1 /* Handle Darwin shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 2009-2013 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
30 #include "gdbthread.h"
33 #include "gdb_assert.h"
37 #include "solib-svr4.h"
39 #include "bfd-target.h"
43 #include "exceptions.h"
45 #include "mach-o/external.h"
47 struct gdb_dyld_image_info
49 /* Base address (which corresponds to the Mach-O header). */
50 CORE_ADDR mach_header;
51 /* Image file path. */
53 /* st.m_time of image file. */
57 /* Content of inferior dyld_all_image_infos structure.
58 See /usr/include/mach-o/dyld_images.h for the documentation. */
59 struct gdb_dyld_all_image_infos
63 /* Number of images. */
65 /* Image description. */
67 /* Notifier (function called when a library is added or removed). */
71 /* Current all_image_infos version. */
72 #define DYLD_VERSION_MIN 1
73 #define DYLD_VERSION_MAX 12
75 /* Per PSPACE specific data. */
78 /* Address of structure dyld_all_image_infos in inferior. */
79 CORE_ADDR all_image_addr;
81 /* Gdb copy of dyld_all_info_infos. */
82 struct gdb_dyld_all_image_infos all_image;
85 /* Per-program-space data key. */
86 static const struct program_space_data *solib_darwin_pspace_data;
89 darwin_pspace_data_cleanup (struct program_space *pspace, void *arg)
94 /* Get the current darwin data. If none is found yet, add it now. This
95 function always returns a valid object. */
97 static struct darwin_info *
98 get_darwin_info (void)
100 struct darwin_info *info;
102 info = program_space_data (current_program_space, solib_darwin_pspace_data);
106 info = XZALLOC (struct darwin_info);
107 set_program_space_data (current_program_space,
108 solib_darwin_pspace_data, info);
112 /* Return non-zero if the version in dyld_all_image is known. */
115 darwin_dyld_version_ok (const struct darwin_info *info)
117 return info->all_image.version >= DYLD_VERSION_MIN
118 && info->all_image.version <= DYLD_VERSION_MAX;
121 /* Read dyld_all_image from inferior. */
124 darwin_load_image_infos (struct darwin_info *info)
127 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
128 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
131 /* If the structure address is not known, don't continue. */
132 if (info->all_image_addr == 0)
135 /* The structure has 4 fields: version (4 bytes), count (4 bytes),
136 info (pointer) and notifier (pointer). */
137 len = 4 + 4 + 2 * ptr_type->length;
138 gdb_assert (len <= sizeof (buf));
139 memset (&info->all_image, 0, sizeof (info->all_image));
141 /* Read structure raw bytes from target. */
142 if (target_read_memory (info->all_image_addr, buf, len))
145 /* Extract the fields. */
146 info->all_image.version = extract_unsigned_integer (buf, 4, byte_order);
147 if (!darwin_dyld_version_ok (info))
150 info->all_image.count = extract_unsigned_integer (buf + 4, 4, byte_order);
151 info->all_image.info = extract_typed_address (buf + 8, ptr_type);
152 info->all_image.notifier = extract_typed_address
153 (buf + 8 + ptr_type->length, ptr_type);
156 /* Link map info to include in an allocated so_list entry. */
160 /* The target location of lm. */
164 struct darwin_so_list
168 /* Darwin specific data. */
172 /* Lookup the value for a specific symbol. */
175 lookup_symbol_from_bfd (bfd *abfd, char *symname)
178 asymbol **symbol_table;
179 unsigned int number_of_symbols;
181 CORE_ADDR symaddr = 0;
183 storage_needed = bfd_get_symtab_upper_bound (abfd);
185 if (storage_needed <= 0)
188 symbol_table = (asymbol **) xmalloc (storage_needed);
189 number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
191 for (i = 0; i < number_of_symbols; i++)
193 asymbol *sym = symbol_table[i];
195 if (strcmp (sym->name, symname) == 0
196 && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
198 /* BFD symbols are section relative. */
199 symaddr = sym->value + sym->section->vma;
203 xfree (symbol_table);
208 /* Return program interpreter string. */
211 find_program_interpreter (void)
215 /* If we have an exec_bfd, get the interpreter from the load commands. */
218 bfd_mach_o_load_command *cmd;
220 if (bfd_mach_o_lookup_command (exec_bfd,
221 BFD_MACH_O_LC_LOAD_DYLINKER, &cmd) == 1)
222 return cmd->command.dylinker.name_str;
225 /* If we didn't find it, read from memory.
