1/* ELF emulation code for targets using elf.em.
2   Copyright (C) 1991-2022 Free Software Foundation, Inc.
3
4   This file is part of the GNU Binutils.
5
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.
10
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.
15
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.  */
20
21#include "sysdep.h"
22#include "bfd.h"
23#include "libiberty.h"
24#include "filenames.h"
25#include "safe-ctype.h"
26#include "bfdlink.h"
27#include "ctf-api.h"
28#include "ld.h"
29#include "ldmain.h"
30#include "ldmisc.h"
31#include "ldexp.h"
32#include "ldlang.h"
33#include "ldfile.h"
34#include "ldemul.h"
35#include "ldbuildid.h"
36#include <ldgram.h>
37#include "elf-bfd.h"
38#ifdef HAVE_GLOB
39#include <glob.h>
40#endif
41#include "ldelf.h"
42#ifdef HAVE_JANSSON
43#include <jansson.h>
44#endif
45
46struct dt_needed
47{
48  bfd *by;
49  const char *name;
50};
51
52/* Style of .note.gnu.build-id section.  */
53const char *ldelf_emit_note_gnu_build_id;
54
55/* Content of .note.package section.  */
56const char *ldelf_emit_note_fdo_package_metadata;
57
58/* These variables are required to pass information back and forth
59   between after_open and check_needed and stat_needed and vercheck.  */
60
61static struct bfd_link_needed_list *global_needed;
62static lang_input_statement_type *global_found;
63static struct stat global_stat;
64static struct bfd_link_needed_list *global_vercheck_needed;
65static bool global_vercheck_failed;
66
67void
68ldelf_after_parse (void)
69{
70  if (bfd_link_pie (&link_info))
71    link_info.flags_1 |= (bfd_vma) DF_1_PIE;
72
73  if (bfd_link_executable (&link_info)
74      && link_info.nointerp)
75    {
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;
79    }
80
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;
84
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;
88
89  after_parse_default ();
90  if (link_info.commonpagesize > link_info.maxpagesize)
91    {
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;
96      else
97	einfo (_("%F%P: common page size (0x%v) > maximum page size (0x%v)\n"),
98	       link_info.commonpagesize, link_info.maxpagesize);
99    }
100}
101
102/* Handle the generation of DT_NEEDED tags.  */
103
104bool
105ldelf_load_symbols (lang_input_statement_type *entry)
106{
107  int link_class = 0;
108
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;
114
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
117     this file at all.  */
118  if (!entry->flags.add_DT_NEEDED_for_dynamic)
119    link_class |= DYN_NO_ADD_NEEDED;
120
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"),
124	   entry->the_bfd);
125
126  if (link_class == 0
127      || (bfd_get_file_flags (entry->the_bfd) & DYNAMIC) == 0)
128    return false;
129
130  bfd_elf_set_dyn_lib_class (entry->the_bfd,
131			     (enum dynamic_lib_link_class) link_class);
132
133  /* Continue on with normal load_symbols processing.  */
134  return false;
135}
136
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.
142
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
147   link path.
148
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.  */
153
154static void
155ldelf_vercheck (lang_input_statement_type *s)
156{
157  const char *soname;
158  struct bfd_link_needed_list *l;
159
160  if (global_vercheck_failed)
161    return;
162  if (s->the_bfd == NULL
163      || (bfd_get_file_flags (s->the_bfd) & DYNAMIC) == 0)
164    return;
165
166  soname = bfd_elf_get_dt_soname (s->the_bfd);
167  if (soname == NULL)
168    soname = lbasename (bfd_get_filename (s->the_bfd));
169
170  for (l = global_vercheck_needed; l != NULL; l = l->next)
171    {
172      const char *suffix;
173
174      if (filename_cmp (soname, l->name) == 0)
175	{
176	  /* Probably can't happen, but it's an easy check.  */
177	  continue;
178	}
179
180      if (strchr (l->name, '/') != NULL)
181	continue;
182
183      suffix = strstr (l->name, ".so.");
184      if (suffix == NULL)
185	continue;
186
187      suffix += sizeof ".so." - 1;
188
189      if (filename_ncmp (soname, l->name, suffix - l->name) == 0)
190	{
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;
197	  return;
198	}
199    }
200}
201
202
203/* See if an input file matches a DT_NEEDED entry by running stat on
204   the file.  */
205
206static void
207ldelf_stat_needed (lang_input_statement_type *s)
208{
209  struct stat st;
210  const char *suffix;
211  const char *soname;
212
213  if (global_found != NULL)
214    return;
215  if (s->the_bfd == NULL)
216    return;
217
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)
221    return;
222
223  if (bfd_stat (s->the_bfd, &st) != 0)
224    {
225      einfo (_("%P: %pB: bfd_stat failed: %E\n"), s->the_bfd);
226      return;
227    }
228
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
235     negatives.  */
236  if (st.st_dev == global_stat.st_dev
237      && st.st_ino == global_stat.st_ino
238      && st.st_ino != 0)
239    {
240      global_found = s;
241      return;
242    }
243
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.  */
252
253  if (strchr (global_needed->name, '/') != NULL)
254    return;
255  suffix = strstr (global_needed->name, ".so.");
256  if (suffix == NULL)
257    return;
258  suffix += sizeof ".so." - 1;
259
260  soname = bfd_elf_get_dt_soname (s->the_bfd);
261  if (soname == NULL)
262    soname = lbasename (s->filename);
263
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);
268}
269
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.  */
273
274static bool
275ldelf_try_needed (struct dt_needed *needed, int force, int is_linux)
276{
277  bfd *abfd;
278  const char *name = needed->name;
279  const char *soname;
280  int link_class;
281
282  abfd = bfd_openr (name, bfd_get_target (link_info.output_bfd));
283  if (abfd == NULL)
284    {
285      if (verbose)
286	info_msg (_("attempt to open %s failed\n"), name);
287      return false;
288    }
289
290  track_dependency_files (name);
291
292  /* Linker needs to decompress sections.  */
293  abfd->flags |= BFD_DECOMPRESS;
294
295  if (! bfd_check_format (abfd, bfd_object))
296    {
297      bfd_close (abfd);
298      return false;
299    }
300  if ((bfd_get_file_flags (abfd) & DYNAMIC) == 0)
301    {
302      bfd_close (abfd);
303      return false;
304    }
305
306  /* For DT_NEEDED, they have to match.  */
307  if (abfd->xvec != link_info.output_bfd->xvec)
308    {
309      bfd_close (abfd);
310      return false;
311    }
312
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.  */
317
318  if (!force)
319    {
320      struct bfd_link_needed_list *needs;
321
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);
324
325      if (needs != NULL)
326	{
327	  global_vercheck_needed = needs;
328	  global_vercheck_failed = false;
329	  lang_for_each_input_file (ldelf_vercheck);
330	  if (global_vercheck_failed)
331	    {
332	      bfd_close (abfd);
333	      /* Return FALSE to force the caller to move on to try
334		 another file on the search path.  */
335	      return false;
336	    }
337
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.  */
344	  if (is_linux)
345	    {
346	      struct bfd_link_needed_list *l;
347
348	      for (l = needs; l != NULL; l = l->next)
349		if (startswith (l->name, "libc.so"))
350		  break;
351	      if (l == NULL)
352		{
353		  bfd_close (abfd);
354		  return false;
355		}
356	    }
357	}
358    }
359
360  /* We've found a dynamic object matching the DT_NEEDED entry.  */
361
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.  */
369
370  if (bfd_stat (abfd, &global_stat) != 0)
371    einfo (_("%F%P: %pB: bfd_stat failed: %E\n"), abfd);
372
373  /* First strip off everything before the last '/'.  */
374  soname = lbasename (bfd_get_filename (abfd));
375
376  if (verbose)
377    info_msg (_("found %s at %s\n"), soname, name);
378
379  global_found = NULL;
380  lang_for_each_input_file (ldelf_stat_needed);
381  if (global_found != NULL)
382    {
383      /* Return TRUE to indicate that we found the file, even though
384	 we aren't going to do anything with it.  */
385      return true;
386    }
387
388  /* Specify the soname to use.  */
389  bfd_elf_set_dt_needed_name (abfd, soname);
390
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;
395
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;
402
403  bfd_elf_set_dyn_lib_class (abfd, (enum dynamic_lib_link_class) link_class);
404
405  *link_info.input_bfds_tail = abfd;
406  link_info.input_bfds_tail = &abfd->link.next;
407
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);
411
412  return true;
413}
414
415/* Search for a needed file in a path.  */
416
417static bool
418ldelf_search_needed (const char *path, struct dt_needed *n, int force,
419		     int is_linux, int elfsize)
420{
421  const char *s;
422  const char *name = n->name;
423  size_t len;
424  struct dt_needed needed;
425
426  if (name[0] == '/')
427    return ldelf_try_needed (n, force, is_linux);
428
429  if (path == NULL || *path == '\0')
430    return false;
431
432  needed.by = n->by;
433  needed.name = n->name;
434
435  len = strlen (name);
436  while (1)
437    {
438      unsigned offset = 0;
439      char * var;
440      char *filename, *sset;
441
442      s = strchr (path, config.rpath_separator);
443      if (s == NULL)
444	s = path + strlen (path);
445
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 == ':'
449	       && s == path + 1
450	       && ISALPHA (*path))
451	{
452	  s = strchr (s + 1, config.rpath_separator);
453	  if (s == NULL)
454	    s = path + strlen (path);
455	}
456#endif
457      filename = (char *) xmalloc (s - path + len + 2);
458      if (s == path)
459	sset = filename;
460      else
461	{
462	  memcpy (filename, path, s - path);
463	  filename[s - path] = '/';
464	  sset = filename + (s - path) + 1;
465	}
466      strcpy (sset, name);
467
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)
475	{
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
480	     not enforced here.
