| /* Handle Darwin shared libraries for GDB, the GNU Debugger. |
| |
| Copyright (C) 2009-2015 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| |
| #include "symtab.h" |
| #include "bfd.h" |
| #include "symfile.h" |
| #include "objfiles.h" |
| #include "gdbcore.h" |
| #include "target.h" |
| #include "inferior.h" |
| #include "regcache.h" |
| #include "gdbthread.h" |
| #include "gdb_bfd.h" |
| |
| #include "solist.h" |
| #include "solib.h" |
| #include "solib-svr4.h" |
| |
| #include "bfd-target.h" |
| #include "elf-bfd.h" |
| #include "exec.h" |
| #include "auxv.h" |
| #include "mach-o.h" |
| #include "mach-o/external.h" |
| |
| struct gdb_dyld_image_info |
| { |
| /* Base address (which corresponds to the Mach-O header). */ |
| CORE_ADDR mach_header; |
| /* Image file path. */ |
| CORE_ADDR file_path; |
| /* st.m_time of image file. */ |
| unsigned long mtime; |
| }; |
| |
| /* Content of inferior dyld_all_image_infos structure. |
| See /usr/include/mach-o/dyld_images.h for the documentation. */ |
| struct gdb_dyld_all_image_infos |
| { |
| /* Version (1). */ |
| unsigned int version; |
| /* Number of images. */ |
| unsigned int count; |
| /* Image description. */ |
| CORE_ADDR info; |
| /* Notifier (function called when a library is added or removed). */ |
| CORE_ADDR notifier; |
| }; |
| |
| /* Current all_image_infos version. */ |
| #define DYLD_VERSION_MIN 1 |
| #define DYLD_VERSION_MAX 14 |
| |
| /* Per PSPACE specific data. */ |
| struct darwin_info |
| { |
| /* Address of structure dyld_all_image_infos in inferior. */ |
| CORE_ADDR all_image_addr; |
| |
| /* Gdb copy of dyld_all_info_infos. */ |
| struct gdb_dyld_all_image_infos all_image; |
| }; |
| |
| /* Per-program-space data key. */ |
| static const struct program_space_data *solib_darwin_pspace_data; |
| |
| static void |
| darwin_pspace_data_cleanup (struct program_space *pspace, void *arg) |
| { |
| xfree (arg); |
| } |
| |
| /* Get the current darwin data. If none is found yet, add it now. This |
| function always returns a valid object. */ |
| |
| static struct darwin_info * |
| get_darwin_info (void) |
| { |
| struct darwin_info *info; |
| |
| info = (struct darwin_info *) program_space_data (current_program_space, |
| solib_darwin_pspace_data); |
| if (info != NULL) |
| return info; |
| |
| info = XCNEW (struct darwin_info); |
| set_program_space_data (current_program_space, |
| solib_darwin_pspace_data, info); |
| return info; |
| } |
| |
| /* Return non-zero if the version in dyld_all_image is known. */ |
| |
| static int |
| darwin_dyld_version_ok (const struct darwin_info *info) |
| { |
| return info->all_image.version >= DYLD_VERSION_MIN |
| && info->all_image.version <= DYLD_VERSION_MAX; |
| } |
| |
| /* Read dyld_all_image from inferior. */ |
| |
| static void |
| darwin_load_image_infos (struct darwin_info *info) |
| { |
| gdb_byte buf[24]; |
| enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
| struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr; |
| int len; |
| |
| /* If the structure address is not known, don't continue. */ |
| if (info->all_image_addr == 0) |
| return; |
| |
| /* The structure has 4 fields: version (4 bytes), count (4 bytes), |
| info (pointer) and notifier (pointer). */ |
| len = 4 + 4 + 2 * ptr_type->length; |
| gdb_assert (len <= sizeof (buf)); |
| memset (&info->all_image, 0, sizeof (info->all_image)); |
| |
| /* Read structure raw bytes from target. */ |
| if (target_read_memory (info->all_image_addr, buf, len)) |
| return; |
| |
