1 /* Work with executable files, for GDB.
3 Copyright (C) 1988-2014 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/>. */
26 #include "filenames.h"
29 #include "completer.h"
33 #include "arch-utils.h"
34 #include "gdbthread.h"
35 #include "progspace.h"
40 #include "readline/readline.h"
48 void (*deprecated_file_changed_hook) (char *);
50 /* Prototypes for local functions */
52 static void file_command (char *, int);
54 static void set_section_command (char *, int);
56 static void exec_files_info (struct target_ops *);
58 static void init_exec_ops (void);
60 void _initialize_exec (void);
62 /* The target vector for executable files. */
64 struct target_ops exec_ops;
66 /* True if the exec target is pushed on the stack. */
67 static int using_exec_ops;
69 /* Whether to open exec and core files read-only or read-write. */
73 show_write_files (struct ui_file *file, int from_tty,
74 struct cmd_list_element *c, const char *value)
76 fprintf_filtered (file, _("Writing into executable and core files is %s.\n"),
82 exec_open (char *args, int from_tty)
84 target_preopen (from_tty);
85 exec_file_attach (args, from_tty);
88 /* Close and clear exec_bfd. If we end up with no target sections to
89 read memory from, this unpushes the exec_ops target. */
100 /* Removing target sections may close the exec_ops target.
101 Clear exec_bfd before doing so to prevent recursion. */
105 remove_target_sections (&exec_bfd);
107 xfree (exec_filename);
108 exec_filename = NULL;
112 /* This is the target_close implementation. Clears all target
113 sections and closes all executable bfds from all program spaces. */
116 exec_close_1 (struct target_ops *self)
121 struct program_space *ss;
122 struct cleanup *old_chain;
124 old_chain = save_current_program_space ();
127 set_current_program_space (ss);
129 /* Delete all target sections. */
131 (current_target_sections,
132 -resize_section_table (current_target_sections, 0));
137 do_cleanups (old_chain);
142 exec_file_clear (int from_tty)
144 /* Remove exec file. */
148 printf_unfiltered (_("No executable file now.\n"));
151 /* Set FILENAME as the new exec file.
153 This function is intended to be behave essentially the same
154 as exec_file_command, except that the latter will detect when
155 a target is being debugged, and will ask the user whether it
156 should be shut down first. (If the answer is "no", then the
157 new file is ignored.)
159 This file is used by exec_file_command, to do the work of opening
160 and processing the exec file after any prompting has happened.
162 And, it is used by child_attach, when the attach command was
163 given a pid but not a exec pathname, and the attach command could
164 figure out the pathname from the pid. (In this case, we shouldn't
165 ask the user whether the current target should be shut down --
166 we're supplying the exec pathname late for good reason.) */
169 exec_file_attach (char *filename, int from_tty)
171 /* Remove any previous exec file. */
174 /* Now open and digest the file the user requested, if any. */
179 printf_unfiltered (_("No executable file now.\n"));
181 set_gdbarch_from_file (NULL);
185 struct cleanup *cleanups;
186 char *scratch_pathname, *canonical_pathname;
188 struct target_section *sections = NULL, *sections_end = NULL;
191 scratch_chan = openp (getenv ("PATH"), OPF_TRY_CWD_FIRST, filename,
192 write_files ? O_RDWR | O_BINARY : O_RDONLY | O_BINARY,
194 #if defined(__GO32__) || defined(_WIN32) || defined(__CYGWIN__)
195 if (scratch_chan < 0)
197 char *exename = alloca (strlen (filename) + 5);
199 strcat (strcpy (exename, filename), ".exe");
200 scratch_chan = openp (getenv ("PATH"), OPF_TRY_CWD_FIRST, exename,
201 write_files ? O_RDWR | O_BINARY : O_RDONLY | O_BINARY,
205 if (scratch_chan < 0)
206 perror_with_name (filename);
208 cleanups = make_cleanup (xfree, scratch_pathname);
210 /* gdb_bfd_open (and its variants) prefers canonicalized pathname for
211 better BFD caching. */
212 canonical_pathname = gdb_realpath (scratch_pathname);
213 make_cleanup (xfree, canonical_pathname);
216 exec_bfd = gdb_bfd_fopen (canonical_pathname, gnutarget,
217 FOPEN_RUB, scratch_chan);
219 exec_bfd = gdb_bfd_open (canonical_pathname, gnutarget, scratch_chan);
