bfd, include, ld, binutils, libctf: CTF should use the dynstr/sym

This is embarrassing.

The whole point of CTF is that it remains intact even after a binary is
stripped, providing a compact mapping from symbols to types for
everything in the externally-visible interface of an ELF object: it has
connections to the symbol table for that purpose, and to the string
table to avoid duplicating symbol names.  So it's a shame that the hooks
I implemented last year served to hook it up to the .symtab and .strtab,
which obviously disappear on strip, leaving any accompanying the CTF
dict containing references to strings (and, soon, symbols) which don't
exist any more because their containing strtab has been vaporized.  The
original Solaris design used .dynsym and .dynstr (well, actually,
.ldynsym, which has more symbols) which do not disappear. So should we.

Thankfully the work we did before serves as guide rails, and adjusting
things to use the .dynstr and .dynsym was fast and easy.  The only
annoyance is that the dynsym is assembled inside elflink.c in a fairly
piecemeal fashion, so that the easiest way to get the symbols out was to
hook in before every call to swap_symbol_out (we also leave in a hook in
front of symbol additions to the .symtab because it seems plausible that
we might want to hook them in future too: for now that hook is unused).
We adjust things so that rather than being offered a whole hash table of
symbols at once, libctf is now given symbols one at a time, with st_name
indexes already resolved and pointing at their final .dynstr offsets:
it's now up to libctf to resolve these to names as needed using the
strtab info we pass it separately.

Some bits might be contentious.  The ctf_new_dynstr callback takes an
elf_internal_sym, and this remains an elf_internal_sym right down
through the generic emulation layers into ldelfgen.  This is no worse
than the elf_sym_strtab we used to pass down, but in the future when we
gain non-ELF CTF symtab support we might want to lower the
elf_internal_sym to some other representation (perhaps a
ctf_link_symbol) in bfd or in ldlang_ctf_new_dynsym.  We rename the
'apply_strsym' hooks to 'acquire_strings' instead, becuse they no longer
have anything to do with symbols.

There are some API changes to pieces of API which are technically public
but actually totally unused by anything and/or unused by anything but ld
so they can change freely: the ctf_link_symbol gains new fields to allow
symbol names to be given as strtab offsets as well as strings, and a
symidx so that the symbol index can be passed in.  ctf_link_shuffle_syms
loses its callback parameter: the idea now is that linkers call the new
ctf_link_add_linker_symbol for every symbol in .dynsym, feed in all the
strtab entries with ctf_link_add_strtab, and then a call to
ctf_link_shuffle_syms will apply both and arrange to use them to reorder
the CTF symtab at CTF serialization time (which is coming in the next
commit).

Inside libctf we have a new preamble flag CTF_F_DYNSTR which is always
set in v3-format CTF dicts from this commit forwards: CTF dicts without
this flag are associated with .strtab like they used to be, so that old
dicts' external strings don't turn to garbage when loaded by new libctf.
Dicts with this flag are associated with .dynstr and .dynsym instead.
(The flag is not the next in sequence because this commit was written
quite late: the missing flags will be filled in by the next commit.)

Tests forthcoming in a later commit in this series.

bfd/ChangeLog
2020-11-20  Nick Alcock  <nick.alcock@oracle.com>

	* elflink.c (elf_finalize_dynstr): Call examine_strtab after
	dynstr finalization.
	(elf_link_swap_symbols_out): Don't call it here.  Call
	ctf_new_symbol before swap_symbol_out.
	(elf_link_output_extsym): Call ctf_new_dynsym before
	swap_symbol_out.
	(bfd_elf_final_link): Likewise.
	* elf.c (swap_out_syms): Pass in bfd_link_info.  Call
	ctf_new_symbol before swap_symbol_out.
	(_bfd_elf_compute_section_file_positions): Adjust.

binutils/ChangeLog
2020-11-20  Nick Alcock  <nick.alcock@oracle.com>

	* readelf.c (dump_section_as_ctf): Use .dynsym and .dynstr, not
	.symtab and .strtab.

include/ChangeLog
2020-11-20  Nick Alcock  <nick.alcock@oracle.com>

	* bfdlink.h (struct elf_sym_strtab): Replace with...
	(struct elf_internal_sym): ... this.
	(struct bfd_link_callbacks) <examine_strtab>: Take only a
	symstrtab argument.
	<ctf_new_symbol>: New.
	<ctf_new_dynsym>: Likewise.
	* ctf-api.h (struct ctf_link_sym) <st_symidx>: New.
	<st_nameidx>: Likewise.
	<st_nameidx_set>: Likewise.
	(ctf_link_iter_symbol_f): Removed.
	(ctf_link_shuffle_syms): Remove most parameters, just takes a
	ctf_dict_t now.
	(ctf_link_add_linker_symbol): New, split from
	ctf_link_shuffle_syms.
	* ctf.h (CTF_F_DYNSTR): New.
	(CTF_F_MAX): Adjust.

