1 /* Copyright (C) 2013-2021 Free Software Foundation, Inc.
3 This file is part of GDB.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19 #include "solib-aix.h"
26 #include "xcoffread.h"
27 #include "observable.h"
29 #include "gdbsupport/scope-exit.h"
31 /* Variable controlling the output of the debugging traces for
33 static bool solib_aix_debug
;
35 /* Print an "aix-solib" debug statement. */
37 #define solib_aix_debug_printf(fmt, ...) \
38 debug_prefixed_printf_cond (solib_aix_debug, "aix-solib",fmt, ##__VA_ARGS__)
40 /* Our private data in struct so_list. */
42 struct lm_info_aix
: public lm_info_base
44 /* The name of the file mapped by the loader. Apart from the entry
45 for the main executable, this is usually a shared library (which,
46 on AIX, is an archive library file, created using the "ar"
50 /* The name of the shared object file with the actual dynamic
51 loading dependency. This may be empty (Eg. main executable). */
52 std::string member_name
;
54 /* The address in inferior memory where the text section got mapped. */
55 CORE_ADDR text_addr
= 0;
57 /* The size of the text section, obtained via the loader data. */
58 ULONGEST text_size
= 0;
60 /* The address in inferior memory where the data section got mapped. */
61 CORE_ADDR data_addr
= 0;
63 /* The size of the data section, obtained via the loader data. */
64 ULONGEST data_size
= 0;
67 /* This module's per-inferior data. */
69 struct solib_aix_inferior_data
71 /* The list of shared libraries.
73 Note that the first element of this list is always the main
74 executable, which is not technically a shared library. But
75 we need that information to perform its relocation, and
76 the same principles applied to shared libraries also apply
77 to the main executable. So it's simpler to keep it as part
79 gdb::optional
<std::vector
<lm_info_aix
>> library_list
;
82 /* Key to our per-inferior data. */
83 static inferior_key
<solib_aix_inferior_data
> solib_aix_inferior_data_handle
;
85 /* Return this module's data for the given inferior.
86 If none is found, add a zero'ed one now. */
88 static struct solib_aix_inferior_data
*
89 get_solib_aix_inferior_data (struct inferior
*inf
)
91 struct solib_aix_inferior_data
*data
;
93 data
= solib_aix_inferior_data_handle
.get (inf
);
95 data
= solib_aix_inferior_data_handle
.emplace (inf
);
100 #if !defined(HAVE_LIBEXPAT)
102 /* Dummy implementation if XML support is not compiled in. */
104 static gdb::optional
<std::vector
<lm_info_aix
>>
105 solib_aix_parse_libraries (const char *library
)
107 static int have_warned
;
112 warning (_("Can not parse XML library list; XML support was disabled "
119 #else /* HAVE_LIBEXPAT */
121 #include "xml-support.h"
123 /* Handle the start of a <library> element. */
126 library_list_start_library (struct gdb_xml_parser
*parser
,
127 const struct gdb_xml_element
*element
,
129 std::vector
<gdb_xml_value
> &attributes
)
131 std::vector
<lm_info_aix
> *list
= (std::vector
<lm_info_aix
> *) user_data
;
133 struct gdb_xml_value
*attr
;
135 attr
= xml_find_attribute (attributes
, "name");
136 item
.filename
= (const char *) attr
->value
.get ();
138 attr
= xml_find_attribute (attributes
, "member");
140 item
.member_name
= (const char *) attr
->value
.get ();
142 attr
= xml_find_attribute (attributes
, "text_addr");
143 item
.text_addr
= * (ULONGEST
*) attr
->value
.get ();
145 attr
= xml_find_attribute (attributes
, "text_size");
146 item
.text_size
= * (ULONGEST
*) attr
->value
.get ();
148 attr
= xml_find_attribute (attributes
, "data_addr");
149 item
.data_addr
= * (ULONGEST
*) attr
->value
.get ();
151 attr
= xml_find_attribute (attributes
, "data_size");
152 item
.data_size
= * (ULONGEST
*) attr
->value
.get ();
154 list
->push_back (std::move (item
));