223 error (_("\"%s\": could not open as an executable file: %s"),
224 scratch_pathname, bfd_errmsg (bfd_get_error ()));
227 gdb_assert (exec_filename == NULL);
228 exec_filename = gdb_realpath_keepfile (scratch_pathname);
230 if (!bfd_check_format_matches (exec_bfd, bfd_object, &matching))
232 /* Make sure to close exec_bfd, or else "run" might try to use
235 error (_("\"%s\": not in executable format: %s"),
237 gdb_bfd_errmsg (bfd_get_error (), matching));
240 if (build_section_table (exec_bfd, §ions, §ions_end))
242 /* Make sure to close exec_bfd, or else "run" might try to use
245 error (_("\"%s\": can't find the file sections: %s"),
246 scratch_pathname, bfd_errmsg (bfd_get_error ()));
249 exec_bfd_mtime = bfd_get_mtime (exec_bfd);
253 set_gdbarch_from_file (exec_bfd);
255 /* Add the executable's sections to the current address spaces'
256 list of sections. This possibly pushes the exec_ops
258 add_target_sections (&exec_bfd, sections, sections_end);
261 /* Tell display code (if any) about the changed file name. */
262 if (deprecated_exec_file_display_hook)
263 (*deprecated_exec_file_display_hook) (filename);
265 do_cleanups (cleanups);
267 bfd_cache_close_all ();
268 observer_notify_executable_changed ();
271 /* Process the first arg in ARGS as the new exec file.
273 Note that we have to explicitly ignore additional args, since we can
274 be called from file_command(), which also calls symbol_file_command()
275 which can take multiple args.
277 If ARGS is NULL, we just want to close the exec file. */
280 exec_file_command (char *args, int from_tty)
285 if (from_tty && target_has_execution
286 && !query (_("A program is being debugged already.\n"
287 "Are you sure you want to change the file? ")))
288 error (_("File not changed."));
292 struct cleanup *cleanups;
294 /* Scan through the args and pick up the first non option arg
297 argv = gdb_buildargv (args);
298 cleanups = make_cleanup_freeargv (argv);
300 for (; (*argv != NULL) && (**argv == '-'); argv++)
304 error (_("No executable file name was specified"));
306 filename = tilde_expand (*argv);
307 make_cleanup (xfree, filename);
308 exec_file_attach (filename, from_tty);
310 do_cleanups (cleanups);
313 exec_file_attach (NULL, from_tty);
316 /* Set both the exec file and the symbol file, in one command.
317 What a novelty. Why did GDB go through four major releases before this
318 command was added? */
321 file_command (char *arg, int from_tty)
323 /* FIXME, if we lose on reading the symbol file, we should revert
324 the exec file, but that's rough. */
325 exec_file_command (arg, from_tty);
326 symbol_file_command (arg, from_tty);
327 if (deprecated_file_changed_hook)
328 deprecated_file_changed_hook (arg);
332 /* Locate all mappable sections of a BFD file.
333 table_pp_char is a char * to get it through bfd_map_over_sections;
334 we cast it back to its proper type. */
337 add_to_section_table (bfd *abfd, struct bfd_section *asect,
340 struct target_section **table_pp = (struct target_section **) table_pp_char;
343 gdb_assert (abfd == asect->owner);
345 /* Check the section flags, but do not discard zero-length sections, since
346 some symbols may still be attached to this section. For instance, we
347 encountered on sparc-solaris 2.10 a shared library with an empty .bss
348 section to which a symbol named "_end" was attached. The address
349 of this symbol still needs to be relocated. */
350 aflag = bfd_get_section_flags (abfd, asect);
351 if (!(aflag & SEC_ALLOC))
354 (*table_pp)->owner = NULL;
355 (*table_pp)->the_bfd_section = asect;
356 (*table_pp)->addr = bfd_section_vma (abfd, asect);
357 (*table_pp)->endaddr = (*table_pp)->addr + bfd_section_size (abfd, asect);
362 resize_section_table (struct target_section_table *table, int num_added)
367 old_count = table->sections_end - table->sections;
369 new_count = num_added + old_count;
373 table->sections = xrealloc (table->sections,
374 sizeof (struct target_section) * new_count);
375 table->sections_end = table->sections + new_count;
379 xfree (table->sections);
380 table->sections = table->sections_end = NULL;
386 /* Builds a section table, given args BFD, SECTABLE_PTR, SECEND_PTR.