481
482	     The ld.so manual page also states that it allows ${ORIGIN},
483	     ${LIB} and ${PLATFORM}, so these are supported as well.
484
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;
489	  char *    v = var + 1;
490	  char *    freeme = NULL;
491	  unsigned  flen = strlen (filename);
492
493	  if (end != NULL)
494	    /* Temporarily terminate the filename at the end of the token.  */
495	    * end = 0;
496
497	  if (*v == '{')
498	    ++ v;
499	  switch (*v++)
500	    {
501	    case 'O':
502	      if (strcmp (v, "RIGIN") == 0 || strcmp (v, "RIGIN}") == 0)
503		{
504		  /* ORIGIN - replace with the full path to the directory
505		     containing the program or shared object.  */
506		  if (needed.by == NULL)
507		    {
508		      if (link_info.output_bfd == NULL)
509			{
510			  break;
511			}
512		      else
513			replacement = bfd_get_filename (link_info.output_bfd);
514		    }
515		  else
516		    replacement = bfd_get_filename (needed.by);
517
518		  if (replacement)
519		    {
520		      char * slash;
521
522		      if (replacement[0] == '/')
523			freeme = xstrdup (replacement);
524		      else
525			{
526			  char * current_dir = getpwd ();
527
528			  freeme = xmalloc (strlen (replacement)
529					    + strlen (current_dir) + 2);
530			  sprintf (freeme, "%s/%s", current_dir, replacement);
531			}
532
533		      replacement = freeme;
534		      if ((slash = strrchr (replacement, '/')) != NULL)
535			* slash = 0;
536		    }
537		}
538	      break;
539
540	    case 'L':
541	      if (strcmp (v, "IB") == 0 || strcmp (v, "IB}") == 0)
542		{
543		  /* LIB - replace with "lib" in 32-bit environments
544		     and "lib64" in 64-bit environments.  */
545
546		  switch (elfsize)
547		    {
548		    case 32: replacement = "lib"; break;
549		    case 64: replacement = "lib64"; break;
550		    default:
551		      abort ();
552		    }
553		}
554	      break;
555
556	    case 'P':
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.  */
562	      /* Fall through.  */
563	    default:
564	      break;
565	    }
566
567	  if (replacement)
568	    {
569	      char * filename2 = xmalloc (flen + strlen (replacement));
570
571	      if (end)
572		{
573		  sprintf (filename2, "%.*s%s/%s",
574			   (int)(var - filename), filename,
575			   replacement, end + 1);
576		  offset = (var - filename) + 1 + strlen (replacement);
577		}
578	      else
579		{
580		  sprintf (filename2, "%.*s%s",
581			   (int)(var - filename), filename,
582			   replacement);
583		  offset = var - filename + strlen (replacement);
584		}
585
586	      free (filename);
587	      filename = filename2;
588	      /* There is no need to restore the path separator (when
589		 end != NULL) as we have replaced the entire string.  */
590	    }
591	  else
592	    {
593	      if (verbose)
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);
599	      if (end)
600		/* Restore the path separator.  */
601		* end = '/';
602
603	      /* PR 20784: Make sure that we resume the scan *after*
604		 the token that we could not replace.  */
605	      offset = (var + 1) - filename;
606	    }
607
608	  free (freeme);
609	}
610
611      needed.name = filename;
612
613      if (ldelf_try_needed (&needed, force, is_linux))
614	return true;
615
616      free (filename);
617
618      if (*s == '\0')
619	break;
620      path = s + 1;
621    }
622
623  return false;
624}
625
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.  */
630
631static const char *
632ldelf_add_sysroot (const char *path)
633{
634  size_t len, extra;
635  const char *p;
636  char *ret, *q;
637  int dos_drive_sysroot = HAS_DRIVE_SPEC (ld_sysroot);
638
639  len = strlen (ld_sysroot);
640  for (extra = 0, p = path; ; )
641    {
642      int dos_drive = HAS_DRIVE_SPEC (p);
643
644      if (dos_drive)
645	p += 2;
646      if (IS_DIR_SEPARATOR (*p)
647	  && (!dos_drive
648	      || (dos_drive_sysroot
649		  && ld_sysroot[0] == p[-2])))
650	{
651	  if (dos_drive && dos_drive_sysroot)
652	    extra += len - 2;
653	  else
654	    extra += len;
655	}
656      p = strchr (p, config.rpath_separator);
657      if (!p)
658	break;
659      ++p;
660    }
661
662  ret = xmalloc (strlen (path) + extra + 1);
663
664  for (q = ret, p = path; ; )
665    {
666      const char *end;
667      int dos_drive = HAS_DRIVE_SPEC (p);
668
669      if (dos_drive)
670	{
671	  *q++ = *p++;
672	  *q++ = *p++;
673	}
674      if (IS_DIR_SEPARATOR (*p)
675	  && (!dos_drive
676	      || (dos_drive_sysroot
677		  && ld_sysroot[0] == p[-2])))
678	{
679	  if (dos_drive && dos_drive_sysroot)
680	    {
681	      strcpy (q, ld_sysroot + 2);
682	      q += len - 2;
683	    }
684	  else
685	    {
686	      strcpy (q, ld_sysroot);
687	      q += len;
688	    }
689	}
690      end = strchr (p, config.rpath_separator);
691      if (end)
692	{
693	  size_t n = end - p + 1;
694	  strncpy (q, p, n);
695	  q += n;
696	  p += n;
697	}
698      else
699	{
700	  strcpy (q, p);
701	  break;
702	}
703    }
704
705  return ret;
706}
707
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>
711#else
712#include "elf-hints-local.h"
713#endif
714
715static bool
716ldelf_check_ld_elf_hints (const struct bfd_link_needed_list *l, int force,
717			  int elfsize)
718{
719  static bool initialized;
720  static const char *ld_elf_hints;
721  struct dt_needed needed;
722
723  if (!initialized)
724    {
725      FILE *f;
726      char *tmppath;
727
728      tmppath = concat (ld_sysroot, _PATH_ELF_HINTS, (const char *) NULL);
729      f = fopen (tmppath, FOPEN_RB);
730      free (tmppath);
731      if (f != NULL)
732	{
733	  struct elfhints_hdr hdr;
734
735	  if (fread (&hdr, 1, sizeof (hdr), f) == sizeof (hdr)
736	      && hdr.magic == ELFHINTS_MAGIC
737	      && hdr.version == 1)
738	    {
739	      if (fseek (f, hdr.strtab + hdr.dirlist, SEEK_SET) != -1)
740		{
741		  char *b;
742
743		  b = xmalloc (hdr.dirlistlen + 1);
744		  if (fread (b, 1, hdr.dirlistlen + 1, f) ==
745		      hdr.dirlistlen + 1)
746		    ld_elf_hints = ldelf_add_sysroot (b);
747
748		  free (b);
749		}
750	    }
751	  fclose (f);
752	}
753
754      initialized = true;
755    }
756
757  if (ld_elf_hints == NULL)
758    return false;
759
760  needed.by = l->by;
761  needed.name = l->name;
762  return ldelf_search_needed (ld_elf_hints, &needed, force, false, elfsize);
763}
764
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.  */
768
769struct ldelf_ld_so_conf
770{
771  char *path;
772  size_t len, alloc;
773};
774
775static bool
776ldelf_parse_ld_so_conf (struct ldelf_ld_so_conf *, const char *);
777
778static void
779ldelf_parse_ld_so_conf_include (struct ldelf_ld_so_conf *info,
780				const char *filename,
781				const char *pattern)
782{
783  char *newp = NULL;
784#ifdef HAVE_GLOB
785  glob_t gl;
786#endif
787
788  if (pattern[0] != '/')
789    {
790      char *p = strrchr (filename, '/');
791      size_t patlen = strlen (pattern) + 1;
792
793      newp = xmalloc (p - filename + 1 + patlen);
794      memcpy (newp, filename, p - filename + 1);
795      memcpy (newp + (p - filename + 1), pattern, patlen);
796      pattern = newp;
797    }
798
799#ifdef HAVE_GLOB
800  if (glob (pattern, 0, NULL, &gl) == 0)
801    {
802      size_t i;
803
804      for (i = 0; i < gl.gl_pathc; ++i)
805	ldelf_parse_ld_so_conf (info, gl.gl_pathv[i]);
806      globfree (&gl);
807    }
808#else
809  /* If we do not have glob, treat the pattern as a literal filename.  */
810  ldelf_parse_ld_so_conf (info, pattern);
811#endif
812
813  free (newp);
814}
815
816static bool
817ldelf_parse_ld_so_conf (struct ldelf_ld_so_conf *info, const char *filename)
818{
819  FILE *f = fopen (filename, FOPEN_RT);
