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- /* Handle shared libraries for GDB, the GNU Debugger.
- Copyright (C) 1990-2022 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 <sys/types.h>
- #include <fcntl.h>
- #include "symtab.h"
- #include "bfd.h"
- #include "build-id.h"
- #include "symfile.h"
- #include "objfiles.h"
- #include "gdbcore.h"
- #include "command.h"
- #include "target.h"
- #include "frame.h"
- #include "gdbsupport/gdb_regex.h"
- #include "inferior.h"
- #include "gdbsupport/environ.h"
- #include "language.h"
- #include "gdbcmd.h"
- #include "completer.h"
- #include "elf/external.h"
- #include "elf/common.h"
- #include "filenames.h" /* for DOSish file names */
- #include "exec.h"
- #include "solist.h"
- #include "observable.h"
- #include "readline/tilde.h"
- #include "remote.h"
- #include "solib.h"
- #include "interps.h"
- #include "filesystem.h"
- #include "gdb_bfd.h"
- #include "gdbsupport/filestuff.h"
- #include "gdbsupport/scoped_fd.h"
- #include "debuginfod-support.h"
- #include "source.h"
- #include "cli/cli-style.h"
- /* Architecture-specific operations. */
- /* Per-architecture data key. */
- static struct gdbarch_data *solib_data;
- static void *
- solib_init (struct obstack *obstack)
- {
- struct target_so_ops **ops;
- ops = OBSTACK_ZALLOC (obstack, struct target_so_ops *);
- *ops = current_target_so_ops;
- return ops;
- }
- static const struct target_so_ops *
- solib_ops (struct gdbarch *gdbarch)
- {
- const struct target_so_ops **ops
- = (const struct target_so_ops **) gdbarch_data (gdbarch, solib_data);
- return *ops;
- }
- /* Set the solib operations for GDBARCH to NEW_OPS. */
- void
- set_solib_ops (struct gdbarch *gdbarch, const struct target_so_ops *new_ops)
- {
- const struct target_so_ops **ops
- = (const struct target_so_ops **) gdbarch_data (gdbarch, solib_data);
- *ops = new_ops;
- }
- /* external data declarations */
- /* FIXME: gdbarch needs to control this variable, or else every
- configuration needs to call set_solib_ops. */
- struct target_so_ops *current_target_so_ops;
- /* Local function prototypes */
- /* If non-empty, this is a search path for loading non-absolute shared library
- symbol files. This takes precedence over the environment variables PATH
- and LD_LIBRARY_PATH. */
- static std::string solib_search_path;
- static void
- show_solib_search_path (struct ui_file *file, int from_tty,
- struct cmd_list_element *c, const char *value)
- {
- gdb_printf (file, _("The search path for loading non-absolute "
- "shared library symbol files is %s.\n"),
- value);
- }
- /* Same as HAVE_DOS_BASED_FILE_SYSTEM, but useable as an rvalue. */
- #if (HAVE_DOS_BASED_FILE_SYSTEM)
- # define DOS_BASED_FILE_SYSTEM 1
- #else
- # define DOS_BASED_FILE_SYSTEM 0
- #endif
- /* Return the full pathname of a binary file (the main executable or a
- shared library file), or NULL if not found. If FD is non-NULL, *FD
- is set to either -1 or an open file handle for the binary file.
- Global variable GDB_SYSROOT is used as a prefix directory
- to search for binary files if they have an absolute path.
- If GDB_SYSROOT starts with "target:" and target filesystem
- is the local filesystem then the "target:" prefix will be
- stripped before the search starts. This ensures that the
- same search algorithm is used for local files regardless of
- whether a "target:" prefix was used.
- Global variable SOLIB_SEARCH_PATH is used as a prefix directory
- (or set of directories, as in LD_LIBRARY_PATH) to search for all
- shared libraries if not found in either the sysroot (if set) or
- the local filesystem. SOLIB_SEARCH_PATH is not used when searching
- for the main executable.
- Search algorithm:
- * If a sysroot is set and path is absolute:
- * Search for sysroot/path.
- * else
- * Look for it literally (unmodified).
- * If IS_SOLIB is non-zero:
- * Look in SOLIB_SEARCH_PATH.
- * If available, use target defined search function.
- * If NO sysroot is set, perform the following two searches:
- * Look in inferior's $PATH.
- * If IS_SOLIB is non-zero:
- * Look in inferior's $LD_LIBRARY_PATH.
- *
- * The last check avoids doing this search when targeting remote
- * machines since a sysroot will almost always be set.
- */
- static gdb::unique_xmalloc_ptr<char>
- solib_find_1 (const char *in_pathname, int *fd, bool is_solib)
- {
- const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- int found_file = -1;
- gdb::unique_xmalloc_ptr<char> temp_pathname;
- const char *fskind = effective_target_file_system_kind ();
- const char *sysroot = gdb_sysroot.c_str ();
- int prefix_len, orig_prefix_len;
- /* If the absolute prefix starts with "target:" but the filesystem
- accessed by the target_fileio_* methods is the local filesystem
- then we strip the "target:" prefix now and work with the local
- filesystem. This ensures that the same search algorithm is used
- for all local files regardless of whether a "target:" prefix was
- used. */
- if (is_target_filename (sysroot) && target_filesystem_is_local ())
- sysroot += strlen (TARGET_SYSROOT_PREFIX);
- /* Strip any trailing slashes from the absolute prefix. */
- prefix_len = orig_prefix_len = strlen (sysroot);
- while (prefix_len > 0 && IS_DIR_SEPARATOR (sysroot[prefix_len - 1]))
- prefix_len--;
- std::string sysroot_holder;
- if (prefix_len == 0)
- sysroot = NULL;
- else if (prefix_len != orig_prefix_len)
- {
- sysroot_holder = std::string (sysroot, prefix_len);
- sysroot = sysroot_holder.c_str ();
- }
- /* If we're on a non-DOS-based system, backslashes won't be
- understood as directory separator, so, convert them to forward
- slashes, iff we're supposed to handle DOS-based file system
- semantics for target paths. */
- if (!DOS_BASED_FILE_SYSTEM && fskind == file_system_kind_dos_based)
- {
- char *p;
- /* Avoid clobbering our input. */
- p = (char *) alloca (strlen (in_pathname) + 1);
- strcpy (p, in_pathname);
- in_pathname = p;
- for (; *p; p++)
- {
- if (*p == '\\')
- *p = '/';
- }
- }
- /* Note, we're interested in IS_TARGET_ABSOLUTE_PATH, not
- IS_ABSOLUTE_PATH. The latter is for host paths only, while
- IN_PATHNAME is a target path. For example, if we're supposed to
- be handling DOS-like semantics we want to consider a
- 'c:/foo/bar.dll' path as an absolute path, even on a Unix box.