| /* Extract the fields. */ |
| info->all_image.version = extract_unsigned_integer (buf, 4, byte_order); |
| if (!darwin_dyld_version_ok (info)) |
| return; |
| |
| info->all_image.count = extract_unsigned_integer (buf + 4, 4, byte_order); |
| info->all_image.info = extract_typed_address (buf + 8, ptr_type); |
| info->all_image.notifier = extract_typed_address |
| (buf + 8 + ptr_type->length, ptr_type); |
| } |
| |
| /* Link map info to include in an allocated so_list entry. */ |
| |
| struct lm_info |
| { |
| /* The target location of lm. */ |
| CORE_ADDR lm_addr; |
| }; |
| |
| struct darwin_so_list |
| { |
| /* Common field. */ |
| struct so_list sl; |
| /* Darwin specific data. */ |
| struct lm_info li; |
| }; |
| |
| /* Lookup the value for a specific symbol. */ |
| |
| static CORE_ADDR |
| lookup_symbol_from_bfd (bfd *abfd, char *symname) |
| { |
| long storage_needed; |
| asymbol **symbol_table; |
| unsigned int number_of_symbols; |
| unsigned int i; |
| CORE_ADDR symaddr = 0; |
| |
| storage_needed = bfd_get_symtab_upper_bound (abfd); |
| |
| if (storage_needed <= 0) |
| return 0; |
| |
| symbol_table = (asymbol **) xmalloc (storage_needed); |
| number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table); |
| |
| for (i = 0; i < number_of_symbols; i++) |
| { |
| asymbol *sym = symbol_table[i]; |
| |
| if (strcmp (sym->name, symname) == 0 |
| && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0) |
| { |
| /* BFD symbols are section relative. */ |
| symaddr = sym->value + sym->section->vma; |
| break; |
| } |
| } |
| xfree (symbol_table); |
| |
| return symaddr; |
| } |
| |
| /* Return program interpreter string. */ |
| |
| static char * |
| find_program_interpreter (void) |
| { |
| char *buf = NULL; |
| |
| /* If we have an exec_bfd, get the interpreter from the load commands. */ |
| if (exec_bfd) |
| { |
| bfd_mach_o_load_command *cmd; |
| |
| if (bfd_mach_o_lookup_command (exec_bfd, |
| BFD_MACH_O_LC_LOAD_DYLINKER, &cmd) == 1) |
| return cmd->command.dylinker.name_str; |
| } |
| |
| /* If we didn't find it, read from memory. |
| FIXME: todo. */ |
| return buf; |
| } |
| |
| /* Not used. I don't see how the main symbol file can be found: the |
| interpreter name is needed and it is known from the executable file. |
| Note that darwin-nat.c implements pid_to_exec_file. */ |
| |
| static int |
| open_symbol_file_object (void *from_ttyp) |
| { |
| return 0; |
| } |
| |
| /* Build a list of currently loaded shared objects. See solib-svr4.c. */ |
| |
| static struct so_list * |
| darwin_current_sos (void) |
| { |
| struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr; |
| enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
| int ptr_len = TYPE_LENGTH (ptr_type); |
| unsigned int image_info_size; |
| struct so_list *head = NULL; |
| struct so_list *tail = NULL; |
| int i; |
| struct darwin_info *info = get_darwin_info (); |
| |
| /* Be sure image infos are loaded. */ |
| darwin_load_image_infos (info); |
| |
| if (!darwin_dyld_version_ok (info)) |
| return NULL; |
| |
| image_info_size = ptr_len * 3; |
| |
| /* Read infos for each solib. |
| The first entry was rumored to be the executable itself, but this is not |
| true when a large number of shared libraries are used (table expanded ?). |
| We now check all entries, but discard executable images. */ |
| for (i = 0; i < info->all_image.count; i++) |
| { |
| CORE_ADDR iinfo = info->all_image.info + i * image_info_size; |
| gdb_byte buf[image_info_size]; |
| CORE_ADDR load_addr; |