820  char *line;
821  size_t linelen;
822
823  if (f == NULL)
824    return false;
825
826  linelen = 256;
827  line = xmalloc (linelen);
828  do
829    {
830      char *p = line, *q;
831
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')
836	{
837	  line = xrealloc (line, 2 * linelen);
838	  p = line + linelen - 1;
839	  linelen += linelen;
840	}
841
842      if (q == NULL && p == line)
843	break;
844
845      p = strchr (line, '\n');
846      if (p)
847	*p = '\0';
848
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, '#');
853      if (p)
854	*p = '\0';
855
856      /* Remove leading whitespace.  NUL is no whitespace character.  */
857      p = line;
858      while (*p == ' ' || *p == '\f' || *p == '\r' || *p == '\t' || *p == '\v')
859	++p;
860
861      /* If the line is blank it is ignored.  */
862      if (p[0] == '\0')
863	continue;
864
865      if (startswith (p, "include") && (p[7] == ' ' || p[7] == '\t'))
866	{
867	  char *dir, c;
868	  p += 8;
869	  do
870	    {
871	      while (*p == ' ' || *p == '\t')
872		++p;
873
874	      if (*p == '\0')
875		break;
876
877	      dir = p;
878
879	      while (*p != ' ' && *p != '\t' && *p)
880		++p;
881
882	      c = *p;
883	      *p++ = '\0';
884	      if (dir[0] != '\0')
885		ldelf_parse_ld_so_conf_include (info, filename, dir);
886	    }
887	  while (c != '\0');
888	}
889      else
890	{
891	  char *dir = p;
892	  while (*p && *p != '=' && *p != ' ' && *p != '\t' && *p != '\f'
893		 && *p != '\r' && *p != '\v')
894	    ++p;
895
896	  while (p != dir && p[-1] == '/')
897	    --p;
898	  if (info->path == NULL)
899	    {
900	      info->alloc = p - dir + 1 + 256;
901	      info->path = xmalloc (info->alloc);
902	      info->len = 0;
903	    }
904	  else
905	    {
906	      if (info->len + 1 + (p - dir) >= info->alloc)
907		{
908		  info->alloc += p - dir + 256;
909		  info->path = xrealloc (info->path, info->alloc);
910		}
911	      info->path[info->len++] = config.rpath_separator;
912	    }
913	  memcpy (info->path + info->len, dir, p - dir);
914	  info->len += p - dir;
915	  info->path[info->len] = '\0';
916	}
917    }
918  while (! feof (f));
919  free (line);
920  fclose (f);
921  return true;
922}
923
924static bool
925ldelf_check_ld_so_conf (const struct bfd_link_needed_list *l, int force,
926			int elfsize, const char *prefix)
927{
928  static bool initialized;
929  static const char *ld_so_conf;
930  struct dt_needed needed;
931
932  if (! initialized)
933    {
934      char *tmppath;
935      struct ldelf_ld_so_conf info;
936
937      info.path = NULL;
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))
942	{
943	  free (tmppath);
944	  tmppath = concat (ld_sysroot, "/etc/ld.so.conf",
945			    (const char *) NULL);
946	  ldelf_parse_ld_so_conf (&info, tmppath);
947	}
948      free (tmppath);
949
950      if (info.path)
951	{
952	  ld_so_conf = ldelf_add_sysroot (info.path);
953	  free (info.path);
954	}
955      initialized = true;
956    }
957
958  if (ld_so_conf == NULL)
959    return false;
960
961
962  needed.by = l->by;
963  needed.name = l->name;
964  return ldelf_search_needed (ld_so_conf, &needed, force, true, elfsize);
965}
966
967/* See if an input file matches a DT_NEEDED entry by name.  */
968
969static void
970ldelf_check_needed (lang_input_statement_type *s)
971{
972  const char *soname;
973
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)
978    return;
979
980  if (s->filename == NULL || s->the_bfd == NULL)
981    return;
982
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)
986    return;
987
988  if (filename_cmp (s->filename, global_needed->name) == 0)
989    {
990      global_found = s;
991      return;
992    }
993
994  if (s->flags.search_dirs)
995    {
996      const char *f = strrchr (s->filename, '/');
997      if (f != NULL
998	  && filename_cmp (f + 1, global_needed->name) == 0)
999	{
1000	  global_found = s;
1001	  return;
1002	}
1003    }
1004
1005  soname = bfd_elf_get_dt_soname (s->the_bfd);
1006  if (soname != NULL
1007      && filename_cmp (soname, global_needed->name) == 0)
1008    {
1009      global_found = s;
1010      return;
1011    }
1012}
1013
1014static void
1015ldelf_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)
1018{
1019  struct bfd_link_needed_list *needed, *l;
1020  bfd *abfd;
1021  bfd **save_input_bfd_tail;
1022
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
1031     loop.  */
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)
1035    {
1036      struct bfd_link_needed_list *ll;
1037      struct dt_needed n, nn;
1038      int force;
1039
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.  */
1042      if (l->by != NULL
1043	  && (bfd_elf_get_dyn_lib_class (l->by) & DYN_AS_NEEDED) != 0)
1044	continue;
1045
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
1048	 effect.  */
1049      if (l->by != NULL
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)
1053	continue;
1054
1055      /* If we've already seen this file, skip it.  */
1056      for (ll = needed; ll != l; ll = ll->next)
1057	if ((ll->by == NULL
1058	     || (bfd_elf_get_dyn_lib_class (ll->by) & DYN_AS_NEEDED) == 0)
1059	    && strcmp (ll->name, l->name) == 0)
1060	  break;
1061      if (ll != l)
1062	continue;
1063
1064      /* See if this file was included in the link explicitly.  */
1065      global_needed = l;
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)
1071	continue;
1072
1073      n.by = l->by;
1074      n.name = l->name;
1075      nn.by = l->by;
1076      if (verbose)
1077	info_msg (_("%s needed by %pB\n"), l->name, l->by);
1078
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)
1082	{
1083	  nn.name = global_found->filename;
1084	  if (ldelf_try_needed (&nn, true, is_linux))
1085	    continue;
1086	}
1087
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.
1095
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++)
1100	{
1101	  size_t len;
1102	  search_dirs_type *search;
1103	  const char *path;
1104	  struct bfd_link_needed_list *rp;
1105	  int found;
1106
1107	  if (ldelf_search_needed (command_line.rpath_link, &n, force,
1108				   is_linux, elfsize))
1109	    break;
1110
1111	  if (use_libpath)
1112	    {
1113	      path = command_line.rpath;
1114	      if (path)
1115		{
1116		  path = ldelf_add_sysroot (path);
1117		  found = ldelf_search_needed (path, &n, force,
1118					       is_linux, elfsize);
1119		  free ((char *) path);
1120		  if (found)
1121		    break;
1122		}
1123	    }
1124	  if (native)
1125	    {
1126	      if (command_line.rpath_link == NULL
1127		  && command_line.rpath == NULL)
1128		{
1129		  path = (const char *) getenv ("LD_RUN_PATH");
1130		  if (path
1131		      && ldelf_search_needed (path, &n, force,
1132					      is_linux, elfsize))
1133		    break;
1134		}
1135	      path = (const char *) getenv ("LD_LIBRARY_PATH");
1136	      if (path
1137		  && ldelf_search_needed (path, &n, force,
1138					  is_linux, elfsize))
1139		break;
1140	    }
1141	  if (use_libpath)
1142	    {
1143	      found = 0;
1144	      rp = bfd_elf_get_runpath_list (link_info.output_bfd, &link_info);
1145	      for (; !found && rp != NULL; rp = rp->next)
1146		{
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);
1152		}
1153	      if (found)
1154		break;
1155
1156	      if (is_freebsd
1157		  && ldelf_check_ld_elf_hints (l, force, elfsize))
1158		break;
1159
1160	      if (is_linux
1161		  && ldelf_check_ld_so_conf (l, force, elfsize, prefix))
1162		break;
1163	    }
1164
1165	  len = strlen (l->name);
1166	  for (search = search_head; search != NULL; search = search->next)
1167	    {
1168	      char *filename;
1169