- With such a path, before giving up on the sysroot, we'll try:
- 1st attempt, c:/foo/bar.dll ==> /sysroot/c:/foo/bar.dll
- 2nd attempt, c:/foo/bar.dll ==> /sysroot/c/foo/bar.dll
- 3rd attempt, c:/foo/bar.dll ==> /sysroot/foo/bar.dll
- */
- if (!IS_TARGET_ABSOLUTE_PATH (fskind, in_pathname) || sysroot == NULL)
- temp_pathname.reset (xstrdup (in_pathname));
- else
- {
- bool need_dir_separator;
- /* Concatenate the sysroot and the target reported filename. We
- may need to glue them with a directory separator. Cases to
- consider:
- | sysroot | separator | in_pathname |
- |-----------------+-----------+----------------|
- | /some/dir | / | c:/foo/bar.dll |
- | /some/dir | | /foo/bar.dll |
- | target: | | c:/foo/bar.dll |
- | target: | | /foo/bar.dll |
- | target:some/dir | / | c:/foo/bar.dll |
- | target:some/dir | | /foo/bar.dll |
- IOW, we don't need to add a separator if IN_PATHNAME already
- has one, or when the sysroot is exactly "target:".
- There's no need to check for drive spec explicitly, as we only
- get here if IN_PATHNAME is considered an absolute path. */
- need_dir_separator = !(IS_DIR_SEPARATOR (in_pathname[0])
- || strcmp (TARGET_SYSROOT_PREFIX, sysroot) == 0);
- /* Cat the prefixed pathname together. */
- temp_pathname.reset (concat (sysroot,
- need_dir_separator ? SLASH_STRING : "",
- in_pathname, (char *) NULL));
- }
- /* Handle files to be accessed via the target. */
- if (is_target_filename (temp_pathname.get ()))
- {
- if (fd != NULL)
- *fd = -1;
- return temp_pathname;
- }
- /* Now see if we can open it. */
- found_file = gdb_open_cloexec (temp_pathname.get (),
- O_RDONLY | O_BINARY, 0).release ();
- /* If the search in gdb_sysroot failed, and the path name has a
- drive spec (e.g, c:/foo), try stripping ':' from the drive spec,
- and retrying in the sysroot:
- c:/foo/bar.dll ==> /sysroot/c/foo/bar.dll. */
- if (found_file < 0
- && sysroot != NULL
- && HAS_TARGET_DRIVE_SPEC (fskind, in_pathname))
- {
- bool need_dir_separator = !IS_DIR_SEPARATOR (in_pathname[2]);
- char drive[2] = { in_pathname[0], '\0' };
- temp_pathname.reset (concat (sysroot,
- SLASH_STRING,
- drive,
- need_dir_separator ? SLASH_STRING : "",
- in_pathname + 2, (char *) NULL));
- found_file = gdb_open_cloexec (temp_pathname.get (),
- O_RDONLY | O_BINARY, 0).release ();
- if (found_file < 0)
- {
- /* If the search in gdb_sysroot still failed, try fully
- stripping the drive spec, and trying once more in the
- sysroot before giving up.
- c:/foo/bar.dll ==> /sysroot/foo/bar.dll. */
- temp_pathname.reset (concat (sysroot,
- need_dir_separator ? SLASH_STRING : "",
- in_pathname + 2, (char *) NULL));
- found_file = gdb_open_cloexec (temp_pathname.get (),
- O_RDONLY | O_BINARY, 0).release ();
- }
- }
- /* We try to find the library in various ways. After each attempt,
- either found_file >= 0 and temp_pathname is a malloc'd string, or
- found_file < 0 and temp_pathname does not point to storage that
- needs to be freed. */
- if (found_file < 0)
- temp_pathname.reset (NULL);
- /* If the search in gdb_sysroot failed, and the path name is
- absolute at this point, make it relative. (openp will try and open the
- file according to its absolute path otherwise, which is not what we want.)
- Affects subsequent searches for this solib. */
- if (found_file < 0 && IS_TARGET_ABSOLUTE_PATH (fskind, in_pathname))
- {
- /* First, get rid of any drive letters etc. */
- while (!IS_TARGET_DIR_SEPARATOR (fskind, *in_pathname))
- in_pathname++;
- /* Next, get rid of all leading dir separators. */
- while (IS_TARGET_DIR_SEPARATOR (fskind, *in_pathname))
- in_pathname++;
- }
- /* If not found, and we're looking for a solib, search the
- solib_search_path (if any). */
- if (is_solib && found_file < 0 && !solib_search_path.empty ())
- found_file = openp (solib_search_path.c_str (),
- OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH,
- in_pathname, O_RDONLY | O_BINARY, &temp_pathname);
- /* If not found, and we're looking for a solib, next search the
- solib_search_path (if any) for the basename only (ignoring the
- path). This is to allow reading solibs from a path that differs
- from the opened path. */
- if (is_solib && found_file < 0 && !solib_search_path.empty ())
- found_file = openp (solib_search_path.c_str (),
- OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH,
- target_lbasename (fskind, in_pathname),
- O_RDONLY | O_BINARY, &temp_pathname);
- /* If not found, and we're looking for a solib, try to use target
- supplied solib search method. */
- if (is_solib && found_file < 0 && ops->find_and_open_solib)
- found_file = ops->find_and_open_solib (in_pathname, O_RDONLY | O_BINARY,
- &temp_pathname);
- /* If not found, next search the inferior's $PATH environment variable. */
- if (found_file < 0 && sysroot == NULL)
- found_file = openp (current_inferior ()->environment.get ("PATH"),
- OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH, in_pathname,
- O_RDONLY | O_BINARY, &temp_pathname);
- /* If not found, and we're looking for a solib, next search the
- inferior's $LD_LIBRARY_PATH environment variable. */
- if (is_solib && found_file < 0 && sysroot == NULL)
- found_file = openp (current_inferior ()->environment.get
- ("LD_LIBRARY_PATH"),
- OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH, in_pathname,
- O_RDONLY | O_BINARY, &temp_pathname);
- if (fd == NULL)
- {
- if (found_file >= 0)
- close (found_file);
- }
- else
- *fd = found_file;
- return temp_pathname;
- }
- /* Return the full pathname of the main executable, or NULL if not
- found. If FD is non-NULL, *FD is set to either -1 or an open file
- handle for the main executable. */
- gdb::unique_xmalloc_ptr<char>
- exec_file_find (const char *in_pathname, int *fd)
- {
- gdb::unique_xmalloc_ptr<char> result;
- const char *fskind = effective_target_file_system_kind ();
- if (in_pathname == NULL)
- return NULL;
- if (!gdb_sysroot.empty () && IS_TARGET_ABSOLUTE_PATH (fskind, in_pathname))
- {
- result = solib_find_1 (in_pathname, fd, false);
- if (result == NULL && fskind == file_system_kind_dos_based)
- {
- char *new_pathname;
- new_pathname = (char *) alloca (strlen (in_pathname) + 5);
- strcpy (new_pathname, in_pathname);
- strcat (new_pathname, ".exe");
- result = solib_find_1 (new_pathname, fd, false);
- }
- }
- else
- {
- /* It's possible we don't have a full path, but rather just a
- filename. Some targets, such as HP-UX, don't provide the
- full path, sigh.
- Attempt to qualify the filename against the source path.
- (If that fails, we'll just fall back on the original
- filename. Not much more we can do...) */
- if (!source_full_path_of (in_pathname, &result))
- result.reset (xstrdup (in_pathname));
- if (fd != NULL)
- *fd = -1;
- }
- return result;
- }
- /* Return the full pathname of a shared library file, or NULL if not
- found. If FD is non-NULL, *FD is set to either -1 or an open file
- handle for the shared library.