ld/ChangeLog
2020-11-20  Nick Alcock  <nick.alcock@oracle.com>

	* ldelfgen.c (struct ctf_strsym_iter_cb_arg): Rename to...
	(struct ctf_strtab_iter_cb_arg): ... this, changing fields:
	<syms>: Remove.
	<symcount>: Remove.
	<symstrtab>: Rename to...
	<strtab>: ... this.
	(ldelf_ctf_strtab_iter_cb): Adjust.
	(ldelf_ctf_symbols_iter_cb): Remove.
	(ldelf_new_dynsym_for_ctf): New, tell libctf about a single
	symbol.
	(ldelf_examine_strtab_for_ctf): Rename to...
	(ldelf_acquire_strings_for_ctf): ... this, only doing the strtab
	portion and not symbols.
	* ldelfgen.h: Adjust declarations accordingly.
	* ldemul.c (ldemul_examine_strtab_for_ctf): Rename to...
	(ldemul_acquire_strings_for_ctf): ... this.
	(ldemul_new_dynsym_for_ctf): New.
	* ldemul.h: Adjust declarations accordingly.
	* ldlang.c (ldlang_ctf_apply_strsym): Rename to...
	(ldlang_ctf_acquire_strings): ... this.
	(ldlang_ctf_new_dynsym): New.
	(lang_write_ctf): Call ldemul_new_dynsym_for_ctf with NULL to do
	the actual symbol shuffle.
	* ldlang.h (struct elf_strtab_hash): Adjust accordingly.
	* ldmain.c (bfd_link_callbacks): Wire up new/renamed callbacks.

libctf/ChangeLog
2020-11-20  Nick Alcock  <nick.alcock@oracle.com>

	* ctf-link.c (ctf_link_shuffle_syms): Adjust.
	(ctf_link_add_linker_symbol): New, unimplemented stub.
	* libctf.ver: Add it.
	* ctf-create.c (ctf_serialize): Set CTF_F_DYNSTR on newly-serialized
	dicts.
	* ctf-open-bfd.c (ctf_bfdopen_ctfsect): Check for the flag: open the
	symtab/strtab if not present, dynsym/dynstr otherwise.
	* ctf-archive.c (ctf_arc_bufpreamble): New, get the preamble from
	some arbitrary member of a CTF archive.
	* ctf-impl.h (ctf_arc_bufpreamble): Declare it.

20 files changed, 187 insertions, 99 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index a00cfe9..f8265f4 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,5 +1,47 @@
 2020-11-20  Nick Alcock  <nick.alcock@oracle.com>
 