230 /* Not used. I don't see how the main symbol file can be found: the
231 interpreter name is needed and it is known from the executable file.
232 Note that darwin-nat.c implements pid_to_exec_file. */
235 open_symbol_file_object (void *from_ttyp)
240 /* Build a list of currently loaded shared objects. See solib-svr4.c. */
242 static struct so_list *
243 darwin_current_sos (void)
245 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
246 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
247 int ptr_len = TYPE_LENGTH (ptr_type);
248 unsigned int image_info_size;
249 struct so_list *head = NULL;
250 struct so_list *tail = NULL;
252 struct darwin_info *info = get_darwin_info ();
254 /* Be sure image infos are loaded. */
255 darwin_load_image_infos (info);
257 if (!darwin_dyld_version_ok (info))
260 image_info_size = ptr_len * 3;
262 /* Read infos for each solib.
263 The first entry was rumored to be the executable itself, but this is not
264 true when a large number of shared libraries are used (table expanded ?).
265 We now check all entries, but discard executable images. */
266 for (i = 0; i < info->all_image.count; i++)
268 CORE_ADDR iinfo = info->all_image.info + i * image_info_size;
269 gdb_byte buf[image_info_size];
272 struct mach_o_header_external hdr;
273 unsigned long hdr_val;
276 struct darwin_so_list *dnew;
278 struct cleanup *old_chain;
280 /* Read image info from inferior. */
281 if (target_read_memory (iinfo, buf, image_info_size))
284 load_addr = extract_typed_address (buf, ptr_type);
285 path_addr = extract_typed_address (buf + ptr_len, ptr_type);
287 /* Read Mach-O header from memory. */
288 if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4))
290 /* Discard wrong magic numbers. Shouldn't happen. */
291 hdr_val = extract_unsigned_integer
292 (hdr.magic, sizeof (hdr.magic), byte_order);
293 if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64)
295 /* Discard executable. Should happen only once. */
296 hdr_val = extract_unsigned_integer
297 (hdr.filetype, sizeof (hdr.filetype), byte_order);
298 if (hdr_val == BFD_MACH_O_MH_EXECUTE)
301 target_read_string (path_addr, &file_path,
302 SO_NAME_MAX_PATH_SIZE - 1, &errcode);
306 /* Create and fill the new so_list element. */
307 dnew = XZALLOC (struct darwin_so_list);
309 old_chain = make_cleanup (xfree, dnew);
311 new->lm_info = &dnew->li;
313 strncpy (new->so_name, file_path, SO_NAME_MAX_PATH_SIZE - 1);
314 new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
315 strcpy (new->so_original_name, new->so_name);
317 new->lm_info->lm_addr = load_addr;
325 discard_cleanups (old_chain);
331 /* Get the load address of the executable. We assume that the dyld info are
335 darwin_read_exec_load_addr (struct darwin_info *info)
337 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
338 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
339 int ptr_len = TYPE_LENGTH (ptr_type);
340 unsigned int image_info_size = ptr_len * 3;
343 /* Read infos for each solib. One of them should be the executable. */
344 for (i = 0; i < info->all_image.count; i++)
346 CORE_ADDR iinfo = info->all_image.info + i * image_info_size;
347 gdb_byte buf[image_info_size];
349 struct mach_o_header_external hdr;
350 unsigned long hdr_val;
352 /* Read image info from inferior. */
353 if (target_read_memory (iinfo, buf, image_info_size))
