_count_sections (so.abfd.get ());
li->offsets.assign (num_sections, 0);
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.c_str ());
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[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 ())
{
symfile_segment_data_up data
= get_symfile_segment_data (so.abfd.get ());
if (data == NULL)
warning (_("\
Could not relocate shared library \"%s\": no segments"), so.so_name.c_str ());
else
{
ULONGEST orig_delta;
int i;
if (!symfile_map_offsets_to_segments (so.abfd.get (), data.get (),
li->offsets,
li->segment_bases.size (),
li->segment_bases.data ()))
warning (_("\
Could not relocate shared library \"%s\": bad offsets"), so.so_name.c_str ());
/* 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->segments[0].base;
for (i = 1; i < data->segments.size (); 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->segments[i].base
!= orig_delta)
break;
}
so.addr_low = li->segment_bases[0];
so.addr_high = (data->segments[i - 1].base
+ data->segments[i - 1].size
+ orig_delta);
gdb_assert (so.addr_low <= so.addr_high);
}
}
}
offset = li->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);
}
const solib_ops solib_target_so_ops =
{
solib_target_relocate_section_addresses,
nullptr,
nullptr,
solib_target_solib_create_inferior_hook,
solib_target_current_sos,
solib_target_open_symbol_file_object,
solib_target_in_dynsym_resolve_code,
solib_bfd_open,
};