1 /* Handle Darwin shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 2009-2015 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"
35 #include "solib-svr4.h"
37 #include "bfd-target.h"
42 #include "mach-o/external.h"
44 struct gdb_dyld_image_info
46 /* Base address (which corresponds to the Mach-O header). */
47 CORE_ADDR mach_header;
48 /* Image file path. */
50 /* st.m_time of image file. */
54 /* Content of inferior dyld_all_image_infos structure.
55 See /usr/include/mach-o/dyld_images.h for the documentation. */
56 struct gdb_dyld_all_image_infos
60 /* Number of images. */
62 /* Image description. */
64 /* Notifier (function called when a library is added or removed). */
68 /* Current all_image_infos version. */
69 #define DYLD_VERSION_MIN 1
70 #define DYLD_VERSION_MAX 14
72 /* Per PSPACE specific data. */
75 /* Address of structure dyld_all_image_infos in inferior. */
76 CORE_ADDR all_image_addr;
78 /* Gdb copy of dyld_all_info_infos. */
79 struct gdb_dyld_all_image_infos all_image;
82 /* Per-program-space data key. */
83 static const struct program_space_data *solib_darwin_pspace_data;
86 darwin_pspace_data_cleanup (struct program_space *pspace, void *arg)
91 /* Get the current darwin data. If none is found yet, add it now. This
92 function always returns a valid object. */
94 static struct darwin_info *
95 get_darwin_info (void)
97 struct darwin_info *info;
99 info = program_space_data (current_program_space, solib_darwin_pspace_data);
103 info = XCNEW (struct darwin_info);
104 set_program_space_data (current_program_space,
105 solib_darwin_pspace_data, info);
109 /* Return non-zero if the version in dyld_all_image is known. */
112 darwin_dyld_version_ok (const struct darwin_info *info)
114 return info->all_image.version >= DYLD_VERSION_MIN
115 && info->all_image.version <= DYLD_VERSION_MAX;
118 /* Read dyld_all_image from inferior. */
121 darwin_load_image_infos (struct darwin_info *info)
124 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
125 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
128 /* If the structure address is not known, don't continue. */
129 if (info->all_image_addr == 0)
132 /* The structure has 4 fields: version (4 bytes), count (4 bytes),
133 info (pointer) and notifier (pointer). */
134 len = 4 + 4 + 2 * ptr_type->length;
135 gdb_assert (len <= sizeof (buf));
136 memset (&info->all_image, 0, sizeof (info->all_image));
138 /* Read structure raw bytes from target. */
139 if (target_read_memory (info->all_image_addr, buf, len))
142 /* Extract the fields. */
143 info->all_image.version = extract_unsigned_integer (buf, 4, byte_order);
144 if (!darwin_dyld_version_ok (info))
147 info->all_image.count = extract_unsigned_integer (buf + 4, 4, byte_order);
148 info->all_image.info = extract_typed_address (buf + 8, ptr_type);
149 info->all_image.notifier = extract_typed_address
150 (buf + 8 + ptr_type->length, ptr_type);
153 /* Link map info to include in an allocated so_list entry. */
157 /* The target location of lm. */
161 struct darwin_so_list
165 /* Darwin specific data. */
169 /* Lookup the value for a specific symbol. */
172 lookup_symbol_from_bfd (bfd *abfd, char *symname)
175 asymbol **symbol_table;
176 unsigned int number_of_symbols;
178 CORE_ADDR symaddr = 0;
180 storage_needed = bfd_get_symtab_upper_bound (abfd);
182 if (storage_needed <= 0)
185 symbol_table = (asymbol **) xmalloc (storage_needed);
186 number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
188 for (i = 0; i < number_of_symbols; i++)
190 asymbol *sym = symbol_table[i];
192 if (strcmp (sym->name, symname) == 0
193 && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
195 /* BFD symbols are section relative. */
196 symaddr = sym->value + sym->section->vma;
200 xfree (symbol_table);
205 /* Return program interpreter string. */
208 find_program_interpreter (void)
212 /* If we have an exec_bfd, get the interpreter from the load commands. */
215 bfd_mach_o_load_command *cmd;
217 if (bfd_mach_o_lookup_command (exec_bfd,
218 BFD_MACH_O_LC_LOAD_DYLINKER, &cmd) == 1)
219 return cmd->command.dylinker.name_str;
222 /* If we didn't find it, read from memory.
227 /* Not used. I don't see how the main symbol file can be found: the
228 interpreter name is needed and it is known from the executable file.
229 Note that darwin-nat.c implements pid_to_exec_file. */
232 open_symbol_file_object (void *from_ttyp)
237 /* Build a list of currently loaded shared objects. See solib-svr4.c. */
239 static struct so_list *
240 darwin_current_sos (void)
242 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
243 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
244 int ptr_len = TYPE_LENGTH (ptr_type);
245 unsigned int image_info_size;
246 struct so_list *head = NULL;
247 struct so_list *tail = NULL;
249 struct darwin_info *info = get_darwin_info ();
251 /* Be sure image infos are loaded. */
252 darwin_load_image_infos (info);
254 if (!darwin_dyld_version_ok (info))
257 image_info_size = ptr_len * 3;
259 /* Read infos for each solib.
