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;
581 section_table_available_memory (VEC(mem_range_s) *memory,
582 CORE_ADDR memaddr, ULONGEST len,
583 struct target_section *sections,
584 struct target_section *sections_end)
586 struct target_section *p;
588 for (p = sections; p < sections_end; p++)
590 if ((bfd_get_section_flags (p->the_bfd_section->owner,
592 & SEC_READONLY) == 0)
595 /* Copy the meta-data, adjusted. */
596 if (mem_ranges_overlap (p->addr, p->endaddr - p->addr, memaddr, len))
598 ULONGEST lo1, hi1, lo2, hi2;
607 r = VEC_safe_push (mem_range_s, memory, NULL);
609 r->start = max (lo1, lo2);
610 r->length = min (hi1, hi2) - r->start;
617 enum target_xfer_status
618 section_table_read_available_memory (gdb_byte *readbuf, ULONGEST offset,
619 ULONGEST len, ULONGEST *xfered_len)
621 VEC(mem_range_s) *available_memory = NULL;
622 struct target_section_table *table;
623 struct cleanup *old_chain;
627 table = target_get_section_table (&exec_ops);
628 available_memory = section_table_available_memory (available_memory,
631 table->sections_end);
633 old_chain = make_cleanup (VEC_cleanup(mem_range_s),
636 normalize_mem_ranges (available_memory);
639 VEC_iterate (mem_range_s, available_memory, i, r);
642 if (mem_ranges_overlap (r->start, r->length, offset, len))
645 enum target_xfer_status status;
647 /* Get the intersection window. */
648 end = min (offset + len, r->start + r->length);
650 gdb_assert (end - offset <= len);
652 if (offset >= r->start)
653 status = exec_read_partial_read_only (readbuf, offset,
658 *xfered_len = r->start - offset;
659 status = TARGET_XFER_E_UNAVAILABLE;
661 do_cleanups (old_chain);
665 do_cleanups (old_chain);
668 return TARGET_XFER_E_UNAVAILABLE;
671 enum target_xfer_status
672 section_table_xfer_memory_partial (gdb_byte *readbuf, const gdb_byte *writebuf,
673 ULONGEST offset, ULONGEST len,
674 ULONGEST *xfered_len,
675 struct target_section *sections,
676 struct target_section *sections_end,
677 const char *section_name)
680 struct target_section *p;
681 ULONGEST memaddr = offset;
682 ULONGEST memend = memaddr + len;
685 internal_error (__FILE__, __LINE__,
686 _("failed internal consistency check"));
688 for (p = sections; p < sections_end; p++)
690 struct bfd_section *asect = p->the_bfd_section;
691 bfd *abfd = asect->owner;
693 if (section_name && strcmp (section_name, asect->name) != 0)
694 continue; /* not the section we need. */
695 if (memaddr >= p->addr)
697 if (memend <= p->endaddr)
699 /* Entire transfer is within this section. */
701 res = bfd_set_section_contents (abfd, asect,
702 writebuf, memaddr - p->addr,
705 res = bfd_get_section_contents (abfd, asect,
706 readbuf, memaddr - p->addr,
712 return TARGET_XFER_OK;
715 return TARGET_XFER_EOF;
717 else if (memaddr >= p->endaddr)
719 /* This section ends before the transfer starts. */
724 /* This section overlaps the transfer. Just do half. */
725 len = p->endaddr - memaddr;
727 res = bfd_set_section_contents (abfd, asect,
728 writebuf, memaddr - p->addr,
731 res = bfd_get_section_contents (abfd, asect,
732 readbuf, memaddr - p->addr,
737 return TARGET_XFER_OK;
740 return TARGET_XFER_EOF;
745 return TARGET_XFER_EOF; /* We can't help. */
748 static struct target_section_table *
749 exec_get_section_table (struct target_ops *ops)
751 return current_target_sections;
754 static enum target_xfer_status
755 exec_xfer_partial (struct target_ops *ops, enum target_object object,
756 const char *annex, gdb_byte *readbuf,
757 const gdb_byte *writebuf,
758 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
