1 /* Handle Darwin shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 2009-2018 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 15
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. */
156 struct lm_info_darwin
: public lm_info_base
158 /* The target location of lm. */
159 CORE_ADDR lm_addr
= 0;
162 /* Lookup the value for a specific symbol. */
165 lookup_symbol_from_bfd (bfd
*abfd
, const char *symname
)
168 asymbol
**symbol_table
;
169 unsigned int number_of_symbols
;
171 CORE_ADDR symaddr
= 0;
173 storage_needed
= bfd_get_symtab_upper_bound (abfd
);
175 if (storage_needed
<= 0)
178 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
179 number_of_symbols
= bfd_canonicalize_symtab (abfd
, symbol_table
);
181 for (i
= 0; i
< number_of_symbols
; i
++)
183 asymbol
*sym
= symbol_table
[i
];
185 if (strcmp (sym
->name
, symname
) == 0
186 && (sym
->section
->flags
& (SEC_CODE
| SEC_DATA
)) != 0)
188 /* BFD symbols are section relative. */
189 symaddr
= sym
->value
+ sym
->section
->vma
;
193 xfree (symbol_table
);
198 /* Return program interpreter string. */
201 find_program_interpreter (void)
205 /* If we have an exec_bfd, get the interpreter from the load commands. */
208 bfd_mach_o_load_command
*cmd
;
210 if (bfd_mach_o_lookup_command (exec_bfd
,
211 BFD_MACH_O_LC_LOAD_DYLINKER
, &cmd
) == 1)
212 return cmd
->command
.dylinker
.name_str
;
215 /* If we didn't find it, read from memory.
220 /* Not used. I don't see how the main symbol file can be found: the
221 interpreter name is needed and it is known from the executable file.
222 Note that darwin-nat.c implements pid_to_exec_file. */
225 open_symbol_file_object (int from_tty
)
230 /* Build a list of currently loaded shared objects. See solib-svr4.c. */
232 static struct so_list
*
233 darwin_current_sos (void)
235 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
236 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
237 int ptr_len
= TYPE_LENGTH (ptr_type
);
238 unsigned int image_info_size
;
239 struct so_list
*head
= NULL
;
240 struct so_list
*tail
= NULL
;
242 struct darwin_info
*info
= get_darwin_info ();
244 /* Be sure image infos are loaded. */
245 darwin_load_image_infos (info
);
247 if (!darwin_dyld_version_ok (info
))
250 image_info_size
= ptr_len
* 3;
252 /* Read infos for each solib.
253 The first entry was rumored to be the executable itself, but this is not
254 true when a large number of shared libraries are used (table expanded ?).
255 We now check all entries, but discard executable images. */
256 for (i
= 0; i
< info
->all_image
.count
; i
++)
258 CORE_ADDR iinfo
= info
->all_image
.info
+ i
* image_info_size
;
259 gdb_byte buf
[image_info_size
];
262 struct mach_o_header_external hdr
;
263 unsigned long hdr_val
;
264 gdb::unique_xmalloc_ptr
<char> file_path
;
266 struct so_list
*newobj
;
267 struct cleanup
*old_chain
;
269 /* Read image info from inferior. */
270 if (target_read_memory (iinfo
, buf
, image_info_size
))
273 load_addr
= extract_typed_address (buf
, ptr_type
);
274 path_addr
= extract_typed_address (buf
+ ptr_len
, ptr_type
);
276 /* Read Mach-O header from memory. */
277 if (target_read_memory (load_addr
, (gdb_byte
*) &hdr
, sizeof (hdr
) - 4))
279 /* Discard wrong magic numbers. Shouldn't happen. */
280 hdr_val
= extract_unsigned_integer
281 (hdr
.magic
, sizeof (hdr
.magic
), byte_order
);
282 if (hdr_val
!= BFD_MACH_O_MH_MAGIC
&& hdr_val
!= BFD_MACH_O_MH_MAGIC_64
)
284 /* Discard executable. Should happen only once. */
285 hdr_val
= extract_unsigned_integer
286 (hdr
.filetype
, sizeof (hdr
.filetype
), byte_order
);
287 if (hdr_val