+	* ldelfgen.c (struct ctf_strsym_iter_cb_arg): Rename to...
+	(struct ctf_strtab_iter_cb_arg): ... this, changing fields:
+	<syms>: Remove.
+	<symcount>: Remove.
+	<symstrtab>: Rename to...
+	<strtab>: ... this.
+	(ldelf_ctf_strtab_iter_cb): Adjust.
+	(ldelf_ctf_symbols_iter_cb): Remove.
+	(ldelf_new_dynsym_for_ctf): New, tell libctf about a single
+	symbol.
+	(ldelf_examine_strtab_for_ctf): Rename to...
+	(ldelf_acquire_strings_for_ctf): ... this, only doing the strtab
+	portion and not symbols.
+	* ldelfgen.h: Adjust declarations accordingly.
+	* ldemul.c (ldemul_examine_strtab_for_ctf): Rename to...
+	(ldemul_acquire_strings_for_ctf): ... this.
+	(ldemul_new_dynsym_for_ctf): New.
+	* ldemul.h: Adjust declarations accordingly.
+	* ldlang.c (ldlang_ctf_apply_strsym): Rename to...
+	(ldlang_ctf_acquire_strings): ... this.
+	(ldlang_ctf_new_dynsym): New.
+	(lang_write_ctf): Call ldemul_new_dynsym_for_ctf with NULL to do
+	the actual symbol shuffle.
+	* ldlang.h (struct elf_strtab_hash): Adjust accordingly.
+	* ldmain.c (bfd_link_callbacks): Wire up new/renamed callbacks.
+
+	* emultempl/aix.em: Adjust for emulation changes:
+	ldemul_examine_strtab_for_ctf renamed to
+	ldemul_acquire_strings_for_ctf, new ldemul_new_dynsym_for_ctf.
+	* emultempl/armcoff.em: Likewise.
+	* emultempl/beos.em: Likewise.
+	* emultempl/elf.em: Likewise.
+	* emultempl/elf-generic.em: Likewise.
+	* emultempl/linux.em: Likewise.
+	* emultempl/msp430.em: Likewise.
+	* emultempl/pe.em: Likewise.
+	* emultempl/pep.em: Likewise.
+	* emultempl/ticoff.em: Likewise.
+	* emultempl/vanilla.em: Likewise.
+
+2020-11-20  Nick Alcock  <nick.alcock@oracle.com>
+
 	* ldlang.c (ctf_output): This is a ctf_dict_t now.
 	(lang_ctf_errs_warnings): Rename ctf_file_t to ctf_dict_t.
 	(ldlang_open_ctf): Adjust comment.
diff --git a/ld/emultempl/aix.em b/ld/emultempl/aix.em
index c1fe705..df7471b 100644
--- a/ld/emultempl/aix.em
+++ b/ld/emultempl/aix.em
@@ -1595,7 +1595,8 @@ struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation = {
   NULL,				/* new_vers_pattern */
   NULL,				/* extra_map_file_text */
   ${LDEMUL_EMIT_CTF_EARLY-NULL},
-  ${LDEMUL_EXAMINE_STRTAB_FOR_CTF-NULL},
+  ${LDEMUL_ACQUIRE_STRINGS_FOR_CTF-NULL},
+  ${LDEMUL_NEW_DYNSYM_FOR_CTF-NULL},
   gld${EMULATION_NAME}_print_symbol
 };
 EOF
diff --git a/ld/emultempl/armcoff.em b/ld/emultempl/armcoff.em
index ff22af4..3a86af9 100644
--- a/ld/emultempl/armcoff.em
+++ b/ld/emultempl/armcoff.em
@@ -286,7 +286,8 @@ struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
   NULL,	/* new_vers_pattern */
   NULL,	/* extra_map_file_text */
   ${LDEMUL_EMIT_CTF_EARLY-NULL},
-  ${LDEMUL_EXAMINE_STRTAB_FOR_CTF-NULL},
+  ${LDEMUL_ACQUIRE_STRINGS_FOR_CTF-NULL},
+  ${LDEMUL_NEW_DYNSYM_FOR_CTF-NULL},
   ${LDEMUL_PRINT_SYMBOL-NULL}
 };
 EOF
diff --git a/ld/emultempl/beos.em b/ld/emultempl/beos.em
index ace6e3a..d025f21 100644
--- a/ld/emultempl/beos.em
+++ b/ld/emultempl/beos.em
@@ -768,7 +768,8 @@ struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
   NULL,	/* new_vers_pattern */
   NULL,	/* extra_map_file_text */
   ${LDEMUL_EMIT_CTF_EARLY-NULL},
-  ${LDEMUL_EXAMINE_STRTAB_FOR_CTF-NULL},
+  ${LDEMUL_ACQUIRE_STRINGS_FOR_CTF-NULL},
+  ${LDEMUL_NEW_DYNSYM_FOR_CTF-NULL},
   ${LDEMUL_PRINT_SYMBOL-NULL}
 };
 EOF
diff --git a/ld/emultempl/elf-generic.em b/ld/emultempl/elf-generic.em
index 7e0923b..a404148 100644
--- a/ld/emultempl/elf-generic.em
+++ b/ld/emultempl/elf-generic.em
@@ -28,4 +28,5 @@ EOF
 # Put these extra routines in ld${EMULATION_NAME}_emulation
 #
 LDEMUL_EMIT_CTF_EARLY=ldelf_emit_ctf_early
-LDEMUL_EXAMINE_STRTAB_FOR_CTF=ldelf_examine_strtab_for_ctf
+LDEMUL_ACQUIRE_STRINGS_FOR_CTF=ldelf_acquire_strings_for_ctf
+LDEMUL_NEW_DYNSYM_FOR_CTF=ldelf_new_dynsym_for_ctf
diff --git a/ld/emultempl/elf.em b/ld/emultempl/elf.em
index 59eed70..cfdf60e 100644
--- a/ld/emultempl/elf.em
+++ b/ld/emultempl/elf.em
@@ -931,7 +931,8 @@ struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