760 struct target_section_table *table = target_get_section_table (ops);
762 if (object == TARGET_OBJECT_MEMORY)
763 return section_table_xfer_memory_partial (readbuf, writebuf,
764 offset, len, xfered_len,
769 return TARGET_XFER_E_IO;
774 print_section_info (struct target_section_table *t, bfd *abfd)
776 struct gdbarch *gdbarch = gdbarch_from_bfd (abfd);
777 struct target_section *p;
778 /* FIXME: 16 is not wide enough when gdbarch_addr_bit > 64. */
779 int wid = gdbarch_addr_bit (gdbarch) <= 32 ? 8 : 16;
781 printf_filtered ("\t`%s', ", bfd_get_filename (abfd));
783 printf_filtered (_("file type %s.\n"), bfd_get_target (abfd));
784 if (abfd == exec_bfd)
786 /* gcc-3.4 does not like the initialization in
787 <p == t->sections_end>. */
788 bfd_vma displacement = 0;
791 for (p = t->sections; p < t->sections_end; p++)
793 struct bfd_section *psect = p->the_bfd_section;
794 bfd *pbfd = psect->owner;
796 if ((bfd_get_section_flags (pbfd, psect) & (SEC_ALLOC | SEC_LOAD))
797 != (SEC_ALLOC | SEC_LOAD))
800 if (bfd_get_section_vma (pbfd, psect) <= abfd->start_address
801 && abfd->start_address < (bfd_get_section_vma (pbfd, psect)
802 + bfd_get_section_size (psect)))
804 displacement = p->addr - bfd_get_section_vma (pbfd, psect);
808 if (p == t->sections_end)
809 warning (_("Cannot find section for the entry point of %s."),
810 bfd_get_filename (abfd));
812 entry_point = gdbarch_addr_bits_remove (gdbarch,
813 bfd_get_start_address (abfd)
815 printf_filtered (_("\tEntry point: %s\n"),
816 paddress (gdbarch, entry_point));
818 for (p = t->sections; p < t->sections_end; p++)
820 struct bfd_section *psect = p->the_bfd_section;
821 bfd *pbfd = psect->owner;
823 printf_filtered ("\t%s", hex_string_custom (p->addr, wid));
824 printf_filtered (" - %s", hex_string_custom (p->endaddr, wid));
826 /* FIXME: A format of "08l" is not wide enough for file offsets
827 larger than 4GB. OTOH, making it "016l" isn't desirable either
828 since most output will then be much wider than necessary. It
829 may make sense to test the size of the file and choose the
830 format string accordingly. */
831 /* FIXME: i18n: Need to rewrite this sentence. */
833 printf_filtered (" @ %s",
834 hex_string_custom (psect->filepos, 8));
835 printf_filtered (" is %s", bfd_section_name (pbfd, psect));
837 printf_filtered (" in %s", bfd_get_filename (pbfd));
838 printf_filtered ("\n");
843 exec_files_info (struct target_ops *t)
846 print_section_info (current_target_sections, exec_bfd);
848 puts_filtered (_("\t<no file loaded>\n"));
852 set_section_command (char *args, int from_tty)
854 struct target_section *p;
857 unsigned long secaddr;
860 struct target_section_table *table;
863 error (_("Must specify section name and its virtual address"));
865 /* Parse out section name. */
866 for (secname = args; !isspace (*args); args++);
867 seclen = args - secname;
869 /* Parse out new virtual address. */
870 secaddr = parse_and_eval_address (args);
872 table = current_target_sections;
873 for (p = table->sections; p < table->sections_end; p++)
875 if (!strncmp (secname, bfd_section_name (p->bfd,
876 p->the_bfd_section), seclen)
877 && bfd_section_name (p->bfd, p->the_bfd_section)[seclen] == '\0')
879 offset = secaddr - p->addr;
881 p->endaddr += offset;
883 exec_files_info (&exec_ops);
887 if (seclen >= sizeof (secprint))
888 seclen = sizeof (secprint) - 1;
889 strncpy (secprint, secname, seclen);
890 secprint[seclen] = '\0';
891 error (_("Section %s not found"), secprint);
894 /* If we can find a section in FILENAME with BFD index INDEX, adjust
898 exec_set_section_address (const char *filename, int index, CORE_ADDR address)