1170	      if (search->cmdline)
1171		continue;
1172	      filename = (char *) xmalloc (strlen (search->name) + len + 2);
1173	      sprintf (filename, "%s/%s", search->name, l->name);
1174	      nn.name = filename;
1175	      if (ldelf_try_needed (&nn, force, is_linux))
1176		break;
1177	      free (filename);
1178	    }
1179	  if (search != NULL)
1180	    break;
1181	}
1182
1183      if (force < 2)
1184	continue;
1185
1186      einfo (_("%P: warning: %s, needed by %pB, not found "
1187	       "(try using -rpath or -rpath-link)\n"),
1188	     l->name, l->by);
1189    }
1190
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)
1200	{
1201	  if (bfd_elf_add_dt_needed_tag (abfd, &link_info) < 0)
1202	    einfo (_("%F%P: failed to add DT_NEEDED dynamic tag\n"));
1203	}
1204
1205  link_info.input_bfds_tail = save_input_bfd_tail;
1206  *save_input_bfd_tail = NULL;
1207}
1208
1209/* This is called before calling plugin 'all symbols read' hook.  */
1210
1211void
1212ldelf_before_plugin_all_symbols_read (int use_libpath, int native,
1213				      int is_linux, int is_freebsd,
1214				      int elfsize, const char *prefix)
1215{
1216  struct elf_link_hash_table *htab = elf_hash_table (&link_info);
1217
1218  if (!is_elf_hash_table (&htab->root))
1219    return;
1220
1221  htab->handling_dt_needed = true;
1222  ldelf_handle_dt_needed (htab, use_libpath, native, is_linux,
1223			  is_freebsd, elfsize, prefix);
1224  htab->handling_dt_needed = false;
1225}
1226
1227/* This is called after all the input files have been opened and all
1228   symbols have been loaded.  */
1229
1230void
1231ldelf_after_open (int use_libpath, int native, int is_linux, int is_freebsd,
1232		  int elfsize, const char *prefix)
1233{
1234  struct elf_link_hash_table *htab;
1235  asection *s;
1236  bfd *abfd;
1237
1238  after_open_default ();
1239
1240  htab = elf_hash_table (&link_info);
1241  if (!is_elf_hash_table (&htab->root))
1242    return;
1243
1244  if (command_line.out_implib_filename)
1245    {
1246      unlink_if_ordinary (command_line.out_implib_filename);
1247      link_info.out_implib_bfd
1248	= bfd_openw (command_line.out_implib_filename,
1249		     bfd_get_target (link_info.output_bfd));
1250
1251      if (link_info.out_implib_bfd == NULL)
1252	{
1253	  einfo (_("%F%P: %s: can't open for writing: %E\n"),
1254		 command_line.out_implib_filename);
1255	}
1256    }
1257
1258  if (ldelf_emit_note_gnu_build_id != NULL
1259      || ldelf_emit_note_fdo_package_metadata != NULL)
1260    {
1261      /* Find an ELF input.  */
1262      for (abfd = link_info.input_bfds;
1263	   abfd != (bfd *) NULL; abfd = abfd->link.next)
1264	if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
1265	    && bfd_count_sections (abfd) != 0
1266	    && !bfd_input_just_syms (abfd))
1267	  break;
1268
1269      /* PR 10555: If there are no ELF input files do not try to
1270	 create a .note.gnu-build-id section.  */
1271      if (abfd == NULL
1272	  || (ldelf_emit_note_gnu_build_id != NULL
1273	      && !ldelf_setup_build_id (abfd)))
1274	{
1275	  free ((char *) ldelf_emit_note_gnu_build_id);
1276	  ldelf_emit_note_gnu_build_id = NULL;
1277	}
1278
1279      if (abfd == NULL
1280	  || (ldelf_emit_note_fdo_package_metadata != NULL
1281	      && !ldelf_setup_package_metadata (abfd)))
1282	{
1283	  free ((char *) ldelf_emit_note_fdo_package_metadata);
1284	  ldelf_emit_note_fdo_package_metadata = NULL;
1285	}
1286    }
1287
1288  get_elf_backend_data (link_info.output_bfd)->setup_gnu_properties (&link_info);
1289
1290  /* Do not allow executable files to be used as inputs to the link.  */
1291  for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next)
1292    {
1293      /* Discard input .note.gnu.build-id sections.  */
1294      s = bfd_get_section_by_name (abfd, ".note.gnu.build-id");
1295      while (s != NULL)
1296	{
1297	  if (s != elf_tdata (link_info.output_bfd)->o->build_id.sec)
1298	    s->flags |= SEC_EXCLUDE;
1299	  s = bfd_get_next_section_by_name (NULL, s);
1300	}
1301
1302      if (abfd->xvec->flavour == bfd_target_elf_flavour
1303	  && !bfd_input_just_syms (abfd)
1304	  && elf_tdata (abfd) != NULL
1305	  /* FIXME: Maybe check for other non-supportable types as well ?  */
1306	  && (elf_tdata (abfd)->elf_header->e_type == ET_EXEC
1307	      || (elf_tdata (abfd)->elf_header->e_type == ET_DYN
1308		  && elf_tdata (abfd)->is_pie)))
1309	einfo (_("%F%P: cannot use executable file '%pB' as input to a link\n"),
1310	       abfd);
1311    }
1312
1313  if (bfd_link_relocatable (&link_info))
1314    {
1315      if (link_info.execstack == !link_info.noexecstack)
1316	{
1317	  /* PR ld/16744: If "-z [no]execstack" has been specified on the
1318	     command line and we are perfoming a relocatable link then no
1319	     PT_GNU_STACK segment will be created and so the
1320	     linkinfo.[no]execstack values set in _handle_option() will have no
1321	     effect.  Instead we create a .note.GNU-stack section in much the
1322	     same way as the assembler does with its --[no]execstack option.  */
1323	  flagword flags = SEC_READONLY | (link_info.execstack ? SEC_CODE : 0);
1324	  (void) bfd_make_section_with_flags (link_info.input_bfds,
1325					      ".note.GNU-stack", flags);
1326	}
1327      return;
1328    }
1329
1330  if (!link_info.traditional_format)
1331    {
1332      bfd *elfbfd = NULL;
1333      bool warn_eh_frame = false;
1334      int seen_type = 0;
1335
1336      for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next)
1337	{
1338	  int type = 0;
1339
1340	  if (bfd_input_just_syms (abfd))
1341	    continue;
1342
1343	  for (s = abfd->sections; s && type < COMPACT_EH_HDR; s = s->next)
1344	    {
1345	      const char *name = bfd_section_name (s);
1346
1347	      if (bfd_is_abs_section (s->output_section))
1348		continue;
1349	      if (startswith (name, ".eh_frame_entry"))
1350		type = COMPACT_EH_HDR;
1351	      else if (strcmp (name, ".eh_frame") == 0 && s->size > 8)
1352		type = DWARF2_EH_HDR;
1353	    }
1354
1355	  if (type != 0)
1356	    {
1357	      if (seen_type == 0)
1358		{
1359		  seen_type = type;
1360		}
1361	      else if (seen_type != type)
1362		{
1363		  einfo (_("%F%P: compact frame descriptions incompatible with"
1364			   " DWARF2 .eh_frame from %pB\n"),
1365			 type == DWARF2_EH_HDR ? abfd : elfbfd);
1366		  break;
1367		}
1368
1369	      if (!elfbfd
1370		  && (type == COMPACT_EH_HDR
1371		      || link_info.eh_frame_hdr_type != 0))
1372		{
1373		  if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
1374		    elfbfd = abfd;
1375
1376		  warn_eh_frame = true;
1377		}
1378	    }
1379
1380	  if (seen_type == COMPACT_EH_HDR)
1381	    link_info.eh_frame_hdr_type = COMPACT_EH_HDR;
1382	}
1383      if (elfbfd)
1384	{
1385	  const struct elf_backend_data *bed;
1386
1387	  bed = get_elf_backend_data (elfbfd);
1388	  s = bfd_make_section_with_flags (elfbfd, ".eh_frame_hdr",
1389					   bed->dynamic_sec_flags
1390					   | SEC_READONLY);
1391	  if (s != NULL
1392	      && bfd_set_section_alignment (s, 2))
1393	    {
1394	      htab->eh_info.hdr_sec = s;
1395	      warn_eh_frame = false;
1396	    }
1397	}
1398      if (warn_eh_frame)
1399	einfo (_("%P: warning: cannot create .eh_frame_hdr section,"
1400		 " --eh-frame-hdr ignored\n"));
1401    }
1402
1403  if (link_info.eh_frame_hdr_type == COMPACT_EH_HDR)
1404    if (!bfd_elf_parse_eh_frame_entries (NULL, &link_info))
1405      einfo (_("%F%P: failed to parse EH frame entries\n"));
1406
1407  ldelf_handle_dt_needed (htab, use_libpath, native, is_linux,
1408			  is_freebsd, elfsize, prefix);
1409}
1410
1411static bfd_size_type
1412id_note_section_size (bfd *abfd ATTRIBUTE_UNUSED)
