1 /* ELF emulation code for targets using elf.em.
2 Copyright (C) 1991-2023 Free Software Foundation, Inc.
4 This file is part of the GNU Binutils.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
23 #include "libiberty.h"
24 #include "filenames.h"
25 #include "safe-ctype.h"
35 #include "ldbuildid.h"
52 /* Style of .note.gnu.build-id section. */
53 const char *ldelf_emit_note_gnu_build_id
;
55 /* Content of .note.package section. */
56 const char *ldelf_emit_note_fdo_package_metadata
;
58 /* These variables are required to pass information back and forth
59 between after_open and check_needed and stat_needed and vercheck. */
61 static struct bfd_link_needed_list
*global_needed
;
62 static lang_input_statement_type
*global_found
;
63 static struct stat global_stat
;
64 static struct bfd_link_needed_list
*global_vercheck_needed
;
65 static bool global_vercheck_failed
;
68 ldelf_after_parse (void)
70 if (bfd_link_pie (&link_info
))
71 link_info
.flags_1
|= (bfd_vma
) DF_1_PIE
;
73 if (bfd_link_executable (&link_info
)
74 && link_info
.nointerp
)
76 if (link_info
.dynamic_undefined_weak
> 0)
77 einfo (_("%P: warning: -z dynamic-undefined-weak ignored\n"));
78 link_info
.dynamic_undefined_weak
= 0;
81 /* Disable DT_RELR if not building PIE nor shared library. */
82 if (!bfd_link_pic (&link_info
))
83 link_info
.enable_dt_relr
= 0;
85 /* Add 3 spare tags for DT_RELR, DT_RELRSZ and DT_RELRENT. */
86 if (link_info
.enable_dt_relr
)
87 link_info
.spare_dynamic_tags
+= 3;
89 after_parse_default ();
90 if (link_info
.commonpagesize
> link_info
.maxpagesize
)
92 if (!link_info
.commonpagesize_is_set
)
93 link_info
.commonpagesize
= link_info
.maxpagesize
;
94 else if (!link_info
.maxpagesize_is_set
)
95 link_info
.maxpagesize
= link_info
.commonpagesize
;
97 einfo (_("%F%P: common page size (0x%v) > maximum page size (0x%v)\n"),
98 link_info
.commonpagesize
, link_info
.maxpagesize
);
102 /* Handle the generation of DT_NEEDED tags. */
105 ldelf_load_symbols (lang_input_statement_type
*entry
)
109 /* Tell the ELF linker that we don't want the output file to have a
110 DT_NEEDED entry for this file, unless it is used to resolve
111 references in a regular object. */
112 if (entry
->flags
.add_DT_NEEDED_for_regular
)
113 link_class
= DYN_AS_NEEDED
;
115 /* Tell the ELF linker that we don't want the output file to have a
116 DT_NEEDED entry for any dynamic library in DT_NEEDED tags from
118 if (!entry
->flags
.add_DT_NEEDED_for_dynamic
)
119 link_class
|= DYN_NO_ADD_NEEDED
;
121 if (entry
->flags
.just_syms
122 && (bfd_get_file_flags (entry
->the_bfd
) & DYNAMIC
) != 0)
123 einfo (_("%F%P: %pB: --just-symbols may not be used on DSO\n"),
127 || (bfd_get_file_flags (entry
->the_bfd
) & DYNAMIC
) == 0)
130 bfd_elf_set_dyn_lib_class (entry
->the_bfd
,
131 (enum dynamic_lib_link_class
) link_class
);
133 /* Continue on with normal load_symbols processing. */
137 /* On Linux, it's possible to have different versions of the same
138 shared library linked against different versions of libc. The
139 dynamic linker somehow tags which libc version to use in
140 /etc/ld.so.cache, and, based on the libc that it sees in the
141 executable, chooses which version of the shared library to use.
143 We try to do a similar check here by checking whether this shared
144 library needs any other shared libraries which may conflict with
145 libraries we have already included in the link. If it does, we
146 skip it, and try to find another shared library farther on down the
149 This is called via lang_for_each_input_file.
150 GLOBAL_VERCHECK_NEEDED is the list of objects needed by the object
151 which we are checking. This sets GLOBAL_VERCHECK_FAILED if we find
152 a conflicting version. */
155 ldelf_vercheck (lang_input_statement_type
*s
)
158 struct bfd_link_needed_list
*l
;
160 if (global_vercheck_failed
)
162 if (s
->the_bfd
== NULL
163 || (bfd_get_file_flags (s
->the_bfd
) & DYNAMIC
) == 0)
166 soname
= bfd_elf_get_dt_soname (s
->the_bfd
);
168 soname
= lbasename (bfd_get_filename (s
->the_bfd
));
170 for (l
= global_vercheck_needed
; l
!= NULL
; l
= l
->next
)
174 if (filename_cmp (soname
, l
->name
) == 0)
176 /* Probably can't happen, but it's an easy check. */
180 if (strchr (l
->name
, '/') != NULL
)
183 suffix
= strstr (l
->name
, ".so.");
187 suffix
+= sizeof ".so." - 1;
189 if (filename_ncmp (soname
, l
->name
, suffix
- l
->name
) == 0)
191 /* Here we know that S is a dynamic object FOO.SO.VER1, and
192 the object we are considering needs a dynamic object
193 FOO.SO.VER2, and VER1 and VER2 are different. This
194 appears to be a version mismatch, so we tell the caller
195 to try a different version of this library. */
196 global_vercheck_failed
= true;
203 /* See if an input file matches a DT_NEEDED entry by running stat on
207 ldelf_stat_needed (lang_input_statement_type
*s
)
213 if (global_found
!= NULL
)
215 if (s
->the_bfd
== NULL
)
218 /* If this input file was an as-needed entry, and wasn't found to be
219 needed at the stage it was linked, then don't say we have loaded it. */
220 if ((bfd_elf_get_dyn_lib_class (s
->the_bfd
) & DYN_AS_NEEDED
) != 0)
223 if (bfd_stat (s
->the_bfd
, &st
) != 0)
225 einfo (_("%P: %pB: bfd_stat failed: %E\n"), s
->the_bfd
);