387 Returns 0 if OK, 1 on error. */
390 build_section_table (struct bfd *some_bfd, struct target_section **start,
391 struct target_section **end)
395 count = bfd_count_sections (some_bfd);
398 *start = (struct target_section *) xmalloc (count * sizeof (**start));
400 bfd_map_over_sections (some_bfd, add_to_section_table, (char *) end);
401 if (*end > *start + count)
402 internal_error (__FILE__, __LINE__,
403 _("failed internal consistency check"));
404 /* We could realloc the table, but it probably loses for most files. */
408 /* Add the sections array defined by [SECTIONS..SECTIONS_END[ to the
409 current set of target sections. */
412 add_target_sections (void *owner,
413 struct target_section *sections,
414 struct target_section *sections_end)
417 struct target_section_table *table = current_target_sections;
419 count = sections_end - sections;
423 int space = resize_section_table (table, count);
426 for (i = 0; i < count; ++i)
428 table->sections[space + i] = sections[i];
429 table->sections[space + i].owner = owner;
432 /* If these are the first file sections we can provide memory
433 from, push the file_stratum target. */
437 push_target (&exec_ops);
442 /* Add the sections of OBJFILE to the current set of target sections. */
445 add_target_sections_of_objfile (struct objfile *objfile)
447 struct target_section_table *table = current_target_sections;
448 struct obj_section *osect;
451 struct target_section *ts;
456 /* Compute the number of sections to add. */
457 ALL_OBJFILE_OSECTIONS (objfile, osect)
459 if (bfd_get_section_size (osect->the_bfd_section) == 0)
467 space = resize_section_table (table, count);
469 ts = table->sections + space;
471 ALL_OBJFILE_OSECTIONS (objfile, osect)
473 if (bfd_get_section_size (osect->the_bfd_section) == 0)
476 gdb_assert (ts < table->sections + space + count);
478 ts->addr = obj_section_addr (osect);
479 ts->endaddr = obj_section_endaddr (osect);
480 ts->the_bfd_section = osect->the_bfd_section;
481 ts->owner = (void *) objfile;
487 /* Remove all target sections owned by OWNER.
488 OWNER must be the same value passed to add_target_sections. */
491 remove_target_sections (void *owner)
493 struct target_section *src, *dest;
494 struct target_section_table *table = current_target_sections;
496 gdb_assert (owner != NULL);
498 dest = table->sections;
499 for (src = table->sections; src < table->sections_end; src++)
500 if (src->owner != owner)
502 /* Keep this section. */
508 /* If we've dropped any sections, resize the section table. */
513 old_count = resize_section_table (table, dest - src);
515 /* If we don't have any more sections to read memory from,
516 remove the file_stratum target from the stack. */
517 if (old_count + (dest - src) == 0)
519 struct program_space *pspace;
522 if (pspace->target_sections.sections
523 != pspace->target_sections.sections_end)
526 unpush_target (&exec_ops);
533 enum target_xfer_status
534 exec_read_partial_read_only (gdb_byte *readbuf, ULONGEST offset,
535 ULONGEST len, ULONGEST *xfered_len)
537 /* It's unduly pedantic to refuse to look at the executable for
538 read-only pieces; so do the equivalent of readonly regions aka
540 if (exec_bfd != NULL)
546 for (s = exec_bfd->sections; s; s = s->next)
548 if ((s->flags & SEC_LOAD) == 0
549 || (s->flags & SEC_READONLY) == 0)
553 size = bfd_get_section_size (s);
554 if (vma <= offset && offset < (vma + size))
558 amt = (vma + size) - offset;
562 amt = bfd_get_section_contents (exec_bfd, s,
563 readbuf, offset - vma, amt);
566 return TARGET_XFER_EOF;
570 return TARGET_XFER_OK;
576 /* Indicate failure to find the requested memory block. */
577 return TARGET_XFER_E_IO;