1413{
1414  const char *style = ldelf_emit_note_gnu_build_id;
1415  bfd_size_type size;
1416  bfd_size_type build_id_size;
1417
1418  size = offsetof (Elf_External_Note, name[sizeof "GNU"]);
1419  size = (size + 3) & -(bfd_size_type) 4;
1420
1421  build_id_size = compute_build_id_size (style);
1422  if (build_id_size)
1423    size += build_id_size;
1424  else
1425    size = 0;
1426
1427  return size;
1428}
1429
1430static bool
1431write_build_id (bfd *abfd)
1432{
1433  const struct elf_backend_data *bed = get_elf_backend_data (abfd);
1434  struct elf_obj_tdata *t = elf_tdata (abfd);
1435  const char *style;
1436  asection *asec;
1437  Elf_Internal_Shdr *i_shdr;
1438  unsigned char *contents, *id_bits;
1439  bfd_size_type size;
1440  file_ptr position;
1441  Elf_External_Note *e_note;
1442
1443  style = t->o->build_id.style;
1444  asec = t->o->build_id.sec;
1445  if (bfd_is_abs_section (asec->output_section))
1446    {
1447      einfo (_("%P: warning: .note.gnu.build-id section discarded,"
1448	       " --build-id ignored\n"));
1449      return true;
1450    }
1451  i_shdr = &elf_section_data (asec->output_section)->this_hdr;
1452
1453  if (i_shdr->contents == NULL)
1454    {
1455      if (asec->contents == NULL)
1456	asec->contents = (unsigned char *) xmalloc (asec->size);
1457      contents = asec->contents;
1458    }
1459  else
1460    contents = i_shdr->contents + asec->output_offset;
1461
1462  e_note = (Elf_External_Note *) contents;
1463  size = offsetof (Elf_External_Note, name[sizeof "GNU"]);
1464  size = (size + 3) & -(bfd_size_type) 4;
1465  id_bits = contents + size;
1466  size = asec->size - size;
1467
1468  /* Clear the build ID field.  */
1469  memset (id_bits, 0, size);
1470
1471  bfd_h_put_32 (abfd, sizeof "GNU", &e_note->namesz);
1472  bfd_h_put_32 (abfd, size, &e_note->descsz);
1473  bfd_h_put_32 (abfd, NT_GNU_BUILD_ID, &e_note->type);
1474  memcpy (e_note->name, "GNU", sizeof "GNU");
1475
1476  generate_build_id (abfd, style, bed->s->checksum_contents, id_bits, size);
1477
1478  position = i_shdr->sh_offset + asec->output_offset;
1479  size = asec->size;
1480  return (bfd_seek (abfd, position, SEEK_SET) == 0
1481	  && bfd_bwrite (contents, size, abfd) == size);
1482}
1483
1484/* Make .note.gnu.build-id section, and set up elf_tdata->build_id.  */
1485
1486bool
1487ldelf_setup_build_id (bfd *ibfd)
1488{
1489  asection *s;
1490  bfd_size_type size;
1491  flagword flags;
1492
1493  size = id_note_section_size (ibfd);
1494  if (size == 0)
1495    {
1496      einfo (_("%P: warning: unrecognized --build-id style ignored\n"));
1497      return false;
1498    }
1499
1500  flags = (SEC_ALLOC | SEC_LOAD | SEC_IN_MEMORY
1501	   | SEC_LINKER_CREATED | SEC_READONLY | SEC_DATA);
1502  s = bfd_make_section_anyway_with_flags (ibfd, ".note.gnu.build-id",
1503					  flags);
1504  if (s != NULL && bfd_set_section_alignment (s, 2))
1505    {
1506      struct elf_obj_tdata *t = elf_tdata (link_info.output_bfd);
1507      t->o->build_id.after_write_object_contents = &write_build_id;
1508      t->o->build_id.style = ldelf_emit_note_gnu_build_id;
1509      t->o->build_id.sec = s;
1510      elf_section_type (s) = SHT_NOTE;
1511      s->size = size;
1512      return true;
1513    }
1514
1515  einfo (_("%P: warning: cannot create .note.gnu.build-id section,"
1516	   " --build-id ignored\n"));
1517  return false;
1518}
1519
1520static bool
1521write_package_metadata (bfd *abfd)
1522{
1523  struct elf_obj_tdata *t = elf_tdata (abfd);
1524  const char *json;
1525  asection *asec;
1526  Elf_Internal_Shdr *i_shdr;
1527  unsigned char *contents, *json_bits;
1528  bfd_size_type size;
1529  file_ptr position;
1530  Elf_External_Note *e_note;
1531
1532  json = t->o->package_metadata.json;
1533  asec = t->o->package_metadata.sec;
1534  if (bfd_is_abs_section (asec->output_section))
1535    {
1536      einfo (_("%P: warning: .note.package section discarded,"
1537	       " --package-metadata ignored\n"));
1538      return true;
1539    }
1540  i_shdr = &elf_section_data (asec->output_section)->this_hdr;
1541
1542  if (i_shdr->contents == NULL)
1543    {
1544      if (asec->contents == NULL)
1545	asec->contents = (unsigned char *) xmalloc (asec->size);
1546      contents = asec->contents;
1547    }
1548  else
1549    contents = i_shdr->contents + asec->output_offset;
1550
1551  e_note = (Elf_External_Note *) contents;
1552  size = offsetof (Elf_External_Note, name[sizeof "FDO"]);
1553  size = (size + 3) & -(bfd_size_type) 4;
1554  json_bits = contents + size;
1555  size = asec->size - size;
1556
1557  /* Clear the package metadata field.  */
1558  memset (json_bits, 0, size);
1559
1560  bfd_h_put_32 (abfd, sizeof "FDO", &e_note->namesz);
1561  bfd_h_put_32 (abfd, size, &e_note->descsz);
1562  bfd_h_put_32 (abfd, FDO_PACKAGING_METADATA, &e_note->type);
1563  memcpy (e_note->name, "FDO", sizeof "FDO");
1564  memcpy (json_bits, json, strlen(json));
1565
1566  position = i_shdr->sh_offset + asec->output_offset;
1567  size = asec->size;
1568  return (bfd_seek (abfd, position, SEEK_SET) == 0
1569	  && bfd_bwrite (contents, size, abfd) == size);
1570}
1571
1572/* Make .note.package section.
1573   https://systemd.io/ELF_PACKAGE_METADATA/  */
1574
1575bool
1576ldelf_setup_package_metadata (bfd *ibfd)
1577{
1578  asection *s;
1579  bfd_size_type size;
1580  size_t json_length;
1581  flagword flags;
1582
1583  /* If the option wasn't specified, silently return. */
1584  if (!ldelf_emit_note_fdo_package_metadata)
1585    return false;
1586
1587  /* The option was specified, but it's empty, log and return. */
1588  json_length = strlen (ldelf_emit_note_fdo_package_metadata);
1589  if (json_length == 0)
1590    {
1591      einfo (_("%P: warning: --package-metadata is empty, ignoring\n"));
1592      return false;
1593    }
1594
1595#ifdef HAVE_JANSSON
1596  json_error_t json_error;
1597  json_t *json = json_loads (ldelf_emit_note_fdo_package_metadata,
1598			     0, &json_error);
1599  if (!json)
1600    {
1601      einfo (_("%P: warning: --package-metadata=%s does not contain valid "
1602	       "JSON, ignoring: %s\n"),
1603	     ldelf_emit_note_fdo_package_metadata, json_error.text);
1604      return false;
1605    }
1606  else
1607    json_decref (json);
1608#endif
1609
1610  size = offsetof (Elf_External_Note, name[sizeof "FDO"]);
1611  size += json_length + 1;
1612  size = (size + 3) & -(bfd_size_type) 4;
1613
1614  flags = (SEC_ALLOC | SEC_LOAD | SEC_IN_MEMORY
1615	   | SEC_LINKER_CREATED | SEC_READONLY | SEC_DATA);
1616  s = bfd_make_section_anyway_with_flags (ibfd, ".note.package",
1617					  flags);
1618  if (s != NULL && bfd_set_section_alignment (s, 2))
1619    {
1620      struct elf_obj_tdata *t = elf_tdata (link_info.output_bfd);
1621      t->o->package_metadata.after_write_object_contents
1622	= &write_package_metadata;
1623      t->o->package_metadata.json = ldelf_emit_note_fdo_package_metadata;
1624      t->o->package_metadata.sec = s;
1625      elf_section_type (s) = SHT_NOTE;
1626      s->size = size;
1627      return true;
1628    }
1629
1630  einfo (_("%P: warning: cannot create .note.package section,"
1631	   " --package-metadata ignored\n"));
1632  return false;
1633}
1634
1635/* Look through an expression for an assignment statement.  */
1636
1637static void
1638ldelf_find_exp_assignment (etree_type *exp)
1639{
1640  bool provide = false;
1641
1642  switch (exp->type.node_class)
1643    {
1644    case etree_provide:
1645    case etree_provided:
1646      provide = true;
1647      /* Fallthru */
1648    case etree_assign:
1649      /* We call record_link_assignment even if the symbol is defined.