229 /* Some operating systems, e.g. Windows, do not provide a meaningful
230 st_ino; they always set it to zero. (Windows does provide a
231 meaningful st_dev.) Do not indicate a duplicate library in that
232 case. While there is no guarantee that a system that provides
233 meaningful inode numbers will never set st_ino to zero, this is
234 merely an optimization, so we do not need to worry about false
236 if (st
.st_dev
== global_stat
.st_dev
237 && st
.st_ino
== global_stat
.st_ino
244 /* We issue a warning if it looks like we are including two
245 different versions of the same shared library. For example,
246 there may be a problem if -lc picks up libc.so.6 but some other
247 shared library has a DT_NEEDED entry of libc.so.5. This is a
248 heuristic test, and it will only work if the name looks like
249 NAME.so.VERSION. FIXME: Depending on file names is error-prone.
250 If we really want to issue warnings about mixing version numbers
251 of shared libraries, we need to find a better way. */
253 if (strchr (global_needed
->name
, '/') != NULL
)
255 suffix
= strstr (global_needed
->name
, ".so.");
258 suffix
+= sizeof ".so." - 1;
260 soname
= bfd_elf_get_dt_soname (s
->the_bfd
);
262 soname
= lbasename (s
->filename
);
264 if (filename_ncmp (soname
, global_needed
->name
,
265 suffix
- global_needed
->name
) == 0)
266 einfo (_("%P: warning: %s, needed by %pB, may conflict with %s\n"),
267 global_needed
->name
, global_needed
->by
, soname
);
270 /* This function is called for each possible name for a dynamic object
271 named by a DT_NEEDED entry. The FORCE parameter indicates whether
272 to skip the check for a conflicting version. */
275 ldelf_try_needed (struct dt_needed
*needed
, int force
, int is_linux
)
278 const char *name
= needed
->name
;
282 abfd
= bfd_openr (name
, bfd_get_target (link_info
.output_bfd
));
286 info_msg (_("attempt to open %s failed\n"), name
);
290 track_dependency_files (name
);
292 /* Linker needs to decompress sections. */
293 abfd
->flags
|= BFD_DECOMPRESS
;
295 if (! bfd_check_format (abfd
, bfd_object
))
300 if ((bfd_get_file_flags (abfd
) & DYNAMIC
) == 0)
306 /* For DT_NEEDED, they have to match. */
307 if (abfd
->xvec
!= link_info
.output_bfd
->xvec
)
313 /* Check whether this object would include any conflicting library
314 versions. If FORCE is set, then we skip this check; we use this
315 the second time around, if we couldn't find any compatible
316 instance of the shared library. */
320 struct bfd_link_needed_list
*needs
;
322 if (! bfd_elf_get_bfd_needed_list (abfd
, &needs
))
323 einfo (_("%F%P: %pB: bfd_elf_get_bfd_needed_list failed: %E\n"), abfd
);
327 global_vercheck_needed
= needs
;
328 global_vercheck_failed
= false;
329 lang_for_each_input_file (ldelf_vercheck
);
330 if (global_vercheck_failed
)
333 /* Return FALSE to force the caller to move on to try
334 another file on the search path. */
338 /* But wait! It gets much worse. On Linux, if a shared
339 library does not use libc at all, we are supposed to skip
340 it the first time around in case we encounter a shared
341 library later on with the same name which does use the
342 version of libc that we want. This is much too horrible
343 to use on any system other than Linux. */
346 struct bfd_link_needed_list
*l
;
348 for (l
= needs
; l
!= NULL
; l
= l
->next
)
349 if (startswith (l
->name
, "libc.so"))
360 /* We've found a dynamic object matching the DT_NEEDED entry. */
362 /* We have already checked that there is no other input file of the
363 same name. We must now check again that we are not including the
364 same file twice. We need to do this because on many systems
365 libc.so is a symlink to, e.g., libc.so.1. The SONAME entry will
366 reference libc.so.1. If we have already included libc.so, we
367 don't want to include libc.so.1 if they are the same file, and we
368 can only check that using stat. */
370 if (bfd_stat (abfd
, &global_stat
) != 0)
371 einfo (_("%F%P: %pB: bfd_stat failed: %E\n"), abfd
);
373 /* First strip off everything before the last '/'. */
374 soname
= lbasename (bfd_get_filename (abfd
));
377 info_msg (_("found %s at %s\n"), soname
, name
);
380 lang_for_each_input_file (ldelf_stat_needed
);
381 if (global_found
!= NULL
)
383 /* Return TRUE to indicate that we found the file, even though
384 we aren't going to do anything with it. */
388 /* Specify the soname to use. */
389 bfd_elf_set_dt_needed_name (abfd
, soname
);
391 /* Tell the ELF linker that we don't want the output file to have a
392 DT_NEEDED entry for this file, unless it is used to resolve
393 references in a regular object. */
394 link_class
= DYN_DT_NEEDED
;
396 /* Tell the ELF linker that we don't want the output file to have a
397 DT_NEEDED entry for this file at all if the entry is from a file
398 with DYN_NO_ADD_NEEDED. */
399 if (needed
->by
!= NULL
400 && (bfd_elf_get_dyn_lib_class (needed
->by
) & DYN_NO_ADD_NEEDED
) != 0)
401 link_class
|= DYN_NO_NEEDED
| DYN_NO_ADD_NEEDED
;
403 bfd_elf_set_dyn_lib_class (abfd
, (enum dynamic_lib_link_class
) link_class
);
405 *link_info
.input_bfds_tail
= abfd
;
406 link_info
.input_bfds_tail
= &abfd
->link
.next
;
408 /* Add this file into the symbol table. */
409 if (! bfd_link_add_symbols (abfd
, &link_info
))
410 einfo (_("%F%P: %pB: error adding symbols: %E\n"), abfd
);
415 /* Search for a needed file in a path. */
418 ldelf_search_needed (const char *path
, struct dt_needed
*n
, int force
,
419 int is_linux
, int elfsize
)
422 const char *name
= n
->name
;
424 struct dt_needed needed
;
427 return ldelf_try_needed (n
, force
, is_linux
);
429 if (path
== NULL
|| *path
== '\0')
433 needed
.name
= n
->name
;
440 char *filename
, *sset
;
442 s
= strchr (path
, config
.rpath_separator
);
444 s
= path
+ strlen (path
);
446 #if HAVE_DOS_BASED_FILE_SYSTEM
447 /* Assume a match on the second char is part of drive specifier. */
448 else if (config
.rpath_separator
== ':'
452 s
= strchr (s
+ 1, config
.rpath_separator
);
454 s
= path
+ strlen (path
);
457 filename
= (char *) xmalloc (s
- path
+ len
+ 2);
462 memcpy (filename
, path
, s
- path
);
463 filename
[s
- path
] = '/';
464 sset
= filename
+ (s
- path
) + 1;
468 /* PR 20535: Support the same pseudo-environment variables that
469 are supported by ld.so. Namely, $ORIGIN, $LIB and $PLATFORM.
470 Since there can be more than one occurrence of these tokens in
471 the path we loop until no more are found. Since we might not
472 be able to substitute some of the tokens we maintain an offset
473 into the filename for where we should begin our scan. */
474 while ((var
= strchr (filename
+ offset
, '$')) != NULL
)
476 /* The ld.so manual page does not say, but I am going to assume that
477 these tokens are terminated by a directory separator character
478 (/) or the end of the string. There is also an implication that
479 $ORIGIN should only be used at the start of a path, but that is
482 The ld.so manual page also states that it allows ${ORIGIN},
483 ${LIB} and ${PLATFORM}, so these are supported as well.
485 FIXME: The code could be a lot cleverer about allocating space
486 for the processed string. */
487 char * end
= strchr (var
, '/');
488 const char *replacement
= NULL
;
490 char * freeme
= NULL
;
491 unsigned flen
= strlen (filename
);
494 /* Temporarily terminate the filename at the end of the token. */
502 if (strcmp (v
, "RIGIN") == 0 || strcmp (v
, "RIGIN}") == 0)
504 /* ORIGIN - replace with the full path to the directory
505 containing the program or shared object. */
506 if (needed
.by
== NULL
)
508 if (link_info
.output_bfd
== NULL
)
513 replacement
= bfd_get_filename (link_info
.output_bfd
);
516 replacement
= bfd_get_filename (needed
.by
);
522 if (replacement
[0] == '/')
523 freeme
= xstrdup (replacement
);
526 char * current_dir
= getpwd ();
528 freeme
= xmalloc (strlen (replacement
)
529 + strlen (current_dir
) + 2);
530 sprintf (freeme
, "%s/%s", current_dir
, replacement
);
533 replacement
= freeme
;
534 if ((slash
= strrchr (replacement
, '/')) != NULL
)
541 if (strcmp (v
, "IB") == 0 || strcmp (v
, "IB}") == 0)
543 /* LIB - replace with "lib" in 32-bit environments
544 and "lib64" in 64-bit environments. */
548 case 32: replacement
= "lib"; break;
549 case 64: replacement
= "lib64"; break;
557 /* Supporting $PLATFORM in a cross-hosted environment is not
558 possible. Supporting it in a native environment involves
559 loading the <sys/auxv.h> header file which loads the
560 system <elf.h> header file, which conflicts with the
561 "include/elf/mips.h" header file. */
569 char * filename2
= xmalloc (flen
+ strlen (replacement
));
573 sprintf (filename2
, "%.*s%s/%s",
574 (int)(var
- filename
), filename
,
575 replacement
, end
+ 1);
576 offset
= (var
- filename
) + 1 + strlen (replacement
);
580 sprintf (filename2
, "%.*s%s",
581 (int)(var
- filename
), filename
,
583 offset
= var
- filename
+ strlen (replacement
);
587 filename
= filename2
;
588 /* There is no need to restore the path separator (when
589 end != NULL) as we have replaced the entire string. */
594 /* We only issue an "unrecognised" message in verbose mode
595 as the $<foo> token might be a legitimate component of
596 a path name in the target's file system. */