- The search algorithm used is described in solib_find_1's comment
- above. */
- gdb::unique_xmalloc_ptr<char>
- solib_find (const char *in_pathname, int *fd)
- {
- const char *solib_symbols_extension
- = gdbarch_solib_symbols_extension (target_gdbarch ());
- /* If solib_symbols_extension is set, replace the file's
- extension. */
- if (solib_symbols_extension != NULL)
- {
- const char *p = in_pathname + strlen (in_pathname);
- while (p > in_pathname && *p != '.')
- p--;
- if (*p == '.')
- {
- char *new_pathname;
- new_pathname
- = (char *) alloca (p - in_pathname + 1
- + strlen (solib_symbols_extension) + 1);
- memcpy (new_pathname, in_pathname, p - in_pathname + 1);
- strcpy (new_pathname + (p - in_pathname) + 1,
- solib_symbols_extension);
- in_pathname = new_pathname;
- }
- }
- return solib_find_1 (in_pathname, fd, true);
- }
- /* Open and return a BFD for the shared library PATHNAME. If FD is not -1,
- it is used as file handle to open the file. Throws an error if the file
- could not be opened. Handles both local and remote file access.
- If unsuccessful, the FD will be closed (unless FD was -1). */
- gdb_bfd_ref_ptr
- solib_bfd_fopen (const char *pathname, int fd)
- {
- gdb_bfd_ref_ptr abfd (gdb_bfd_open (pathname, gnutarget, fd));
- if (abfd != NULL && !gdb_bfd_has_target_filename (abfd.get ()))
- bfd_set_cacheable (abfd.get (), 1);
- if (abfd == NULL)
- {
- /* Arrange to free PATHNAME when the error is thrown. */
- error (_("Could not open `%s' as an executable file: %s"),
- pathname, bfd_errmsg (bfd_get_error ()));
- }
- return abfd;
- }
- /* Find shared library PATHNAME and open a BFD for it. */
- gdb_bfd_ref_ptr
- solib_bfd_open (const char *pathname)
- {
- int found_file;
- const struct bfd_arch_info *b;
- /* Search for shared library file. */
- gdb::unique_xmalloc_ptr<char> found_pathname
- = solib_find (pathname, &found_file);
- if (found_pathname == NULL)
- {
- /* Return failure if the file could not be found, so that we can
- accumulate messages about missing libraries. */
- if (errno == ENOENT)
- return NULL;
- perror_with_name (pathname);
- }
- /* Open bfd for shared library. */
- gdb_bfd_ref_ptr abfd (solib_bfd_fopen (found_pathname.get (), found_file));
- /* Check bfd format. */
- if (!bfd_check_format (abfd.get (), bfd_object))
- error (_("`%s': not in executable format: %s"),
- bfd_get_filename (abfd.get ()), bfd_errmsg (bfd_get_error ()));
- /* Check bfd arch. */
- b = gdbarch_bfd_arch_info (target_gdbarch ());
- if (!b->compatible (b, bfd_get_arch_info (abfd.get ())))
- error (_("`%s': Shared library architecture %s is not compatible "
- "with target architecture %s."), bfd_get_filename (abfd.get ()),
- bfd_get_arch_info (abfd.get ())->printable_name,
- b->printable_name);
- return abfd;
- }
- /* Mapping of a core file's shared library sonames to their respective
- build-ids. Added to the registries of core file bfds. */
- typedef std::unordered_map<std::string, std::string> soname_build_id_map;
- /* Key used to associate a soname_build_id_map to a core file bfd. */
- static const struct bfd_key<soname_build_id_map> cbfd_soname_build_id_data_key;
- /* See solib.h. */
- void
- set_cbfd_soname_build_id (gdb_bfd_ref_ptr abfd,
- const char *soname,
- const bfd_build_id *build_id)
- {
- gdb_assert (abfd.get () != nullptr);
- gdb_assert (soname != nullptr);
- gdb_assert (build_id != nullptr);
- soname_build_id_map *mapptr = cbfd_soname_build_id_data_key.get (abfd.get ());
- if (mapptr == nullptr)
- mapptr = cbfd_soname_build_id_data_key.emplace (abfd.get ());
- (*mapptr)[soname] = build_id_to_string (build_id);
- }
- /* See solib.h. */
- gdb::unique_xmalloc_ptr<char>
- get_cbfd_soname_build_id (gdb_bfd_ref_ptr abfd, const char *soname)
- {
- if (abfd.get () == nullptr || soname == nullptr)
- return {};
- soname_build_id_map *mapptr
- = cbfd_soname_build_id_data_key.get (abfd.get ());
- if (mapptr == nullptr)
- return {};
- auto it = mapptr->find (lbasename (soname));
- if (it == mapptr->end ())
- return {};
- return make_unique_xstrdup (it->second.c_str ());
- }
- /* Given a pointer to one of the shared objects in our list of mapped
- objects, use the recorded name to open a bfd descriptor for the
- object, build a section table, relocate all the section addresses
- by the base address at which the shared object was mapped, and then
- add the sections to the target's section table.
- FIXME: In most (all?) cases the shared object file name recorded in
- the dynamic linkage tables will be a fully qualified pathname. For
- cases where it isn't, do we really mimic the systems search
- mechanism correctly in the below code (particularly the tilde
- expansion stuff?). */
- static int
- solib_map_sections (struct so_list *so)
- {
- const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- gdb::unique_xmalloc_ptr<char> filename (tilde_expand (so->so_name));
- gdb_bfd_ref_ptr abfd (ops->bfd_open (filename.get ()));
- gdb::unique_xmalloc_ptr<char> build_id_hexstr
- = get_cbfd_soname_build_id (current_program_space->cbfd, so->so_name);
- /* If we already know the build-id of this solib from a core file, verify
- it matches ABFD's build-id. If there is a mismatch or the solib wasn't
- found, attempt to query debuginfod for the correct solib. */
- if (build_id_hexstr.get () != nullptr)
- {
- bool mismatch = false;
- if (abfd != nullptr && abfd->build_id != nullptr)
- {
- std::string build_id = build_id_to_string (abfd->build_id);
- if (build_id != build_id_hexstr.get ())
- mismatch = true;
- }
- if (abfd == nullptr || mismatch)
- {
- scoped_fd fd = debuginfod_exec_query ((const unsigned char*)
- build_id_hexstr.get (),
- 0, so->so_name, &filename);
- if (fd.get () >= 0)
- abfd = ops->bfd_open (filename.get ());
- else if (mismatch)
- warning (_("Build-id of %ps does not match core file."),
- styled_string (file_name_style.style (), filename.get ()));
- }
- }
- if (abfd == NULL)
- return 0;
- /* Leave bfd open, core_xfer_memory and "info files" need it. */
- so->abfd = abfd.release ();
- /* Copy the full path name into so_name, allowing symbol_file_add
- to find it later. This also affects the =library-loaded GDB/MI
- event, and in particular the part of that notification providing
- the library's host-side path. If we let the target dictate
- that objfile's path, and the target is different from the host,
- GDB/MI will not provide the correct host-side path. */
- if (strlen (bfd_get_filename (so->abfd)) >= SO_NAME_MAX_PATH_SIZE)
- error (_("Shared library file name is too long."));
- strcpy (so->so_name, bfd_get_filename (so->abfd));
- if (so->sections == nullptr)
- so->sections = new target_section_table;
- *so->sections = build_section_table (so->abfd);
- for (target_section &p : *so->sections)
- {
- /* Relocate the section binding addresses as recorded in the shared
- object's file by the base address to which the object was actually
- mapped. */
- ops->relocate_section_addresses (so, &p);
- /* If the target didn't provide information about the address
- range of the shared object, assume we want the location of
- the .text section. */
- if (so->addr_low == 0 && so->addr_high == 0
- && strcmp (p.the_bfd_section->name, ".text") == 0)
- {
- so->addr_low = p.addr;
- so->addr_high = p.endaddr;
- }
- }
- /* Add the shared object's sections to the current set of file
- section tables. Do this immediately after mapping the object so
- that later nodes in the list can query this object, as is needed
- in solib-osf.c. */
- current_program_space->add_target_sections (so, *so->sections);
- return 1;
- }
- /* Free symbol-file related contents of SO and reset for possible reloading
- of SO. If we have opened a BFD for SO, close it. If we have placed SO's
- sections in some target's section table, the caller is responsible for
- removing them.