157 /* Handle the start of a <library-list-aix> element. */
160 library_list_start_list (struct gdb_xml_parser
*parser
,
161 const struct gdb_xml_element
*element
,
163 std::vector
<gdb_xml_value
> &attributes
)
166 = (char *) xml_find_attribute (attributes
, "version")->value
.get ();
168 if (strcmp (version
, "1.0") != 0)
169 gdb_xml_error (parser
,
170 _("Library list has unsupported version \"%s\""),
174 /* The allowed elements and attributes for an AIX library list
175 described in XML format. The root element is a <library-list-aix>. */
177 static const struct gdb_xml_attribute library_attributes
[] =
179 { "name", GDB_XML_AF_NONE
, NULL
, NULL
},
180 { "member", GDB_XML_AF_OPTIONAL
, NULL
, NULL
},
181 { "text_addr", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
182 { "text_size", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
183 { "data_addr", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
184 { "data_size", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
185 { NULL
, GDB_XML_AF_NONE
, NULL
, NULL
}
188 static const struct gdb_xml_element library_list_children
[] =
190 { "library", library_attributes
, NULL
,
191 GDB_XML_EF_REPEATABLE
| GDB_XML_EF_OPTIONAL
,
192 library_list_start_library
, NULL
},
193 { NULL
, NULL
, NULL
, GDB_XML_EF_NONE
, NULL
, NULL
}
196 static const struct gdb_xml_attribute library_list_attributes
[] =
198 { "version", GDB_XML_AF_NONE
, NULL
, NULL
},
199 { NULL
, GDB_XML_AF_NONE
, NULL
, NULL
}
202 static const struct gdb_xml_element library_list_elements
[] =
204 { "library-list-aix", library_list_attributes
, library_list_children
,
205 GDB_XML_EF_NONE
, library_list_start_list
, NULL
},
206 { NULL
, NULL
, NULL
, GDB_XML_EF_NONE
, NULL
, NULL
}
209 /* Parse LIBRARY, a string containing the loader info in XML format,
210 and return a vector of lm_info_aix objects.
212 Return an empty option if the parsing failed. */
214 static gdb::optional
<std::vector
<lm_info_aix
>>
215 solib_aix_parse_libraries (const char *library
)
217 std::vector
<lm_info_aix
> result
;
219 if (gdb_xml_parse_quick (_("aix library list"), "library-list-aix.dtd",
220 library_list_elements
, library
, &result
) == 0)
226 #endif /* HAVE_LIBEXPAT */
228 /* Return the loader info for the given inferior (INF), or an empty
229 option if the list could not be computed.
231 Cache the result in per-inferior data, so as to avoid recomputing it
232 each time this function is called.
234 If an error occurs while computing this list, and WARNING_MSG
235 is not NULL, then print a warning including WARNING_MSG and
236 a description of the error. */
238 static gdb::optional
<std::vector
<lm_info_aix
>> &
239 solib_aix_get_library_list (struct inferior
*inf
, const char *warning_msg
)
241 struct solib_aix_inferior_data
*data
;
243 /* If already computed, return the cached value. */
244 data
= get_solib_aix_inferior_data (inf
);
245 if (data
->library_list
.has_value ())
246 return data
->library_list
;
248 gdb::optional
<gdb::char_vector
> library_document
249 = target_read_stralloc (current_top_target (), TARGET_OBJECT_LIBRARIES_AIX
,
251 if (!library_document
&& warning_msg
!= NULL
)
253 warning (_("%s (failed to read TARGET_OBJECT_LIBRARIES_AIX)"),
255 return data
->library_list
;
258 solib_aix_debug_printf ("TARGET_OBJECT_LIBRARIES_AIX = %s",
259 library_document
->data ());
261 data
->library_list
= solib_aix_parse_libraries (library_document
->data ());
262 if (!data
->library_list
.has_value () && warning_msg
!= NULL
)
263 warning (_("%s (missing XML support?)"), warning_msg
);
265 return data
->library_list
;
268 /* If the .bss section's VMA is set to an address located before
269 the end of the .data section, causing the two sections to overlap,
270 return the overlap in bytes. Otherwise, return zero.