597 info_msg (_("unrecognised or unsupported token "
598 "'%s' in search path\n"), var
);
600 /* Restore the path separator. */
603 /* PR 20784: Make sure that we resume the scan *after*
604 the token that we could not replace. */
605 offset
= (var
+ 1) - filename
;
611 needed
.name
= filename
;
613 if (ldelf_try_needed (&needed
, force
, is_linux
))
626 /* Prefix the sysroot to absolute paths in PATH, a string containing
627 paths separated by config.rpath_separator. If running on a DOS
628 file system, paths containing a drive spec won't have the sysroot
629 prefix added, unless the sysroot also specifies the same drive. */
632 ldelf_add_sysroot (const char *path
)
637 int dos_drive_sysroot
= HAS_DRIVE_SPEC (ld_sysroot
);
639 len
= strlen (ld_sysroot
);
640 for (extra
= 0, p
= path
; ; )
642 int dos_drive
= HAS_DRIVE_SPEC (p
);
646 if (IS_DIR_SEPARATOR (*p
)
648 || (dos_drive_sysroot
649 && ld_sysroot
[0] == p
[-2])))
651 if (dos_drive
&& dos_drive_sysroot
)
656 p
= strchr (p
, config
.rpath_separator
);
662 ret
= xmalloc (strlen (path
) + extra
+ 1);
664 for (q
= ret
, p
= path
; ; )
667 int dos_drive
= HAS_DRIVE_SPEC (p
);
674 if (IS_DIR_SEPARATOR (*p
)
676 || (dos_drive_sysroot
677 && ld_sysroot
[0] == p
[-2])))
679 if (dos_drive
&& dos_drive_sysroot
)
681 strcpy (q
, ld_sysroot
+ 2);
686 strcpy (q
, ld_sysroot
);
690 end
= strchr (p
, config
.rpath_separator
);
693 size_t n
= end
- p
+ 1;
708 /* Read the system search path the FreeBSD way rather than the Linux way. */
709 #ifdef HAVE_ELF_HINTS_H
710 #include <elf-hints.h>
712 #include "elf-hints-local.h"
716 ldelf_check_ld_elf_hints (const struct bfd_link_needed_list
*l
, int force
,
719 static bool initialized
;
720 static const char *ld_elf_hints
;
721 struct dt_needed needed
;
728 tmppath
= concat (ld_sysroot
, _PATH_ELF_HINTS
, (const char *) NULL
);
729 f
= fopen (tmppath
, FOPEN_RB
);
733 struct elfhints_hdr hdr
;
735 if (fread (&hdr
, 1, sizeof (hdr
), f
) == sizeof (hdr
)
736 && hdr
.magic
== ELFHINTS_MAGIC
739 if (fseek (f
, hdr
.strtab
+ hdr
.dirlist
, SEEK_SET
) != -1)
743 b
= xmalloc (hdr
.dirlistlen
+ 1);
744 if (fread (b
, 1, hdr
.dirlistlen
+ 1, f
) ==
746 ld_elf_hints
= ldelf_add_sysroot (b
);
757 if (ld_elf_hints
== NULL
)
761 needed
.name
= l
->name
;
762 return ldelf_search_needed (ld_elf_hints
, &needed
, force
, false, elfsize
);
765 /* For a native linker, check the file /etc/ld.so.conf for directories
766 in which we may find shared libraries. /etc/ld.so.conf is really
767 only meaningful on Linux. */
769 struct ldelf_ld_so_conf
776 ldelf_parse_ld_so_conf (struct ldelf_ld_so_conf
*, const char *);
779 ldelf_parse_ld_so_conf_include (struct ldelf_ld_so_conf
*info
,
780 const char *filename
,
788 if (pattern
[0] != '/')
790 char *p
= strrchr (filename
, '/');
791 size_t patlen
= strlen (pattern
) + 1;
793 newp
= xmalloc (p
- filename
+ 1 + patlen
);
794 memcpy (newp
, filename
, p
- filename
+ 1);
795 memcpy (newp
+ (p
- filename
+ 1), pattern
, patlen
);
800 if (glob (pattern
, 0, NULL
, &gl
) == 0)
804 for (i
= 0; i
< gl
.gl_pathc
; ++i
)
805 ldelf_parse_ld_so_conf (info
, gl
.gl_pathv
[i
]);
809 /* If we do not have glob, treat the pattern as a literal filename. */
810 ldelf_parse_ld_so_conf (info
, pattern
);
817 ldelf_parse_ld_so_conf (struct ldelf_ld_so_conf
*info
, const char *filename
)
819 FILE *f
= fopen (filename
, FOPEN_RT
);
827 line
= xmalloc (linelen
);
832 /* Normally this would use getline(3), but we need to be portable. */
833 while ((q
= fgets (p
, linelen
- (p
- line
), f
)) != NULL
834 && strlen (q
) == linelen
- (p
- line
) - 1
835 && line
[linelen
- 2] != '\n')
837 line
= xrealloc (line
, 2 * linelen
);
838 p
= line
+ linelen
- 1;
842 if (q
== NULL
&& p
== line
)
845 p
= strchr (line
, '\n');
849 /* Because the file format does not know any form of quoting we
850 can search forward for the next '#' character and if found
851 make it terminating the line. */
852 p
= strchr (line
, '#');
856 /* Remove leading whitespace. NUL is no whitespace character. */
858 while (*p
== ' ' || *p
== '\f' || *p
== '\r' || *p
== '\t' || *p
== '\v')
861 /* If the line is blank it is ignored. */
865 if (startswith (p
, "include") && (p
[7] == ' ' || p
[7] == '\t'))
871 while (*p
== ' ' || *p
== '\t')
879 while (*p
!= ' ' && *p
!= '\t' && *p
)
885 ldelf_parse_ld_so_conf_include (info
, filename
, dir
);
892 while (*p
&& *p
!= '=' && *p
!= ' ' && *p
!= '\t' && *p
!= '\f'
893 && *p
!= '\r' && *p
!= '\v')
896 while (p
!= dir
&& p
[-1] == '/')
898 if (info
->path
== NULL
)
900 info
->alloc
= p
- dir
+ 1 + 256;
901 info
->path
= xmalloc (info
->alloc
);
906 if (info
->len
+ 1 + (p
- dir
) >= info
->alloc
)
908 info
->alloc
+= p
- dir
+ 256;
909 info
->path
= xrealloc (info
->path
, info
->alloc
);
911 info
->path
[info
->len
++] = config
.rpath_separator
;
913 memcpy (info
->path
+ info
->len
, dir
, p
- dir
);
914 info
->len
+= p
- dir
;
915 info
->path
[info
->len
] = '\0';
925 ldelf_check_ld_so_conf (const struct bfd_link_needed_list
*l
, int force
,
926 int elfsize
, const char *prefix
)
928 static bool initialized
;
929 static const char *ld_so_conf
;
930 struct dt_needed needed
;
935 struct ldelf_ld_so_conf info
;
938 info
.len
= info
.alloc
= 0;
939 tmppath
= concat (ld_sysroot
, prefix
, "/etc/ld.so.conf",
940 (const char *) NULL
);
941 if (!ldelf_parse_ld_so_conf (&info
, tmppath
))
944 tmppath
= concat (ld_sysroot
, "/etc/ld.so.conf",
945 (const char *) NULL
);
946 ldelf_parse_ld_so_conf (&info
, tmppath
);
952 ld_so_conf
= ldelf_add_sysroot (info
.path
);
958 if (ld_so_conf
== NULL
)
963 needed
.name
= l
->name
;
964 return ldelf_search_needed (ld_so_conf
, &needed
, force
, true, elfsize
);
967 /* See if an input file matches a DT_NEEDED entry by name. */
970 ldelf_check_needed (lang_input_statement_type
*s
)
974 /* Stop looking if we've found a loaded lib. */
975 if (global_found
!= NULL
976 && (bfd_elf_get_dyn_lib_class (global_found
->the_bfd
)
977 & DYN_AS_NEEDED
) == 0)
980 if (s
->filename
== NULL
|| s
->the_bfd
== NULL
)
983 /* Don't look for a second non-loaded as-needed lib. */
984 if (global_found
!= NULL
985 && (bfd_elf_get_dyn_lib_class (s
->the_bfd
) & DYN_AS_NEEDED
) != 0)
988 if (filename_cmp (s
->filename
, global_needed
->name
) == 0)
994 if (s
->flags
.search_dirs
)
996 const char *f
= strrchr (s
->filename
, '/');
998 && filename_cmp (f
+ 1, global_needed
->name
) == 0)
1005 soname
= bfd_elf_get_dt_soname (s
->the_bfd
);
1007 && filename_cmp (soname
, global_needed
->name
) == 0)
1015 ldelf_handle_dt_needed (struct elf_link_hash_table
*htab
,
1016 int use_libpath
, int native
, int is_linux
,
1017 int is_freebsd
, int elfsize
, const char *prefix
)
1019 struct bfd_link_needed_list
*needed
, *l
;
1021 bfd
**save_input_bfd_tail
;
1023 /* Get the list of files which appear in DT_NEEDED entries in
1024 dynamic objects included in the link (often there will be none).
1025 For each such file, we want to track down the corresponding
1026 library, and include the symbol table in the link. This is what
1027 the runtime dynamic linker will do. Tracking the files down here
1028 permits one dynamic object to include another without requiring
1029 special action by the person doing the link. Note that the
1030 needed list can actually grow while we are stepping through this
1032 save_input_bfd_tail
= link_info
.input_bfds_tail
;
1033 needed
= bfd_elf_get_needed_list (link_info
.output_bfd
, &link_info
);
1034 for (l
= needed
; l
!= NULL
; l
= l
->next
)
1036 struct bfd_link_needed_list
*ll
;
1037 struct dt_needed n
, nn
;
1040 /* If the lib that needs this one was --as-needed and wasn't
1041 found to be needed, then this lib isn't needed either. */
1043 && (bfd_elf_get_dyn_lib_class (l
->by
) & DYN_AS_NEEDED
) != 0)
1046 /* Skip the lib if --no-copy-dt-needed-entries and when we are
1047 handling DT_NEEDED entries or --allow-shlib-undefined is in
1050 && (htab
->handling_dt_needed
1051 || link_info
.unresolved_syms_in_shared_libs
== RM_IGNORE
)
1052 && (bfd_elf_get_dyn_lib_class (l
->by
) & DYN_NO_ADD_NEEDED
) != 0)
1055 /* If we've already seen this file, skip it. */
1056 for (ll
= needed
; ll
!= l
; ll
= ll
->next
)
1058 || (bfd_elf_get_dyn_lib_class (ll
->by
) & DYN_AS_NEEDED
) == 0)
1059 && strcmp (ll
->name
, l
->name
) == 0)
1064 /* See if this file was included in the link explicitly. */
1066 global_found
= NULL
;
1067 lang_for_each_input_file (ldelf_check_needed
);
1068 if (global_found
!= NULL
1069 && (bfd_elf_get_dyn_lib_class (global_found
->the_bfd
)
1070 & DYN_AS_NEEDED
) == 0)
1077 info_msg (_("%s needed by %pB\n"), l
->name
, l
->by
);
1079 /* As-needed libs specified on the command line (or linker script)
1080 take priority over libs found in search dirs. */
1081 if (global_found
!= NULL
)
1083 nn
.name
= global_found
->filename
;
1084 if (ldelf_try_needed (&nn
, true, is_linux
))
1088 /* We need to find this file and include the symbol table. We
1089 want to search for the file in the same way that the dynamic
1090 linker will search. That means that we want to use
1091 rpath_link, rpath, then the environment variable
1092 LD_LIBRARY_PATH (native only), then the DT_RPATH/DT_RUNPATH
1093 entries (native only), then the linker script LIB_SEARCH_DIRS.