580 /* Appends all read-only memory ranges found in the target section
581 table defined by SECTIONS and SECTIONS_END, starting at (and
582 intersected with) MEMADDR for LEN bytes. Returns the augmented
585 static VEC(mem_range_s) *
586 section_table_available_memory (VEC(mem_range_s) *memory,
587 CORE_ADDR memaddr, ULONGEST len,
588 struct target_section *sections,
589 struct target_section *sections_end)
591 struct target_section *p;
593 for (p = sections; p < sections_end; p++)
595 if ((bfd_get_section_flags (p->the_bfd_section->owner,
597 & SEC_READONLY) == 0)
600 /* Copy the meta-data, adjusted. */
601 if (mem_ranges_overlap (p->addr, p->endaddr - p->addr, memaddr, len))
603 ULONGEST lo1, hi1, lo2, hi2;
612 r = VEC_safe_push (mem_range_s, memory, NULL);
614 r->start = max (lo1, lo2);
615 r->length = min (hi1, hi2) - r->start;
622 enum target_xfer_status
623 section_table_read_available_memory (gdb_byte *readbuf, ULONGEST offset,
624 ULONGEST len, ULONGEST *xfered_len)
626 VEC(mem_range_s) *available_memory = NULL;
627 struct target_section_table *table;
628 struct cleanup *old_chain;
632 table = target_get_section_table (&exec_ops);
633 available_memory = section_table_available_memory (available_memory,
636 table->sections_end);
638 old_chain = make_cleanup (VEC_cleanup(mem_range_s),
641 normalize_mem_ranges (available_memory);
644 VEC_iterate (mem_range_s, available_memory, i, r);
647 if (mem_ranges_overlap (r->start, r->length, offset, len))
650 enum target_xfer_status status;
652 /* Get the intersection window. */
653 end = min (offset + len, r->start + r->length);
655 gdb_assert (end - offset <= len);
657 if (offset >= r->start)
658 status = exec_read_partial_read_only (readbuf, offset,
663 *xfered_len = r->start - offset;
664 status = TARGET_XFER_UNAVAILABLE;
666 do_cleanups (old_chain);
670 do_cleanups (old_chain);
673 return TARGET_XFER_UNAVAILABLE;
676 enum target_xfer_status
677 section_table_xfer_memory_partial (gdb_byte *readbuf, const gdb_byte *writebuf,
678 ULONGEST offset, ULONGEST len,
679 ULONGEST *xfered_len,
680 struct target_section *sections,
681 struct target_section *sections_end,
682 const char *section_name)
685 struct target_section *p;
686 ULONGEST memaddr = offset;
687 ULONGEST memend = memaddr + len;
690 internal_error (__FILE__, __LINE__,
691 _("failed internal consistency check"));
693 for (p = sections; p < sections_end; p++)
695 struct bfd_section *asect = p->the_bfd_section;
696 bfd *abfd = asect->owner;
698 if (section_name && strcmp (section_name, asect->name) != 0)
699 continue; /* not the section we need. */
700 if (memaddr >= p->addr)
702 if (memend <= p->endaddr)
704 /* Entire transfer is within this section. */
706 res = bfd_set_section_contents (abfd, asect,
707 writebuf, memaddr - p->addr,
710 res = bfd_get_section_contents (abfd, asect,
711 readbuf, memaddr - p->addr,
717 return TARGET_XFER_OK;
720 return TARGET_XFER_EOF;
722 else if (memaddr >= p->endaddr)
724 /* This section ends before the transfer starts. */
729 /* This section overlaps the transfer. Just do half. */
730 len = p->endaddr - memaddr;
732 res = bfd_set_section_contents (abfd, asect,
733 writebuf, memaddr - p->addr,
736 res = bfd_get_section_contents (abfd, asect,
737 readbuf, memaddr - p->addr,
742 return TARGET_XFER_OK;
745 return TARGET_XFER_EOF;
750 return TARGET_XFER_EOF; /* We can't help. */
753 static struct target_section_table *
754 exec_get_section_table (struct target_ops *ops)
756 return current_target_sections;
759 static enum target_xfer_status
760 exec_xfer_partial (struct target_ops *ops, enum target_object object,
761 const char *annex, gdb_byte *readbuf,