356 load_addr = extract_typed_address (buf, ptr_type);
358 /* Read Mach-O header from memory. */
359 if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4))
361 /* Discard wrong magic numbers. Shouldn't happen. */
362 hdr_val = extract_unsigned_integer
363 (hdr.magic, sizeof (hdr.magic), byte_order);
364 if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64)
366 /* Check executable. */
367 hdr_val = extract_unsigned_integer
368 (hdr.filetype, sizeof (hdr.filetype), byte_order);
369 if (hdr_val == BFD_MACH_O_MH_EXECUTE)
376 /* Return 1 if PC lies in the dynamic symbol resolution code of the
380 darwin_in_dynsym_resolve_code (CORE_ADDR pc)
386 /* No special symbol handling. */
389 darwin_special_symbol_handling (void)
393 /* A wrapper for bfd_mach_o_fat_extract that handles reference
394 counting properly. This will either return NULL, or return a new
395 reference to a BFD. */
398 gdb_bfd_mach_o_fat_extract (bfd *abfd, bfd_format format,
399 const bfd_arch_info_type *arch)
401 bfd *result = bfd_mach_o_fat_extract (abfd, format, arch);
407 gdb_bfd_ref (result);
409 gdb_bfd_mark_parent (result, abfd);
414 /* Extract dyld_all_image_addr when the process was just created, assuming the
415 current PC is at the entry of the dynamic linker. */
418 darwin_solib_get_all_image_info_addr_at_init (struct darwin_info *info)
421 CORE_ADDR load_addr = 0;
422 bfd *dyld_bfd = NULL;
423 struct cleanup *cleanup;
425 /* This method doesn't work with an attached process. */
426 if (current_inferior ()->attach_flag)
429 /* Find the program interpreter. */
430 interp_name = find_program_interpreter ();
434 cleanup = make_cleanup (null_cleanup, NULL);
436 /* Create a bfd for the interpreter. */
437 dyld_bfd = gdb_bfd_open (interp_name, gnutarget, -1);
442 make_cleanup_bfd_unref (dyld_bfd);
443 sub = gdb_bfd_mach_o_fat_extract (dyld_bfd, bfd_object,
444 gdbarch_bfd_arch_info (target_gdbarch ()));
448 make_cleanup_bfd_unref (sub);
455 do_cleanups (cleanup);
459 /* We find the dynamic linker's base address by examining
460 the current pc (which should point at the entry point for the
461 dynamic linker) and subtracting the offset of the entry point. */
462 load_addr = (regcache_read_pc (get_current_regcache ())
463 - bfd_get_start_address (dyld_bfd));
465 /* Now try to set a breakpoint in the dynamic linker. */
466 info->all_image_addr =
467 lookup_symbol_from_bfd (dyld_bfd, "_dyld_all_image_infos");
469 do_cleanups (cleanup);
471 if (info->all_image_addr == 0)
474 info->all_image_addr += load_addr;
477 /* Extract dyld_all_image_addr reading it from
478 TARGET_OBJECT_DARWIN_DYLD_INFO. */
481 darwin_solib_read_all_image_info_addr (struct darwin_info *info)
483 gdb_byte buf[8 + 8 + 4];
485 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
487 len = target_read (¤t_target, TARGET_OBJECT_DARWIN_DYLD_INFO, NULL,
488 buf, 0, sizeof (buf));
489 if (len != sizeof (buf))
492 info->all_image_addr = extract_unsigned_integer (buf, 8, byte_order);
495 /* Shared library startup support. See documentation in solib-svr4.c. */
498 darwin_solib_create_inferior_hook (int from_tty)
500 struct darwin_info *info = get_darwin_info ();
503 info->all_image_addr = 0;
505 darwin_solib_read_all_image_info_addr (info);
507 if (info->all_image_addr == 0)
508 darwin_solib_get_all_image_info_addr_at_init (info);
510 if (info->all_image_addr == 0)
