1 /* Handle Darwin shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 2009-2017 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
= (struct darwin_info
*) program_space_data (current_program_space
,
100 solib_darwin_pspace_data
);
104 info
= XCNEW (struct darwin_info
);
105 set_program_space_data (current_program_space
,
106 solib_darwin_pspace_data
, info
);
110 /* Return non-zero if the version in dyld_all_image is known. */
113 darwin_dyld_version_ok (const struct darwin_info
*info
)
115 return info
->all_image
.version
>= DYLD_VERSION_MIN
116 && info
->all_image
.version
<= DYLD_VERSION_MAX
;
119 /* Read dyld_all_image from inferior. */
122 darwin_load_image_infos (struct darwin_info
*info
)
125 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
126 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
129 /* If the structure address is not known, don't continue. */
130 if (info
->all_image_addr
== 0)
133 /* The structure has 4 fields: version (4 bytes), count (4 bytes),
134 info (pointer) and notifier (pointer). */
135 len
= 4 + 4 + 2 * TYPE_LENGTH (ptr_type
);
136 gdb_assert (len
<= sizeof (buf
));
137 memset (&info
->all_image
, 0, sizeof (info
->all_image
));
139 /* Read structure raw bytes from target. */
140 if (target_read_memory (info
->all_image_addr
, buf
, len
))
143 /* Extract the fields. */
144 info
->all_image
.version
= extract_unsigned_integer (buf
, 4, byte_order
);
145 if (!darwin_dyld_version_ok (info
))
148 info
->all_image
.count
= extract_unsigned_integer (buf
+ 4, 4, byte_order
);
149 info
->all_image
.info
= extract_typed_address (buf
+ 8, ptr_type
);
150 info
->all_image
.notifier
= extract_typed_address
151 (buf
+ 8 + TYPE_LENGTH (ptr_type
), ptr_type
);
154 /* Link map info to include in an allocated so_list entry. */
158 /* The target location of lm. */
162 struct darwin_so_list
166 /* Darwin specific data. */
170 /* Lookup the value for a specific symbol. */
173 lookup_symbol_from_bfd (bfd
*abfd
, char *symname
)
176 asymbol
**symbol_table
;
177 unsigned int number_of_symbols
;
179 CORE_ADDR symaddr
= 0;
181 storage_needed
= bfd_get_symtab_upper_bound (abfd
);
183 if (storage_needed
<= 0)
186 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
187 number_of_symbols
= bfd_canonicalize_symtab (abfd
, symbol_table
);
189 for (i
= 0; i
< number_of_symbols
; i
++)
191 asymbol
*sym
= symbol_table
[i
];
193 if (strcmp (sym
->name
, symname
) == 0
194 && (sym
->section
->flags
& (SEC_CODE
| SEC_DATA
)) != 0)
196 /* BFD symbols are section relative. */
197 symaddr
= sym
->value
+ sym
->section
->vma
;
201 xfree (symbol_table
);
206 /* Return program interpreter string. */
209 find_program_interpreter (void)
213 /* If we have an exec_bfd, get the interpreter from the load commands. */
216 bfd_mach_o_load_command
*cmd
;
218 if (bfd_mach_o_lookup_command (exec_bfd
,
219 BFD_MACH_O_LC_LOAD_DYLINKER
, &cmd
) == 1)
220 return cmd
->command
.dylinker
.name_str
;
223 /* If we didn't find it, read from memory.
228 /* Not used. I don't see how the main symbol file can be found: the
229 interpreter name is needed and it is known from the executable file.
230 Note that darwin-nat.c implements pid_to_exec_file. */
233 open_symbol_file_object (void *from_ttyp
)
238 /* Build a list of currently loaded shared objects. See solib-svr4.c. */
240 static struct so_list
*
241 darwin_current_sos (void)
243 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
244 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
245 int ptr_len
= TYPE_LENGTH (ptr_type
);
246 unsigned int image_info_size
;
247 struct so_list
*head
= NULL
;
248 struct so_list
*tail
= NULL
;
250 struct darwin_info
*info
= get_darwin_info ();
252 /* Be sure image infos are loaded. */
253 darwin_load_image_infos (info
);
255 if (!darwin_dyld_version_ok (info
))
258 image_info_size
= ptr_len
* 3;
260 /* Read infos for each solib.
261 The first entry was rumored to be the executable itself, but this is not
262 true when a large number of shared libraries are used (table expanded ?).