- This function doesn't mess with objfiles at all. If there is an
- objfile associated with SO that needs to be removed, the caller is
- responsible for taking care of that. */
- static void
- clear_so (struct so_list *so)
- {
- const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- delete so->sections;
- so->sections = NULL;
- gdb_bfd_unref (so->abfd);
- so->abfd = NULL;
- /* Our caller closed the objfile, possibly via objfile_purge_solibs. */
- so->symbols_loaded = 0;
- so->objfile = NULL;
- so->addr_low = so->addr_high = 0;
- /* Restore the target-supplied file name. SO_NAME may be the path
- of the symbol file. */
- strcpy (so->so_name, so->so_original_name);
- /* Do the same for target-specific data. */
- if (ops->clear_so != NULL)
- ops->clear_so (so);
- }
- /* Free the storage associated with the `struct so_list' object SO.
- If we have opened a BFD for SO, close it.
- The caller is responsible for removing SO from whatever list it is
- a member of. If we have placed SO's sections in some target's
- section table, the caller is responsible for removing them.
- This function doesn't mess with objfiles at all. If there is an
- objfile associated with SO that needs to be removed, the caller is
- responsible for taking care of that. */
- void
- free_so (struct so_list *so)
- {
- const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- clear_so (so);
- ops->free_so (so);
- xfree (so);
- }
- /* Read in symbols for shared object SO. If SYMFILE_VERBOSE is set in FLAGS,
- be chatty about it. Return true if any symbols were actually loaded. */
- bool
- solib_read_symbols (struct so_list *so, symfile_add_flags flags)
- {
- if (so->symbols_loaded)
- {
- /* If needed, we've already warned in our caller. */
- }
- else if (so->abfd == NULL)
- {
- /* We've already warned about this library, when trying to open
- it. */
- }
- else
- {
- flags |= current_inferior ()->symfile_flags;
- try
- {
- /* Have we already loaded this shared object? */
- so->objfile = nullptr;
- for (objfile *objfile : current_program_space->objfiles ())
- {
- if (filename_cmp (objfile_name (objfile), so->so_name) == 0
- && objfile->addr_low == so->addr_low)
- {
- so->objfile = objfile;
- break;
- }
- }
- if (so->objfile == NULL)
- {
- section_addr_info sap
- = build_section_addr_info_from_section_table (*so->sections);
- so->objfile = symbol_file_add_from_bfd (so->abfd, so->so_name,
- flags, &sap,
- OBJF_SHARED, NULL);
- so->objfile->addr_low = so->addr_low;
- }
- so->symbols_loaded = 1;
- }
- catch (const gdb_exception_error &e)
- {
- exception_fprintf (gdb_stderr, e, _("Error while reading shared"
- " library symbols for %s:\n"),
- so->so_name);
- }
- return true;
- }
- return false;
- }
- /* Return true if KNOWN->objfile is used by any other so_list object
- in the list of shared libraries. Return false otherwise. */
- static bool
- solib_used (const struct so_list *const known)
- {
- for (const struct so_list *pivot : current_program_space->solibs ())
- if (pivot != known && pivot->objfile == known->objfile)
- return true;
- return false;
- }
- /* See solib.h. */
- void
- update_solib_list (int from_tty)
- {
- const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- struct so_list *inferior = ops->current_sos();
- struct so_list *gdb, **gdb_link;
- /* We can reach here due to changing solib-search-path or the
- sysroot, before having any inferior. */
- if (target_has_execution () && inferior_ptid != null_ptid)
- {
- struct inferior *inf = current_inferior ();
- /* If we are attaching to a running process for which we
- have not opened a symbol file, we may be able to get its
- symbols now! */
- if (inf->attach_flag
- && current_program_space->symfile_object_file == NULL)
- {
- try
- {
- ops->open_symbol_file_object (from_tty);
- }
- catch (const gdb_exception &ex)
- {
- exception_fprintf (gdb_stderr, ex,
- "Error reading attached "
- "process's symbol file.\n");
- }
- }
- }
- /* GDB and the inferior's dynamic linker each maintain their own
- list of currently loaded shared objects; we want to bring the
- former in sync with the latter. Scan both lists, seeing which
- shared objects appear where. There are three cases:
- - A shared object appears on both lists. This means that GDB
- knows about it already, and it's still loaded in the inferior.
- Nothing needs to happen.
- - A shared object appears only on GDB's list. This means that
- the inferior has unloaded it. We should remove the shared
- object from GDB's tables.
- - A shared object appears only on the inferior's list. This
- means that it's just been loaded. We should add it to GDB's
- tables.