   ${LDEMUL_NEW_VERS_PATTERN-NULL},
   ${LDEMUL_EXTRA_MAP_FILE_TEXT-NULL},
   ${LDEMUL_EMIT_CTF_EARLY-NULL},
-  ${LDEMUL_EXAMINE_STRTAB_FOR_CTF-NULL},
+  ${LDEMUL_ACQUIRE_STRINGS_FOR_CTF-NULL},
+  ${LDEMUL_NEW_DYNSYM_FOR_CTF-NULL},
   ${LDEMUL_PRINT_SYMBOL-NULL}
 };
 EOF
diff --git a/ld/emultempl/generic.em b/ld/emultempl/generic.em
index 24d3c1d..5a69c01 100644
--- a/ld/emultempl/generic.em
+++ b/ld/emultempl/generic.em
@@ -161,7 +161,8 @@ struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
   ${LDEMUL_NEW_VERS_PATTERN-NULL},
   ${LDEMUL_EXTRA_MAP_FILE_TEXT-NULL},
   ${LDEMUL_EMIT_CTF_EARLY-NULL},
-  ${LDEMUL_EXAMINE_STRTAB_FOR_CTF-NULL},
+  ${LDEMUL_ACQUIRE_STRINGS_FOR_CTF-NULL},
+  ${LDEMUL_NEW_DYNSYM_FOR_CTF-NULL},
   ${LDEMUL_PRINT_SYMBOL-NULL}
 };
 EOF
diff --git a/ld/emultempl/linux.em b/ld/emultempl/linux.em
index 1444610..0cff374 100644
--- a/ld/emultempl/linux.em
+++ b/ld/emultempl/linux.em
@@ -219,7 +219,8 @@ struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
   NULL,	/* new_vers_pattern */
   NULL,	/* extra_map_file_text */
   ${LDEMUL_EMIT_CTF_EARLY-NULL},
-  ${LDEMUL_EXAMINE_STRTAB_FOR_CTF-NULL},
+  ${LDEMUL_ACQUIRE_STRINGS_FOR_CTF-NULL},
+  ${LDEMUL_NEW_DYNSYM_FOR_CTF-NULL},
   ${LDEMUL_PRINT_SYMBOL-NULL}
 };
 EOF
diff --git a/ld/emultempl/msp430.em b/ld/emultempl/msp430.em
index 7b78a53..31cba4a 100644
--- a/ld/emultempl/msp430.em
+++ b/ld/emultempl/msp430.em
@@ -936,7 +936,8 @@ struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
   ${LDEMUL_NEW_VERS_PATTERN-NULL},
   ${LDEMUL_EXTRA_MAP_FILE_TEXT-NULL},
   ${LDEMUL_EMIT_CTF_EARLY-NULL},
-  ${LDEMUL_EXAMINE_STRTAB_FOR_CTF-NULL},
+  ${LDEMUL_ACQUIRE_STRINGS_FOR_CTF-NULL},
+  ${LDEMUL_NEW_DYNSYM_FOR_CTF-NULL},
   ${LDEMUL_PRINT_SYMBOL-NULL}
 };
 EOF
diff --git a/ld/emultempl/pe.em b/ld/emultempl/pe.em
index 00db3d0..e07dc9c 100644
--- a/ld/emultempl/pe.em
+++ b/ld/emultempl/pe.em
@@ -2415,7 +2415,8 @@ struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
   NULL,	/* new_vers_pattern.  */
   NULL,	/* extra_map_file_text.  */
   ${LDEMUL_EMIT_CTF_EARLY-NULL},
-  ${LDEMUL_EXAMINE_STRTAB_FOR_CTF-NULL},
+  ${LDEMUL_ACQUIRE_STRINGS_FOR_CTF-NULL},
+  ${LDEMUL_NEW_DYNSYM_FOR_CTF-NULL},
   ${LDEMUL_PRINT_SYMBOL-NULL}
 };
 EOF
diff --git a/ld/emultempl/pep.em b/ld/emultempl/pep.em
index 2f4bdfb..74468be 100644
--- a/ld/emultempl/pep.em
+++ b/ld/emultempl/pep.em
@@ -2235,7 +2235,8 @@ struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
   NULL,	/* new_vers_pattern.  */
   NULL,	/* extra_map_file_text */
   ${LDEMUL_EMIT_CTF_EARLY-NULL},
-  ${LDEMUL_EXAMINE_STRTAB_FOR_CTF-NULL},
+  ${LDEMUL_ACQUIRE_STRINGS_FOR_CTF-NULL},
+  ${LDEMUL_NEW_DYNSYM_FOR_CTF-NULL},
   ${LDEMUL_PRINT_SYMBOL-NULL}
 };
 EOF
diff --git a/ld/emultempl/ticoff.em b/ld/emultempl/ticoff.em
index 11ddd0c..1cf82be 100644
--- a/ld/emultempl/ticoff.em
+++ b/ld/emultempl/ticoff.em
@@ -186,7 +186,8 @@ struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
   NULL,	/* new_vers_pattern */
   NULL,  /* extra_map_file_text */
   ${LDEMUL_EMIT_CTF_EARLY-NULL},
-  ${LDEMUL_EXAMINE_STRTAB_FOR_CTF-NULL},
+  ${LDEMUL_ACQUIRE_STRINGS_FOR_CTF-NULL},
+  ${LDEMUL_NEW_DYNSYM_FOR_CTF-NULL},
   ${LDEMUL_PRINT_SYMBOL-NULL}
 };
 EOF
diff --git a/ld/emultempl/vanilla.em b/ld/emultempl/vanilla.em
index 70d193c..324e38a 100644
--- a/ld/emultempl/vanilla.em
+++ b/ld/emultempl/vanilla.em
@@ -87,7 +87,8 @@ struct ld_emulation_xfer_struct ld_vanilla_emulation =
   NULL,	/* new_vers_pattern */
   NULL,	/* extra_map_file_text */
   NULL, /* emit_ctf_early */
-  NULL, /* examine_strtab_for_ctf */
+  NULL, /* acquire_strings_for_ctf */
+  NULL, /* new_dynsym_for_ctf */
   NULL  /* print_symbol */
 };
 EOF
diff --git a/ld/ldelfgen.c b/ld/ldelfgen.c
index e9496f9..ca531ee 100644
--- a/ld/ldelfgen.c
+++ b/ld/ldelfgen.c
@@ -28,6 +28,7 @@
 #include "ldexp.h"
 #include "ldlang.h"
 #include "elf-bfd.h"
+#include "elf/internal.h"
 #include "ldelfgen.h"
 