1094 We do not search using the -L arguments.
1096 We search twice. The first time, we skip objects which may
1097 introduce version mismatches. The second time, we force
1098 their use. See ldelf_vercheck comment. */
1099 for (force
= 0; force
< 2; force
++)
1102 search_dirs_type
*search
;
1104 struct bfd_link_needed_list
*rp
;
1107 if (ldelf_search_needed (command_line
.rpath_link
, &n
, force
,
1113 path
= command_line
.rpath
;
1116 path
= ldelf_add_sysroot (path
);
1117 found
= ldelf_search_needed (path
, &n
, force
,
1119 free ((char *) path
);
1126 if (command_line
.rpath_link
== NULL
1127 && command_line
.rpath
== NULL
)
1129 path
= (const char *) getenv ("LD_RUN_PATH");
1131 && ldelf_search_needed (path
, &n
, force
,
1135 path
= (const char *) getenv ("LD_LIBRARY_PATH");
1137 && ldelf_search_needed (path
, &n
, force
,
1144 rp
= bfd_elf_get_runpath_list (link_info
.output_bfd
, &link_info
);
1145 for (; !found
&& rp
!= NULL
; rp
= rp
->next
)
1147 path
= ldelf_add_sysroot (rp
->name
);
1148 found
= (rp
->by
== l
->by
1149 && ldelf_search_needed (path
, &n
, force
,
1150 is_linux
, elfsize
));
1151 free ((char *) path
);
1157 && ldelf_check_ld_elf_hints (l
, force
, elfsize
))
1161 && ldelf_check_ld_so_conf (l
, force
, elfsize
, prefix
))
1165 len
= strlen (l
->name
);
1166 for (search
= search_head
; search
!= NULL
; search
= search
->next
)
1170 if (search
->cmdline
)
1172 filename
= (char *) xmalloc (strlen (search
->name
) + len
+ 2);
1173 sprintf (filename
, "%s/%s", search
->name
, l
->name
);
1175 if (ldelf_try_needed (&nn
, force
, is_linux
))
1186 einfo (_("%P: warning: %s, needed by %pB, not found "
1187 "(try using -rpath or -rpath-link)\n"),
1191 /* Don't add DT_NEEDED when loading shared objects from DT_NEEDED for
1192 plugin symbol resolution while handling DT_NEEDED entries. */
1193 if (!htab
->handling_dt_needed
)
1194 for (abfd
= link_info
.input_bfds
; abfd
; abfd
= abfd
->link
.next
)
1195 if (bfd_get_format (abfd
) == bfd_object
1196 && ((abfd
->flags
) & DYNAMIC
) != 0
1197 && bfd_get_flavour (abfd
) == bfd_target_elf_flavour
1198 && (elf_dyn_lib_class (abfd
) & (DYN_AS_NEEDED
| DYN_NO_NEEDED
)) == 0
1199 && elf_dt_name (abfd
) != NULL
)
1201 if (bfd_elf_add_dt_needed_tag (abfd
, &link_info
) < 0)
1202 einfo (_("%F%P: failed to add DT_NEEDED dynamic tag\n"));
1205 link_info
.input_bfds_tail
= save_input_bfd_tail
;
1206 *save_input_bfd_tail
= NULL
;
1209 /* This is called before calling plugin 'all symbols read' hook. */
1212 ldelf_before_plugin_all_symbols_read (int use_libpath
, int native
,
1213 int is_linux
, int is_freebsd
,
1214 int elfsize
, const char *prefix
)
1216 struct elf_link_hash_table
*htab
= elf_hash_table (&link_info
);
1218 if (!link_info
.lto_plugin_active
1219 || !is_elf_hash_table (&htab
->root
))
1222 htab
->handling_dt_needed
= true;
1223 ldelf_handle_dt_needed (htab
, use_libpath
, native
, is_linux
,
1224 is_freebsd
, elfsize
, prefix
);
1225 htab
->handling_dt_needed
= false;
1228 /* This is called after all the input files have been opened and all
1229 symbols have been loaded. */
1232 ldelf_after_open (int use_libpath
, int native
, int is_linux
, int is_freebsd
,
1233 int elfsize
, const char *prefix
)
1235 struct elf_link_hash_table
*htab
;
1239 after_open_default ();
1241 htab
= elf_hash_table (&link_info
);
1242 if (!is_elf_hash_table (&htab
->root
))
1245 if (command_line
.out_implib_filename
)
1247 unlink_if_ordinary (command_line
.out_implib_filename
);
1248 link_info
.out_implib_bfd
1249 = bfd_openw (command_line
.out_implib_filename
,
1250 bfd_get_target (link_info
.output_bfd
));
1252 if (link_info
.out_implib_bfd
== NULL
)
1254 einfo (_("%F%P: %s: can't open for writing: %E\n"),
1255 command_line
.out_implib_filename
);
1259 if (ldelf_emit_note_gnu_build_id
!= NULL
1260 || ldelf_emit_note_fdo_package_metadata
!= NULL
)
1262 /* Find an ELF input. */
1263 for (abfd
= link_info
.input_bfds
;
1264 abfd
!= (bfd
*) NULL
; abfd
= abfd
->link
.next
)
1265 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
1266 && bfd_count_sections (abfd
) != 0
1267 && !bfd_input_just_syms (abfd
))
1270 /* PR 10555: If there are no ELF input files do not try to
1271 create a .note.gnu-build-id section. */
1273 || (ldelf_emit_note_gnu_build_id
!= NULL
1274 && !ldelf_setup_build_id (abfd
)))
1276 free ((char *) ldelf_emit_note_gnu_build_id
);
1277 ldelf_emit_note_gnu_build_id
= NULL
;
1281 || (ldelf_emit_note_fdo_package_metadata
!= NULL
1282 && !ldelf_setup_package_metadata (abfd
)))
1284 free ((char *) ldelf_emit_note_fdo_package_metadata
);
1285 ldelf_emit_note_fdo_package_metadata
= NULL
;
1289 get_elf_backend_data (link_info
.output_bfd
)->setup_gnu_properties (&link_info
);
1291 /* Do not allow executable files to be used as inputs to the link. */
1292 for (abfd
= link_info
.input_bfds
; abfd
; abfd
= abfd
->link
.next
)
1294 /* Discard input .note.gnu.build-id sections. */
1295 s
= bfd_get_section_by_name (abfd
, ".note.gnu.build-id");
1298 if (s
!= elf_tdata (link_info
.output_bfd
)->o
->build_id
.sec
)
1299 s
->flags
|= SEC_EXCLUDE
;
1300 s
= bfd_get_next_section_by_name (NULL
, s
);
1303 if (abfd
->xvec
->flavour
== bfd_target_elf_flavour
1304 && !bfd_input_just_syms (abfd
)
1305 && elf_tdata (abfd
) != NULL
1306 /* FIXME: Maybe check for other non-supportable types as well ? */
1307 && (elf_tdata (abfd
)->elf_header
->e_type
== ET_EXEC
1308 || (elf_tdata (abfd
)->elf_header
->e_type
== ET_DYN
1309 && elf_tdata (abfd
)->is_pie
)))
1310 einfo (_("%F%P: cannot use executable file '%pB' as input to a link\n"),
1314 if (bfd_link_relocatable (&link_info
))
1316 if (link_info
.execstack
== !link_info
.noexecstack
)
1318 /* PR ld/16744: If "-z [no]execstack" has been specified on the
1319 command line and we are perfoming a relocatable link then no
1320 PT_GNU_STACK segment will be created and so the
1321 linkinfo.[no]execstack values set in _handle_option() will have no
1322 effect. Instead we create a .note.GNU-stack section in much the
1323 same way as the assembler does with its --[no]execstack option. */
1324 flagword flags
= SEC_READONLY