274 The GNU linker sometimes sets the start address of the .bss session
275 before the end of the .data section, making the 2 sections overlap.
276 The loader appears to handle this situation gracefully, by simply
277 loading the bss section right after the end of the .data section.
279 This means that the .data and the .bss sections are sometimes
280 no longer relocated by the same amount. The problem is that
281 the ldinfo data does not contain any information regarding
282 the relocation of the .bss section, assuming that it would be
283 identical to the information provided for the .data section
284 (this is what would normally happen if the program was linked
287 GDB therefore needs to detect those cases, and make the corresponding
288 adjustment to the .bss section offset computed from the ldinfo data
289 when necessary. This function returns the adjustment amount (or
290 zero when no adjustment is needed). */
293 solib_aix_bss_data_overlap (bfd
*abfd
)
295 struct bfd_section
*data_sect
, *bss_sect
;
297 data_sect
= bfd_get_section_by_name (abfd
, ".data");
298 if (data_sect
== NULL
)
299 return 0; /* No overlap possible. */
301 bss_sect
= bfd_get_section_by_name (abfd
, ".bss");
302 if (bss_sect
== NULL
)
303 return 0; /* No overlap possible. */
305 /* Assume the problem only occurs with linkers that place the .bss
306 section after the .data section (the problem has only been
307 observed when using the GNU linker, and the default linker
308 script always places the .data and .bss sections in that order). */
309 if (bfd_section_vma (bss_sect
) < bfd_section_vma (data_sect
))
312 if (bfd_section_vma (bss_sect
)
313 < bfd_section_vma (data_sect
) + bfd_section_size (data_sect
))
314 return (bfd_section_vma (data_sect
) + bfd_section_size (data_sect
)
315 - bfd_section_vma (bss_sect
));
320 /* Implement the "relocate_section_addresses" target_so_ops method. */
323 solib_aix_relocate_section_addresses (struct so_list
*so
,
324 struct target_section
*sec
)
326 struct bfd_section
*bfd_sect
= sec
->the_bfd_section
;
327 bfd
*abfd
= bfd_sect
->owner
;
328 const char *section_name
= bfd_section_name (bfd_sect
);
329 lm_info_aix
*info
= (lm_info_aix
*) so
->lm_info
;
331 if (strcmp (section_name
, ".text") == 0)
333 sec
->addr
= info
->text_addr
;
334 sec
->endaddr
= sec
->addr
+ info
->text_size
;
336 /* The text address given to us by the loader contains
337 XCOFF headers, so we need to adjust by this much. */
338 sec
->addr
+= bfd_sect
->filepos
;
340 else if (strcmp (section_name
, ".data") == 0)
342 sec
->addr
= info
->data_addr
;
343 sec
->endaddr
= sec
->addr
+ info
->data_size
;
345 else if (strcmp (section_name
, ".bss") == 0)
347 /* The information provided by the loader does not include
348 the address of the .bss section, but we know that it gets
349 relocated by the same offset as the .data section. So,
350 compute the relocation offset for the .data section, and
351 apply it to the .bss section as well. If the .data section
352 is not defined (which seems highly unlikely), do our best
353 by assuming no relocation. */
354 struct bfd_section
*data_sect
355 = bfd_get_section_by_name (abfd
, ".data");
356 CORE_ADDR data_offset
= 0;
358 if (data_sect