 void
@@ -103,11 +104,9 @@ ldelf_emit_ctf_early (void)
 /* Callbacks used to map from bfd types to libctf types, under libctf's
    control.  */
 
-struct ctf_strsym_iter_cb_arg
+struct ctf_strtab_iter_cb_arg
 {
-  struct elf_sym_strtab *syms;
-  bfd_size_type symcount;
-  struct elf_strtab_hash *symstrtab;
+  struct elf_strtab_hash *strtab;
   size_t next_i;
   size_t next_idx;
 };
@@ -121,20 +120,20 @@ ldelf_ctf_strtab_iter_cb (uint32_t *offset, void *arg_)
   bfd_size_type off;
   const char *ret;
 
-  struct ctf_strsym_iter_cb_arg *arg =
-    (struct ctf_strsym_iter_cb_arg *) arg_;
+  struct ctf_strtab_iter_cb_arg *arg =
+    (struct ctf_strtab_iter_cb_arg *) arg_;
 
   /* There is no zeroth string.  */
   if (arg->next_i == 0)
     arg->next_i = 1;
 
-  if (arg->next_i >= _bfd_elf_strtab_len (arg->symstrtab))
+  if (arg->next_i >= _bfd_elf_strtab_len (arg->strtab))
     {
       arg->next_i = 0;
       return NULL;
     }
 
-  ret = _bfd_elf_strtab_str (arg->symstrtab, arg->next_i++, &off);
+  ret = _bfd_elf_strtab_str (arg->strtab, arg->next_i++, &off);
   *offset = off;
 
   /* If we've overflowed, we cannot share any further strings: the CTF
@@ -145,69 +144,74 @@ ldelf_ctf_strtab_iter_cb (uint32_t *offset, void *arg_)
   return ret;
 }
 
-/* Return symbols from the symbol table to libctf, one by one.  We assume (and
-   assert) that the symbols in the elf_link_hash_table are in strictly ascending
-   order, and that none will be added in between existing ones.  Returns NULL
-   when iteration is complete.  */
-
-static struct ctf_link_sym *
-ldelf_ctf_symbols_iter_cb (struct ctf_link_sym *dest,
-					   void *arg_)
+void
+ldelf_acquire_strings_for_ctf
+  (struct ctf_dict *ctf_output, struct elf_strtab_hash *strtab)
 {
-  struct ctf_strsym_iter_cb_arg *arg =
-    (struct ctf_strsym_iter_cb_arg *) arg_;
+  struct ctf_strtab_iter_cb_arg args = { strtab, 0, 0 };
+  if (!ctf_output)
+    return;
 