260 The first entry was rumored to be the executable itself, but this is not
261 true when a large number of shared libraries are used (table expanded ?).
262 We now check all entries, but discard executable images. */
263 for (i = 0; i < info->all_image.count; i++)
265 CORE_ADDR iinfo = info->all_image.info + i * image_info_size;
266 gdb_byte buf[image_info_size];
269 struct mach_o_header_external hdr;
270 unsigned long hdr_val;
273 struct darwin_so_list *dnew;
274 struct so_list *newobj;
275 struct cleanup *old_chain;
277 /* Read image info from inferior. */
278 if (target_read_memory (iinfo, buf, image_info_size))
281 load_addr = extract_typed_address (buf, ptr_type);
282 path_addr = extract_typed_address (buf + ptr_len, ptr_type);
284 /* Read Mach-O header from memory. */
285 if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4))
287 /* Discard wrong magic numbers. Shouldn't happen. */
288 hdr_val = extract_unsigned_integer
289 (hdr.magic, sizeof (hdr.magic), byte_order);
290 if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64)
292 /* Discard executable. Should happen only once. */
293 hdr_val = extract_unsigned_integer
294 (hdr.filetype, sizeof (hdr.filetype), byte_order);
295 if (hdr_val == BFD_MACH_O_MH_EXECUTE)
298 target_read_string (path_addr, &file_path,
299 SO_NAME_MAX_PATH_SIZE - 1, &errcode);
303 /* Create and fill the new so_list element. */
304 dnew = XCNEW (struct darwin_so_list);
306 old_chain = make_cleanup (xfree, dnew);
308 newobj->lm_info = &dnew->li;
310 strncpy (newobj->so_name, file_path, SO_NAME_MAX_PATH_SIZE - 1);
311 newobj->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
312 strcpy (newobj->so_original_name, newobj->so_name);
314 newobj->lm_info->lm_addr = load_addr;
322 discard_cleanups (old_chain);
328 /* Get the load address of the executable. We assume that the dyld info are
332 darwin_read_exec_load_addr (struct darwin_info *info)
334 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
335 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
336 int ptr_len = TYPE_LENGTH (ptr_type);
337 unsigned int image_info_size = ptr_len * 3;
340 /* Read infos for each solib. One of them should be the executable. */
341 for (i = 0; i < info->all_image.count; i++)
343 CORE_ADDR iinfo = info->all_image.info + i * image_info_size;
344 gdb_byte buf[image_info_size];
346 struct mach_o_header_external hdr;
347 unsigned long hdr_val;
349 /* Read image info from inferior. */
350 if (target_read_memory (iinfo, buf, image_info_size))
353 load_addr = extract_typed_address (buf, ptr_type);
355 /* Read Mach-O header from memory. */
356 if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4))
358 /* Discard wrong magic numbers. Shouldn't happen. */
359 hdr_val = extract_unsigned_integer
360 (hdr.magic, sizeof (hdr.magic), byte_order);
361 if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64)
363 /* Check executable. */
364 hdr_val = extract_unsigned_integer
365 (hdr.filetype, sizeof (hdr.filetype), byte_order);
366 if (hdr_val == BFD_MACH_O_MH_EXECUTE)
373 /* Return 1 if PC lies in the dynamic symbol resolution code of the
377 darwin_in_dynsym_resolve_code (CORE_ADDR pc)
383 /* No special symbol handling. */
386 darwin_special_symbol_handling (void)
390 /* A wrapper for bfd_mach_o_fat_extract that handles reference
391 counting properly. This will either return NULL, or return a new
392 reference to a BFD. */
395 gdb_bfd_mach_o_fat_extract (bfd *abfd, bfd_format format,
396 const bfd_arch_info_type *arch)
398 bfd *result = bfd_mach_o_fat_extract (abfd, format, arch);
404 gdb_bfd_ref (result);
406 gdb_bfd_mark_parent (result, abfd);
411 /* Extract dyld_all_image_addr when the process was just created, assuming the
412 current PC is at the entry of the dynamic linker. */
415 darwin_solib_get_all_image_info_addr_at_init (struct darwin_info *info)
418 CORE_ADDR load_addr = 0;
419 bfd *dyld_bfd = NULL;
420 struct cleanup *cleanup;
422 /* This method doesn't work with an attached process. */
423 if (current_inferior ()->attach_flag)
426 /* Find the program interpreter. */
427 interp_name = find_program_interpreter ();
431 cleanup = make_cleanup (null_cleanup, NULL);
433 /* Create a bfd for the interpreter. */
434 dyld_bfd = gdb_bfd_open (interp_name, gnutarget, -1);
439 make_cleanup_bfd_unref (dyld_bfd);
440 sub = gdb_bfd_mach_o_fat_extract (dyld_bfd, bfd_object,
441 gdbarch_bfd_arch_info (target_gdbarch ()));
445 make_cleanup_bfd_unref (sub);
452 do_cleanups (cleanup);