- So we walk GDB's list, checking each entry to see if it appears
- in the inferior's list too. If it does, no action is needed, and
- we remove it from the inferior's list. If it doesn't, the
- inferior has unloaded it, and we remove it from GDB's list. By
- the time we're done walking GDB's list, the inferior's list
- contains only the new shared objects, which we then add. */
- gdb = current_program_space->so_list;
- gdb_link = ¤t_program_space->so_list;
- while (gdb)
- {
- struct so_list *i = inferior;
- struct so_list **i_link = &inferior;
- /* Check to see whether the shared object *gdb also appears in
- the inferior's current list. */
- while (i)
- {
- if (ops->same)
- {
- if (ops->same (gdb, i))
- break;
- }
- else
- {
- if (! filename_cmp (gdb->so_original_name, i->so_original_name))
- break;
- }
- i_link = &i->next;
- i = *i_link;
- }
- /* If the shared object appears on the inferior's list too, then
- it's still loaded, so we don't need to do anything. Delete
- it from the inferior's list, and leave it on GDB's list. */
- if (i)
- {
- *i_link = i->next;
- free_so (i);
- gdb_link = &gdb->next;
- gdb = *gdb_link;
- }
- /* If it's not on the inferior's list, remove it from GDB's tables. */
- else
- {
- /* Notify any observer that the shared object has been
- unloaded before we remove it from GDB's tables. */
- gdb::observers::solib_unloaded.notify (gdb);
- current_program_space->deleted_solibs.push_back (gdb->so_name);
- *gdb_link = gdb->next;
- /* Unless the user loaded it explicitly, free SO's objfile. */
- if (gdb->objfile && ! (gdb->objfile->flags & OBJF_USERLOADED)
- && !solib_used (gdb))
- gdb->objfile->unlink ();
- /* Some targets' section tables might be referring to
- sections from so->abfd; remove them. */
- current_program_space->remove_target_sections (gdb);
- free_so (gdb);
- gdb = *gdb_link;
- }
- }
- /* Now the inferior's list contains only shared objects that don't
- appear in GDB's list --- those that are newly loaded. Add them
- to GDB's shared object list. */
- if (inferior)
- {
- int not_found = 0;
- const char *not_found_filename = NULL;
- struct so_list *i;
- /* Add the new shared objects to GDB's list. */
- *gdb_link = inferior;
- /* Fill in the rest of each of the `struct so_list' nodes. */
- for (i = inferior; i; i = i->next)
- {
- i->pspace = current_program_space;
- current_program_space->added_solibs.push_back (i);
- try
- {
- /* Fill in the rest of the `struct so_list' node. */
- if (!solib_map_sections (i))
- {
- not_found++;
- if (not_found_filename == NULL)
- not_found_filename = i->so_original_name;
- }
- }
- catch (const gdb_exception_error &e)
- {
- exception_fprintf (gdb_stderr, e,
- _("Error while mapping shared "
- "library sections:\n"));
- }
- /* Notify any observer that the shared object has been
- loaded now that we've added it to GDB's tables. */
- gdb::observers::solib_loaded.notify (i);
- }
- /* If a library was not found, issue an appropriate warning
- message. We have to use a single call to warning in case the
- front end does something special with warnings, e.g., pop up
- a dialog box. It Would Be Nice if we could get a "warning: "
- prefix on each line in the CLI front end, though - it doesn't
- stand out well. */
- if (not_found == 1)
- warning (_("Could not load shared library symbols for %s.\n"
- "Do you need \"set solib-search-path\" "
- "or \"set sysroot\"?"),
- not_found_filename);
- else if (not_found > 1)
- warning (_("\
- Could not load shared library symbols for %d libraries, e.g. %s.\n\
- Use the \"info sharedlibrary\" command to see the complete listing.\n\
- Do you need \"set solib-search-path\" or \"set sysroot\"?"),
- not_found, not_found_filename);
- }
- }
- /* Return non-zero if NAME is the libpthread shared library.
- Uses a fairly simplistic heuristic approach where we check
- the file name against "/libpthread". This can lead to false
- positives, but this should be good enough in practice.
- As of glibc-2.34, functions formerly residing in libpthread have
- been moved to libc, so "/libc." needs to be checked too. (Matching
- the "." will avoid matching libraries such as libcrypt.) */
- bool
- libpthread_name_p (const char *name)
- {
- return (strstr (name, "/libpthread") != NULL
- || strstr (name, "/libc.") != NULL );
- }
- /* Return non-zero if SO is the libpthread shared library. */
- static bool
- libpthread_solib_p (struct so_list *so)
- {
- return libpthread_name_p (so->so_name);
- }
- /* Read in symbolic information for any shared objects whose names
- match PATTERN. (If we've already read a shared object's symbol
- info, leave it alone.) If PATTERN is zero, read them all.
- If READSYMS is 0, defer reading symbolic information until later
- but still do any needed low level processing.
- FROM_TTY is described for update_solib_list, above. */
- void
- solib_add (const char *pattern, int from_tty, int readsyms)
- {
- if (print_symbol_loading_p (from_tty, 0, 0))
- {
- if (pattern != NULL)
- {
- gdb_printf (_("Loading symbols for shared libraries: %s\n"),
- pattern);
- }
- else
- gdb_printf (_("Loading symbols for shared libraries.\n"));
- }
- current_program_space->solib_add_generation++;
- if (pattern)
- {
- char *re_err = re_comp (pattern);
- if (re_err)
- error (_("Invalid regexp: %s"), re_err);
- }
- update_solib_list (from_tty);
- /* Walk the list of currently loaded shared libraries, and read
- symbols for any that match the pattern --- or any whose symbols
- aren't already loaded, if no pattern was given. */
- {
- bool any_matches = false;
- bool loaded_any_symbols = false;
- symfile_add_flags add_flags = SYMFILE_DEFER_BP_RESET;
- if (from_tty)
- add_flags |= SYMFILE_VERBOSE;
- for (struct so_list *gdb : current_program_space->solibs ())
- if (! pattern || re_exec (gdb->so_name))
- {
- /* Normally, we would read the symbols from that library
- only if READSYMS is set. However, we're making a small
- exception for the pthread library, because we sometimes
- need the library symbols to be loaded in order to provide
- thread support (x86-linux for instance). */
- const int add_this_solib =
- (readsyms || libpthread_solib_p (gdb));
- any_matches = true;
- if (add_this_solib)
- {
- if (gdb->symbols_loaded)
- {
- /* If no pattern was given, be quiet for shared
- libraries we have already loaded. */
- if (pattern && (from_tty || info_verbose))
- gdb_printf (_("Symbols already loaded for %s\n"),
- gdb->so_name);
- }
- else if (solib_read_symbols (gdb, add_flags))
- loaded_any_symbols = true;
- }
- }
- if (loaded_any_symbols)
- breakpoint_re_set ();
- if (from_tty && pattern && ! any_matches)
- gdb_printf
- ("No loaded shared libraries match the pattern `%s'.\n", pattern);
- if (loaded_any_symbols)
- {
- /* Getting new symbols may change our opinion about what is
- frameless. */
- reinit_frame_cache ();
- }
- }
- }
- /* Implement the "info sharedlibrary" command. Walk through the
- shared library list and print information about each attached
- library matching PATTERN. If PATTERN is elided, print them
- all. */
- static void
- info_sharedlibrary_command (const char *pattern, int from_tty)
- {
- bool so_missing_debug_info = false;
- int addr_width;
- int nr_libs;
- struct gdbarch *gdbarch = target_gdbarch ();
- struct ui_out *uiout = current_uiout;
- if (pattern)
- {
- char *re_err = re_comp (pattern);
- if (re_err)
- error (_("Invalid regexp: %s"), re_err);
- }
- /* "0x", a little whitespace, and two hex digits per byte of pointers. */
- addr_width = 4 + (gdbarch_ptr_bit (gdbarch) / 4);
- update_solib_list (from_tty);
- /* ui_out_emit_table table_emitter needs to know the number of rows,
- so we need to make two passes over the libs. */
- nr_libs = 0;
- for (struct so_list *so : current_program_space->solibs ())
- {
- if (so->so_name[0])
- {
- if (pattern && ! re_exec (so->so_name))
- continue;
- ++nr_libs;
- }
- }
- {
- ui_out_emit_table table_emitter (uiout, 4, nr_libs, "SharedLibraryTable");
- /* The "- 1" is because ui_out adds one space between columns. */
- uiout->table_header (addr_width - 1, ui_left, "from", "From");
- uiout->table_header (addr_width - 1, ui_left, "to", "To");
- uiout->table_header (12 - 1, ui_left, "syms-read", "Syms Read");
- uiout->table_header (0, ui_noalign, "name", "Shared Object Library");
- uiout->table_body ();
- for (struct so_list *so : current_program_space->solibs ())
- {
- if (! so->so_name[0])
- continue;
- if (pattern && ! re_exec (so->so_name))
- continue;
- ui_out_emit_tuple tuple_emitter (uiout, "lib");
- if (so->addr_high != 0)
- {
- uiout->field_core_addr ("from", gdbarch, so->addr_low);
- uiout->field_core_addr ("to", gdbarch, so->addr_high);
- }
- else
- {
- uiout->field_skip ("from");
- uiout->field_skip ("to");
- }
- if (! top_level_interpreter ()->interp_ui_out ()->is_mi_like_p ()
- && so->symbols_loaded
- && !objfile_has_symbols (so->objfile))
- {
- so_missing_debug_info = true;
- uiout->field_string ("syms-read", "Yes (*)");
- }
- else
- uiout->field_string ("syms-read", so->symbols_loaded ? "Yes" : "No");
- uiout->field_string ("name", so->so_name, file_name_style.style ());
- uiout->text ("\n");
- }
- }
- if (nr_libs == 0)
- {
- if (pattern)
- uiout->message (_("No shared libraries matched.\n"));
- else
- uiout->message (_("No shared libraries loaded at this time.\n"));
- }
- else
- {
- if (so_missing_debug_info)
- uiout->message (_("(*): Shared library is missing "
- "debugging information.\n"));
- }
- }
- /* See solib.h. */
- bool
- solib_contains_address_p (const struct so_list *const solib,
- CORE_ADDR address)
- {
- if (solib->sections == nullptr)
- return false;
- for (target_section &p : *solib->sections)
- if (p.addr <= address && address < p.endaddr)
- return true;
- return false;
- }
- /* If ADDRESS is in a shared lib in program space PSPACE, return its
- name.