== BFD_MACH_O_MH_EXECUTE
)
290 target_read_string (path_addr
, &file_path
,
291 SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
295 /* Create and fill the new so_list element. */
296 newobj
= XCNEW (struct so_list
);
297 old_chain
= make_cleanup (xfree
, newobj
);
299 lm_info_darwin
*li
= new lm_info_darwin
;
300 newobj
->lm_info
= li
;
302 strncpy (newobj
->so_name
, file_path
.get (), SO_NAME_MAX_PATH_SIZE
- 1);
303 newobj
->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
304 strcpy (newobj
->so_original_name
, newobj
->so_name
);
305 li
->lm_addr
= load_addr
;
313 discard_cleanups (old_chain
);
319 /* Check LOAD_ADDR points to a Mach-O executable header. Return LOAD_ADDR
320 in case of success, 0 in case of failure. */
323 darwin_validate_exec_header (CORE_ADDR load_addr
)
325 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
326 struct mach_o_header_external hdr
;
327 unsigned long hdr_val
;
329 /* Read Mach-O header from memory. */
330 if (target_read_memory (load_addr
, (gdb_byte
*) &hdr
, sizeof (hdr
) - 4))
333 /* Discard wrong magic numbers. Shouldn't happen. */
334 hdr_val
= extract_unsigned_integer
335 (hdr
.magic
, sizeof (hdr
.magic
), byte_order
);
336 if (hdr_val
!= BFD_MACH_O_MH_MAGIC
&& hdr_val
!= BFD_MACH_O_MH_MAGIC_64
)
339 /* Check executable. */
340 hdr_val
= extract_unsigned_integer
341 (hdr
.filetype
, sizeof (hdr
.filetype
), byte_order
);
342 if (hdr_val
== BFD_MACH_O_MH_EXECUTE
)
348 /* Get the load address of the executable using dyld list of images.
349 We assume that the dyld info are correct (which is wrong if the target
350 is stopped at the first instruction). */
353 darwin_read_exec_load_addr_from_dyld (struct darwin_info
*info
)
355 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
356 int ptr_len
= TYPE_LENGTH (ptr_type
);
357 unsigned int image_info_size
= ptr_len
* 3;
360 /* Read infos for each solib. One of them should be the executable. */
361 for (i
= 0; i
< info
->all_image
.count
; i
++)
363 CORE_ADDR iinfo
= info
->all_image
.info
+ i
* image_info_size
;
364 gdb_byte buf
[image_info_size
];
367 /* Read image info from inferior. */
368 if (target_read_memory (iinfo
, buf
, image_info_size
))
371 load_addr
= extract_typed_address (buf
, ptr_type
);
372 if (darwin_validate_exec_header (load_addr
) == load_addr
)
379 /* Get the load address of the executable when the PC is at the dyld
380 entry point using parameter passed by the kernel (at SP). */
383 darwin_read_exec_load_addr_at_init (struct darwin_info
*info
)
385 struct gdbarch
*gdbarch
= target_gdbarch ();
386 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
387 int addr_size
= gdbarch_addr_bit (gdbarch
) / 8;
388 ULONGEST load_ptr_addr
;
393 if (regcache_cooked_read_unsigned (get_current_regcache (),
394 gdbarch_sp_regnum (gdbarch
),
395 &load_ptr_addr
) != REG_VALID
)
398 /* Read value at SP (image load address). */
399 if (target_read_memory (load_ptr_addr
, buf
, addr_size
))
402 load_addr
= extract_unsigned_integer (buf
, addr_size
, byte_order
);
404 return darwin_validate_exec_header (load_addr
);
407 /* Return 1 if PC lies in the dynamic symbol resolution code of the
411 darwin_in_dynsym_resolve_code (CORE_ADDR pc
)
416 /* A wrapper for bfd_mach_o_fat_extract that handles reference
417 counting properly. This will either return NULL, or return a new
418 reference to a BFD. */
420 static gdb_bfd_ref_ptr
421 gdb_bfd_mach_o_fat_extract (bfd
*abfd
, bfd_format format
,
422 const bfd_arch_info_type
*arch
)
424 bfd
*result
= bfd_mach_o_fat_extract (abfd
, format
, arch
);
430 gdb_bfd_ref (result
);