263 We now check all entries, but discard executable images. */
264 for (i
= 0; i
< info
->all_image
.count
; i
++)
266 CORE_ADDR iinfo
= info
->all_image
.info
+ i
* image_info_size
;
267 gdb_byte buf
[image_info_size
];
270 struct mach_o_header_external hdr
;
271 unsigned long hdr_val
;
274 struct darwin_so_list
*dnew
;
275 struct so_list
*newobj
;
276 struct cleanup
*old_chain
;
278 /* Read image info from inferior. */
279 if (target_read_memory (iinfo
, buf
, image_info_size
))
282 load_addr
= extract_typed_address (buf
, ptr_type
);
283 path_addr
= extract_typed_address (buf
+ ptr_len
, ptr_type
);
285 /* Read Mach-O header from memory. */
286 if (target_read_memory (load_addr
, (gdb_byte
*) &hdr
, sizeof (hdr
) - 4))
288 /* Discard wrong magic numbers. Shouldn't happen. */
289 hdr_val
= extract_unsigned_integer
290 (hdr
.magic
, sizeof (hdr
.magic
), byte_order
);
291 if (hdr_val
!= BFD_MACH_O_MH_MAGIC
&& hdr_val
!= BFD_MACH_O_MH_MAGIC_64
)
293 /* Discard executable. Should happen only once. */
294 hdr_val
= extract_unsigned_integer
295 (hdr
.filetype
, sizeof (hdr
.filetype
), byte_order
);
296 if (hdr_val
== BFD_MACH_O_MH_EXECUTE
)
299 target_read_string (path_addr
, &file_path
,
300 SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
304 /* Create and fill the new so_list element. */
305 dnew
= XCNEW (struct darwin_so_list
);
307 old_chain
= make_cleanup (xfree
, dnew
);
309 newobj
->lm_info
= &dnew
->li
;
311 strncpy (newobj
->so_name
, file_path
, SO_NAME_MAX_PATH_SIZE
- 1);
312 newobj
->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
313 strcpy (newobj
->so_original_name
, newobj
->so_name
);
315 newobj
->lm_info
->lm_addr
= load_addr
;
323 discard_cleanups (old_chain
);
329 /* Check LOAD_ADDR points to a Mach-O executable header. Return LOAD_ADDR
330 in case of success, 0 in case of failure. */
333 darwin_validate_exec_header (CORE_ADDR load_addr
)
335 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
336 struct mach_o_header_external hdr
;
337 unsigned long hdr_val
;
339 /* Read Mach-O header from memory. */
340 if (target_read_memory (load_addr
, (gdb_byte
*) &hdr
, sizeof (hdr
) - 4))
343 /* Discard wrong magic numbers. Shouldn't happen. */
344 hdr_val
= extract_unsigned_integer
345 (hdr
.magic
, sizeof (hdr
.magic
), byte_order
);
346 if (hdr_val
!= BFD_MACH_O_MH_MAGIC
&& hdr_val
!= BFD_MACH_O_MH_MAGIC_64
)
349 /* Check executable. */
350 hdr_val
= extract_unsigned_integer
351 (hdr
.filetype
, sizeof (hdr
.filetype
), byte_order
);
352 if (hdr_val
== BFD_MACH_O_MH_EXECUTE
)
358 /* Get the load address of the executable using dyld list of images.