1650	 This is because if it is defined by a dynamic object, we
1651	 actually want to use the value defined by the linker script,
1652	 not the value from the dynamic object (because we are setting
1653	 symbols like etext).  If the symbol is defined by a regular
1654	 object, then, as it happens, calling record_link_assignment
1655	 will do no harm.  */
1656      if (strcmp (exp->assign.dst, ".") != 0)
1657	{
1658	  if (!bfd_elf_record_link_assignment (link_info.output_bfd,
1659					       &link_info,
1660					       exp->assign.dst, provide,
1661					       exp->assign.hidden))
1662	    einfo (_("%F%P: failed to record assignment to %s: %E\n"),
1663		   exp->assign.dst);
1664	}
1665      ldelf_find_exp_assignment (exp->assign.src);
1666      break;
1667
1668    case etree_binary:
1669      ldelf_find_exp_assignment (exp->binary.lhs);
1670      ldelf_find_exp_assignment (exp->binary.rhs);
1671      break;
1672
1673    case etree_trinary:
1674      ldelf_find_exp_assignment (exp->trinary.cond);
1675      ldelf_find_exp_assignment (exp->trinary.lhs);
1676      ldelf_find_exp_assignment (exp->trinary.rhs);
1677      break;
1678
1679    case etree_unary:
1680      ldelf_find_exp_assignment (exp->unary.child);
1681      break;
1682
1683    default:
1684      break;
1685    }
1686}
1687
1688/* This is called by the before_allocation routine via
1689   lang_for_each_statement.  It locates any assignment statements, and
1690   tells the ELF backend about them, in case they are assignments to
1691   symbols which are referred to by dynamic objects.  */
1692
1693static void
1694ldelf_find_statement_assignment (lang_statement_union_type *s)
1695{
1696  if (s->header.type == lang_assignment_statement_enum)
1697    ldelf_find_exp_assignment (s->assignment_statement.exp);
1698}
1699
1700/* Used by before_allocation and handle_option. */
1701
1702void
1703ldelf_append_to_separated_string (char **to, char *op_arg)
1704{
1705  if (*to == NULL)
1706    *to = xstrdup (op_arg);
1707  else
1708    {
1709      size_t to_len = strlen (*to);
1710      size_t op_arg_len = strlen (op_arg);
1711      char *buf;
1712      char *cp = *to;
1713
1714      /* First see whether OPTARG is already in the path.  */
1715      do
1716	{
1717	  if (strncmp (op_arg, cp, op_arg_len) == 0
1718	      && (cp[op_arg_len] == 0
1719		  || cp[op_arg_len] == config.rpath_separator))
1720	    /* We found it.  */
1721	    break;
1722
1723	  /* Not yet found.  */
1724	  cp = strchr (cp, config.rpath_separator);
1725	  if (cp != NULL)
1726	    ++cp;
1727	}
1728      while (cp != NULL);
1729
1730      if (cp == NULL)
1731	{
1732	  buf = xmalloc (to_len + op_arg_len + 2);
1733	  sprintf (buf, "%s%c%s", *to,
1734		   config.rpath_separator, op_arg);
1735	  free (*to);
1736	  *to = buf;
1737	}
1738    }
1739}
1740
1741/* This is called after the sections have been attached to output
1742   sections, but before any sizes or addresses have been set.  */
1743
1744void
1745ldelf_before_allocation (char *audit, char *depaudit,
1746			 const char *default_interpreter_name)
1747{
1748  const char *rpath;
1749  asection *sinterp;
1750  bfd *abfd;
1751  struct bfd_link_hash_entry *ehdr_start = NULL;
1752  unsigned char ehdr_start_save_type = 0;
1753  char ehdr_start_save_u[sizeof ehdr_start->u
1754			 - sizeof ehdr_start->u.def.next] = "";
1755
1756  if (is_elf_hash_table (link_info.hash))
1757    {
1758      _bfd_elf_tls_setup (link_info.output_bfd, &link_info);
1759
1760      /* Make __ehdr_start hidden if it has been referenced, to
1761	 prevent the symbol from being dynamic.  */
1762      if (!bfd_link_relocatable (&link_info))
1763	{
1764	  struct elf_link_hash_table *htab = elf_hash_table (&link_info);
1765	  struct elf_link_hash_entry *h
1766	    = elf_link_hash_lookup (htab, "__ehdr_start", false, false, true);
1767
1768	  /* Only adjust the export class if the symbol was referenced
1769	     and not defined, otherwise leave it alone.  */
1770	  if (h != NULL
1771	      && (h->root.type == bfd_link_hash_new
1772		  || h->root.type == bfd_link_hash_undefined
1773		  || h->root.type == bfd_link_hash_undefweak
1774		  || h->root.type == bfd_link_hash_common))
1775	    {
1776	      /* Don't leave the symbol undefined.  Undefined hidden
1777		 symbols typically won't have dynamic relocations, but
1778		 we most likely will need dynamic relocations for
1779		 __ehdr_start if we are building a PIE or shared
1780		 library.  */
1781	      ehdr_start = &h->root;
1782	      ehdr_start_save_type = ehdr_start->type;
1783	      memcpy (ehdr_start_save_u,
1784		      (char *) &ehdr_start->u + sizeof ehdr_start->u.def.next,
1785		      sizeof ehdr_start_save_u);
1786	      ehdr_start->type = bfd_link_hash_defined;
1787	      /* It will be converted to section-relative later.  */
1788	      ehdr_start->u.def.section = bfd_abs_section_ptr;
1789	      ehdr_start->u.def.value = 0;
1790	    }
1791	}
1792
1793      /* If we are going to make any variable assignments, we need to
1794	 let the ELF backend know about them in case the variables are
1795	 referred to by dynamic objects.  */
1796      lang_for_each_statement (ldelf_find_statement_assignment);
1797    }
1798
1799  /* Let the ELF backend work out the sizes of any sections required
1800     by dynamic linking.  */
1801  rpath = command_line.rpath;
1802  if (rpath == NULL)
1803    rpath = (const char *) getenv ("LD_RUN_PATH");
1804
1805  for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next)
1806    if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
1807      {
1808	const char *audit_libs = elf_dt_audit (abfd);
1809
1810	/* If the input bfd contains an audit entry, we need to add it as
1811	   a dep audit entry.  */
1812	if (audit_libs && *audit_libs != '\0')
1813	  {
1814	    char *cp = xstrdup (audit_libs);
1815	    do
1816	      {
1817		int more = 0;
1818		char *cp2 = strchr (cp, config.rpath_separator);
1819
1820		if (cp2)
1821		  {
1822		    *cp2 = '\0';
1823		    more = 1;
1824		  }
1825
1826		if (cp != NULL && *cp != '\0')
1827		  ldelf_append_to_separated_string (&depaudit, cp);
1828
1829		cp = more ? ++cp2 : NULL;
1830	      }
1831	    while (cp != NULL);
1832	  }
1833      }
1834
1835  if (! (bfd_elf_size_dynamic_sections
1836	 (link_info.output_bfd, command_line.soname, rpath,
1837	  command_line.filter_shlib, audit, depaudit,
1838	  (const char * const *) command_line.auxiliary_filters,
1839	  &link_info, &sinterp)))
1840    einfo (_("%F%P: failed to set dynamic section sizes: %E\n"));
1841
1842  if (sinterp != NULL)
1843    {
1844      /* Let the user override the dynamic linker we are using.  */
1845      if (command_line.interpreter != NULL)
1846	default_interpreter_name = command_line.interpreter;
1847      if (default_interpreter_name != NULL)
1848	{
1849	  sinterp->contents = (bfd_byte *) default_interpreter_name;
1850	  sinterp->size = strlen ((char *) sinterp->contents) + 1;
1851	}
1852    }
1853
1854  /* Look for any sections named .gnu.warning.  As a GNU extensions,
1855     we treat such sections as containing warning messages.  We print
1856     out the warning message, and then zero out the section size so
1857     that it does not get copied into the output file.  */
1858
1859  {
1860    LANG_FOR_EACH_INPUT_STATEMENT (is)
1861      {
1862	asection *s;
1863	bfd_size_type sz;
1864	char *msg;
1865
1866	if (is->flags.just_syms)
1867	  continue;
1868
1869	s = bfd_get_section_by_name (is->the_bfd, ".gnu.warning");
1870	if (s == NULL)
1871	  continue;
1872
1873	sz = s->size;
1874	msg = (char *) xmalloc ((size_t) (sz + 1));
1875	if (! bfd_get_section_contents (is->the_bfd, s,	msg,
1876					(file_ptr) 0, sz))
1877	  einfo (_("%F%P: %pB: can't read contents of section .gnu.warning: %E\n"),
1878		 is->the_bfd);
1879	msg[sz] = '\0';
1880	(*link_info.callbacks->warning) (&link_info, msg,
1881					 (const char *) NULL, is->the_bfd,
1882					 (asection *) NULL, (bfd_vma) 0);
1883	free (msg);
1884
1885	/* Clobber the section size, so that we don't waste space
1886	   copying the warning into the output file.  If we've already
1887	   sized the output section, adjust its size.  The adjustment
1888	   is on rawsize because targets that size sections early will
1889	   have called lang_reset_memory_regions after sizing.  */
1890	if (s->output_section != NULL
1891	    && s->output_section->rawsize >= s->size)
1892	  s->output_section->rawsize -= s->size;
1893
1894	s->size = 0;
1895
1896	/* Also set SEC_EXCLUDE, so that local symbols defined in the
1897	   warning section don't get copied to the output.  */
1898	s->flags |= SEC_EXCLUDE | SEC_KEEP;
1899      }
1900  }
1901
1902  before_allocation_default ();
1903
1904  if (!bfd_elf_size_dynsym_hash_dynstr (link_info.output_bfd, &link_info))
1905    einfo (_("%F%P: failed to set dynamic section sizes: %E\n"));
1906
1907  if (ehdr_start != NULL)
1908    {
1909      /* If we twiddled __ehdr_start to defined earlier, put it back
1910	 as it was.  */
1911      ehdr_start->type = ehdr_start_save_type;
1912      memcpy ((char *) &ehdr_start->u + sizeof ehdr_start->u.def.next,
1913	      ehdr_start_save_u,
1914	      sizeof ehdr_start_save_u);
1915    }
1916}
1917/* Try to open a dynamic archive.  This is where we know that ELF
1918   dynamic libraries have an extension of .so (or .sl on oddball systems
1919   like hpux).  */
1920
1921bool
1922ldelf_open_dynamic_archive (const char *arch, search_dirs_type *search,
1923			    lang_input_statement_type *entry)
1924{
1925  const char *filename;
1926  char *string;
1927  size_t len;
1928  bool opened = false;
1929
1930  if (! entry->flags.maybe_archive)
1931    return false;
1932
1933  filename = entry->filename;
1934  len = strlen (search->name) + strlen (filename);
1935  if (entry->flags.full_name_provided)
1936    {
1937      len += sizeof "/";
1938      string = (char *) xmalloc (len);
1939      sprintf (string, "%s/%s", search->name, filename);
1940    }
1941  else
1942    {
1943      size_t xlen = 0;
1944
1945      len += strlen (arch) + sizeof "/lib.so";
1946#ifdef EXTRA_SHLIB_EXTENSION
1947      xlen = (strlen (EXTRA_SHLIB_EXTENSION) > 3
1948	      ? strlen (EXTRA_SHLIB_EXTENSION) - 3
1949	      : 0);
1950#endif
1951      string = (char *) xmalloc (len + xlen);
1952      sprintf (string, "%s/lib%s%s.so", search->name, filename, arch);
1953#ifdef EXTRA_SHLIB_EXTENSION
1954      /* Try the .so extension first.  If that fails build a new filename
1955	 using EXTRA_SHLIB_EXTENSION.  */
1956      opened = ldfile_try_open_bfd (string, entry);
1957      if (!opened)
1958	strcpy (string + len - 4, EXTRA_SHLIB_EXTENSION);
1959#endif
1960    }
1961
1962  if (!opened && !ldfile_try_open_bfd (string, entry))
1963    {
1964      free (string);
1965      return false;
1966    }
1967
1968  entry->filename = string;
1969
1970  /* We have found a dynamic object to include in the link.  The ELF
1971     backend linker will create a DT_NEEDED entry in the .dynamic
1972     section naming this file.  If this file includes a DT_SONAME
1973     entry, it will be used.  Otherwise, the ELF linker will just use
1974     the name of the file.  For an archive found by searching, like
1975     this one, the DT_NEEDED entry should consist of just the name of
1976     the file, without the path information used to find it.  Note
1977     that we only need to do this if we have a dynamic object; an
1978     archive will never be referenced by a DT_NEEDED entry.