456 /* We find the dynamic linker's base address by examining
457 the current pc (which should point at the entry point for the
458 dynamic linker) and subtracting the offset of the entry point. */
459 load_addr = (regcache_read_pc (get_current_regcache ())
460 - bfd_get_start_address (dyld_bfd));
462 /* Now try to set a breakpoint in the dynamic linker. */
463 info->all_image_addr =
464 lookup_symbol_from_bfd (dyld_bfd, "_dyld_all_image_infos");
466 do_cleanups (cleanup);
468 if (info->all_image_addr == 0)
471 info->all_image_addr += load_addr;
474 /* Extract dyld_all_image_addr reading it from
475 TARGET_OBJECT_DARWIN_DYLD_INFO. */
478 darwin_solib_read_all_image_info_addr (struct darwin_info *info)
480 gdb_byte buf[8 + 8 + 4];
482 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
484 len = target_read (¤t_target, TARGET_OBJECT_DARWIN_DYLD_INFO, NULL,
485 buf, 0, sizeof (buf));
486 if (len != sizeof (buf))
489 info->all_image_addr = extract_unsigned_integer (buf, 8, byte_order);
492 /* Shared library startup support. See documentation in solib-svr4.c. */
495 darwin_solib_create_inferior_hook (int from_tty)
497 struct darwin_info *info = get_darwin_info ();
500 info->all_image_addr = 0;
502 darwin_solib_read_all_image_info_addr (info);
504 if (info->all_image_addr == 0)
505 darwin_solib_get_all_image_info_addr_at_init (info);
507 if (info->all_image_addr == 0)
510 darwin_load_image_infos (info);
512 if (!darwin_dyld_version_ok (info))
514 warning (_("unhandled dyld version (%d)"), info->all_image.version);
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)
526 /* Find the base address of the executable. */
527 vmaddr = bfd_mach_o_get_base_address (exec_bfd);
530 if (vmaddr != load_addr)
531 objfile_rebase (symfile_objfile, load_addr - vmaddr);
536 darwin_clear_solib (void)
538 struct darwin_info *info = get_darwin_info ();
540 info->all_image_addr = 0;
541 info->all_image.version = 0;
545 darwin_free_so (struct so_list *so)
549 /* The section table is built from bfd sections using bfd VMAs.
550 Relocate these VMAs according to solib info. */
553 darwin_relocate_section_addresses (struct so_list *so,
554 struct target_section *sec)
556 sec->addr += so->lm_info->lm_addr;
557 sec->endaddr += so->lm_info->lm_addr;
559 /* Best effort to set addr_high/addr_low. This is used only by
560 'info sharedlibary'. */
561 if (so->addr_high == 0)
563 so->addr_low = sec->addr;
564 so->addr_high = sec->endaddr;
566 if (sec->endaddr > so->addr_high)
567 so->addr_high = sec->endaddr;
568 if (sec->addr < so->addr_low)
569 so->addr_low = sec->addr;
572 static struct symbol *
573 darwin_lookup_lib_symbol (struct objfile *objfile,
575 const domain_enum domain)
581 darwin_bfd_open (char *pathname)
583 char *found_pathname;
588 /* Search for shared library file. */
589 found_pathname = solib_find (pathname, &found_file);
590 if (found_pathname == NULL)
591 perror_with_name (pathname);
593 /* Open bfd for shared library. */
594 abfd = solib_bfd_fopen (found_pathname, found_file);
596 res = gdb_bfd_mach_o_fat_extract (abfd, bfd_object,
597 gdbarch_bfd_arch_info (target_gdbarch ()));
600 make_cleanup_bfd_unref (abfd);
601 error (_("`%s': not a shared-library: %s"),
602 bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
605 /* The current filename for fat-binary BFDs is a name generated
606 by BFD, usually a string containing the name of the architecture.
607 Reset its value to the actual filename. */
608 xfree (bfd_get_filename (res));
609 res->filename = xstrdup (pathname);
611 gdb_bfd_unref (abfd);
615 struct target_so_ops darwin_so_ops;
617 /* -Wmissing-prototypes */
618 extern initialize_file_ftype _initialize_darwin_solib;
621 _initialize_darwin_solib (void)
623 solib_darwin_pspace_data
624 = register_program_space_data_with_cleanup (NULL,
625 darwin_pspace_data_cleanup);
627 darwin_so_ops.relocate_section_addresses = darwin_relocate_section_addresses;
628 darwin_so_ops.free_so = darwin_free_so;
629 darwin_so_ops.clear_solib = darwin_clear_solib;
630 darwin_so_ops.solib_create_inferior_hook = darwin_solib_create_inferior_hook;
631 darwin_so_ops.special_symbol_handling = darwin_special_symbol_handling;
632 darwin_so_ops.current_sos = darwin_current_sos;
633 darwin_so_ops.open_symbol_file_object = open_symbol_file_object;
634 darwin_so_ops.in_dynsym_resolve_code = darwin_in_dynsym_resolve_code;
635 darwin_so_ops.lookup_lib_global_symbol = darwin_lookup_lib_symbol;
636 darwin_so_ops.bfd_open = darwin_bfd_open;
637 darwin_so_ops.validate = default_solib_validate;