!= NULL
)
359 data_offset
= info
->data_addr
- bfd_section_vma (data_sect
);
361 sec
->addr
= bfd_section_vma (bfd_sect
) + data_offset
;
362 sec
->addr
+= solib_aix_bss_data_overlap (abfd
);
363 sec
->endaddr
= sec
->addr
+ bfd_section_size (bfd_sect
);
367 /* All other sections should not be relocated. */
368 sec
->addr
= bfd_section_vma (bfd_sect
);
369 sec
->endaddr
= sec
->addr
+ bfd_section_size (bfd_sect
);
373 /* Implement the "free_so" target_so_ops method. */
376 solib_aix_free_so (struct so_list
*so
)
378 lm_info_aix
*li
= (lm_info_aix
*) so
->lm_info
;
380 solib_aix_debug_printf ("%s", so
->so_name
);
385 /* Implement the "clear_solib" target_so_ops method. */
388 solib_aix_clear_solib (void)
390 /* Nothing needed. */
393 /* Compute and return the OBJFILE's section_offset array, using
394 the associated loader info (INFO). */
396 static section_offsets
397 solib_aix_get_section_offsets (struct objfile
*objfile
,
400 bfd
*abfd
= objfile
->obfd
;
402 section_offsets
offsets (objfile
->section_offsets
.size ());
406 if (objfile
->sect_index_text
!= -1)
408 struct bfd_section
*sect
409 = objfile
->sections
[objfile
->sect_index_text
].the_bfd_section
;
411 offsets
[objfile
->sect_index_text
]
412 = info
->text_addr
+ sect
->filepos
- bfd_section_vma (sect
);
417 if (objfile
->sect_index_data
!= -1)
419 struct bfd_section
*sect
420 = objfile
->sections
[objfile
->sect_index_data
].the_bfd_section
;
422 offsets
[objfile
->sect_index_data
]
423 = info
->data_addr
- bfd_section_vma (sect
);
428 The offset of the .bss section should be identical to the offset
429 of the .data section. If no .data section (which seems hard to
430 believe it is possible), assume it is zero. */
432 if (objfile
->sect_index_bss
!= -1
433 && objfile
->sect_index_data
!= -1)
435 offsets
[objfile
->sect_index_bss
]
436 = (offsets
[objfile
->sect_index_data
]
437 + solib_aix_bss_data_overlap (abfd
));
440 /* All other sections should not need relocation. */
445 /* Implement the "solib_create_inferior_hook" target_so_ops method. */
448 solib_aix_solib_create_inferior_hook (int from_tty
)
450 const char *warning_msg
= "unable to relocate main executable";
452 /* We need to relocate the main executable... */
454 gdb::optional
<std::vector
<lm_info_aix
>> &library_list
455 = solib_aix_get_library_list (current_inferior (), warning_msg
);
456 if (!library_list
.has_value ())
457 return; /* Warning already printed. */
459 if (library_list
->empty ())
461 warning (_("unable to relocate main executable (no info from loader)"));
465 lm_info_aix
&exec_info
= (*library_list
)[0];
466 if (current_program_space
->symfile_object_file
!= NULL
)
468 objfile
*objf
= current_program_space
->symfile_object_file
;
469 section_offsets offsets
= solib_aix_get_section_offsets (objf
,
472 objfile_relocate (objf
, offsets
);
476 /* Implement the "current_sos" target_so_ops method. */
478 static struct so_list
*
479 solib_aix_current_sos (void)
481 struct so_list
*start
= NULL
, *last
= NULL
;
484 gdb::optional
<std::vector
<lm_info_aix
>> &library_list
485 = solib_aix_get_library_list (current_inferior (), NULL
);
486 if (!library_list
.has_value ())
489 /* Build a struct so_list for each entry on the list.