1979
1980     FIXME: This approach--using bfd_elf_set_dt_needed_name--is not
1981     very pretty.  I haven't been able to think of anything that is
1982     pretty, though.  */
1983  if (bfd_check_format (entry->the_bfd, bfd_object)
1984      && (entry->the_bfd->flags & DYNAMIC) != 0)
1985    {
1986      ASSERT (entry->flags.maybe_archive && entry->flags.search_dirs);
1987
1988      /* Rather than duplicating the logic above.  Just use the
1989	 filename we recorded earlier.  */
1990
1991      if (!entry->flags.full_name_provided)
1992	filename = lbasename (entry->filename);
1993      bfd_elf_set_dt_needed_name (entry->the_bfd, filename);
1994    }
1995
1996  return true;
1997}
1998
1999/* A variant of lang_output_section_find used by place_orphan.  */
2000
2001static lang_output_section_statement_type *
2002output_rel_find (int isdyn, int rela)
2003{
2004  lang_output_section_statement_type *lookup;
2005  lang_output_section_statement_type *last = NULL;
2006  lang_output_section_statement_type *last_alloc = NULL;
2007  lang_output_section_statement_type *last_ro_alloc = NULL;
2008  lang_output_section_statement_type *last_rel = NULL;
2009  lang_output_section_statement_type *last_rel_alloc = NULL;
2010
2011  for (lookup = (void *) lang_os_list.head;
2012       lookup != NULL;
2013       lookup = lookup->next)
2014    {
2015      if (lookup->constraint >= 0
2016	  && startswith (lookup->name, ".rel"))
2017	{
2018	  int lookrela = lookup->name[4] == 'a';
2019
2020	  /* .rel.dyn must come before all other reloc sections, to suit
2021	     GNU ld.so.  */
2022	  if (isdyn)
2023	    break;
2024
2025	  /* Don't place after .rel.plt as doing so results in wrong
2026	     dynamic tags.  */
2027	  if (strcmp (".plt", lookup->name + 4 + lookrela) == 0)
2028	    break;
2029
2030	  if (rela == lookrela || last_rel == NULL)
2031	    last_rel = lookup;
2032	  if ((rela == lookrela || last_rel_alloc == NULL)
2033	      && lookup->bfd_section != NULL
2034	      && (lookup->bfd_section->flags & SEC_ALLOC) != 0)
2035	    last_rel_alloc = lookup;
2036	}
2037
2038      last = lookup;
2039      if (lookup->bfd_section != NULL
2040	  && (lookup->bfd_section->flags & SEC_ALLOC) != 0)
2041	{
2042	  last_alloc = lookup;
2043	  if ((lookup->bfd_section->flags & SEC_READONLY) != 0)
2044	    last_ro_alloc = lookup;
2045	}
2046    }
2047
2048  if (last_rel_alloc)
2049    return last_rel_alloc;
2050
2051  if (last_rel)
2052    return last_rel;
2053
2054  if (last_ro_alloc)
2055    return last_ro_alloc;
2056
2057  if (last_alloc)
2058    return last_alloc;
2059
2060  return last;
2061}
2062
2063/* Return whether IN is suitable to be part of OUT.  */
2064
2065static bool
2066elf_orphan_compatible (asection *in, asection *out)
2067{
2068  /* Non-zero sh_info implies a section with SHF_INFO_LINK with
2069     unknown semantics for the generic linker, or a SHT_REL/SHT_RELA
2070     section where sh_info specifies a symbol table.  (We won't see
2071     SHT_GROUP, SHT_SYMTAB or SHT_DYNSYM sections here.)  We clearly
2072     can't merge SHT_REL/SHT_RELA using differing symbol tables, and
2073     shouldn't merge sections with differing unknown semantics.  */
2074  if (elf_section_data (out)->this_hdr.sh_info
2075      != elf_section_data (in)->this_hdr.sh_info)
2076    return false;
2077  /* We can't merge with a member of an output section group or merge
2078     two sections with differing SHF_EXCLUDE or other processor and OS
2079     specific flags when doing a relocatable link.  */
2080  if (bfd_link_relocatable (&link_info)
2081      && (elf_next_in_group (out) != NULL
2082	  || ((elf_section_flags (out) ^ elf_section_flags (in))
2083	      & (SHF_MASKPROC | SHF_MASKOS)) != 0))
2084    return false;
2085  return _bfd_elf_match_sections_by_type (link_info.output_bfd, out,
2086					  in->owner, in);
2087}
2088
2089/* Place an orphan section.  We use this to put random SHF_ALLOC
2090   sections in the right segment.  */
2091
2092lang_output_section_statement_type *
2093ldelf_place_orphan (asection *s, const char *secname, int constraint)
2094{
2095  static struct orphan_save hold[] =
2096    {
2097      { ".text",
2098	SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE,
2099	0, 0, 0, 0 },
2100      { ".rodata",
2101	SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_DATA,
2102	0, 0, 0, 0 },
2103      { ".tdata",
2104	SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_THREAD_LOCAL,
2105	0, 0, 0, 0 },
2106      { ".data",
2107	SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_DATA,
2108	0, 0, 0, 0 },
2109      { ".bss",
2110	SEC_ALLOC,
2111	0, 0, 0, 0 },
2112      { 0,
2113	SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_DATA,
2114	0, 0, 0, 0 },
2115      { ".interp",
2116	SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_DATA,
2117	0, 0, 0, 0 },
2118      { ".sdata",
2119	SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_SMALL_DATA,
2120	0, 0, 0, 0 },
2121      { ".comment",
2122	SEC_HAS_CONTENTS,
2123	0, 0, 0, 0 },
2124    };
2125  enum orphan_save_index
2126    {
2127      orphan_text = 0,
2128      orphan_rodata,
2129      orphan_tdata,
2130      orphan_data,
2131      orphan_bss,
2132      orphan_rel,
2133      orphan_interp,
2134      orphan_sdata,
2135      orphan_nonalloc
2136    };
2137  static int orphan_init_done = 0;
2138  struct orphan_save *place;
2139  lang_output_section_statement_type *after;
2140  lang_output_section_statement_type *os;
2141  lang_output_section_statement_type *match_by_name = NULL;
2142  int isdyn = 0;
2143  int elfinput = s->owner->xvec->flavour == bfd_target_elf_flavour;
2144  int elfoutput = link_info.output_bfd->xvec->flavour == bfd_target_elf_flavour;
2145  unsigned int sh_type = elfinput ? elf_section_type (s) : SHT_NULL;
2146  flagword flags;
2147  asection *nexts;
2148
2149  if (!bfd_link_relocatable (&link_info)
2150      && link_info.combreloc
2151      && (s->flags & SEC_ALLOC))
2152    {
2153      if (elfinput)
2154	switch (sh_type)
2155	  {
2156	  case SHT_RELA:
2157	    secname = ".rela.dyn";
2158	    isdyn = 1;
2159	    break;
2160	  case SHT_REL:
2161	    secname = ".rel.dyn";
2162	    isdyn = 1;
2163	    break;
2164	  default:
2165	    break;
2166	  }
2167      else if (startswith (secname, ".rel"))
2168	{
2169	  secname = secname[4] == 'a' ? ".rela.dyn" : ".rel.dyn";
2170	  isdyn = 1;
2171	}
2172    }
2173
2174  if (!bfd_link_relocatable (&link_info)
2175      && elfinput
2176      && elfoutput
2177      && (s->flags & SEC_ALLOC) != 0
2178      && (elf_tdata (s->owner)->has_gnu_osabi & elf_gnu_osabi_mbind) != 0
2179      && (elf_section_flags (s) & SHF_GNU_MBIND) != 0)
2180    {
2181      /* Find the output mbind section with the same type, attributes
2182	 and sh_info field.  */
2183      for (os = (void *) lang_os_list.head;
2184	   os != NULL;
2185	   os = os->next)
2186	if (os->bfd_section != NULL
2187	    && !bfd_is_abs_section (os->bfd_section)
2188	    && (elf_section_flags (os->bfd_section) & SHF_GNU_MBIND) != 0
2189	    && ((s->flags & (SEC_ALLOC
2190			     | SEC_LOAD
2191			     | SEC_HAS_CONTENTS
2192			     | SEC_READONLY
2193			     | SEC_CODE))
2194		== (os->bfd_section->flags & (SEC_ALLOC
2195					      | SEC_LOAD
2196					      | SEC_HAS_CONTENTS
2197					      | SEC_READONLY
2198					      | SEC_CODE)))
2199	    && (elf_section_data (os->bfd_section)->this_hdr.sh_info
2200		== elf_section_data (s)->this_hdr.sh_info))
2201	    {
2202	      lang_add_section (&os->children, s, NULL, NULL, os);
2203	      return os;
2204	    }
2205
2206      /* Create the output mbind section with the ".mbind." prefix
2207	 in section name.  */
2208      if ((s->flags & (SEC_LOAD | SEC_HAS_CONTENTS)) == 0)
2209	secname = ".mbind.bss";
2210      else if ((s->flags & SEC_READONLY) == 0)
2211	secname = ".mbind.data";
2212      else if ((s->flags & SEC_CODE) == 0)
2213	secname = ".mbind.rodata";
2214      else
2215	secname = ".mbind.text";
2216      elf_tdata (link_info.output_bfd)->has_gnu_osabi |= elf_gnu_osabi_mbind;
2217    }
2218
2219  /* Look through the script to see where to place this section.  The
2220     script includes entries added by previous lang_insert_orphan
2221     calls, so this loop puts multiple compatible orphans of the same
2222     name into a single output section.  */
2223  if (constraint == 0)
2224    for (os = lang_output_section_find (secname);
2225	 os != NULL;
2226	 os = next_matching_output_section_statement (os, 0))
2227      {
2228	/* If we don't match an existing output section, tell
2229	   lang_insert_orphan to create a new output section.  */
2230	constraint = SPECIAL;
2231
2232	/* Check to see if we already have an output section statement
2233	   with this name, and its bfd section has compatible flags.