| CORE_ADDR path_addr; |
| struct mach_o_header_external hdr; |
| unsigned long hdr_val; |
| char *file_path; |
| int errcode; |
| struct darwin_so_list *dnew; |
| struct so_list *newobj; |
| struct cleanup *old_chain; |
| |
| /* Read image info from inferior. */ |
| if (target_read_memory (iinfo, buf, image_info_size)) |
| break; |
| |
| load_addr = extract_typed_address (buf, ptr_type); |
| path_addr = extract_typed_address (buf + ptr_len, ptr_type); |
| |
| /* Read Mach-O header from memory. */ |
| if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4)) |
| break; |
| /* Discard wrong magic numbers. Shouldn't happen. */ |
| hdr_val = extract_unsigned_integer |
| (hdr.magic, sizeof (hdr.magic), byte_order); |
| if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64) |
| continue; |
| /* Discard executable. Should happen only once. */ |
| hdr_val = extract_unsigned_integer |
| (hdr.filetype, sizeof (hdr.filetype), byte_order); |
| if (hdr_val == BFD_MACH_O_MH_EXECUTE) |
| continue; |
| |
| target_read_string (path_addr, &file_path, |
| SO_NAME_MAX_PATH_SIZE - 1, &errcode); |
| if (errcode) |
| break; |
| |
| /* Create and fill the new so_list element. */ |
| dnew = XCNEW (struct darwin_so_list); |
| newobj = &dnew->sl; |
| old_chain = make_cleanup (xfree, dnew); |
| |
| newobj->lm_info = &dnew->li; |
| |
| strncpy (newobj->so_name, file_path, SO_NAME_MAX_PATH_SIZE - 1); |
| newobj->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; |
| strcpy (newobj->so_original_name, newobj->so_name); |
| xfree (file_path); |
| newobj->lm_info->lm_addr = load_addr; |
| |
| if (head == NULL) |
| head = newobj; |
| else |
| tail->next = newobj; |
| tail = newobj; |
| |
| discard_cleanups (old_chain); |
| } |
| |
| return head; |
| } |
| |
| /* Get the load address of the executable. We assume that the dyld info are |
| correct. */ |
| |
| static CORE_ADDR |
| darwin_read_exec_load_addr (struct darwin_info *info) |
| { |
| struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr; |
| enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
| int ptr_len = TYPE_LENGTH (ptr_type); |
| unsigned int image_info_size = ptr_len * 3; |
| int i; |
| |
| /* Read infos for each solib. One of them should be the executable. */ |
| for (i = 0; i < info->all_image.count; i++) |
| { |
| CORE_ADDR iinfo = info->all_image.info + i * image_info_size; |
| gdb_byte buf[image_info_size]; |
| CORE_ADDR load_addr; |
| struct mach_o_header_external hdr; |
| unsigned long hdr_val; |
| |
| /* Read image info from inferior. */ |
| if (target_read_memory (iinfo, buf, image_info_size)) |
| break; |
| |
| load_addr = extract_typed_address (buf, ptr_type); |
| |
| /* Read Mach-O header from memory. */ |
| if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4)) |
| break; |
| /* Discard wrong magic numbers. Shouldn't happen. */ |
| hdr_val = extract_unsigned_integer |
| (hdr.magic, sizeof (hdr.magic), byte_order); |
| if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64) |
| continue; |
| /* Check executable. */ |
| hdr_val = extract_unsigned_integer |
| (hdr.filetype, sizeof (hdr.filetype), byte_order); |
| if (hdr_val == BFD_MACH_O_MH_EXECUTE) |
| return load_addr; |
| } |
| |
| return 0; |
| } |
| |
| /* Return 1 if PC lies in the dynamic symbol resolution code of the |
| run time loader. */ |
| |
| static int |
| darwin_in_dynsym_resolve_code (CORE_ADDR pc) |
| { |
| return 0; |
| } |
| |
| |
| /* No special symbol handling. */ |
| |
| static void |
| darwin_special_symbol_handling (void) |