359 We assume that the dyld info are correct (which is wrong if the target
360 is stopped at the first instruction). */
363 darwin_read_exec_load_addr_from_dyld (struct darwin_info
*info
)
365 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
366 int ptr_len
= TYPE_LENGTH (ptr_type
);
367 unsigned int image_info_size
= ptr_len
* 3;
370 /* Read infos for each solib. One of them should be the executable. */
371 for (i
= 0; i
< info
->all_image
.count
; i
++)
373 CORE_ADDR iinfo
= info
->all_image
.info
+ i
* image_info_size
;
374 gdb_byte buf
[image_info_size
];
377 /* Read image info from inferior. */
378 if (target_read_memory (iinfo
, buf
, image_info_size
))
381 load_addr
= extract_typed_address (buf
, ptr_type
);
382 if (darwin_validate_exec_header (load_addr
) == load_addr
)
389 /* Get the load address of the executable when the PC is at the dyld
390 entry point using parameter passed by the kernel (at SP). */
393 darwin_read_exec_load_addr_at_init (struct darwin_info
*info
)
395 struct gdbarch
*gdbarch
= target_gdbarch ();
396 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
397 int addr_size
= gdbarch_addr_bit (gdbarch
) / 8;
398 ULONGEST load_ptr_addr
;
403 if (regcache_cooked_read_unsigned (get_current_regcache (),
404 gdbarch_sp_regnum (gdbarch
),
405 &load_ptr_addr
) != REG_VALID
)
408 /* Read value at SP (image load address). */
409 if (target_read_memory (load_ptr_addr
, buf
, addr_size
))
412 load_addr
= extract_unsigned_integer (buf
, addr_size
, byte_order
);
414 return darwin_validate_exec_header (load_addr
);
417 /* Return 1 if PC lies in the dynamic symbol resolution code of the
421 darwin_in_dynsym_resolve_code (CORE_ADDR pc
)
426 /* A wrapper for bfd_mach_o_fat_extract that handles reference
427 counting properly. This will either return NULL, or return a new
428 reference to a BFD. */
430 static gdb_bfd_ref_ptr
431 gdb_bfd_mach_o_fat_extract (bfd
*abfd
, bfd_format format
,
432 const bfd_arch_info_type
*arch
)
434 bfd
*result
= bfd_mach_o_fat_extract (abfd
, format
, arch
);
440 gdb_bfd_ref (result
);
442 gdb_bfd_mark_parent (result
, abfd
);
444 return gdb_bfd_ref_ptr (result
);
447 /* Extract dyld_all_image_addr when the process was just created, assuming the
448 current PC is at the entry of the dynamic linker. */
451 darwin_solib_get_all_image_info_addr_at_init (struct darwin_info
*info
)
454 CORE_ADDR load_addr
= 0;
456 /* This method doesn't work with an attached process. */
457 if (current_inferior ()->attach_flag
)
460 /* Find the program interpreter. */
461 interp_name
= find_program_interpreter ();
465 /* Create a bfd for the interpreter. */
466 gdb_bfd_ref_ptr
dyld_bfd (gdb_bfd_open (interp_name
, gnutarget
, -1));
467 if (dyld_bfd
!= NULL
)
470 (gdb_bfd_mach_o_fat_extract (dyld_bfd
.get (), bfd_object
,
471 gdbarch_bfd_arch_info (target_gdbarch ())));
477 if (dyld_bfd
== NULL
)
480 /* We find the dynamic linker's base address by examining
481 the current pc (which should point at the entry point for the
482 dynamic linker) and subtracting the offset of the entry point. */
483 load_addr
= (regcache_read_pc (get_current_regcache ())
484 - bfd_get_start_address (dyld_bfd
.get ()));
486 /* Now try to set a breakpoint in the dynamic linker. */
487 info
->all_image_addr
=
488 lookup_symbol_from_bfd (dyld_bfd
.get (), "_dyld_all_image_infos");
490 if (info
->all_image_addr
== 0)
493 info
->all_image_addr
+= load_addr
;
496 /* Extract dyld_all_image_addr reading it from
497 TARGET_OBJECT_DARWIN_DYLD_INFO. */
500 darwin_solib_read_all_image_info_addr (struct darwin_info
*info
)
504 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
507 if (TYPE_LENGTH (ptr_type
) > sizeof (buf
))
510 len
= target_read (¤t_target
, TARGET_OBJECT_DARWIN_DYLD_INFO
, NULL
,
511 buf
, 0, TYPE_LENGTH (ptr_type
));
515 /* The use of BIG endian is intended, as BUF is a raw stream of bytes. This
516 makes the support of remote protocol easier. */
517 info
->all_image_addr
= extract_unsigned_integer (buf
, len
, BFD_ENDIAN_BIG
);
520 /* Shared library startup support. See documentation in solib-svr4.c. */
523 darwin_solib_create_inferior_hook (int from_tty
)
525 struct darwin_info
*info
= get_darwin_info ();
528 info
->all_image_addr
= 0;
530 darwin_solib_read_all_image_info_addr (info
);
532 if (info
->all_image_addr
== 0)
533 darwin_solib_get_all_image_info_addr_at_init (info
);
535 if (info
->all_image_addr
== 0)
538 darwin_load_image_infos (info
);
540 if (!darwin_dyld_version_ok (info
))
542 warning (_("unhandled dyld version (%d)"), info
->all_image
.version
);
546 /* Add the breakpoint which is hit by dyld when the list of solib is
548 create_solib_event_breakpoint (target_gdbarch (), info
->all_image
.notifier
);
550 if (info
->all_image
.count
!= 0)
552 /* Possible relocate the main executable (PIE). */
553 load_addr
= darwin_read_exec_load_addr_from_dyld (info
);
558 Do not break on the notifier if dyld is not initialized (deduced from
559 count == 0). In that case, dyld hasn't relocated itself and the
560 notifier may point to a wrong address. */
562 load_addr
= darwin_read_exec_load_addr_at_init (info
);
565 if (load_addr
!= 0 && symfile_objfile
!= NULL
)
569 /* Find the base address of the executable. */
570 vmaddr
= bfd_mach_o_get_base_address (exec_bfd
);
573 if (vmaddr
!= load_addr
)
574 objfile_rebase (symfile_objfile
, load_addr
- vmaddr
);
579 darwin_clear_solib (void)
581 struct darwin_info
*info
= get_darwin_info ();
583 info
->all_image_addr
= 0;
584 info
->all_image
.version
= 0;
588 darwin_free_so (struct so_list
*so
)
592 /* The section table is built from bfd sections using bfd VMAs.