| (link_info
.execstack
? SEC_CODE
: 0);
1325 (void) bfd_make_section_with_flags (link_info
.input_bfds
,
1326 ".note.GNU-stack", flags
);
1331 if (!link_info
.traditional_format
)
1334 bool warn_eh_frame
= false;
1337 for (abfd
= link_info
.input_bfds
; abfd
; abfd
= abfd
->link
.next
)
1341 if (bfd_input_just_syms (abfd
))
1344 for (s
= abfd
->sections
; s
&& type
< COMPACT_EH_HDR
; s
= s
->next
)
1346 const char *name
= bfd_section_name (s
);
1348 if (bfd_is_abs_section (s
->output_section
))
1350 if (startswith (name
, ".eh_frame_entry"))
1351 type
= COMPACT_EH_HDR
;
1352 else if (strcmp (name
, ".eh_frame") == 0 && s
->size
> 8)
1353 type
= DWARF2_EH_HDR
;
1362 else if (seen_type
!= type
)
1364 einfo (_("%F%P: compact frame descriptions incompatible with"
1365 " DWARF2 .eh_frame from %pB\n"),
1366 type
== DWARF2_EH_HDR
? abfd
: elfbfd
);
1371 && (type
== COMPACT_EH_HDR
1372 || link_info
.eh_frame_hdr_type
!= 0))
1374 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
1377 warn_eh_frame
= true;
1381 if (seen_type
== COMPACT_EH_HDR
)
1382 link_info
.eh_frame_hdr_type
= COMPACT_EH_HDR
;
1386 const struct elf_backend_data
*bed
;
1388 bed
= get_elf_backend_data (elfbfd
);
1389 s
= bfd_make_section_with_flags (elfbfd
, ".eh_frame_hdr",
1390 bed
->dynamic_sec_flags
1393 && bfd_set_section_alignment (s
, 2))
1395 htab
->eh_info
.hdr_sec
= s
;
1396 warn_eh_frame
= false;
1400 einfo (_("%P: warning: cannot create .eh_frame_hdr section,"
1401 " --eh-frame-hdr ignored\n"));
1404 if (link_info
.eh_frame_hdr_type
== COMPACT_EH_HDR
)
1405 if (!bfd_elf_parse_eh_frame_entries (NULL
, &link_info
))
1406 einfo (_("%F%P: failed to parse EH frame entries\n"));
1408 ldelf_handle_dt_needed (htab
, use_libpath
, native
, is_linux
,
1409 is_freebsd
, elfsize
, prefix
);
1412 static bfd_size_type
1413 id_note_section_size (bfd
*abfd ATTRIBUTE_UNUSED
)
1415 const char *style
= ldelf_emit_note_gnu_build_id
;
1417 bfd_size_type build_id_size
;
1419 size
= offsetof (Elf_External_Note
, name
[sizeof "GNU"]);
1420 size
= (size
+ 3) & -(bfd_size_type
) 4;
1422 build_id_size
= compute_build_id_size (style
);
1424 size
+= build_id_size
;
1432 write_build_id (bfd
*abfd
)
1434 const struct elf_backend_data
*bed
= get_elf_backend_data (abfd
);
1435 struct elf_obj_tdata
*t
= elf_tdata (abfd
);
1438 Elf_Internal_Shdr
*i_shdr
;
1439 unsigned char *contents
, *id_bits
;
1442 Elf_External_Note
*e_note
;
1444 style
= t
->o
->build_id
.style
;
1445 asec
= t
->o
->build_id
.sec
;
1446 if (bfd_is_abs_section (asec
->output_section
))
1448 einfo (_("%P: warning: .note.gnu.build-id section discarded,"
1449 " --build-id ignored\n"));
1452 i_shdr
= &elf_section_data (asec
->output_section
)->this_hdr
;
1454 if (i_shdr
->contents
== NULL
)
1456 if (asec
->contents
== NULL
)
1457 asec
->contents
= (unsigned char *) xmalloc (asec
->size
);
1458 contents
= asec
->contents
;
1461 contents
= i_shdr
->contents
+ asec
->output_offset
;
1463 e_note
= (Elf_External_Note
*) contents
;
1464 size
= offsetof (Elf_External_Note
, name
[sizeof "GNU"]);
1465 size
= (size
+ 3) & -(bfd_size_type
) 4;
1466 id_bits
= contents
+ size
;
1467 size
= asec
->size
- size
;
1469 /* Clear the build ID field. */
1470 memset (id_bits
, 0, size
);
1472 bfd_h_put_32 (abfd
, sizeof "GNU", &e_note
->namesz
);
1473 bfd_h_put_32 (abfd
, size
, &e_note
->descsz
);
1474 bfd_h_put_32 (abfd
, NT_GNU_BUILD_ID
, &e_note
->type
);
1475 memcpy (e_note
->name
, "GNU", sizeof "GNU");
1477 generate_build_id (abfd
, style
, bed
->s
->checksum_contents
, id_bits
, size
);
1479 position
= i_shdr
->sh_offset
+ asec
->output_offset
;
1481 return (bfd_seek (abfd
, position
, SEEK_SET
) == 0
1482 && bfd_bwrite (contents
, size
, abfd
) == size
);
1485 /* Make .note.gnu.build-id section, and set up elf_tdata->build_id. */
1488 ldelf_setup_build_id (bfd
*ibfd
)
1494 size
= id_note_section_size (ibfd
);
1497 einfo (_("%P: warning: unrecognized --build-id style ignored\n"));
1501 flags
= (SEC_ALLOC
| SEC_LOAD
| SEC_IN_MEMORY
1502 | SEC_LINKER_CREATED
| SEC_READONLY
| SEC_DATA
);
1503 s
= bfd_make_section_anyway_with_flags (ibfd
, ".note.gnu.build-id",
1505 if (s
!= NULL
&& bfd_set_section_alignment (s
, 2))
1507 struct elf_obj_tdata
*t
= elf_tdata (link_info
.output_bfd
);
1508 t
->o
->build_id
.after_write_object_contents
= &write_build_id
;
1509 t
->o
->build_id
.style
= ldelf_emit_note_gnu_build_id
;
1510 t
->o
->build_id
.sec
= s
;
1511 elf_section_type (s
) = SHT_NOTE
;
1516 einfo (_("%P: warning: cannot create .note.gnu.build-id section,"
1517 " --build-id ignored\n"));
1522 write_package_metadata (bfd
*abfd
)
1524 struct elf_obj_tdata
*t
= elf_tdata (abfd
);
1527 Elf_Internal_Shdr
*i_shdr
;
1528 unsigned char *contents
, *json_bits
;
1531 Elf_External_Note
*e_note
;
1533 json
= t
->o
->package_metadata
.json
;
1534 asec
= t
->o
->package_metadata
.sec
;
1535 if (bfd_is_abs_section (asec
->output_section
))
1537 einfo (_("%P: warning: .note.package section discarded,"
1538 " --package-metadata ignored\n"));
1541 i_shdr
= &elf_section_data (asec
->output_section
)->this_hdr
;
1543 if (i_shdr
->contents
== NULL
)
1545 if (asec
->contents
== NULL
)
1546 asec
->contents
= (unsigned char *) xmalloc (asec
->size
);
1547 contents
= asec
->contents
;
1550 contents
= i_shdr
->contents
+ asec
->output_offset
;
1552 e_note
= (Elf_External_Note
*) contents
;
1553 size
= offsetof (Elf_External_Note
, name
[sizeof "FDO"]);
1554 size
= (size
+ 3) & -(bfd_size_type
) 4;
1555 json_bits
= contents
+ size
;
1556 size
= asec
->size
- size
;
1558 /* Clear the package metadata field. */
1559 memset (json_bits
, 0, size
);
1561 bfd_h_put_32 (abfd
, sizeof "FDO", &e_note
->namesz
);
1562 bfd_h_put_32 (abfd
, size
, &e_note
->descsz
);
1563 bfd_h_put_32 (abfd
, FDO_PACKAGING_METADATA
, &e_note
->type
);
1564 memcpy (e_note
->name
, "FDO", sizeof "FDO");
1565 memcpy (json_bits
, json
, strlen(json
));
1567 position
= i_shdr
->sh_offset
+ asec
->output_offset
;
1569 return (bfd_seek (abfd
, position
, SEEK_SET
) == 0
1570 && bfd_bwrite (contents
, size
, abfd
) == size
);
1573 /* Make .note.package section.