- Provides a hook for other gdb routines to discover whether or not a
- particular address is within the mapped address space of a shared
- library.
- For example, this routine is called at one point to disable
- breakpoints which are in shared libraries that are not currently
- mapped in. */
- char *
- solib_name_from_address (struct program_space *pspace, CORE_ADDR address)
- {
- struct so_list *so = NULL;
- for (so = pspace->so_list; so; so = so->next)
- if (solib_contains_address_p (so, address))
- return (so->so_name);
- return (0);
- }
- /* See solib.h. */
- bool
- solib_keep_data_in_core (CORE_ADDR vaddr, unsigned long size)
- {
- const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- if (ops->keep_data_in_core)
- return ops->keep_data_in_core (vaddr, size) != 0;
- else
- return false;
- }
- /* Called by free_all_symtabs */
- void
- clear_solib (void)
- {
- const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- disable_breakpoints_in_shlibs ();
- while (current_program_space->so_list)
- {
- struct so_list *so = current_program_space->so_list;
- current_program_space->so_list = so->next;
- gdb::observers::solib_unloaded.notify (so);
- current_program_space->remove_target_sections (so);
- free_so (so);
- }
- ops->clear_solib ();
- }
- /* Shared library startup support. When GDB starts up the inferior,
- it nurses it along (through the shell) until it is ready to execute
- its first instruction. At this point, this function gets
- called. */
- void
- solib_create_inferior_hook (int from_tty)
- {
- const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- ops->solib_create_inferior_hook (from_tty);
- }
- /* See solib.h. */
- bool
- in_solib_dynsym_resolve_code (CORE_ADDR pc)
- {
- const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- return ops->in_dynsym_resolve_code (pc) != 0;
- }
- /* Implements the "sharedlibrary" command. */
- static void
- sharedlibrary_command (const char *args, int from_tty)
- {
- dont_repeat ();
- solib_add (args, from_tty, 1);
- }
- /* Implements the command "nosharedlibrary", which discards symbols
- that have been auto-loaded from shared libraries. Symbols from
- shared libraries that were added by explicit request of the user
- are not discarded. Also called from remote.c. */
- void
- no_shared_libraries (const char *ignored, int from_tty)
- {
- /* The order of the two routines below is important: clear_solib notifies
- the solib_unloaded observers, and some of these observers might need
- access to their associated objfiles. Therefore, we can not purge the
- solibs' objfiles before clear_solib has been called. */
- clear_solib ();
- objfile_purge_solibs ();
- }
- /* See solib.h. */
- void
- update_solib_breakpoints (void)
- {
- const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- if (ops->update_breakpoints != NULL)
- ops->update_breakpoints ();
- }
- /* See solib.h. */
- void
- handle_solib_event (void)
- {
- const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- if (ops->handle_event != NULL)
- ops->handle_event ();
- current_inferior ()->pspace->clear_solib_cache ();
- /* Check for any newly added shared libraries if we're supposed to
- be adding them automatically. Switch terminal for any messages
- produced by breakpoint_re_set. */
- target_terminal::ours_for_output ();
- solib_add (NULL, 0, auto_solib_add);
- target_terminal::inferior ();
- }
- /* Reload shared libraries, but avoid reloading the same symbol file
- we already have loaded. */
- static void
- reload_shared_libraries_1 (int from_tty)
- {
- if (print_symbol_loading_p (from_tty, 0, 0))
- gdb_printf (_("Loading symbols for shared libraries.\n"));
- for (struct so_list *so : current_program_space->solibs ())
- {
- const char *found_pathname = NULL;
- bool was_loaded = so->symbols_loaded != 0;
- symfile_add_flags add_flags = SYMFILE_DEFER_BP_RESET;
- if (from_tty)
- add_flags |= SYMFILE_VERBOSE;
- gdb::unique_xmalloc_ptr<char> filename
- (tilde_expand (so->so_original_name));
- gdb_bfd_ref_ptr abfd (solib_bfd_open (filename.get ()));
- if (abfd != NULL)
- found_pathname = bfd_get_filename (abfd.get ());
- /* If this shared library is no longer associated with its previous
- symbol file, close that. */
- if ((found_pathname == NULL && was_loaded)
- || (found_pathname != NULL
- && filename_cmp (found_pathname, so->so_name) != 0))
- {
- if (so->objfile && ! (so->objfile->flags & OBJF_USERLOADED)
- && !solib_used (so))
- so->objfile->unlink ();
- current_program_space->remove_target_sections (so);
- clear_so (so);
- }
- /* If this shared library is now associated with a new symbol
- file, open it. */
- if (found_pathname != NULL
- && (!was_loaded
- || filename_cmp (found_pathname, so->so_name) != 0))
- {
- bool got_error = false;
- try
- {
- solib_map_sections (so);
- }
- catch (const gdb_exception_error &e)
- {
- exception_fprintf (gdb_stderr, e,
- _("Error while mapping "
- "shared library sections:\n"));
- got_error = true;
- }
- if (!got_error
- && (auto_solib_add || was_loaded || libpthread_solib_p (so)))
- solib_read_symbols (so, add_flags);
- }
- }
- }
- static void
- reload_shared_libraries (const char *ignored, int from_tty,
- struct cmd_list_element *e)
- {
- const struct target_so_ops *ops;
- reload_shared_libraries_1 (from_tty);
- ops = solib_ops (target_gdbarch ());
- /* Creating inferior hooks here has two purposes. First, if we reload
- shared libraries then the address of solib breakpoint we've computed
- previously might be no longer valid. For example, if we forgot to set
- solib-absolute-prefix and are setting it right now, then the previous
- breakpoint address is plain wrong. Second, installing solib hooks
- also implicitly figures were ld.so is and loads symbols for it.