-  if (arg->next_i > arg->symcount)
+  if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour)
     {
-      arg->next_i = 0;
-      arg->next_idx = 0;
-      return NULL;
+      if (ctf_link_add_strtab (ctf_output, ldelf_ctf_strtab_iter_cb,
+			       &args) < 0)
+	einfo (_("%F%P: warning: CTF strtab association failed; strings will "
+		 "not be shared: %s\n"),
+	       ctf_errmsg (ctf_errno (ctf_output)));
     }
-
-  ASSERT (arg->syms[arg->next_i].dest_index == arg->next_idx);
-  dest->st_name = _bfd_elf_strtab_str (arg->symstrtab, arg->next_i, NULL);
-  dest->st_shndx = arg->syms[arg->next_i].sym.st_shndx;
-  dest->st_type = ELF_ST_TYPE (arg->syms[arg->next_i].sym.st_info);
-  dest->st_value = arg->syms[arg->next_i].sym.st_value;
-  arg->next_i++;
-  return dest;
 }
 
 void
-ldelf_examine_strtab_for_ctf
-  (struct ctf_dict *ctf_output, struct elf_sym_strtab *syms,
-   bfd_size_type symcount, struct elf_strtab_hash *symstrtab)
+ldelf_new_dynsym_for_ctf (struct ctf_dict *ctf_output, int symidx,
+			  struct elf_internal_sym *sym)
 {
-  struct ctf_strsym_iter_cb_arg args = { syms, symcount, symstrtab,
-					  0, 0 };
-   if (!ctf_output)
+  ctf_link_sym_t lsym;
+
+  if (!ctf_output)
      return;
 
-   if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour
-       && !bfd_link_relocatable (&link_info))
+  /* New symbol.  */
+  if (sym != NULL)
     {
-      if (ctf_link_add_strtab (ctf_output, ldelf_ctf_strtab_iter_cb,
-			       &args) < 0)
-	einfo (_("%F%P: warning: CTF strtab association failed; strings will "
-		 "not be shared: %s\n"),
-	       ctf_errmsg (ctf_errno (ctf_output)));
+      lsym.st_name = NULL;
+      lsym.st_nameidx = sym->st_name;
+      lsym.st_nameidx_set = 1;
+      lsym.st_symidx = symidx;
+      lsym.st_shndx = sym->st_shndx;
+      lsym.st_type = ELF_ST_TYPE (sym->st_info);
+      lsym.st_value = sym->st_value;
+      if (ctf_link_add_linker_symbol (ctf_output, &lsym) < 0)
+	{
+	  einfo (_("%F%P: warning: CTF symbol addition failed; CTF will "
+		   "not be tied to symbols: %s\n"),
+		 ctf_errmsg (ctf_errno (ctf_output)));
+	}
+    }
+  else
+    {
+      /* Shuffle all the symbols.  */
 
-      if (ctf_link_shuffle_syms (ctf_output, ldelf_ctf_symbols_iter_cb,
-				 &args) < 0)
-	einfo (_("%F%P: warning: CTF symbol shuffling failed; slight space "
-		 "cost: %s\n"), ctf_errmsg (ctf_errno (ctf_output)));
+      if (ctf_link_shuffle_syms (ctf_output) < 0)
+	einfo (_("%F%P: warning: CTF symbol shuffling failed; CTF will "
+		 "not be tied to symbols: %s\n"),
+	       ctf_errmsg (ctf_errno (ctf_output)));
     }
 }
 #else
-extern int ldelf_emit_ctf_early (void)
+int
+ldelf_emit_ctf_early (void)
 {
   return 0;
 }
 
-extern void ldelf_examine_strtab_for_ctf
-  (struct ctf_dict *ctf_output ATTRIBUTE_UNUSED,
-   struct elf_sym_strtab *syms ATTRIBUTE_UNUSED,
-   bfd_size_type symcount ATTRIBUTE_UNUSED,
-   struct elf_strtab_hash *symstrtab ATTRIBUTE_UNUSED)
+void
+ldelf_acquire_strings_for_ctf (struct ctf_dict *ctf_output ATTRIBUTE_UNUSED,
+			       struct elf_strtab_hash *strtab ATTRIBUTE_UNUSED)
+{}
+void
+ldelf_new_dynsym_for_ctf (struct ctf_dict *ctf_output ATTRIBUTE_UNUSED,
+			  int symidx ATTRIBUTE_UNUSED,
+			  struct elf_internal_sym *sym ATTRIBUTE_UNUSED)
 {}
 #endif
diff --git a/ld/ldelfgen.h b/ld/ldelfgen.h
index 93bdf29..3392c2b 100644
--- a/ld/ldelfgen.h
+++ b/ld/ldelfgen.h
@@ -18,12 +18,13 @@
    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
    MA 02110-1301, USA.  */
 