490 We skip the first entry, since this is the entry corresponding
491 to the main executable, not a shared library. */
492 for (ix
= 1; ix
< library_list
->size (); ix
++)
494 struct so_list
*new_solib
= XCNEW (struct so_list
);
497 lm_info_aix
&info
= (*library_list
)[ix
];
498 if (info
.member_name
.empty ())
500 /* INFO.FILENAME is probably not an archive, but rather
501 a shared object. Unusual, but it should be possible
502 to link a program against a shared object directory,
503 without having to put it in an archive first. */
504 so_name
= info
.filename
;
508 /* This is the usual case on AIX, where the shared object
509 is a member of an archive. Create a synthetic so_name
510 that follows the same convention as AIX's ldd tool
511 (Eg: "/lib/libc.a(shr.o)"). */
512 so_name
= string_printf ("%s(%s)", info
.filename
.c_str (),
513 info
.member_name
.c_str ());
515 strncpy (new_solib
->so_original_name
, so_name
.c_str (),
516 SO_NAME_MAX_PATH_SIZE
- 1);
517 new_solib
->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
518 memcpy (new_solib
->so_name
, new_solib
->so_original_name
,
519 SO_NAME_MAX_PATH_SIZE
);
520 new_solib
->lm_info
= new lm_info_aix (info
);
522 /* Add it to the list. */
524 last
= start
= new_solib
;
527 last
->next
= new_solib
;
535 /* Implement the "open_symbol_file_object" target_so_ops method. */
538 solib_aix_open_symbol_file_object (int from_tty
)
543 /* Implement the "in_dynsym_resolve_code" target_so_ops method. */
546 solib_aix_in_dynsym_resolve_code (CORE_ADDR pc
)
551 /* Implement the "bfd_open" target_so_ops method. */
553 static gdb_bfd_ref_ptr
554 solib_aix_bfd_open (const char *pathname
)
556 /* The pathname is actually a synthetic filename with the following
557 form: "/path/to/sharedlib(member.o)" (double-quotes excluded).
558 split this into archive name and member name.
560 FIXME: This is a little hacky. Perhaps we should provide access
561 to the solib's lm_info here? */
562 const int path_len
= strlen (pathname
);
567 if (pathname
[path_len
- 1] != ')')
568 return solib_bfd_open (pathname
);
570 /* Search for the associated parens. */
571 sep
= strrchr (pathname
, '(');
574 /* Should never happen, but recover as best as we can (trying
575 to open pathname without decoding, possibly leading to
576 a failure), rather than triggering an assert failure). */
577 warning (_("missing '(' in shared object pathname: %s"), pathname
);
578 return solib_bfd_open (pathname
);
580 filename_len
= sep
- pathname
;
582 std::string
filename (string_printf ("%.*s", filename_len
, pathname
));
583 std::string
member_name (string_printf ("%.*s", path_len
- filename_len
- 2,
586 /* Calling solib_find makes certain that sysroot path is set properly
587 if program has a dependency on .a archive and sysroot is set via
588 set sysroot command. */
589 gdb::unique_xmalloc_ptr
<char> found_pathname
590 = solib_find (filename
.c_str (), &found_file
);
591 if (found_pathname
== NULL
)
592 perror_with_name (pathname
);
593 gdb_bfd_ref_ptr
archive_bfd (solib_bfd_fopen (found_pathname
.get (),
595 if (archive_bfd
== NULL
)
597 warning (_("Could not open `%s' as an executable file: %s"),
598 filename
.c_str (), bfd_errmsg (bfd_get_error ()));
602 if (bfd_check_format (archive_bfd
.get (), bfd_object
))
605 if (! bfd_check_format (archive_bfd
.get (), bfd_archive
))
607 warning (_("\"%s\": not in executable format: %s."),
608 filename
.c_str (), bfd_errmsg (bfd_get_error ()));
612 gdb_bfd_ref_ptr object_bfd
613 (gdb_bfd_openr_next_archived_file (archive_bfd
.get (), NULL
));
614 while (object_bfd
!= NULL
)
616 if (member_name
== bfd_get_filename (object_bfd
.get ()))
619 object_bfd
= gdb_bfd_openr_next_archived_file (archive_bfd
.get (),
623 if (object_bfd
== NULL
)
625 warning (_("\"%s\": member \"%s\" missing."), filename