- Absent this call, if we've just connected to a target and set
- solib-absolute-prefix or solib-search-path, we'll lose all information
- about ld.so. */
- if (target_has_execution ())
- {
- /* Reset or free private data structures not associated with
- so_list entries. */
- ops->clear_solib ();
- /* Remove any previous solib event breakpoint. This is usually
- done in common code, at breakpoint_init_inferior time, but
- we're not really starting up the inferior here. */
- remove_solib_event_breakpoints ();
- solib_create_inferior_hook (from_tty);
- }
- /* Sometimes the platform-specific hook loads initial shared
- libraries, and sometimes it doesn't. If it doesn't FROM_TTY will be
- incorrectly 0 but such solib targets should be fixed anyway. If we
- made all the inferior hook methods consistent, this call could be
- removed. Call it only after the solib target has been initialized by
- solib_create_inferior_hook. */
- solib_add (NULL, 0, auto_solib_add);
- breakpoint_re_set ();
- /* We may have loaded or unloaded debug info for some (or all)
- shared libraries. However, frames may still reference them. For
- example, a frame's unwinder might still point at DWARF FDE
- structures that are now freed. Also, getting new symbols may
- change our opinion about what is frameless. */
- reinit_frame_cache ();
- }
- /* Wrapper for reload_shared_libraries that replaces "remote:"
- at the start of gdb_sysroot with "target:". */
- static void
- gdb_sysroot_changed (const char *ignored, int from_tty,
- struct cmd_list_element *e)
- {
- const char *old_prefix = "remote:";
- const char *new_prefix = TARGET_SYSROOT_PREFIX;
- if (startswith (gdb_sysroot.c_str (), old_prefix))
- {
- static bool warning_issued = false;
- gdb_assert (strlen (old_prefix) == strlen (new_prefix));
- gdb_sysroot = new_prefix + gdb_sysroot.substr (strlen (old_prefix));
- if (!warning_issued)
- {
- warning (_("\"%s\" is deprecated, use \"%s\" instead."),
- old_prefix, new_prefix);
- warning (_("sysroot set to \"%s\"."), gdb_sysroot.c_str ());
- warning_issued = true;
- }
- }
- reload_shared_libraries (ignored, from_tty, e);
- }
- static void
- show_auto_solib_add (struct ui_file *file, int from_tty,
- struct cmd_list_element *c, const char *value)
- {
- gdb_printf (file, _("Autoloading of shared library symbols is %s.\n"),
- value);
- }
- /* Lookup the value for a specific symbol from dynamic symbol table. Look
- up symbol from ABFD. MATCH_SYM is a callback function to determine
- whether to pick up a symbol. DATA is the input of this callback
- function. Return NULL if symbol is not found. */
- CORE_ADDR
- gdb_bfd_lookup_symbol_from_symtab (bfd *abfd,
- int (*match_sym) (const asymbol *,
- const void *),
- const void *data)
- {
- long storage_needed = bfd_get_symtab_upper_bound (abfd);
- CORE_ADDR symaddr = 0;
- if (storage_needed > 0)
- {
- unsigned int i;
- gdb::def_vector<asymbol *> storage (storage_needed / sizeof (asymbol *));
- asymbol **symbol_table = storage.data ();
- unsigned int number_of_symbols =
- bfd_canonicalize_symtab (abfd, symbol_table);
- for (i = 0; i < number_of_symbols; i++)
- {
- asymbol *sym = *symbol_table++;
- if (match_sym (sym, data))
- {
- struct gdbarch *gdbarch = target_gdbarch ();
- symaddr = sym->value;
- /* Some ELF targets fiddle with addresses of symbols they
- consider special. They use minimal symbols to do that
- and this is needed for correct breakpoint placement,
- but we do not have full data here to build a complete
- minimal symbol, so just set the address and let the
- targets cope with that. */
- if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
- && gdbarch_elf_make_msymbol_special_p (gdbarch))
- {
- struct minimal_symbol msym {};
- SET_MSYMBOL_VALUE_ADDRESS (&msym, symaddr);
- gdbarch_elf_make_msymbol_special (gdbarch, sym, &msym);
- symaddr = MSYMBOL_VALUE_RAW_ADDRESS (&msym);
- }
- /* BFD symbols are section relative. */
- symaddr += sym->section->vma;
- break;
- }
- }
- }
- return symaddr;
- }
- /* See solib.h. */
- int
- gdb_bfd_scan_elf_dyntag (const int desired_dyntag, bfd *abfd, CORE_ADDR *ptr,
- CORE_ADDR *ptr_addr)
- {
- int arch_size, step, sect_size;
- long current_dyntag;
- CORE_ADDR dyn_ptr, dyn_addr;
- gdb_byte *bufend, *bufstart, *buf;
- Elf32_External_Dyn *x_dynp_32;
- Elf64_External_Dyn *x_dynp_64;
- struct bfd_section *sect;
- if (abfd == NULL)
- return 0;
- if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
- return 0;
- arch_size = bfd_get_arch_size (abfd);
- if (arch_size == -1)
- return 0;
- /* Find the start address of the .dynamic section. */
- sect = bfd_get_section_by_name (abfd, ".dynamic");
- if (sect == NULL)
- return 0;
- bool found = false;
- for (const target_section &target_section
- : current_program_space->target_sections ())
- if (sect == target_section.the_bfd_section)
- {
- dyn_addr = target_section.addr;
- found = true;
- break;
- }
- if (!found)
- {
- /* ABFD may come from OBJFILE acting only as a symbol file without being
- loaded into the target (see add_symbol_file_command). This case is
- such fallback to the file VMA address without the possibility of
- having the section relocated to its actual in-memory address. */
- dyn_addr = bfd_section_vma (sect);
- }
- /* Read in .dynamic from the BFD. We will get the actual value
- from memory later. */
- sect_size = bfd_section_size (sect);
- buf = bufstart = (gdb_byte *) alloca (sect_size);
- if (!bfd_get_section_contents (abfd, sect,
- buf, 0, sect_size))
- return 0;
- /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
- step = (arch_size == 32) ? sizeof (Elf32_External_Dyn)
- : sizeof (Elf64_External_Dyn);
- for (bufend = buf + sect_size;
- buf < bufend;
- buf += step)
- {
- if (arch_size == 32)
- {
- x_dynp_32 = (Elf32_External_Dyn *) buf;
- current_dyntag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_tag);
- dyn_ptr = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_un.d_ptr);
- }
- else
- {
- x_dynp_64 = (Elf64_External_Dyn *) buf;
- current_dyntag = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_tag);
- dyn_ptr = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_un.d_ptr);
- }
- if (current_dyntag == DT_NULL)
- return 0;
- if (current_dyntag == desired_dyntag)