432 gdb_bfd_mark_parent (result
, abfd
);
434 return gdb_bfd_ref_ptr (result
);
437 /* Extract dyld_all_image_addr when the process was just created, assuming the
438 current PC is at the entry of the dynamic linker. */
441 darwin_solib_get_all_image_info_addr_at_init (struct darwin_info
*info
)
444 CORE_ADDR load_addr
= 0;
446 /* This method doesn't work with an attached process. */
447 if (current_inferior ()->attach_flag
)
450 /* Find the program interpreter. */
451 interp_name
= find_program_interpreter ();
455 /* Create a bfd for the interpreter. */
456 gdb_bfd_ref_ptr
dyld_bfd (gdb_bfd_open (interp_name
, gnutarget
, -1));
457 if (dyld_bfd
!= NULL
)
460 (gdb_bfd_mach_o_fat_extract (dyld_bfd
.get (), bfd_object
,
461 gdbarch_bfd_arch_info (target_gdbarch ())));
467 if (dyld_bfd
== NULL
)
470 /* We find the dynamic linker's base address by examining
471 the current pc (which should point at the entry point for the
472 dynamic linker) and subtracting the offset of the entry point. */
473 load_addr
= (regcache_read_pc (get_current_regcache ())
474 - bfd_get_start_address (dyld_bfd
.get ()));
476 /* Now try to set a breakpoint in the dynamic linker. */
477 info
->all_image_addr
=
478 lookup_symbol_from_bfd (dyld_bfd
.get (), "_dyld_all_image_infos");
480 if (info
->all_image_addr
== 0)
483 info
->all_image_addr
+= load_addr
;
486 /* Extract dyld_all_image_addr reading it from
487 TARGET_OBJECT_DARWIN_DYLD_INFO. */
490 darwin_solib_read_all_image_info_addr (struct darwin_info
*info
)
494 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
497 if (TYPE_LENGTH (ptr_type
) > sizeof (buf
))
500 len
= target_read (target_stack
, TARGET_OBJECT_DARWIN_DYLD_INFO
, NULL
,
501 buf
, 0, TYPE_LENGTH (ptr_type
));
505 /* The use of BIG endian is intended, as BUF is a raw stream of bytes. This
506 makes the support of remote protocol easier. */
507 info
->all_image_addr
= extract_unsigned_integer (buf
, len
, BFD_ENDIAN_BIG
);
510 /* Shared library startup support. See documentation in solib-svr4.c. */
513 darwin_solib_create_inferior_hook (int from_tty
)
515 struct darwin_info
*info
= get_darwin_info ();
518 info
->all_image_addr
= 0;
520 darwin_solib_read_all_image_info_addr (info
);
522 if (info
->all_image_addr
== 0)
523 darwin_solib_get_all_image_info_addr_at_init (info
);
525 if (info
->all_image_addr
== 0)
528 darwin_load_image_infos (info
);
530 if (!darwin_dyld_version_ok (info
))
532 warning (_("unhandled dyld version (%d)"), info
->all_image
.version
);
536 /* Add the breakpoint which is hit by dyld when the list of solib is
538 create_solib_event_breakpoint (target_gdbarch (), info
->all_image
.notifier
);
540 if (info
->all_image
.count
!= 0)
542 /* Possible relocate the main executable (PIE). */
543 load_addr
= darwin_read_exec_load_addr_from_dyld (info
);
548 Do not break on the notifier if dyld is not initialized (deduced from
549 count == 0). In that case, dyld hasn't relocated itself and the
550 notifier may point to a wrong address. */
552 load_addr
= darwin_read_exec_load_addr_at_init (info
);
555 if (load_addr
!= 0 && symfile_objfile
!= NULL
)
559 /* Find the base address of the executable. */
560 vmaddr
= bfd_mach_o_get_base_address (exec_bfd
);
563 if (vmaddr
!= load_addr
)
564 objfile_rebase (symfile_objfile
, load_addr
- vmaddr
);
569 darwin_clear_solib (void)
571 struct darwin_info
*info
= get_darwin_info ();
573 info
->all_image_addr
= 0;
574 info
->all_image
.version
= 0;
578 darwin_free_so (struct so_list
*so
)
580 lm_info_darwin
*li
= (lm_info_darwin
*) so
->lm_info
;
585 /* The section table is built from bfd sections using bfd VMAs.