900 struct target_section *p;
901 struct target_section_table *table;
903 table = current_target_sections;
904 for (p = table->sections; p < table->sections_end; p++)
906 if (filename_cmp (filename, p->the_bfd_section->owner->filename) == 0
907 && index == p->the_bfd_section->index)
909 p->endaddr += address - p->addr;
915 /* If mourn is being called in all the right places, this could be say
916 `gdb internal error' (since generic_mourn calls
917 breakpoint_init_inferior). */
920 ignore (struct target_ops *ops, struct gdbarch *gdbarch,
921 struct bp_target_info *bp_tgt)
927 exec_has_memory (struct target_ops *ops)
929 /* We can provide memory if we have any file/target sections to read
931 return (current_target_sections->sections
932 != current_target_sections->sections_end);
935 static char *exec_make_note_section (struct target_ops *self, bfd *, int *);
937 /* Fill in the exec file target vector. Very few entries need to be
943 exec_ops.to_shortname = "exec";
944 exec_ops.to_longname = "Local exec file";
945 exec_ops.to_doc = "Use an executable file as a target.\n\
946 Specify the filename of the executable file.";
947 exec_ops.to_open = exec_open;
948 exec_ops.to_close = exec_close_1;
949 exec_ops.to_attach = find_default_attach;
950 exec_ops.to_xfer_partial = exec_xfer_partial;
951 exec_ops.to_get_section_table = exec_get_section_table;
952 exec_ops.to_files_info = exec_files_info;
953 exec_ops.to_insert_breakpoint = ignore;
954 exec_ops.to_remove_breakpoint = ignore;
955 exec_ops.to_create_inferior = find_default_create_inferior;
956 exec_ops.to_stratum = file_stratum;
957 exec_ops.to_has_memory = exec_has_memory;
958 exec_ops.to_make_corefile_notes = exec_make_note_section;
959 exec_ops.to_find_memory_regions = objfile_find_memory_regions;
960 exec_ops.to_magic = OPS_MAGIC;
964 _initialize_exec (void)
966 struct cmd_list_element *c;
972 c = add_cmd ("file", class_files, file_command, _("\
973 Use FILE as program to be debugged.\n\
974 It is read for its symbols, for getting the contents of pure memory,\n\
975 and it is the program executed when you use the `run' command.\n\
976 If FILE cannot be found as specified, your execution directory path\n\
977 ($PATH) is searched for a command of that name.\n\
978 No arg means to have no executable file and no symbols."), &cmdlist);
979 set_cmd_completer (c, filename_completer);
982 c = add_cmd ("exec-file", class_files, exec_file_command, _("\
983 Use FILE as program for getting contents of pure memory.\n\
984 If FILE cannot be found as specified, your execution directory path\n\
985 is searched for a command of that name.\n\
986 No arg means have no executable file."), &cmdlist);
987 set_cmd_completer (c, filename_completer);
989 add_com ("section", class_files, set_section_command, _("\
990 Change the base address of section SECTION of the exec file to ADDR.\n\
991 This can be used if the exec file does not contain section addresses,\n\
992 (such as in the a.out format), or when the addresses specified in the\n\
993 file itself are wrong. Each section must be changed separately. The\n\
994 ``info files'' command lists all the sections and their addresses."));
996 add_setshow_boolean_cmd ("write", class_support, &write_files, _("\
997 Set writing into executable and core files."), _("\
998 Show writing into executable and core files."), NULL,
1001 &setlist, &showlist);
1003 add_target_with_completer (&exec_ops, filename_completer);
1007 exec_make_note_section (struct target_ops *self, bfd *obfd, int *note_size)
1009 error (_("Can't create a corefile"));