1 /* Handle Darwin shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 2009-2012 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)
91 struct darwin_info *info;
93 info = program_space_data (pspace, solib_darwin_pspace_data);
97 /* Get the current darwin data. If none is found yet, add it now. This
98 function always returns a valid object. */
100 static struct darwin_info *
101 get_darwin_info (void)
103 struct darwin_info *info;
105 info = program_space_data (current_program_space, solib_darwin_pspace_data);
109 info = XZALLOC (struct darwin_info);
110 set_program_space_data (current_program_space,
111 solib_darwin_pspace_data, info);
115 /* Return non-zero if the version in dyld_all_image is known. */
118 darwin_dyld_version_ok (const struct darwin_info *info)
120 return info->all_image.version >= DYLD_VERSION_MIN
121 && info->all_image.version <= DYLD_VERSION_MAX;
124 /* Read dyld_all_image from inferior. */
127 darwin_load_image_infos (struct darwin_info *info)
130 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
131 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
134 /* If the structure address is not known, don't continue. */
135 if (info->all_image_addr == 0)
138 /* The structure has 4 fields: version (4 bytes), count (4 bytes),
139 info (pointer) and notifier (pointer). */
140 len = 4 + 4 + 2 * ptr_type->length;
141 gdb_assert (len <= sizeof (buf));
142 memset (&info->all_image, 0, sizeof (info->all_image));
144 /* Read structure raw bytes from target. */
145 if (target_read_memory (info->all_image_addr, buf, len))
148 /* Extract the fields. */
149 info->all_image.version = extract_unsigned_integer (buf, 4, byte_order);
150 if (!darwin_dyld_version_ok (info))
153 info->all_image.count = extract_unsigned_integer (buf + 4, 4, byte_order);
154 info->all_image.info = extract_typed_address (buf + 8, ptr_type);
155 info->all_image.notifier = extract_typed_address
156 (buf + 8 + ptr_type->length, ptr_type);
159 /* Link map info to include in an allocated so_list entry. */
163 /* The target location of lm. */
167 struct darwin_so_list
171 /* Darwin specific data. */
175 /* Lookup the value for a specific symbol. */
178 lookup_symbol_from_bfd (bfd *abfd, char *symname)
181 asymbol **symbol_table;
182 unsigned int number_of_symbols;
184 CORE_ADDR symaddr = 0;
186 storage_needed = bfd_get_symtab_upper_bound (abfd);
188 if (storage_needed <= 0)
191 symbol_table = (asymbol **) xmalloc (storage_needed);
192 number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
194 for (i = 0; i < number_of_symbols; i++)
196 asymbol *sym = symbol_table[i];
198 if (strcmp (sym->name, symname) == 0
199 && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
201 /* BFD symbols are section relative. */
202 symaddr = sym->value + sym->section->vma;
206 xfree (symbol_table);
211 /* Return program interpreter string. */
214 find_program_interpreter (void)
216 gdb_byte *buf = NULL;
218 /* If we have an exec_bfd, get the interpreter from the load commands. */
221 bfd_mach_o_load_command *cmd;
223 if (bfd_mach_o_lookup_command (exec_bfd,
224 BFD_MACH_O_LC_LOAD_DYLINKER, &cmd) == 1)
225 return cmd->command.dylinker.name_str;
228 /* If we didn't find it, read from memory.
233 /* Not used. I don't see how the main symbol file can be found: the
234 interpreter name is needed and it is known from the executable file.
235 Note that darwin-nat.c implements pid_to_exec_file. */
238 open_symbol_file_object (void *from_ttyp)
243 /* Build a list of currently loaded shared objects. See solib-svr4.c. */
245 static struct so_list *
246 darwin_current_sos (void)
248 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
249 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
250 int ptr_len = TYPE_LENGTH (ptr_type);
251 unsigned int image_info_size;
252 struct so_list *head = NULL;
253 struct so_list *tail = NULL;
255 struct darwin_info *info = get_darwin_info ();
257 /* Be sure image infos are loaded. */
258 darwin_load_image_infos (info);
260 if (!darwin_dyld_version_ok (info))
263 image_info_size = ptr_len * 3;
265 /* Read infos for each solib.
266 The first entry was rumored to be the executable itself, but this is not
267 true when a large number of shared libraries are used (table expanded ?).
