638 lines
17 KiB
C
638 lines
17 KiB
C
/* Handle Darwin shared libraries for GDB, the GNU Debugger.
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Copyright (C) 2009-2015 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "symtab.h"
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#include "bfd.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "gdbcore.h"
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#include "target.h"
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#include "inferior.h"
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#include "regcache.h"
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#include "gdbthread.h"
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#include "gdb_bfd.h"
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#include "solist.h"
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#include "solib.h"
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#include "solib-svr4.h"
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#include "bfd-target.h"
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#include "elf-bfd.h"
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#include "exec.h"
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#include "auxv.h"
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#include "mach-o.h"
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#include "mach-o/external.h"
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struct gdb_dyld_image_info
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{
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/* Base address (which corresponds to the Mach-O header). */
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CORE_ADDR mach_header;
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/* Image file path. */
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CORE_ADDR file_path;
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/* st.m_time of image file. */
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unsigned long mtime;
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};
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/* Content of inferior dyld_all_image_infos structure.
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See /usr/include/mach-o/dyld_images.h for the documentation. */
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struct gdb_dyld_all_image_infos
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{
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/* Version (1). */
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unsigned int version;
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/* Number of images. */
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unsigned int count;
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/* Image description. */
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CORE_ADDR info;
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/* Notifier (function called when a library is added or removed). */
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CORE_ADDR notifier;
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};
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/* Current all_image_infos version. */
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#define DYLD_VERSION_MIN 1
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#define DYLD_VERSION_MAX 14
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/* Per PSPACE specific data. */
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struct darwin_info
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{
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/* Address of structure dyld_all_image_infos in inferior. */
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CORE_ADDR all_image_addr;
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/* Gdb copy of dyld_all_info_infos. */
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struct gdb_dyld_all_image_infos all_image;
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};
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/* Per-program-space data key. */
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static const struct program_space_data *solib_darwin_pspace_data;
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static void
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darwin_pspace_data_cleanup (struct program_space *pspace, void *arg)
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{
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xfree (arg);
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}
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/* Get the current darwin data. If none is found yet, add it now. This
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function always returns a valid object. */
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static struct darwin_info *
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get_darwin_info (void)
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{
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struct darwin_info *info;
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info = program_space_data (current_program_space, solib_darwin_pspace_data);
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if (info != NULL)
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return info;
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info = XCNEW (struct darwin_info);
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set_program_space_data (current_program_space,
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solib_darwin_pspace_data, info);
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return info;
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}
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/* Return non-zero if the version in dyld_all_image is known. */
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static int
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darwin_dyld_version_ok (const struct darwin_info *info)
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{
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return info->all_image.version >= DYLD_VERSION_MIN
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&& info->all_image.version <= DYLD_VERSION_MAX;
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}
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/* Read dyld_all_image from inferior. */
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static void
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darwin_load_image_infos (struct darwin_info *info)
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{
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gdb_byte buf[24];
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enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
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struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
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int len;
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/* If the structure address is not known, don't continue. */
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if (info->all_image_addr == 0)
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return;
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/* The structure has 4 fields: version (4 bytes), count (4 bytes),
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info (pointer) and notifier (pointer). */
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len = 4 + 4 + 2 * ptr_type->length;
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gdb_assert (len <= sizeof (buf));
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memset (&info->all_image, 0, sizeof (info->all_image));
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/* Read structure raw bytes from target. */
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if (target_read_memory (info->all_image_addr, buf, len))
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return;
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/* Extract the fields. */
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info->all_image.version = extract_unsigned_integer (buf, 4, byte_order);
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if (!darwin_dyld_version_ok (info))
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return;
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info->all_image.count = extract_unsigned_integer (buf + 4, 4, byte_order);
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info->all_image.info = extract_typed_address (buf + 8, ptr_type);
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info->all_image.notifier = extract_typed_address
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(buf + 8 + ptr_type->length, ptr_type);
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}
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/* Link map info to include in an allocated so_list entry. */
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struct lm_info
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{
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/* The target location of lm. */
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CORE_ADDR lm_addr;
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};
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struct darwin_so_list
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{
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/* Common field. */
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struct so_list sl;
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/* Darwin specific data. */
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struct lm_info li;
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};
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/* Lookup the value for a specific symbol. */
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static CORE_ADDR
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lookup_symbol_from_bfd (bfd *abfd, char *symname)
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{
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long storage_needed;
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asymbol **symbol_table;
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unsigned int number_of_symbols;
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unsigned int i;
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CORE_ADDR symaddr = 0;
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storage_needed = bfd_get_symtab_upper_bound (abfd);
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if (storage_needed <= 0)
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return 0;
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symbol_table = (asymbol **) xmalloc (storage_needed);
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number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
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for (i = 0; i < number_of_symbols; i++)
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{
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asymbol *sym = symbol_table[i];
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if (strcmp (sym->name, symname) == 0
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&& (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
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{
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/* BFD symbols are section relative. */
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symaddr = sym->value + sym->section->vma;
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break;
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}
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}
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xfree (symbol_table);
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return symaddr;
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}
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/* Return program interpreter string. */
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static char *
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find_program_interpreter (void)
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{
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char *buf = NULL;
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/* If we have an exec_bfd, get the interpreter from the load commands. */
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if (exec_bfd)
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{
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bfd_mach_o_load_command *cmd;
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if (bfd_mach_o_lookup_command (exec_bfd,
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BFD_MACH_O_LC_LOAD_DYLINKER, &cmd) == 1)
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return cmd->command.dylinker.name_str;
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}
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/* If we didn't find it, read from memory.