593 Relocate these VMAs according to solib info. */
596 darwin_relocate_section_addresses (struct so_list
*so
,
597 struct target_section
*sec
)
599 sec
->addr
+= so
->lm_info
->lm_addr
;
600 sec
->endaddr
+= so
->lm_info
->lm_addr
;
602 /* Best effort to set addr_high/addr_low. This is used only by
603 'info sharedlibary'. */
604 if (so
->addr_high
== 0)
606 so
->addr_low
= sec
->addr
;
607 so
->addr_high
= sec
->endaddr
;
609 if (sec
->endaddr
> so
->addr_high
)
610 so
->addr_high
= sec
->endaddr
;
611 if (sec
->addr
< so
->addr_low
)
612 so
->addr_low
= sec
->addr
;
615 static struct block_symbol
616 darwin_lookup_lib_symbol (struct objfile
*objfile
,
618 const domain_enum domain
)
620 return (struct block_symbol
) {NULL
, NULL
};
623 static gdb_bfd_ref_ptr
624 darwin_bfd_open (char *pathname
)
626 char *found_pathname
;
629 /* Search for shared library file. */
630 found_pathname
= solib_find (pathname
, &found_file
);
631 if (found_pathname
== NULL
)
632 perror_with_name (pathname
);
634 /* Open bfd for shared library. */
635 gdb_bfd_ref_ptr
abfd (solib_bfd_fopen (found_pathname
, found_file
));
638 (gdb_bfd_mach_o_fat_extract (abfd
.get (), bfd_object
,
639 gdbarch_bfd_arch_info (target_gdbarch ())));
641 error (_("`%s': not a shared-library: %s"),
642 bfd_get_filename (abfd
.get ()), bfd_errmsg (bfd_get_error ()));
644 /* The current filename for fat-binary BFDs is a name generated
645 by BFD, usually a string containing the name of the architecture.
646 Reset its value to the actual filename. */
647 xfree (bfd_get_filename (res
.get ()));
648 res
->filename
= xstrdup (pathname
);
653 struct target_so_ops darwin_so_ops
;
655 /* -Wmissing-prototypes */
656 extern initialize_file_ftype _initialize_darwin_solib
;
659 _initialize_darwin_solib (void)
661 solib_darwin_pspace_data
662 = register_program_space_data_with_cleanup (NULL
,
663 darwin_pspace_data_cleanup
);
665 darwin_so_ops
.relocate_section_addresses
= darwin_relocate_section_addresses
;
666 darwin_so_ops
.free_so
= darwin_free_so
;
667 darwin_so_ops
.clear_solib
= darwin_clear_solib
;
668 darwin_so_ops
.solib_create_inferior_hook
= darwin_solib_create_inferior_hook
;
669 darwin_so_ops
.current_sos
= darwin_current_sos
;
670 darwin_so_ops
.open_symbol_file_object
= open_symbol_file_object
;
671 darwin_so_ops
.in_dynsym_resolve_code
= darwin_in_dynsym_resolve_code
;
672 darwin_so_ops
.lookup_lib_global_symbol
= darwin_lookup_lib_symbol
;
673 darwin_so_ops
.bfd_open
= darwin_bfd_open
;