268 We now check all entries, but discard executable images. */
269 for (i = 0; i < info->all_image.count; i++)
271 CORE_ADDR iinfo = info->all_image.info + i * image_info_size;
272 char buf[image_info_size];
275 struct mach_o_header_external hdr;
276 unsigned long hdr_val;
279 struct darwin_so_list *dnew;
281 struct cleanup *old_chain;
283 /* Read image info from inferior. */
284 if (target_read_memory (iinfo, buf, image_info_size))
287 load_addr = extract_typed_address (buf, ptr_type);
288 path_addr = extract_typed_address (buf + ptr_len, ptr_type);
290 /* Read Mach-O header from memory. */
291 if (target_read_memory (load_addr, (char *) &hdr, sizeof (hdr) - 4))
293 /* Discard wrong magic numbers. Shouldn't happen. */
294 hdr_val = extract_unsigned_integer
295 (hdr.magic, sizeof (hdr.magic), byte_order);
296 if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64)
298 /* Discard executable. Should happen only once. */
299 hdr_val = extract_unsigned_integer
300 (hdr.filetype, sizeof (hdr.filetype), byte_order);
301 if (hdr_val == BFD_MACH_O_MH_EXECUTE)
304 target_read_string (path_addr, &file_path,
305 SO_NAME_MAX_PATH_SIZE - 1, &errcode);
309 /* Create and fill the new so_list element. */
310 dnew = XZALLOC (struct darwin_so_list);
312 old_chain = make_cleanup (xfree, dnew);
314 new->lm_info = &dnew->li;
316 strncpy (new->so_name, file_path, SO_NAME_MAX_PATH_SIZE - 1);
317 new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
318 strcpy (new->so_original_name, new->so_name);
320 new->lm_info->lm_addr = load_addr;
328 discard_cleanups (old_chain);
334 /* Get the load address of the executable. We assume that the dyld info are
338 darwin_read_exec_load_addr (struct darwin_info *info)
340 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
341 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
342 int ptr_len = TYPE_LENGTH (ptr_type);
343 unsigned int image_info_size = ptr_len * 3;
346 /* Read infos for each solib. One of them should be the executable. */
347 for (i = 0; i < info->all_image.count; i++)
349 CORE_ADDR iinfo = info->all_image.info + i * image_info_size;
350 char buf[image_info_size];
352 struct mach_o_header_external hdr;
353 unsigned long hdr_val;
355 /* Read image info from inferior. */
356 if (target_read_memory (iinfo, buf, image_info_size))
359 load_addr = extract_typed_address (buf, ptr_type);
361 /* Read Mach-O header from memory. */
362 if (target_read_memory (load_addr, (char *) &hdr, sizeof (hdr) - 4))
364 /* Discard wrong magic numbers. Shouldn't happen. */
365 hdr_val = extract_unsigned_integer
366 (hdr.magic, sizeof (hdr.magic), byte_order);
367 if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64)
369 /* Check executable. */
370 hdr_val = extract_unsigned_integer
371 (hdr.filetype, sizeof (hdr.filetype), byte_order);
372 if (hdr_val == BFD_MACH_O_MH_EXECUTE)
379 /* Return 1 if PC lies in the dynamic symbol resolution code of the
383 darwin_in_dynsym_resolve_code (CORE_ADDR pc)
389 /* No special symbol handling. */
392 darwin_special_symbol_handling (void)
396 /* A wrapper for bfd_mach_o_fat_extract that handles reference
397 counting properly. This will either return NULL, or return a new
398 reference to a BFD. */
401 gdb_bfd_mach_o_fat_extract (bfd *abfd, bfd_format format,
402 const bfd_arch_info_type *arch)
404 bfd *result = bfd_mach_o_fat_extract (abfd, format, arch);
410 gdb_bfd_ref (result);
412 gdb_bfd_mark_parent (result, abfd);
417 /* Extract dyld_all_image_addr when the process was just created, assuming the
418 current PC is at the entry of the dynamic linker. */
421 darwin_solib_get_all_image_info_addr_at_init (struct darwin_info *info)
423 gdb_byte *interp_name;
424 CORE_ADDR load_addr = 0;
425 bfd *dyld_bfd = NULL;
426 struct cleanup *cleanup;
428 /* This method doesn't work with an attached process. */
429 if (current_inferior ()->attach_flag)
432 /* Find the program interpreter. */
433 interp_name = find_program_interpreter ();
437 cleanup = make_cleanup (null_cleanup, NULL);
439 /* Create a bfd for the interpreter. */
440 dyld_bfd = gdb_bfd_open (interp_name, gnutarget, -1);
445 make_cleanup_bfd_unref (dyld_bfd);
446 sub = gdb_bfd_mach_o_fat_extract (dyld_bfd, bfd_object,
447 gdbarch_bfd_arch_info (target_gdbarch ()));
451 make_cleanup_bfd_unref (sub);
458 do_cleanups (cleanup);
462 /* We find the dynamic linker's base address by examining
463 the current pc (which should point at the entry point for the
464 dynamic linker) and subtracting the offset of the entry point. */