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FIXME: todo. */
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return buf;
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}
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/* Not used. I don't see how the main symbol file can be found: the
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interpreter name is needed and it is known from the executable file.
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Note that darwin-nat.c implements pid_to_exec_file. */
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static int
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open_symbol_file_object (void *from_ttyp)
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{
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return 0;
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}
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/* Build a list of currently loaded shared objects. See solib-svr4.c. */
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static struct so_list *
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darwin_current_sos (void)
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{
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struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
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enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
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int ptr_len = TYPE_LENGTH (ptr_type);
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unsigned int image_info_size;
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struct so_list *head = NULL;
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struct so_list *tail = NULL;
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int i;
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struct darwin_info *info = get_darwin_info ();
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/* Be sure image infos are loaded. */
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darwin_load_image_infos (info);
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if (!darwin_dyld_version_ok (info))
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return NULL;
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image_info_size = ptr_len * 3;
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/* Read infos for each solib.
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The first entry was rumored to be the executable itself, but this is not
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true when a large number of shared libraries are used (table expanded ?).
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We now check all entries, but discard executable images. */
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for (i = 0; i < info->all_image.count; i++)
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{
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CORE_ADDR iinfo = info->all_image.info + i * image_info_size;
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gdb_byte buf[image_info_size];
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CORE_ADDR load_addr;
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CORE_ADDR path_addr;
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struct mach_o_header_external hdr;
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unsigned long hdr_val;
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char *file_path;
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int errcode;
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struct darwin_so_list *dnew;
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struct so_list *new;
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struct cleanup *old_chain;
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/* Read image info from inferior. */
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if (target_read_memory (iinfo, buf, image_info_size))
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break;
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load_addr = extract_typed_address (buf, ptr_type);
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path_addr = extract_typed_address (buf + ptr_len, ptr_type);
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/* Read Mach-O header from memory. */
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if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4))
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break;
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/* Discard wrong magic numbers. Shouldn't happen. */
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hdr_val = extract_unsigned_integer
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(hdr.magic, sizeof (hdr.magic), byte_order);
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if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64)
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continue;
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/* Discard executable. Should happen only once. */
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hdr_val = extract_unsigned_integer
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(hdr.filetype, sizeof (hdr.filetype), byte_order);
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if (hdr_val == BFD_MACH_O_MH_EXECUTE)
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continue;
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target_read_string (path_addr, &file_path,
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SO_NAME_MAX_PATH_SIZE - 1, &errcode);
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if (errcode)
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break;
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/* Create and fill the new so_list element. */
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dnew = XCNEW (struct darwin_so_list);
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new = &dnew->sl;
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old_chain = make_cleanup (xfree, dnew);
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new->lm_info = &dnew->li;
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strncpy (new->so_name, file_path, SO_NAME_MAX_PATH_SIZE - 1);
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new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
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strcpy (new->so_original_name, new->so_name);
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xfree (file_path);
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new->lm_info->lm_addr = load_addr;
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if (head == NULL)
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head = new;
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else
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tail->next = new;
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tail = new;
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discard_cleanups (old_chain);
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}
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return head;
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}
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/* Get the load address of the executable. We assume that the dyld info are
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correct. */
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static CORE_ADDR
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darwin_read_exec_load_addr (struct darwin_info *info)
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{
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struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
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enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
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int ptr_len = TYPE_LENGTH (ptr_type);
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unsigned int image_info_size = ptr_len * 3;
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int i;
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/* Read infos for each solib. One of them should be the executable. */
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for (i = 0; i < info->all_image.count; i++)
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{
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CORE_ADDR iinfo = info->all_image.info + i * image_info_size;
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gdb_byte buf[image_info_size];
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CORE_ADDR load_addr;
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struct mach_o_header_external hdr;
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unsigned long hdr_val;
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/* Read image info from inferior. */
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if (target_read_memory (iinfo, buf, image_info_size))
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break;
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load_addr = extract_typed_address (buf, ptr_type);
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/* Read Mach-O header from memory. */
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if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4))
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break;
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/* Discard wrong magic numbers. Shouldn't happen. */
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hdr_val = extract_unsigned_integer
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(hdr.magic, sizeof (hdr.magic), byte_order);
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if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64)
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continue;
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/* Check executable. */
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hdr_val = extract_unsigned_integer
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(hdr.filetype, sizeof (hdr.filetype), byte_order);
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if (hdr_val == BFD_MACH_O_MH_EXECUTE)
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return load_addr;