1574 https://systemd.io/ELF_PACKAGE_METADATA/ */
1577 ldelf_setup_package_metadata (bfd
*ibfd
)
1584 /* If the option wasn't specified, silently return. */
1585 if (!ldelf_emit_note_fdo_package_metadata
)
1588 /* The option was specified, but it's empty, log and return. */
1589 json_length
= strlen (ldelf_emit_note_fdo_package_metadata
);
1590 if (json_length
== 0)
1592 einfo (_("%P: warning: --package-metadata is empty, ignoring\n"));
1597 json_error_t json_error
;
1598 json_t
*json
= json_loads (ldelf_emit_note_fdo_package_metadata
,
1602 einfo (_("%P: warning: --package-metadata=%s does not contain valid "
1603 "JSON, ignoring: %s\n"),
1604 ldelf_emit_note_fdo_package_metadata
, json_error
.text
);
1611 size
= offsetof (Elf_External_Note
, name
[sizeof "FDO"]);
1612 size
+= json_length
+ 1;
1613 size
= (size
+ 3) & -(bfd_size_type
) 4;
1615 flags
= (SEC_ALLOC
| SEC_LOAD
| SEC_IN_MEMORY
1616 | SEC_LINKER_CREATED
| SEC_READONLY
| SEC_DATA
);
1617 s
= bfd_make_section_anyway_with_flags (ibfd
, ".note.package",
1619 if (s
!= NULL
&& bfd_set_section_alignment (s
, 2))
1621 struct elf_obj_tdata
*t
= elf_tdata (link_info
.output_bfd
);
1622 t
->o
->package_metadata
.after_write_object_contents
1623 = &write_package_metadata
;
1624 t
->o
->package_metadata
.json
= ldelf_emit_note_fdo_package_metadata
;
1625 t
->o
->package_metadata
.sec
= s
;
1626 elf_section_type (s
) = SHT_NOTE
;
1631 einfo (_("%P: warning: cannot create .note.package section,"
1632 " --package-metadata ignored\n"));
1636 /* Look through an expression for an assignment statement. */
1639 ldelf_find_exp_assignment (etree_type
*exp
)
1641 bool provide
= false;
1643 switch (exp
->type
.node_class
)
1646 case etree_provided
:
1650 /* We call record_link_assignment even if the symbol is defined.
1651 This is because if it is defined by a dynamic object, we
1652 actually want to use the value defined by the linker script,
1653 not the value from the dynamic object (because we are setting
1654 symbols like etext). If the symbol is defined by a regular
1655 object, then, as it happens, calling record_link_assignment
1657 if (strcmp (exp
->assign
.dst
, ".") != 0)
1659 if (!bfd_elf_record_link_assignment (link_info
.output_bfd
,
1661 exp
->assign
.dst
, provide
,
1662 exp
->assign
.hidden
))
1663 einfo (_("%F%P: failed to record assignment to %s: %E\n"),
1666 ldelf_find_exp_assignment (exp
->assign
.src
);
1670 ldelf_find_exp_assignment (exp
->binary
.lhs
);
1671 ldelf_find_exp_assignment (exp
->binary
.rhs
);
1675 ldelf_find_exp_assignment (exp
->trinary
.cond
);
1676 ldelf_find_exp_assignment (exp
->trinary
.lhs
);
1677 ldelf_find_exp_assignment (exp
->trinary
.rhs
);
1681 ldelf_find_exp_assignment (exp
->unary
.child
);
1689 /* This is called by the before_allocation routine via
1690 lang_for_each_statement. It locates any assignment statements, and
1691 tells the ELF backend about them, in case they are assignments to
1692 symbols which are referred to by dynamic objects. */
1695 ldelf_find_statement_assignment (lang_statement_union_type
*s
)
1697 if (s
->header
.type
== lang_assignment_statement_enum
)
1698 ldelf_find_exp_assignment (s
->assignment_statement
.exp
);
1701 /* Used by before_allocation and handle_option. */
1704 ldelf_append_to_separated_string (char **to
, char *op_arg
)
1707 *to
= xstrdup (op_arg
);
1710 size_t to_len
= strlen (*to
);
1711 size_t op_arg_len
= strlen (op_arg
);
1715 /* First see whether OPTARG is already in the path. */
1718 if (strncmp (op_arg
, cp
, op_arg_len
) == 0
1719 && (cp
[op_arg_len
] == 0
1720 || cp
[op_arg_len
] == config
.rpath_separator
))
1724 /* Not yet found. */
1725 cp
= strchr (cp
, config
.rpath_separator
);
1733 buf
= xmalloc (to_len
+ op_arg_len
+ 2);
1734 sprintf (buf
, "%s%c%s", *to
,
1735 config
.rpath_separator
, op_arg
);
1742 /* This is called after the sections have been attached to output
1743 sections, but before any sizes or addresses have been set. */
1746 ldelf_before_allocation (char *audit
, char *depaudit
,
1747 const char *default_interpreter_name
)
1752 struct bfd_link_hash_entry
*ehdr_start
= NULL
;
1753 unsigned char ehdr_start_save_type
= 0;
1754 char ehdr_start_save_u
[sizeof ehdr_start
->u
1755 - sizeof ehdr_start
->u
.def
.next
] = "";
1757 if (is_elf_hash_table (link_info
.hash
))
1759 _bfd_elf_tls_setup (link_info
.output_bfd
, &link_info
);
1761 /* Make __ehdr_start hidden if it has been referenced, to
1762 prevent the symbol from being dynamic. */
1763 if (!bfd_link_relocatable (&link_info
))
1765 struct elf_link_hash_table
*htab
= elf_hash_table (&link_info
);
1766 struct elf_link_hash_entry
*h
1767 = elf_link_hash_lookup (htab
, "__ehdr_start", false, false, true);
1769 /* Only adjust the export class if the symbol was referenced
1770 and not defined, otherwise leave it alone. */
1772 && (h
->root
.type
== bfd_link_hash_new
1773 || h
->root
.type
== bfd_link_hash_undefined
1774 || h
->root
.type
== bfd_link_hash_undefweak
1775 || h
->root
.type
== bfd_link_hash_common
))
1777 /* Don't leave the symbol undefined. Undefined hidden
1778 symbols typically won't have dynamic relocations, but
1779 we most likely will need dynamic relocations for
1780 __ehdr_start if we are building a PIE or shared
1782 ehdr_start
= &h
->root
;
1783 ehdr_start_save_type
= ehdr_start
->type
;
1784 memcpy (ehdr_start_save_u
,
1785 (char *) &ehdr_start
->u
+ sizeof ehdr_start
->u
.def
.next
,
1786 sizeof ehdr_start_save_u
);
1787 ehdr_start
->type
= bfd_link_hash_defined
;
1788 /* It will be converted to section-relative later. */
1789 ehdr_start
->u
.def
.section
= bfd_abs_section_ptr
;
1790 ehdr_start
->u
.def
.value
= 0;
1794 /* If we are going to make any variable assignments, we need to
1795 let the ELF backend know about them in case the variables are
1796 referred to by dynamic objects. */
1797 lang_for_each_statement (ldelf_find_statement_assignment
);
1800 /* Let the ELF backend work out the sizes of any sections required
1801 by dynamic linking. */
1802 rpath
= command_line
.rpath
;
1804 rpath
= (const char *) getenv ("LD_RUN_PATH");
1806 for (abfd
= link_info
.input_bfds
; abfd
; abfd
= abfd
->link
.next
)
1807 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
1809 const char *audit_libs
= elf_dt_audit (abfd
);
1811 /* If the input bfd contains an audit entry, we need to add it as
1812 a dep audit entry. */
1813 if (audit_libs
&& *audit_libs
!= '\0')
1815 char *cp
= xstrdup (audit_libs
);
1819 char *cp2
= strchr (cp
, config
.rpath_separator
);
1827 if (cp
!= NULL
&& *cp
!= '\0')
1828 ldelf_append_to_separated_string (&depaudit
, cp
);
1830 cp
= more
? ++cp2
: NULL
;
1836 if (! (bfd_elf_size_dynamic_sections
1837 (link_info
.output_bfd
, command_line
.soname
, rpath
,
1838 command_line
.filter_shlib
, audit
, depaudit
,
1839 (const char * const *) command_line
.auxiliary_filters
,
1840 &link_info
, &sinterp
)))
1841 einfo (_("%F%P: failed to set dynamic section sizes: %E\n"));
1843 if (sinterp
!= NULL
)
1845 /* Let the user override the dynamic linker we are using. */
1846 if (command_line
.interpreter
!= NULL
)
1847 default_interpreter_name
= command_line
.interpreter
;
1848 if (default_interpreter_name
!= NULL
)
1850 sinterp
->contents
= (bfd_byte
*) default_interpreter_name
;
1851 sinterp
->size
= strlen ((char *) sinterp
->contents
) + 1;
1855 /* Look for any sections named .gnu.warning. As a GNU extensions,
1856 we treat such sections as containing warning messages. We print
1857 out the warning message, and then zero out the section size so
1858 that it does not get copied into the output file. */
1861 LANG_FOR_EACH_INPUT_STATEMENT (is
)
1867 if (is
->flags
.just_syms
)
1870 s
= bfd_get_section_by_name (is
->the_bfd
, ".gnu.warning");
1875 msg
= (char *) xmalloc ((size_t) (sz
+ 1));
1876 if (! bfd_get_section_contents (is
->the_bfd
, s
, msg
,
1878 einfo (_("%F%P: %pB: can't read contents of section .gnu.warning: %E\n"),
1881 (*link_info
.callbacks
->warning
) (&link_info
, msg
,
1882 (const char *) NULL
, is
->the_bfd
,
1883 (asection
*) NULL
, (bfd_vma
) 0);
1886 /* Clobber the section size, so that we don't waste space
1887 copying the warning into the output file. If we've already
1888 sized the output section, adjust its size. The adjustment
1889 is on rawsize because targets that size sections early will
1890 have called lang_reset_memory_regions after sizing. */
1891 if (s
->output_section
!= NULL
1892 && s
->output_section
->rawsize
>= s
->size
)
1893 s
->output_section
->rawsize
-= s
->size
;
1897 /* Also set SEC_EXCLUDE, so that local symbols defined in the
1898 warning section don't get copied to the output. */
1899 s
->flags
|= SEC_EXCLUDE
| SEC_KEEP
;
1903 before_allocation_default ();