-struct elf_sym_strtab;
+struct elf_internal_sym;
 struct elf_strtab_hash;
 struct ctf_dict;
 
 extern void ldelf_map_segments (bfd_boolean);
 extern int ldelf_emit_ctf_early (void);
-extern void ldelf_examine_strtab_for_ctf
-  (struct ctf_dict *ctf_output, struct elf_sym_strtab *syms,
-   bfd_size_type symcount, struct elf_strtab_hash *symstrtab);
+extern void ldelf_acquire_strings_for_ctf
+  (struct ctf_dict *ctf_output, struct elf_strtab_hash *strtab);
+extern void ldelf_new_dynsym_for_ctf
+  (struct ctf_dict *ctf_output, int symidx, struct elf_internal_sym *sym);
diff --git a/ld/ldemul.c b/ld/ldemul.c
index 6dc5112..920afc8 100644
--- a/ld/ldemul.c
+++ b/ld/ldemul.c
@@ -418,15 +418,19 @@ ldemul_emit_ctf_early (void)
 }
 
 void
-ldemul_examine_strtab_for_ctf (struct ctf_dict *ctf_output,
-			       struct elf_sym_strtab *syms,
-			       bfd_size_type symcount,
-			       struct elf_strtab_hash *symstrtab)
+ldemul_acquire_strings_for_ctf (struct ctf_dict *ctf_output,
+				struct elf_strtab_hash *symstrtab)
+{
+  if (ld_emulation->acquire_strings_for_ctf)
+    ld_emulation->acquire_strings_for_ctf (ctf_output, symstrtab);
+}
 
+void
+ldemul_new_dynsym_for_ctf (struct ctf_dict *ctf_output, int symidx,
+			   struct elf_internal_sym *sym)
 {
-  if (ld_emulation->examine_strtab_for_ctf)
-    ld_emulation->examine_strtab_for_ctf (ctf_output, syms,
-					  symcount, symstrtab);
+  if (ld_emulation->new_dynsym_for_ctf)
+    ld_emulation->new_dynsym_for_ctf (ctf_output, symidx, sym);
 }
 
 bfd_boolean
diff --git a/ld/ldemul.h b/ld/ldemul.h
index 5efe4aa..0b9653e 100644
--- a/ld/ldemul.h
+++ b/ld/ldemul.h
@@ -109,9 +109,11 @@ extern void ldemul_extra_map_file_text
 extern int ldemul_emit_ctf_early
   (void);
 /* Called from per-target code to examine the strtab and symtab.  */
-extern void ldemul_examine_strtab_for_ctf
-  (struct ctf_dict *, struct elf_sym_strtab *, bfd_size_type,
-   struct elf_strtab_hash *);
+extern void ldemul_acquire_strings_for_ctf
+  (struct ctf_dict *, struct elf_strtab_hash *);
+extern void ldemul_new_dynsym_for_ctf
+  (struct ctf_dict *, int symidx, struct elf_internal_sym *);
+
 extern bfd_boolean ldemul_print_symbol
   (struct bfd_link_hash_entry *hash_entry, void *ptr);
 
@@ -230,14 +232,22 @@ typedef struct ld_emulation_xfer_struct {
   int (*emit_ctf_early)
     (void);
 
-  /* Called to examine the string and symbol table late enough in linking that
-     they are finally laid out.  If emit_ctf_early returns true, this is not
-     called and ldemul_maybe_emit_ctf() emits CTF in 'early' mode: otherwise, it
-     waits until 'late'. (Late mode needs explicit support at per-target link
-     time to get called at all).  If set, called by ld when the examine_strtab
+  /* Called to examine the string table late enough in linking that it is
+     finally laid out.  If emit_ctf_early returns true, this is not called, and
+     ldemul_maybe_emit_ctf emits CTF in 'early' mode: otherwise, it waits
+     until 'late'. (Late mode needs explicit support at per-target link time to
+     get called at all).  If set, called by ld when the examine_strtab
      bfd_link_callback is invoked by per-target code.  */
-  void (*examine_strtab_for_ctf) (struct ctf_dict *, struct elf_sym_strtab *,
-				  bfd_size_type, struct elf_strtab_hash *);
+  void (*acquire_strings_for_ctf) (struct ctf_dict *, struct elf_strtab_hash *);
+
+  /* Called when a new symbol is added to the dynamic symbol table.  If
+     emit_ctf_early returns true, this is not called, and ldemul_maybe_emit_ctf
+     emits CTF in 'early' mode: otherwise, it waits until 'late'. (Late mode
+     needs explicit support at per-target link time to get called at all).  If
+     set, called by ld when the ctf_new_symbol bfd_link_callback is invoked by
+     per-target code.  Called with a NULL symbol when no further symbols will be
+     provided.  */
+  void (*new_dynsym_for_ctf) (struct ctf_dict *, int, struct elf_internal_sym *);
 