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}
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return 0;
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}
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/* Return 1 if PC lies in the dynamic symbol resolution code of the
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run time loader. */
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static int
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darwin_in_dynsym_resolve_code (CORE_ADDR pc)
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{
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return 0;
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}
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/* No special symbol handling. */
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static void
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darwin_special_symbol_handling (void)
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{
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}
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/* A wrapper for bfd_mach_o_fat_extract that handles reference
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counting properly. This will either return NULL, or return a new
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reference to a BFD. */
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static bfd *
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gdb_bfd_mach_o_fat_extract (bfd *abfd, bfd_format format,
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const bfd_arch_info_type *arch)
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{
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bfd *result = bfd_mach_o_fat_extract (abfd, format, arch);
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if (result == NULL)
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return NULL;
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if (result == abfd)
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gdb_bfd_ref (result);
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else
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gdb_bfd_mark_parent (result, abfd);
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return result;
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}
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/* Extract dyld_all_image_addr when the process was just created, assuming the
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current PC is at the entry of the dynamic linker. */
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static void
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darwin_solib_get_all_image_info_addr_at_init (struct darwin_info *info)
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{
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char *interp_name;
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CORE_ADDR load_addr = 0;
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bfd *dyld_bfd = NULL;
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struct cleanup *cleanup;
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/* This method doesn't work with an attached process. */
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if (current_inferior ()->attach_flag)
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return;
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/* Find the program interpreter. */
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interp_name = find_program_interpreter ();
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if (!interp_name)
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return;
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cleanup = make_cleanup (null_cleanup, NULL);
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/* Create a bfd for the interpreter. */
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dyld_bfd = gdb_bfd_open (interp_name, gnutarget, -1);
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if (dyld_bfd)
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{
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bfd *sub;
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make_cleanup_bfd_unref (dyld_bfd);
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sub = gdb_bfd_mach_o_fat_extract (dyld_bfd, bfd_object,
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gdbarch_bfd_arch_info (target_gdbarch ()));
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if (sub)
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{
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dyld_bfd = sub;
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make_cleanup_bfd_unref (sub);
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}
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else
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dyld_bfd = NULL;
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}
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if (!dyld_bfd)
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{
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do_cleanups (cleanup);
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return;
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}
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/* We find the dynamic linker's base address by examining
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the current pc (which should point at the entry point for the
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dynamic linker) and subtracting the offset of the entry point. */
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load_addr = (regcache_read_pc (get_current_regcache ())
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- bfd_get_start_address (dyld_bfd));
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/* Now try to set a breakpoint in the dynamic linker. */
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info->all_image_addr =
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lookup_symbol_from_bfd (dyld_bfd, "_dyld_all_image_infos");
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do_cleanups (cleanup);
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if (info->all_image_addr == 0)
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return;
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info->all_image_addr += load_addr;
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}
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/* Extract dyld_all_image_addr reading it from
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TARGET_OBJECT_DARWIN_DYLD_INFO. */
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static void
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darwin_solib_read_all_image_info_addr (struct darwin_info *info)
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{
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gdb_byte buf[8 + 8 + 4];
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LONGEST len;
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enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
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len = target_read (¤t_target, TARGET_OBJECT_DARWIN_DYLD_INFO, NULL,
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buf, 0, sizeof (buf));
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if (len != sizeof (buf))
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return;
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info->all_image_addr = extract_unsigned_integer (buf, 8, byte_order);
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}
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/* Shared library startup support. See documentation in solib-svr4.c. */
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static void
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darwin_solib_create_inferior_hook (int from_tty)
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{
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struct darwin_info *info = get_darwin_info ();
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CORE_ADDR load_addr;
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info->all_image_addr = 0;
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darwin_solib_read_all_image_info_addr (info);
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if (info->all_image_addr == 0)
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darwin_solib_get_all_image_info_addr_at_init (info);
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if (info->all_image_addr == 0)
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return;
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darwin_load_image_infos (info);
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if (!darwin_dyld_version_ok (info))
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{
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warning (_("unhandled dyld version (%d)"), info->all_image.version);
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return;
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}
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create_solib_event_breakpoint (target_gdbarch (), info->all_image.notifier);
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/* Possible relocate the main executable (PIE). */
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load_addr = darwin_read_exec_load_addr (info);
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if (load_addr != 0 && symfile_objfile != NULL)
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{
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CORE_ADDR vmaddr;
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||
/* Find the base address of the executable. */
|
||
vmaddr = bfd_mach_o_get_base_address (exec_bfd);
|
||
|
||
/* Relocate. */
|
||
if (vmaddr != load_addr)
|
||
objfile_rebase (symfile_objfile, load_addr - vmaddr);
|
||
}
|
||
}
|
||
|
||
static void
|
||
darwin_clear_solib (void)
|
||
{
|
||
struct darwin_info *info = get_darwin_info ();
|
||
|
||
info->all_image_addr = 0;
|
||
info->all_image.version = 0;
|
||
}
|
||
|
||
static void
|
||
darwin_free_so (struct so_list *so)
|
||
{
|
||
}
|
||
|
||
/* The section table is built from bfd sections using bfd VMAs.