- {
- /* If requested, try to read the runtime value of this .dynamic
- entry. */
- if (ptr)
- {
- struct type *ptr_type;
- gdb_byte ptr_buf[8];
- CORE_ADDR ptr_addr_1;
- ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
- ptr_addr_1 = dyn_addr + (buf - bufstart) + arch_size / 8;
- if (target_read_memory (ptr_addr_1, ptr_buf, arch_size / 8) == 0)
- dyn_ptr = extract_typed_address (ptr_buf, ptr_type);
- *ptr = dyn_ptr;
- if (ptr_addr)
- *ptr_addr = dyn_addr + (buf - bufstart);
- }
- return 1;
- }
- }
- return 0;
- }
- /* See solib.h. */
- gdb::unique_xmalloc_ptr<char>
- gdb_bfd_read_elf_soname (const char *filename)
- {
- gdb_bfd_ref_ptr abfd = gdb_bfd_open (filename, gnutarget);
- if (abfd == nullptr)
- return {};
- /* Check that ABFD is an ET_DYN ELF file. */
- if (!bfd_check_format (abfd.get (), bfd_object)
- || !(bfd_get_file_flags (abfd.get ()) & DYNAMIC))
- return {};
- CORE_ADDR idx;
- if (!gdb_bfd_scan_elf_dyntag (DT_SONAME, abfd.get (), &idx, nullptr))
- return {};
- struct bfd_section *dynstr = bfd_get_section_by_name (abfd.get (), ".dynstr");
- int sect_size = bfd_section_size (dynstr);
- if (dynstr == nullptr || sect_size <= idx)
- return {};
- /* Read soname from the string table. */
- gdb::byte_vector dynstr_buf;
- if (!gdb_bfd_get_full_section_contents (abfd.get (), dynstr, &dynstr_buf))
- return {};
- /* Ensure soname is null-terminated before returning a copy. */
- char *soname = (char *) dynstr_buf.data () + idx;
- if (strnlen (soname, sect_size - idx) == sect_size - idx)
- return {};
- return make_unique_xstrdup (soname);
- }
- /* Lookup the value for a specific symbol from symbol table. Look up symbol
- from ABFD. MATCH_SYM is a callback function to determine whether to pick
- up a symbol. DATA is the input of this callback function. Return NULL
- if symbol is not found. */
- static CORE_ADDR
- bfd_lookup_symbol_from_dyn_symtab (bfd *abfd,
- int (*match_sym) (const asymbol *,
- const void *),
- const void *data)
- {
- long storage_needed = bfd_get_dynamic_symtab_upper_bound (abfd);
- CORE_ADDR symaddr = 0;
- if (storage_needed > 0)
- {
- unsigned int i;
- gdb::def_vector<asymbol *> storage (storage_needed / sizeof (asymbol *));
- asymbol **symbol_table = storage.data ();
- unsigned int number_of_symbols =
- bfd_canonicalize_dynamic_symtab (abfd, symbol_table);
- for (i = 0; i < number_of_symbols; i++)
- {
- asymbol *sym = *symbol_table++;
- if (match_sym (sym, data))
- {
- /* BFD symbols are section relative. */
- symaddr = sym->value + sym->section->vma;
- break;
- }
- }
- }
- return symaddr;
- }
- /* Lookup the value for a specific symbol from symbol table and dynamic
- symbol table. Look up symbol from ABFD. MATCH_SYM is a callback
- function to determine whether to pick up a symbol. DATA is the
- input of this callback function. Return NULL if symbol is not
- found. */
- CORE_ADDR
- gdb_bfd_lookup_symbol (bfd *abfd,
- int (*match_sym) (const asymbol *, const void *),
- const void *data)
- {
- CORE_ADDR symaddr = gdb_bfd_lookup_symbol_from_symtab (abfd, match_sym, data);
- /* On FreeBSD, the dynamic linker is stripped by default. So we'll
- have to check the dynamic string table too. */
- if (symaddr == 0)
- symaddr = bfd_lookup_symbol_from_dyn_symtab (abfd, match_sym, data);
- return symaddr;
- }
- /* The shared library list may contain user-loaded object files that
- can be removed out-of-band by the user. So upon notification of
- free_objfile remove all references to any user-loaded file that is
- about to be freed. */
- static void
- remove_user_added_objfile (struct objfile *objfile)
- {
- if (objfile != 0 && objfile->flags & OBJF_USERLOADED)
- {
- for (struct so_list *so : current_program_space->solibs ())
- if (so->objfile == objfile)
- so->objfile = NULL;
- }
- }
- void _initialize_solib ();
- void
- _initialize_solib ()
- {
- solib_data = gdbarch_data_register_pre_init (solib_init);
- gdb::observers::free_objfile.attach (remove_user_added_objfile,
- "solib");
- gdb::observers::inferior_execd.attach ([] (inferior *inf)
- {
- solib_create_inferior_hook (0);
- }, "solib");
- add_com ("sharedlibrary", class_files, sharedlibrary_command,
- _("Load shared object library symbols for files matching REGEXP."));
- cmd_list_element *info_sharedlibrary_cmd
- = add_info ("sharedlibrary", info_sharedlibrary_command,
- _("Status of loaded shared object libraries."));
- add_info_alias ("dll", info_sharedlibrary_cmd, 1);
- add_com ("nosharedlibrary", class_files, no_shared_libraries,
- _("Unload all shared object library symbols."));
- add_setshow_boolean_cmd ("auto-solib-add", class_support,
- &auto_solib_add, _("\
- Set autoloading of shared library symbols."), _("\
- Show autoloading of shared library symbols."), _("\
- If \"on\", symbols from all shared object libraries will be loaded\n\
- automatically when the inferior begins execution, when the dynamic linker\n\
- informs gdb that a new library has been loaded, or when attaching to the\n\
- inferior. Otherwise, symbols must be loaded manually, using \
- `sharedlibrary'."),
- NULL,
- show_auto_solib_add,
- &setlist, &showlist);
- set_show_commands sysroot_cmds
- = add_setshow_optional_filename_cmd ("sysroot", class_support,
- &gdb_sysroot, _("\
- Set an alternate system root."), _("\
- Show the current system root."), _("\
- The system root is used to load absolute shared library symbol files.\n\
- For other (relative) files, you can add directories using\n\
- `set solib-search-path'."),
- gdb_sysroot_changed,
- NULL,
- &setlist, &showlist);
- add_alias_cmd ("solib-absolute-prefix", sysroot_cmds.set, class_support, 0,
- &setlist);
- add_alias_cmd ("solib-absolute-prefix", sysroot_cmds.show, class_support, 0,
- &showlist);
- add_setshow_optional_filename_cmd ("solib-search-path", class_support,
- &solib_search_path, _("\
- Set the search path for loading non-absolute shared library symbol files."),
- _("\
- Show the search path for loading non-absolute shared library symbol files."),
- _("\
- This takes precedence over the environment variables \
- PATH and LD_LIBRARY_PATH."),
- reload_shared_libraries,
- show_solib_search_path,
- &setlist, &showlist);
- }
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