.c_str (),
626 member_name
.c_str ());
630 if (! bfd_check_format (object_bfd
.get (), bfd_object
))
632 warning (_("%s(%s): not in object format: %s."),
633 filename
.c_str (), member_name
.c_str (),
634 bfd_errmsg (bfd_get_error ()));
638 /* Override the returned bfd's name with the name returned from solib_find
639 along with appended parenthesized member name in order to allow commands
640 listing all shared libraries to display. Otherwise, we would only be
641 displaying the name of the archive member object. */
642 std::string fname
= string_printf ("%s%s",
643 bfd_get_filename (archive_bfd
.get ()),
645 bfd_set_filename (object_bfd
.get (), fname
.c_str ());
650 /* Return the obj_section corresponding to OBJFILE's data section,
651 or NULL if not found. */
652 /* FIXME: Define in a more general location? */
654 static struct obj_section
*
655 data_obj_section_from_objfile (struct objfile
*objfile
)
657 struct obj_section
*osect
;
659 ALL_OBJFILE_OSECTIONS (objfile
, osect
)
660 if (strcmp (bfd_section_name (osect
->the_bfd_section
), ".data") == 0)
666 /* Return the TOC value corresponding to the given PC address,
667 or raise an error if the value could not be determined. */
670 solib_aix_get_toc_value (CORE_ADDR pc
)
672 struct obj_section
*pc_osect
= find_pc_section (pc
);
673 struct obj_section
*data_osect
;
676 if (pc_osect
== NULL
)
677 error (_("unable to find TOC entry for pc %s "
678 "(no section contains this PC)"),
679 core_addr_to_string (pc
));
681 data_osect
= data_obj_section_from_objfile (pc_osect
->objfile
);
682 if (data_osect
== NULL
)
683 error (_("unable to find TOC entry for pc %s "
684 "(%s has no data section)"),
685 core_addr_to_string (pc
), objfile_name (pc_osect
->objfile
));
687 result
= (obj_section_addr (data_osect
)
688 + xcoff_get_toc_offset (pc_osect
->objfile
));
690 solib_aix_debug_printf ("pc=%s -> %s", core_addr_to_string (pc
),
691 core_addr_to_string (result
));
696 /* This module's normal_stop observer. */
699 solib_aix_normal_stop_observer (struct bpstats
*unused_1
, int unused_2
)
701 struct solib_aix_inferior_data
*data
702 = get_solib_aix_inferior_data (current_inferior ());
704 /* The inferior execution has been resumed, and it just stopped
705 again. This means that the list of shared libraries may have
706 evolved. Reset our cached value. */
707 data
->library_list
.reset ();
710 /* Implements the "show debug aix-solib" command. */
713 show_solib_aix_debug (struct ui_file
*file
, int from_tty
,
714 struct cmd_list_element
*c
, const char *value
)
716 fprintf_filtered (file
, _("solib-aix debugging is %s.\n"), value
);
719 /* The target_so_ops for AIX targets. */
720 struct target_so_ops solib_aix_so_ops
;
722 void _initialize_solib_aix ();
724 _initialize_solib_aix ()
726 solib_aix_so_ops
.relocate_section_addresses
727 = solib_aix_relocate_section_addresses
;
728 solib_aix_so_ops
.free_so
= solib_aix_free_so
;
729 solib_aix_so_ops
.clear_solib
= solib_aix_clear_solib
;
730 solib_aix_so_ops
.solib_create_inferior_hook
731 = solib_aix_solib_create_inferior_hook
;
732 solib_aix_so_ops
.current_sos
= solib_aix_current_sos
;
733 solib_aix_so_ops
.open_symbol_file_object
734 = solib_aix_open_symbol_file_object
;
735 solib_aix_so_ops
.in_dynsym_resolve_code
736 = solib_aix_in_dynsym_resolve_code
;
737 solib_aix_so_ops
.bfd_open
= solib_aix_bfd_open
;
739 gdb::observers::normal_stop
.attach (solib_aix_normal_stop_observer
);
741 /* Debug this file's internals. */
742 add_setshow_boolean_cmd ("aix-solib", class_maintenance
,
743 &solib_aix_debug
, _("\
744 Control the debugging traces for the solib-aix module."), _("\
745 Show whether solib-aix debugging traces are enabled."), _("\
746 When on, solib-aix debugging traces are enabled."),
748 show_solib_aix_debug
,
749 &setdebuglist
, &showdebuglist
);