1905 if (!bfd_elf_size_dynsym_hash_dynstr (link_info
.output_bfd
, &link_info
))
1906 einfo (_("%F%P: failed to set dynamic section sizes: %E\n"));
1908 if (ehdr_start
!= NULL
)
1910 /* If we twiddled __ehdr_start to defined earlier, put it back
1912 ehdr_start
->type
= ehdr_start_save_type
;
1913 memcpy ((char *) &ehdr_start
->u
+ sizeof ehdr_start
->u
.def
.next
,
1915 sizeof ehdr_start_save_u
);
1918 /* Try to open a dynamic archive. This is where we know that ELF
1919 dynamic libraries have an extension of .so (or .sl on oddball systems
1923 ldelf_open_dynamic_archive (const char *arch
, search_dirs_type
*search
,
1924 lang_input_statement_type
*entry
)
1926 const char *filename
;
1929 bool opened
= false;
1931 if (! entry
->flags
.maybe_archive
)
1934 filename
= entry
->filename
;
1935 len
= strlen (search
->name
) + strlen (filename
);
1936 if (entry
->flags
.full_name_provided
)
1939 string
= (char *) xmalloc (len
);
1940 sprintf (string
, "%s/%s", search
->name
, filename
);
1946 len
+= strlen (arch
) + sizeof "/lib.so";
1947 #ifdef EXTRA_SHLIB_EXTENSION
1948 xlen
= (strlen (EXTRA_SHLIB_EXTENSION
) > 3
1949 ? strlen (EXTRA_SHLIB_EXTENSION
) - 3
1952 string
= (char *) xmalloc (len
+ xlen
);
1953 sprintf (string
, "%s/lib%s%s.so", search
->name
, filename
, arch
);
1954 #ifdef EXTRA_SHLIB_EXTENSION
1955 /* Try the .so extension first. If that fails build a new filename
1956 using EXTRA_SHLIB_EXTENSION. */
1957 opened
= ldfile_try_open_bfd (string
, entry
);
1959 strcpy (string
+ len
- 4, EXTRA_SHLIB_EXTENSION
);
1963 if (!opened
&& !ldfile_try_open_bfd (string
, entry
))
1969 entry
->filename
= string
;
1971 /* We have found a dynamic object to include in the link. The ELF
1972 backend linker will create a DT_NEEDED entry in the .dynamic
1973 section naming this file. If this file includes a DT_SONAME
1974 entry, it will be used. Otherwise, the ELF linker will just use
1975 the name of the file. For an archive found by searching, like
1976 this one, the DT_NEEDED entry should consist of just the name of
1977 the file, without the path information used to find it. Note
1978 that we only need to do this if we have a dynamic object; an
1979 archive will never be referenced by a DT_NEEDED entry.
1981 FIXME: This approach--using bfd_elf_set_dt_needed_name--is not
1982 very pretty. I haven't been able to think of anything that is
1984 if (bfd_check_format (entry
->the_bfd
, bfd_object
)
1985 && (entry
->the_bfd
->flags
& DYNAMIC
) != 0)
1987 ASSERT (entry
->flags
.maybe_archive
&& entry
->flags
.search_dirs
);
1989 /* Rather than duplicating the logic above. Just use the
1990 filename we recorded earlier. */
1992 if (!entry
->flags
.full_name_provided
)
1993 filename
= lbasename (entry
->filename
);
1994 bfd_elf_set_dt_needed_name (entry
->the_bfd
, filename
);
2000 /* A variant of lang_output_section_find used by place_orphan. */
2002 static lang_output_section_statement_type
*
2003 output_rel_find (int isdyn
, int rela
)
2005 lang_output_section_statement_type
*lookup
;
2006 lang_output_section_statement_type
*last
= NULL
;
2007 lang_output_section_statement_type
*last_alloc
= NULL
;
2008 lang_output_section_statement_type
*last_ro_alloc
= NULL
;
2009 lang_output_section_statement_type
*last_rel
= NULL
;
2010 lang_output_section_statement_type
*last_rel_alloc
= NULL
;
2012 for (lookup
= (void *) lang_os_list
.head
;
2014 lookup
= lookup
->next
)
2016 if (lookup
->constraint
>= 0
2017 && startswith (lookup
->name
, ".rel"))
2019 int lookrela
= lookup
->name
[4] == 'a';
2021 /* .rel.dyn must come before all other reloc sections, to suit
2026 /* Don't place after .rel.plt as doing so results in wrong
2028 if (strcmp (".plt", lookup
->name
+ 4 + lookrela
) == 0)
2031 if (rela
== lookrela
|| last_rel
== NULL
)
2033 if ((rela
== lookrela
|| last_rel_alloc
== NULL
)
2034 && lookup
->bfd_section
!= NULL
2035 && (lookup
->bfd_section
->flags
& SEC_ALLOC
) != 0)
2036 last_rel_alloc
= lookup
;
2040 if (lookup
->bfd_section
!= NULL
2041 && (lookup
->bfd_section
->flags
& SEC_ALLOC
) != 0)
2043 last_alloc
= lookup
;
2044 if ((lookup
->bfd_section
->flags
& SEC_READONLY
) != 0)
2045 last_ro_alloc
= lookup
;
2050 return last_rel_alloc
;
2056 return last_ro_alloc
;
2064 /* Return whether IN is suitable to be part of OUT. */
2067 elf_orphan_compatible (asection
*in
, asection
*out
)
2069 /* Non-zero sh_info implies a section with SHF_INFO_LINK with
2070 unknown semantics for the generic linker, or a SHT_REL/SHT_RELA
2071 section where sh_info specifies a symbol table. (We won't see
2072 SHT_GROUP, SHT_SYMTAB or SHT_DYNSYM sections here.) We clearly
2073 can't merge SHT_REL/SHT_RELA using differing symbol tables, and
2074 shouldn't merge sections with differing unknown semantics. */
2075 if (elf_section_data (out
)->this_hdr
.sh_info
2076 != elf_section_data (in
)->this_hdr
.sh_info
)
2078 /* We can't merge with a member of an output section group or merge
2079 two sections with differing SHF_EXCLUDE or other processor and OS
2080 specific flags when doing a relocatable link. */
2081 if (bfd_link_relocatable (&link_info
)
2082 && (elf_next_in_group (out
) != NULL
2083 || ((elf_section_flags (out
) ^ elf_section_flags (in
))
2084 & (SHF_MASKPROC
| SHF_MASKOS
)) != 0))
2086 return _bfd_elf_match_sections_by_type (link_info
.output_bfd
, out
,
2090 /* Place an orphan section. We use this to put random SHF_ALLOC
2091 sections in the right segment. */
2093 lang_output_section_statement_type
*
2094 ldelf_place_orphan (asection
*s
, const char *secname
, int constraint
)
2096 static struct orphan_save hold
[] =
2099 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_CODE
,
2102 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_DATA
,
2105 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_DATA
| SEC_THREAD_LOCAL
,
2108 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_DATA
,
2114 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_DATA
,
2117 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_READONLY
| SEC_DATA
,
2120 SEC_HAS_CONTENTS
| SEC_ALLOC
| SEC_LOAD
| SEC_DATA
| SEC_SMALL_DATA
,
2126 enum orphan_save_index
2138 static int orphan_init_done
= 0;
2139 struct orphan_save
*place
;
2140 lang_output_section_statement_type
*after
;
2141 lang_output_section_statement_type
*os
;
2142 lang_output_section_statement_type
*match_by_name
= NULL
;
2144 int elfinput
= s
->owner
->xvec
->flavour
== bfd_target_elf_flavour
;
2145 int elfoutput
= link_info
.output_bfd
->xvec
->flavour
== bfd_target_elf_flavour
;
2146 unsigned int sh_type
= elfinput
? elf_section_type (s
) : SHT_NULL
;
2150 if (!bfd_link_relocatable (&link_info
)
2151 && link_info
.combreloc
2152 && (s
->flags
& SEC_ALLOC
))
2158 secname
= ".rela.dyn";
2162 secname
= ".rel.dyn";
2168 else if (startswith (secname
, ".rel"))
2170 secname
= secname
[4] == 'a' ? ".rela.dyn" : ".rel.dyn";
2175 if (!bfd_link_relocatable (&link_info
)
2178 && (s
->flags
& SEC_ALLOC
) != 0
2179 && (elf_tdata (s
->owner
)->has_gnu_osabi
& elf_gnu_osabi_mbind
) != 0
2180 && (elf_section_flags (s
) & SHF_GNU_MBIND
) != 0)
2182 /* Find the output mbind section with the same type, attributes
2183 and sh_info field. */
2184 for (os
= (void *) lang_os_list
.head
;
2187 if (os
->bfd_section
!= NULL
2188 && !bfd_is_abs_section (os
->bfd_section
)
2189 && (elf_section_flags (os
->bfd_section
) & SHF_GNU_MBIND
) != 0
2190 && ((s
->flags
& (SEC_ALLOC
2195 == (os
->bfd_section
->flags
& (SEC_ALLOC
2200 && (elf_section_data (os
->bfd_section
)->this_hdr
.sh_info
2201 == elf_section_data (s
)->this_hdr
.sh_info
))
2203 lang_add_section (&os
->children
, s
, NULL
, NULL
, os
);
2207 /* Create the output mbind section with the ".mbind." prefix
2209 if ((s
->flags
& (SEC_LOAD
| SEC_HAS_CONTENTS
)) == 0)
2210 secname
= ".mbind.bss";
2211 else if ((s
->flags
& SEC_READONLY
) == 0)
2212 secname
= ".mbind.data";
2213 else if ((s
->flags
& SEC_CODE
) == 0)
2214 secname
= ".mbind.rodata";
2216 secname
= ".mbind.text";
2217 elf_tdata (link_info
.output_bfd
)->has_gnu_osabi
|= elf_gnu_osabi_mbind
;
2220 /* Look through the script to see where to place this section. The
2221 script includes entries added by previous lang_insert_orphan
2222 calls, so this loop puts multiple compatible orphans of the same
2223 name into a single output section. */
2224 if (constraint
== 0)
2225 for (os
= lang_output_section_find (secname
);
2227 os
= next_matching_output_section_statement (os
, 0))
2229 /* If we don't match an existing output section, tell
2230 lang_insert_orphan to create a new output section. */
2231 constraint
= SPECIAL
;
2233 /* Check to see if we already have an output section statement
2234 with this name, and its bfd section has compatible flags.