465 load_addr = (regcache_read_pc (get_current_regcache ())
466 - bfd_get_start_address (dyld_bfd));
468 /* Now try to set a breakpoint in the dynamic linker. */
469 info->all_image_addr =
470 lookup_symbol_from_bfd (dyld_bfd, "_dyld_all_image_infos");
472 do_cleanups (cleanup);
474 if (info->all_image_addr == 0)
477 info->all_image_addr += load_addr;
480 /* Extract dyld_all_image_addr reading it from
481 TARGET_OBJECT_DARWIN_DYLD_INFO. */
484 darwin_solib_read_all_image_info_addr (struct darwin_info *info)
486 gdb_byte buf[8 + 8 + 4];
488 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
490 len = target_read (¤t_target, TARGET_OBJECT_DARWIN_DYLD_INFO, NULL,
491 buf, 0, sizeof (buf));
492 if (len != sizeof (buf))
495 info->all_image_addr = extract_unsigned_integer (buf, 8, byte_order);
498 /* Shared library startup support. See documentation in solib-svr4.c. */
501 darwin_solib_create_inferior_hook (int from_tty)
503 struct darwin_info *info = get_darwin_info ();
506 info->all_image_addr = 0;
508 darwin_solib_read_all_image_info_addr (info);
510 if (info->all_image_addr == 0)
511 darwin_solib_get_all_image_info_addr_at_init (info);
513 if (info->all_image_addr == 0)
516 darwin_load_image_infos (info);
518 if (!darwin_dyld_version_ok (info))
521 create_solib_event_breakpoint (target_gdbarch (), info->all_image.notifier);
523 /* Possible relocate the main executable (PIE). */
524 load_addr = darwin_read_exec_load_addr (info);
525 if (load_addr != 0 && symfile_objfile != NULL)
527 CORE_ADDR vmaddr = 0;
528 struct mach_o_data_struct *md = bfd_mach_o_get_data (exec_bfd);
531 /* Find the base address of the executable. */
532 for (i = 0; i < md->header.ncmds; i++)
534 struct bfd_mach_o_load_command *cmd = &md->commands[i];
536 if (cmd->type != BFD_MACH_O_LC_SEGMENT
537 && cmd->type != BFD_MACH_O_LC_SEGMENT_64)
539 if (cmd->command.segment.fileoff == 0
540 && cmd->command.segment.vmaddr != 0
541 && cmd->command.segment.filesize != 0)
543 vmaddr = cmd->command.segment.vmaddr;
549 if (vmaddr != load_addr)
550 objfile_rebase (symfile_objfile, load_addr - vmaddr);
555 darwin_clear_solib (void)
557 struct darwin_info *info = get_darwin_info ();
559 info->all_image_addr = 0;
560 info->all_image.version = 0;
564 darwin_free_so (struct so_list *so)
568 /* The section table is built from bfd sections using bfd VMAs.
569 Relocate these VMAs according to solib info. */
572 darwin_relocate_section_addresses (struct so_list *so,
573 struct target_section *sec)
575 sec->addr += so->lm_info->lm_addr;
576 sec->endaddr += so->lm_info->lm_addr;
578 /* Best effort to set addr_high/addr_low. This is used only by
579 'info sharedlibary'. */
580 if (so->addr_high == 0)
582 so->addr_low = sec->addr;
583 so->addr_high = sec->endaddr;
585 if (sec->endaddr > so->addr_high)
586 so->addr_high = sec->endaddr;
587 if (sec->addr < so->addr_low)
588 so->addr_low = sec->addr;
591 static struct symbol *
592 darwin_lookup_lib_symbol (const struct objfile *objfile,
594 const domain_enum domain)
600 darwin_bfd_open (char *pathname)
602 char *found_pathname;
607 /* Search for shared library file. */
608 found_pathname = solib_find (pathname, &found_file);
609 if (found_pathname == NULL)
610 perror_with_name (pathname);
612 /* Open bfd for shared library. */
613 abfd = solib_bfd_fopen (found_pathname, found_file);
615 res = gdb_bfd_mach_o_fat_extract (abfd, bfd_object,
616 gdbarch_bfd_arch_info (target_gdbarch ()));
619 make_cleanup_bfd_unref (abfd);
620 error (_("`%s': not a shared-library: %s"),
621 bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
624 gdb_bfd_unref (abfd);
628 struct target_so_ops darwin_so_ops;
630 /* -Wmissing-prototypes */
631 extern initialize_file_ftype _initialize_darwin_solib;
634 _initialize_darwin_solib (void)
636 solib_darwin_pspace_data
637 = register_program_space_data_with_cleanup (NULL,
638 darwin_pspace_data_cleanup);
640 darwin_so_ops.relocate_section_addresses = darwin_relocate_section_addresses;
641 darwin_so_ops.free_so = darwin_free_so;
642 darwin_so_ops.clear_solib = darwin_clear_solib;
643 darwin_so_ops.solib_create_inferior_hook = darwin_solib_create_inferior_hook;
644 darwin_so_ops.special_symbol_handling = darwin_special_symbol_handling;
645 darwin_so_ops.current_sos = darwin_current_sos;
646 darwin_so_ops.open_symbol_file_object = open_symbol_file_object;
647 darwin_so_ops.in_dynsym_resolve_code = darwin_in_dynsym_resolve_code;
648 darwin_so_ops.lookup_lib_global_symbol = darwin_lookup_lib_symbol;
649 darwin_so_ops.bfd_open = darwin_bfd_open;