586 Relocate these VMAs according to solib info. */
589 darwin_relocate_section_addresses (struct so_list
*so
,
590 struct target_section
*sec
)
592 lm_info_darwin
*li
= (lm_info_darwin
*) so
->lm_info
;
594 sec
->addr
+= li
->lm_addr
;
595 sec
->endaddr
+= li
->lm_addr
;
597 /* Best effort to set addr_high/addr_low. This is used only by
598 'info sharedlibary'. */
599 if (so
->addr_high
== 0)
601 so
->addr_low
= sec
->addr
;
602 so
->addr_high
= sec
->endaddr
;
604 if (sec
->endaddr
> so
->addr_high
)
605 so
->addr_high
= sec
->endaddr
;
606 if (sec
->addr
< so
->addr_low
)
607 so
->addr_low
= sec
->addr
;
610 static struct block_symbol
611 darwin_lookup_lib_symbol (struct objfile
*objfile
,
613 const domain_enum domain
)
615 return (struct block_symbol
) {NULL
, NULL
};
618 static gdb_bfd_ref_ptr
619 darwin_bfd_open (const char *pathname
)
623 /* Search for shared library file. */
624 gdb::unique_xmalloc_ptr
<char> found_pathname
625 = solib_find (pathname
, &found_file
);
626 if (found_pathname
== NULL
)
627 perror_with_name (pathname
);
629 /* Open bfd for shared library. */
630 gdb_bfd_ref_ptr
abfd (solib_bfd_fopen (found_pathname
.get (), found_file
));
633 (gdb_bfd_mach_o_fat_extract (abfd
.get (), bfd_object
,
634 gdbarch_bfd_arch_info (target_gdbarch ())));
636 error (_("`%s': not a shared-library: %s"),
637 bfd_get_filename (abfd
.get ()), bfd_errmsg (bfd_get_error ()));
639 /* The current filename for fat-binary BFDs is a name generated
640 by BFD, usually a string containing the name of the architecture.
641 Reset its value to the actual filename. */
642 xfree (bfd_get_filename (res
.get ()));
643 res
->filename
= xstrdup (pathname
);
648 struct target_so_ops darwin_so_ops
;
651 _initialize_darwin_solib (void)
653 solib_darwin_pspace_data
654 = register_program_space_data_with_cleanup (NULL
,
655 darwin_pspace_data_cleanup
);
657 darwin_so_ops
.relocate_section_addresses
= darwin_relocate_section_addresses
;
658 darwin_so_ops
.free_so
= darwin_free_so
;
659 darwin_so_ops
.clear_solib
= darwin_clear_solib
;
660 darwin_so_ops
.solib_create_inferior_hook
= darwin_solib_create_inferior_hook
;
661 darwin_so_ops
.current_sos
= darwin_current_sos
;
662 darwin_so_ops
.open_symbol_file_object
= open_symbol_file_object
;
663 darwin_so_ops
.in_dynsym_resolve_code
= darwin_in_dynsym_resolve_code
;
664 darwin_so_ops
.lookup_lib_global_symbol
= darwin_lookup_lib_symbol
;
665 darwin_so_ops
.bfd_open
= darwin_bfd_open
;