| { |
| } |
| |
| /* A wrapper for bfd_mach_o_fat_extract that handles reference |
| counting properly. This will either return NULL, or return a new |
| reference to a BFD. */ |
| |
| static bfd * |
| gdb_bfd_mach_o_fat_extract (bfd *abfd, bfd_format format, |
| const bfd_arch_info_type *arch) |
| { |
| bfd *result = bfd_mach_o_fat_extract (abfd, format, arch); |
| |
| if (result == NULL) |
| return NULL; |
| |
| if (result == abfd) |
| gdb_bfd_ref (result); |
| else |
| gdb_bfd_mark_parent (result, abfd); |
| |
| return result; |
| } |
| |
| /* Extract dyld_all_image_addr when the process was just created, assuming the |
| current PC is at the entry of the dynamic linker. */ |
| |
| static void |
| darwin_solib_get_all_image_info_addr_at_init (struct darwin_info *info) |
| { |
| char *interp_name; |
| CORE_ADDR load_addr = 0; |
| bfd *dyld_bfd = NULL; |
| struct cleanup *cleanup; |
| |
| /* This method doesn't work with an attached process. */ |
| if (current_inferior ()->attach_flag) |
| return; |
| |
| /* Find the program interpreter. */ |
| interp_name = find_program_interpreter (); |
| if (!interp_name) |
| return; |
| |
| cleanup = make_cleanup (null_cleanup, NULL); |
| |
| /* Create a bfd for the interpreter. */ |
| dyld_bfd = gdb_bfd_open (interp_name, gnutarget, -1); |
| if (dyld_bfd) |
| { |
| bfd *sub; |
| |
| make_cleanup_bfd_unref (dyld_bfd); |
| sub = gdb_bfd_mach_o_fat_extract (dyld_bfd, bfd_object, |
| gdbarch_bfd_arch_info (target_gdbarch ())); |
| if (sub) |
| { |
| dyld_bfd = sub; |
| make_cleanup_bfd_unref (sub); |
| } |
| else |
| dyld_bfd = NULL; |
| } |
| if (!dyld_bfd) |
| { |
| do_cleanups (cleanup); |
| return; |
| } |
| |
| /* We find the dynamic linker's base address by examining |
| the current pc (which should point at the entry point for the |
| dynamic linker) and subtracting the offset of the entry point. */ |
| load_addr = (regcache_read_pc (get_current_regcache ()) |
| - bfd_get_start_address (dyld_bfd)); |
| |
| /* Now try to set a breakpoint in the dynamic linker. */ |
| info->all_image_addr = |
| lookup_symbol_from_bfd (dyld_bfd, "_dyld_all_image_infos"); |
| |
| do_cleanups (cleanup); |
| |
| if (info->all_image_addr == 0) |
| return; |
| |
| info->all_image_addr += load_addr; |
| } |
| |
| /* Extract dyld_all_image_addr reading it from |
| TARGET_OBJECT_DARWIN_DYLD_INFO. */ |
| |
| static void |
| darwin_solib_read_all_image_info_addr (struct darwin_info *info) |
| { |
| gdb_byte buf[8 + 8 + 4]; |
| LONGEST len; |
| enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
| |
| len = target_read (current_target, TARGET_OBJECT_DARWIN_DYLD_INFO, NULL, |
| buf, 0, sizeof (buf)); |
| if (len != sizeof (buf)) |
| return; |
| |
| info->all_image_addr = extract_unsigned_integer (buf, 8, byte_order); |
| } |
| |
| /* Shared library startup support. See documentation in solib-svr4.c. */ |
| |
| static void |
| darwin_solib_create_inferior_hook (int from_tty) |
| { |
| struct darwin_info *info = get_darwin_info (); |
| CORE_ADDR load_addr; |
| |
| info->all_image_addr = 0; |
| |
| darwin_solib_read_all_image_info_addr (info); |
| |
| if (info->all_image_addr == 0) |
| darwin_solib_get_all_image_info_addr_at_init (info); |
| |
| if (info->all_image_addr == 0) |
| return; |
| |
| darwin_load_image_infos (info); |
| |
| if (!darwin_dyld_version_ok (info)) |
| { |
| warning (_("unhandled dyld version (%d)"), info->all_image.version); |
| return; |
| } |
| |
| create_solib_event_breakpoint (target_gdbarch (), info->all_image.notifier); |