|
||
Relocate these VMAs according to solib info. */
|
||
|
||
static void
|
||
darwin_relocate_section_addresses (struct so_list *so,
|
||
struct target_section *sec)
|
||
{
|
||
sec->addr += so->lm_info->lm_addr;
|
||
sec->endaddr += so->lm_info->lm_addr;
|
||
|
||
/* Best effort to set addr_high/addr_low. This is used only by
|
||
'info sharedlibary'. */
|
||
if (so->addr_high == 0)
|
||
{
|
||
so->addr_low = sec->addr;
|
||
so->addr_high = sec->endaddr;
|
||
}
|
||
if (sec->endaddr > so->addr_high)
|
||
so->addr_high = sec->endaddr;
|
||
if (sec->addr < so->addr_low)
|
||
so->addr_low = sec->addr;
|
||
}
|
||
|
||
static struct symbol *
|
||
darwin_lookup_lib_symbol (struct objfile *objfile,
|
||
const char *name,
|
||
const domain_enum domain)
|
||
{
|
||
return NULL;
|
||
}
|
||
|
||
static bfd *
|
||
darwin_bfd_open (char *pathname)
|
||
{
|
||
char *found_pathname;
|
||
int found_file;
|
||
bfd *abfd;
|
||
bfd *res;
|
||
|
||
/* Search for shared library file. */
|
||
found_pathname = solib_find (pathname, &found_file);
|
||
if (found_pathname == NULL)
|
||
perror_with_name (pathname);
|
||
|
||
/* Open bfd for shared library. */
|
||
abfd = solib_bfd_fopen (found_pathname, found_file);
|
||
|
||
res = gdb_bfd_mach_o_fat_extract (abfd, bfd_object,
|
||
gdbarch_bfd_arch_info (target_gdbarch ()));
|
||
if (!res)
|
||
{
|
||
make_cleanup_bfd_unref (abfd);
|
||
error (_("`%s': not a shared-library: %s"),
|
||
bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
|
||
}
|
||
|
||
/* The current filename for fat-binary BFDs is a name generated
|
||
by BFD, usually a string containing the name of the architecture.
|
||
Reset its value to the actual filename. */
|
||
xfree (bfd_get_filename (res));
|
||
res->filename = xstrdup (pathname);
|
||
|
||
gdb_bfd_unref (abfd);
|
||
return res;
|
||
}
|
||
|
||
struct target_so_ops darwin_so_ops;
|
||
|
||
/* -Wmissing-prototypes */
|
||
extern initialize_file_ftype _initialize_darwin_solib;
|
||
|
||
void
|
||
_initialize_darwin_solib (void)
|
||
{
|
||
solib_darwin_pspace_data
|
||
= register_program_space_data_with_cleanup (NULL,
|
||
darwin_pspace_data_cleanup);
|
||
|
||
darwin_so_ops.relocate_section_addresses = darwin_relocate_section_addresses;
|
||
darwin_so_ops.free_so = darwin_free_so;
|
||
darwin_so_ops.clear_solib = darwin_clear_solib;
|
||
darwin_so_ops.solib_create_inferior_hook = darwin_solib_create_inferior_hook;
|
||
darwin_so_ops.special_symbol_handling = darwin_special_symbol_handling;
|
||
darwin_so_ops.current_sos = darwin_current_sos;
|
||
darwin_so_ops.open_symbol_file_object = open_symbol_file_object;
|
||
darwin_so_ops.in_dynsym_resolve_code = darwin_in_dynsym_resolve_code;
|
||
darwin_so_ops.lookup_lib_global_symbol = darwin_lookup_lib_symbol;
|
||
darwin_so_ops.bfd_open = darwin_bfd_open;
|
||
}
|