2234	   If the section already exists but does not have any flags
2235	   set, then it has been created by the linker, possibly as a
2236	   result of a --section-start command line switch.  */
2237	if (os->bfd_section != NULL
2238	    && (os->bfd_section->flags == 0
2239		|| (((s->flags ^ os->bfd_section->flags)
2240		     & (SEC_LOAD | SEC_ALLOC)) == 0
2241		    && (!elfinput
2242			|| !elfoutput
2243			|| elf_orphan_compatible (s, os->bfd_section)))))
2244	  {
2245	    lang_add_section (&os->children, s, NULL, NULL, os);
2246	    return os;
2247	  }
2248
2249	/* Save unused output sections in case we can match them
2250	   against orphans later.  */
2251	if (os->bfd_section == NULL)
2252	  match_by_name = os;
2253      }
2254
2255  /* If we didn't match an active output section, see if we matched an
2256     unused one and use that.  */
2257  if (match_by_name)
2258    {
2259      lang_add_section (&match_by_name->children, s, NULL, NULL, match_by_name);
2260      return match_by_name;
2261    }
2262
2263  if (!orphan_init_done)
2264    {
2265      struct orphan_save *ho;
2266
2267      for (ho = hold; ho < hold + sizeof (hold) / sizeof (hold[0]); ++ho)
2268	if (ho->name != NULL)
2269	  {
2270	    ho->os = lang_output_section_find (ho->name);
2271	    if (ho->os != NULL && ho->os->flags == 0)
2272	      ho->os->flags = ho->flags;
2273	  }
2274      orphan_init_done = 1;
2275    }
2276
2277  /* If this is a final link, then always put .gnu.warning.SYMBOL
2278     sections into the .text section to get them out of the way.  */
2279  if (bfd_link_executable (&link_info)
2280      && startswith (s->name, ".gnu.warning.")
2281      && hold[orphan_text].os != NULL)
2282    {
2283      os = hold[orphan_text].os;
2284      lang_add_section (&os->children, s, NULL, NULL, os);
2285      return os;
2286    }
2287
2288  flags = s->flags;
2289  if (!bfd_link_relocatable (&link_info))
2290    {
2291      nexts = s;
2292      while ((nexts = bfd_get_next_section_by_name (nexts->owner, nexts))
2293	     != NULL)
2294	if (nexts->output_section == NULL
2295	    && (nexts->flags & SEC_EXCLUDE) == 0
2296	    && ((nexts->flags ^ flags) & (SEC_LOAD | SEC_ALLOC)) == 0
2297	    && (nexts->owner->flags & DYNAMIC) == 0
2298	    && !bfd_input_just_syms (nexts->owner)
2299	    && _bfd_elf_match_sections_by_type (nexts->owner, nexts,
2300						s->owner, s))
2301	  flags = (((flags ^ SEC_READONLY)
2302		    | (nexts->flags ^ SEC_READONLY))
2303		   ^ SEC_READONLY);
2304    }
2305
2306  /* Decide which segment the section should go in based on the
2307     section name and section flags.  We put loadable .note sections
2308     right after the .interp section, so that the PT_NOTE segment is
2309     stored right after the program headers where the OS can read it
2310     in the first page.  */
2311
2312  place = NULL;
2313  if ((flags & (SEC_ALLOC | SEC_DEBUGGING)) == 0)
2314    place = &hold[orphan_nonalloc];
2315  else if ((flags & SEC_ALLOC) == 0)
2316    ;
2317  else if ((flags & SEC_LOAD) != 0
2318	   && (elfinput
2319	       ? sh_type == SHT_NOTE
2320	       : startswith (secname, ".note")))
2321    place = &hold[orphan_interp];
2322  else if ((flags & (SEC_LOAD | SEC_HAS_CONTENTS | SEC_THREAD_LOCAL)) == 0)
2323    place = &hold[orphan_bss];
2324  else if ((flags & SEC_SMALL_DATA) != 0)
2325    place = &hold[orphan_sdata];
2326  else if ((flags & SEC_THREAD_LOCAL) != 0)
2327    place = &hold[orphan_tdata];
2328  else if ((flags & SEC_READONLY) == 0)
2329    place = &hold[orphan_data];
2330  else if ((flags & SEC_LOAD) != 0
2331	   && (elfinput
2332	       ? sh_type == SHT_RELA || sh_type == SHT_REL
2333	       : startswith (secname, ".rel")))
2334    place = &hold[orphan_rel];
2335  else if ((flags & SEC_CODE) == 0)
2336    place = &hold[orphan_rodata];
2337  else
2338    place = &hold[orphan_text];
2339
2340  after = NULL;
2341  if (place != NULL)
2342    {
2343      if (place->os == NULL)
2344	{
2345	  if (place->name != NULL)
2346	    place->os = lang_output_section_find (place->name);
2347	  else
2348	    {
2349	      int rela = elfinput ? sh_type == SHT_RELA : secname[4] == 'a';
2350	      place->os = output_rel_find (isdyn, rela);
2351	    }
2352	}
2353      after = place->os;
2354      if (after == NULL)
2355	after
2356	  = lang_output_section_find_by_flags (s, flags, &place->os,
2357					       _bfd_elf_match_sections_by_type);
2358      if (after == NULL)
2359	/* *ABS* is always the first output section statement.  */
2360	after = (void *) lang_os_list.head;
2361    }
2362
2363  return lang_insert_orphan (s, secname, constraint, after, place, NULL, NULL);
2364}
2365
2366void
2367ldelf_before_place_orphans (void)
2368{
2369  bfd *abfd;
2370
2371  for (abfd = link_info.input_bfds;
2372       abfd != (bfd *) NULL; abfd = abfd->link.next)
2373    if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
2374	&& bfd_count_sections (abfd) != 0
2375	&& !bfd_input_just_syms (abfd))
2376      {
2377	asection *isec;
2378	for (isec = abfd->sections; isec != NULL; isec = isec->next)
2379	  {
2380	    /* Discard a section if any of its linked-to section has
2381	       been discarded.  */
2382	    asection *linked_to_sec;
2383	    for (linked_to_sec = elf_linked_to_section (isec);
2384		 linked_to_sec != NULL && !linked_to_sec->linker_mark;
2385		 linked_to_sec = elf_linked_to_section (linked_to_sec))
2386	      {
2387		if (discarded_section (linked_to_sec))
2388		  {
2389		    isec->output_section = bfd_abs_section_ptr;
2390		    isec->flags |= SEC_EXCLUDE;
2391		    break;
2392		  }
2393		linked_to_sec->linker_mark = 1;
2394	      }
2395	    for (linked_to_sec = elf_linked_to_section (isec);
2396		 linked_to_sec != NULL && linked_to_sec->linker_mark;
2397		 linked_to_sec = elf_linked_to_section (linked_to_sec))
2398	      linked_to_sec->linker_mark = 0;
2399	  }
2400      }
2401}
2402
2403void
2404ldelf_set_output_arch (void)
2405{
2406  set_output_arch_default ();
2407  if (link_info.output_bfd->xvec->flavour == bfd_target_elf_flavour)
2408    elf_link_info (link_info.output_bfd) = &link_info;
2409}
2410