2235 If the section already exists but does not have any flags
2236 set, then it has been created by the linker, possibly as a
2237 result of a --section-start command line switch. */
2238 if (os
->bfd_section
!= NULL
2239 && (os
->bfd_section
->flags
== 0
2240 || (((s
->flags
^ os
->bfd_section
->flags
)
2241 & (SEC_LOAD
| SEC_ALLOC
)) == 0
2244 || elf_orphan_compatible (s
, os
->bfd_section
)))))
2246 lang_add_section (&os
->children
, s
, NULL
, NULL
, os
);
2250 /* Save unused output sections in case we can match them
2251 against orphans later. */
2252 if (os
->bfd_section
== NULL
)
2256 /* If we didn't match an active output section, see if we matched an
2257 unused one and use that. */
2260 lang_add_section (&match_by_name
->children
, s
, NULL
, NULL
, match_by_name
);
2261 return match_by_name
;
2264 if (!orphan_init_done
)
2266 struct orphan_save
*ho
;
2268 for (ho
= hold
; ho
< hold
+ sizeof (hold
) / sizeof (hold
[0]); ++ho
)
2269 if (ho
->name
!= NULL
)
2271 ho
->os
= lang_output_section_find (ho
->name
);
2272 if (ho
->os
!= NULL
&& ho
->os
->flags
== 0)
2273 ho
->os
->flags
= ho
->flags
;
2275 orphan_init_done
= 1;
2278 /* If this is a final link, then always put .gnu.warning.SYMBOL
2279 sections into the .text section to get them out of the way. */
2280 if (bfd_link_executable (&link_info
)
2281 && startswith (s
->name
, ".gnu.warning.")
2282 && hold
[orphan_text
].os
!= NULL
)
2284 os
= hold
[orphan_text
].os
;
2285 lang_add_section (&os
->children
, s
, NULL
, NULL
, os
);
2290 if (!bfd_link_relocatable (&link_info
))
2293 while ((nexts
= bfd_get_next_section_by_name (nexts
->owner
, nexts
))
2295 if (nexts
->output_section
== NULL
2296 && (nexts
->flags
& SEC_EXCLUDE
) == 0
2297 && ((nexts
->flags
^ flags
) & (SEC_LOAD
| SEC_ALLOC
)) == 0
2298 && (nexts
->owner
->flags
& DYNAMIC
) == 0
2299 && !bfd_input_just_syms (nexts
->owner
)
2300 && _bfd_elf_match_sections_by_type (nexts
->owner
, nexts
,
2302 flags
= (((flags
^ SEC_READONLY
)
2303 | (nexts
->flags
^ SEC_READONLY
))
2307 /* Decide which segment the section should go in based on the
2308 section name and section flags. We put loadable .note sections
2309 right after the .interp section, so that the PT_NOTE segment is
2310 stored right after the program headers where the OS can read it
2311 in the first page. */
2314 if ((flags
& (SEC_ALLOC
| SEC_DEBUGGING
)) == 0)
2315 place
= &hold
[orphan_nonalloc
];
2316 else if ((flags
& SEC_ALLOC
) == 0)
2318 else if ((flags
& SEC_LOAD
) != 0
2320 ? sh_type
== SHT_NOTE
2321 : startswith (secname
, ".note")))
2322 place
= &hold
[orphan_interp
];
2323 else if ((flags
& (SEC_LOAD
| SEC_HAS_CONTENTS
| SEC_THREAD_LOCAL
)) == 0)
2324 place
= &hold
[orphan_bss
];
2325 else if ((flags
& SEC_SMALL_DATA
) != 0)
2326 place
= &hold
[orphan_sdata
];
2327 else if ((flags
& SEC_THREAD_LOCAL
) != 0)
2328 place
= &hold
[orphan_tdata
];
2329 else if ((flags
& SEC_READONLY
) == 0)
2330 place
= &hold
[orphan_data
];
2331 else if ((flags
& SEC_LOAD
) != 0
2333 ? sh_type
== SHT_RELA
|| sh_type
== SHT_REL
2334 : startswith (secname
, ".rel")))
2335 place
= &hold
[orphan_rel
];
2336 else if ((flags
& SEC_CODE
) == 0)
2337 place
= &hold
[orphan_rodata
];
2339 place
= &hold
[orphan_text
];
2344 if (place
->os
== NULL
)
2346 if (place
->name
!= NULL
)
2347 place
->os
= lang_output_section_find (place
->name
);
2350 int rela
= elfinput
? sh_type
== SHT_RELA
: secname
[4] == 'a';
2351 place
->os
= output_rel_find (isdyn
, rela
);
2357 = lang_output_section_find_by_flags (s
, flags
, &place
->os
,
2358 _bfd_elf_match_sections_by_type
);
2360 /* *ABS* is always the first output section statement. */
2361 after
= (void *) lang_os_list
.head
;
2364 return lang_insert_orphan (s
, secname
, constraint
, after
, place
, NULL
, NULL
);
2368 ldelf_before_place_orphans (void)
2372 for (abfd
= link_info
.input_bfds
;
2373 abfd
!= (bfd
*) NULL
; abfd
= abfd
->link
.next
)
2374 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
2375 && bfd_count_sections (abfd
) != 0
2376 && !bfd_input_just_syms (abfd
))
2379 for (isec
= abfd
->sections
; isec
!= NULL
; isec
= isec
->next
)
2381 /* Discard a section if any of its linked-to section has
2383 asection
*linked_to_sec
;
2384 for (linked_to_sec
= elf_linked_to_section (isec
);
2385 linked_to_sec
!= NULL
&& !linked_to_sec
->linker_mark
;
2386 linked_to_sec
= elf_linked_to_section (linked_to_sec
))
2388 if (discarded_section (linked_to_sec
))
2390 isec
->output_section
= bfd_abs_section_ptr
;
2391 isec
->flags
|= SEC_EXCLUDE
;
2394 linked_to_sec
->linker_mark
= 1;
2396 for (linked_to_sec
= elf_linked_to_section (isec
);
2397 linked_to_sec
!= NULL
&& linked_to_sec
->linker_mark
;
2398 linked_to_sec
= elf_linked_to_section (linked_to_sec
))
2399 linked_to_sec
->linker_mark
= 0;
2405 ldelf_set_output_arch (void)
2407 set_output_arch_default ();
2408 if (link_info
.output_bfd
->xvec
->flavour
== bfd_target_elf_flavour
)
2409 elf_link_info (link_info
.output_bfd
) = &link_info
;