762 const gdb_byte *writebuf,
763 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
765 struct target_section_table *table = target_get_section_table (ops);
767 if (object == TARGET_OBJECT_MEMORY)
768 return section_table_xfer_memory_partial (readbuf, writebuf,
769 offset, len, xfered_len,
774 return TARGET_XFER_E_IO;
779 print_section_info (struct target_section_table *t, bfd *abfd)
781 struct gdbarch *gdbarch = gdbarch_from_bfd (abfd);
782 struct target_section *p;
783 /* FIXME: 16 is not wide enough when gdbarch_addr_bit > 64. */
784 int wid = gdbarch_addr_bit (gdbarch) <= 32 ? 8 : 16;
786 printf_filtered ("\t`%s', ", bfd_get_filename (abfd));
788 printf_filtered (_("file type %s.\n"), bfd_get_target (abfd));
789 if (abfd == exec_bfd)
791 /* gcc-3.4 does not like the initialization in
792 <p == t->sections_end>. */
793 bfd_vma displacement = 0;
796 for (p = t->sections; p < t->sections_end; p++)
798 struct bfd_section *psect = p->the_bfd_section;
799 bfd *pbfd = psect->owner;
801 if ((bfd_get_section_flags (pbfd, psect) & (SEC_ALLOC | SEC_LOAD))
802 != (SEC_ALLOC | SEC_LOAD))
805 if (bfd_get_section_vma (pbfd, psect) <= abfd->start_address
806 && abfd->start_address < (bfd_get_section_vma (pbfd, psect)
807 + bfd_get_section_size (psect)))
809 displacement = p->addr - bfd_get_section_vma (pbfd, psect);
813 if (p == t->sections_end)
814 warning (_("Cannot find section for the entry point of %s."),
815 bfd_get_filename (abfd));
817 entry_point = gdbarch_addr_bits_remove (gdbarch,
818 bfd_get_start_address (abfd)
820 printf_filtered (_("\tEntry point: %s\n"),
821 paddress (gdbarch, entry_point));
823 for (p = t->sections; p < t->sections_end; p++)
825 struct bfd_section *psect = p->the_bfd_section;
826 bfd *pbfd = psect->owner;
828 printf_filtered ("\t%s", hex_string_custom (p->addr, wid));
829 printf_filtered (" - %s", hex_string_custom (p->endaddr, wid));
831 /* FIXME: A format of "08l" is not wide enough for file offsets
832 larger than 4GB. OTOH, making it "016l" isn't desirable either
833 since most output will then be much wider than necessary. It
834 may make sense to test the size of the file and choose the
835 format string accordingly. */
836 /* FIXME: i18n: Need to rewrite this sentence. */
838 printf_filtered (" @ %s",
839 hex_string_custom (psect->filepos, 8));
840 printf_filtered (" is %s", bfd_section_name (pbfd, psect));
842 printf_filtered (" in %s", bfd_get_filename (pbfd));
843 printf_filtered ("\n");
848 exec_files_info (struct target_ops *t)
851 print_section_info (current_target_sections, exec_bfd);
853 puts_filtered (_("\t<no file loaded>\n"));
857 set_section_command (char *args, int from_tty)
859 struct target_section *p;
862 unsigned long secaddr;
865 struct target_section_table *table;
868 error (_("Must specify section name and its virtual address"));
870 /* Parse out section name. */
871 for (secname = args; !isspace (*args); args++);
872 seclen = args - secname;
874 /* Parse out new virtual address. */
875 secaddr = parse_and_eval_address (args);
877 table = current_target_sections;
878 for (p = table->sections; p < table->sections_end; p++)
880 if (!strncmp (secname, bfd_section_name (p->bfd,
881 p->the_bfd_section), seclen)
882 && bfd_section_name (p->bfd, p->the_bfd_section)[seclen] == '\0')
884 offset = secaddr - p->addr;
886 p->endaddr += offset;
888 exec_files_info (&exec_ops);
892 if (seclen >= sizeof (secprint))
893 seclen = sizeof (secprint) - 1;
894 strncpy (secprint, secname, seclen);
895 secprint[seclen] = '\0';
896 error (_("Section %s not found"), secprint);
899 /* If we can find a section in FILENAME with BFD index INDEX, adjust