513 darwin_load_image_infos (info);
515 if (!darwin_dyld_version_ok (info))
518 create_solib_event_breakpoint (target_gdbarch (), info->all_image.notifier);
520 /* Possible relocate the main executable (PIE). */
521 load_addr = darwin_read_exec_load_addr (info);
522 if (load_addr != 0 && symfile_objfile != NULL)
524 CORE_ADDR vmaddr = 0;
525 struct mach_o_data_struct *md = bfd_mach_o_get_data (exec_bfd);
528 /* Find the base address of the executable. */
529 for (i = 0; i < md->header.ncmds; i++)
531 struct bfd_mach_o_load_command *cmd = &md->commands[i];
533 if (cmd->type != BFD_MACH_O_LC_SEGMENT
534 && cmd->type != BFD_MACH_O_LC_SEGMENT_64)
536 if (cmd->command.segment.fileoff == 0
537 && cmd->command.segment.vmaddr != 0
538 && cmd->command.segment.filesize != 0)
540 vmaddr = cmd->command.segment.vmaddr;
546 if (vmaddr != load_addr)
547 objfile_rebase (symfile_objfile, load_addr - vmaddr);
552 darwin_clear_solib (void)
554 struct darwin_info *info = get_darwin_info ();
556 info->all_image_addr = 0;
557 info->all_image.version = 0;
561 darwin_free_so (struct so_list *so)
565 /* The section table is built from bfd sections using bfd VMAs.
566 Relocate these VMAs according to solib info. */
569 darwin_relocate_section_addresses (struct so_list *so,
570 struct target_section *sec)
572 sec->addr += so->lm_info->lm_addr;
573 sec->endaddr += so->lm_info->lm_addr;
575 /* Best effort to set addr_high/addr_low. This is used only by
576 'info sharedlibary'. */
577 if (so->addr_high == 0)
579 so->addr_low = sec->addr;
580 so->addr_high = sec->endaddr;
582 if (sec->endaddr > so->addr_high)
583 so->addr_high = sec->endaddr;
584 if (sec->addr < so->addr_low)
585 so->addr_low = sec->addr;
588 static struct symbol *
589 darwin_lookup_lib_symbol (const struct objfile *objfile,
591 const domain_enum domain)
597 darwin_bfd_open (char *pathname)
599 char *found_pathname;
604 /* Search for shared library file. */
605 found_pathname = solib_find (pathname, &found_file);
606 if (found_pathname == NULL)
607 perror_with_name (pathname);
609 /* Open bfd for shared library. */
610 abfd = solib_bfd_fopen (found_pathname, found_file);
612 res = gdb_bfd_mach_o_fat_extract (abfd, bfd_object,
613 gdbarch_bfd_arch_info (target_gdbarch ()));
616 make_cleanup_bfd_unref (abfd);
617 error (_("`%s': not a shared-library: %s"),
618 bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
621 gdb_bfd_unref (abfd);
625 struct target_so_ops darwin_so_ops;
627 /* -Wmissing-prototypes */
628 extern initialize_file_ftype _initialize_darwin_solib;
631 _initialize_darwin_solib (void)
633 solib_darwin_pspace_data
634 = register_program_space_data_with_cleanup (NULL,
635 darwin_pspace_data_cleanup);
637 darwin_so_ops.relocate_section_addresses = darwin_relocate_section_addresses;
638 darwin_so_ops.free_so = darwin_free_so;
639 darwin_so_ops.clear_solib = darwin_clear_solib;
640 darwin_so_ops.solib_create_inferior_hook = darwin_solib_create_inferior_hook;
641 darwin_so_ops.special_symbol_handling = darwin_special_symbol_handling;
642 darwin_so_ops.current_sos = darwin_current_sos;
643 darwin_so_ops.open_symbol_file_object = open_symbol_file_object;
644 darwin_so_ops.in_dynsym_resolve_code = darwin_in_dynsym_resolve_code;
645 darwin_so_ops.lookup_lib_global_symbol = darwin_lookup_lib_symbol;
646 darwin_so_ops.bfd_open = darwin_bfd_open;