   /* Called when printing a symbol to the map file.   AIX uses this
      hook to flag gc'd symbols.  */
diff --git a/ld/ldlang.c b/ld/ldlang.c
index eaf90a6..b70937a 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -3826,14 +3826,20 @@ lang_merge_ctf (void)
   lang_ctf_errs_warnings (ctf_output);
 }
 
-/* Let the emulation examine the symbol table and strtab to help it optimize the
-   CTF, if supported.  */
+/* Let the emulation acquire strings from the dynamic strtab to help it optimize
+   the CTF, if supported.  */
 
 void
-ldlang_ctf_apply_strsym (struct elf_sym_strtab *syms, bfd_size_type symcount,
-			 struct elf_strtab_hash *symstrtab)
+ldlang_ctf_acquire_strings (struct elf_strtab_hash *dynstrtab)
 {
-  ldemul_examine_strtab_for_ctf (ctf_output, syms, symcount, symstrtab);
+  ldemul_acquire_strings_for_ctf (ctf_output, dynstrtab);
+}
+
+/* Inform the emulation about the addition of a new dynamic symbol, in BFD
+   internal format.  */
+void ldlang_ctf_new_dynsym (int symidx, struct elf_internal_sym *sym)
+{
+  ldemul_new_dynsym_for_ctf (ctf_output, symidx, sym);
 }
 
 /* Write out the CTF section.  Called early, if the emulation isn't going to
@@ -3860,6 +3866,11 @@ lang_write_ctf (int late)
 	return;
     }
 
+  /* Inform the emulation that all the symbols that will be received have
+     been.  */
+
+  ldemul_new_dynsym_for_ctf (ctf_output, 0, NULL);
+
   /* Emit CTF.  */
 
   output_sect = bfd_get_section_by_name (link_info.output_bfd, ".ctf");
@@ -3922,11 +3933,11 @@ ldlang_open_ctf (void)
 
 static void lang_merge_ctf (void) {}
 void
-ldlang_ctf_apply_strsym (struct elf_sym_strtab *syms ATTRIBUTE_UNUSED,
-			 bfd_size_type symcount ATTRIBUTE_UNUSED,
-			 struct elf_strtab_hash *symstrtab ATTRIBUTE_UNUSED)
-{
-}
+ldlang_ctf_acquire_strings (struct elf_strtab_hash *dynstrtab
+			    ATTRIBUTE_UNUSED) {}
+void
+ldlang_ctf_new_dynsym (int symidx ATTRIBUTE_UNUSED,
+		       struct elf_internal_sym *sym ATTRIBUTE_UNUSED) {}
 static void lang_write_ctf (int late ATTRIBUTE_UNUSED) {}
 void ldlang_write_ctf_late (void) {}
 #endif
diff --git a/ld/ldlang.h b/ld/ldlang.h
index 196debf..6675c57 100644
--- a/ld/ldlang.h
+++ b/ld/ldlang.h
@@ -689,8 +689,10 @@ extern bfd_boolean load_symbols
 
 struct elf_sym_strtab;
 struct elf_strtab_hash;
-extern void ldlang_ctf_apply_strsym
-  (struct elf_sym_strtab *, bfd_size_type, struct elf_strtab_hash *);
+extern void ldlang_ctf_acquire_strings
+  (struct elf_strtab_hash *);
+extern void ldlang_ctf_new_dynsym
+  (int symidx, struct elf_internal_sym *);
 extern void ldlang_write_ctf_late
   (void);
 extern bfd_boolean
diff --git a/ld/ldmain.c b/ld/ldmain.c
index cc3df76..f8a03c6 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -151,7 +151,9 @@ static struct bfd_link_callbacks link_callbacks =
   info_msg,
   minfo,
   ldlang_override_segment_assignment,
-  ldlang_ctf_apply_strsym,
+  ldlang_ctf_acquire_strings,
+  NULL,
+  ldlang_ctf_new_dynsym,
   ldlang_write_ctf_late
 };