903 exec_set_section_address (const char *filename, int index, CORE_ADDR address)
905 struct target_section *p;
906 struct target_section_table *table;
908 table = current_target_sections;
909 for (p = table->sections; p < table->sections_end; p++)
911 if (filename_cmp (filename, p->the_bfd_section->owner->filename) == 0
912 && index == p->the_bfd_section->index)
914 p->endaddr += address - p->addr;
920 /* If mourn is being called in all the right places, this could be say
921 `gdb internal error' (since generic_mourn calls
922 breakpoint_init_inferior). */
925 ignore (struct target_ops *ops, struct gdbarch *gdbarch,
926 struct bp_target_info *bp_tgt)
932 exec_has_memory (struct target_ops *ops)
934 /* We can provide memory if we have any file/target sections to read
936 return (current_target_sections->sections
937 != current_target_sections->sections_end);
940 static char *exec_make_note_section (struct target_ops *self, bfd *, int *);
942 /* Fill in the exec file target vector. Very few entries need to be
948 exec_ops.to_shortname = "exec";
949 exec_ops.to_longname = "Local exec file";
950 exec_ops.to_doc = "Use an executable file as a target.\n\
951 Specify the filename of the executable file.";
952 exec_ops.to_open = exec_open;
953 exec_ops.to_close = exec_close_1;
954 exec_ops.to_attach = find_default_attach;
955 exec_ops.to_xfer_partial = exec_xfer_partial;
956 exec_ops.to_get_section_table = exec_get_section_table;
957 exec_ops.to_files_info = exec_files_info;
958 exec_ops.to_insert_breakpoint = ignore;
959 exec_ops.to_remove_breakpoint = ignore;
960 exec_ops.to_create_inferior = find_default_create_inferior;
961 exec_ops.to_stratum = file_stratum;
962 exec_ops.to_has_memory = exec_has_memory;
963 exec_ops.to_make_corefile_notes = exec_make_note_section;
964 exec_ops.to_find_memory_regions = objfile_find_memory_regions;
965 exec_ops.to_magic = OPS_MAGIC;
969 _initialize_exec (void)
971 struct cmd_list_element *c;
977 c = add_cmd ("file", class_files, file_command, _("\
978 Use FILE as program to be debugged.\n\
979 It is read for its symbols, for getting the contents of pure memory,\n\
980 and it is the program executed when you use the `run' command.\n\
981 If FILE cannot be found as specified, your execution directory path\n\
982 ($PATH) is searched for a command of that name.\n\
983 No arg means to have no executable file and no symbols."), &cmdlist);
984 set_cmd_completer (c, filename_completer);
987 c = add_cmd ("exec-file", class_files, exec_file_command, _("\
988 Use FILE as program for getting contents of pure memory.\n\
989 If FILE cannot be found as specified, your execution directory path\n\
990 is searched for a command of that name.\n\
991 No arg means have no executable file."), &cmdlist);
992 set_cmd_completer (c, filename_completer);
994 add_com ("section", class_files, set_section_command, _("\
995 Change the base address of section SECTION of the exec file to ADDR.\n\
996 This can be used if the exec file does not contain section addresses,\n\
997 (such as in the a.out format), or when the addresses specified in the\n\
998 file itself are wrong. Each section must be changed separately. The\n\
999 ``info files'' command lists all the sections and their addresses."));
1001 add_setshow_boolean_cmd ("write", class_support, &write_files, _("\
1002 Set writing into executable and core files."), _("\
1003 Show writing into executable and core files."), NULL,
1006 &setlist, &showlist);
1008 add_target_with_completer (&exec_ops, filename_completer);
1012 exec_make_note_section (struct target_ops *self, bfd *obfd, int *note_size)
1014 error (_("Can't create a corefile"));