| |
| /* Possible relocate the main executable (PIE). */ |
| load_addr = darwin_read_exec_load_addr (info); |
| if (load_addr != 0 && symfile_objfile != NULL) |
| { |
| CORE_ADDR vmaddr; |
| |
| /* Find the base address of the executable. */ |
| vmaddr = bfd_mach_o_get_base_address (exec_bfd); |
| |
| /* Relocate. */ |
| if (vmaddr != load_addr) |
| objfile_rebase (symfile_objfile, load_addr - vmaddr); |
| } |
| } |
| |
| static void |
| darwin_clear_solib (void) |
| { |
| struct darwin_info *info = get_darwin_info (); |
| |
| info->all_image_addr = 0; |
| info->all_image.version = 0; |
| } |
| |
| static void |
| darwin_free_so (struct so_list *so) |
| { |
| } |
| |
| /* The section table is built from bfd sections using bfd VMAs. |
| Relocate these VMAs according to solib info. */ |
| |
| static void |
| darwin_relocate_section_addresses (struct so_list *so, |
| struct target_section *sec) |
| { |
| sec->addr += so->lm_info->lm_addr; |
| sec->endaddr += so->lm_info->lm_addr; |
| |
| /* Best effort to set addr_high/addr_low. This is used only by |
| 'info sharedlibary'. */ |
| if (so->addr_high == 0) |
| { |
| so->addr_low = sec->addr; |
| so->addr_high = sec->endaddr; |
| } |
| if (sec->endaddr > so->addr_high) |
| so->addr_high = sec->endaddr; |
| if (sec->addr < so->addr_low) |
| so->addr_low = sec->addr; |
| } |
| |
| static struct block_symbol |
| darwin_lookup_lib_symbol (struct objfile *objfile, |
| const char *name, |
| const domain_enum domain) |
| { |
| return (struct block_symbol) {NULL, NULL}; |
| } |
| |
| static bfd * |
| darwin_bfd_open (char *pathname) |
| { |
| char *found_pathname; |
| int found_file; |
| bfd *abfd; |
| bfd *res; |
| |
| /* Search for shared library file. */ |
| found_pathname = solib_find (pathname, &found_file); |
| if (found_pathname == NULL) |
| perror_with_name (pathname); |
| |
| /* Open bfd for shared library. */ |
| abfd = solib_bfd_fopen (found_pathname, found_file); |
| |
| res = gdb_bfd_mach_o_fat_extract (abfd, bfd_object, |
| gdbarch_bfd_arch_info (target_gdbarch ())); |
| if (!res) |
| { |
| make_cleanup_bfd_unref (abfd); |
| error (_("`%s': not a shared-library: %s"), |
| bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ())); |
| } |
| |
| /* The current filename for fat-binary BFDs is a name generated |
| by BFD, usually a string containing the name of the architecture. |
| Reset its value to the actual filename. */ |
| xfree (bfd_get_filename (res)); |
| res->filename = xstrdup (pathname); |
| |
| gdb_bfd_unref (abfd); |
| return res; |
| } |
| |
| struct target_so_ops darwin_so_ops; |
| |
| /* -Wmissing-prototypes */ |
| extern initialize_file_ftype _initialize_darwin_solib; |
| |
| void |
| _initialize_darwin_solib (void) |
| { |
| solib_darwin_pspace_data |
| = register_program_space_data_with_cleanup (NULL, |
| darwin_pspace_data_cleanup); |
| |
| darwin_so_ops.relocate_section_addresses = darwin_relocate_section_addresses; |
| darwin_so_ops.free_so = darwin_free_so; |
| darwin_so_ops.clear_solib = darwin_clear_solib; |
| darwin_so_ops.solib_create_inferior_hook = darwin_solib_create_inferior_hook; |
| darwin_so_ops.special_symbol_handling = darwin_special_symbol_handling; |
| darwin_so_ops.current_sos = darwin_current_sos; |
| darwin_so_ops.open_symbol_file_object = open_symbol_file_object; |
| darwin_so_ops.in_dynsym_resolve_code = darwin_in_dynsym_resolve_code; |
| darwin_so_ops.lookup_lib_global_symbol = darwin_lookup_lib_symbol; |
| darwin_so_ops.bfd_open = darwin_bfd_open; |
| } |