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From 51ffcfc2c67b4c4aa1620fb4c9834c38d150e1c5 Mon Sep 17 00:00:00 2001
From: "Maciej W. Rozycki" <macro@imgtec.com>
Date: Wed, 26 Apr 2017 22:23:44 +0100
Subject: PR ld/21334: Always call `_bfd_elf_link_renumber_dynsyms' if required
Complement commit e17b0c351f0b ("MIPS/BFD: Respect the ELF gABI dynamic
symbol table sort requirement") and correct an inconsistency in dynamic
symbol accounting data causing an assertion failure in the MIPS backend:
ld: BFD (GNU Binutils) 2.28.51.20170330 assertion fail
../../binutils-gdb/bfd/elfxx-mips.c:3860
in the course of making a GOT entry in a static binary to satisfy a GOT
relocation present in input, due to the local dynamic symbol count not
having been established.
To do so let backends request `_bfd_elf_link_renumber_dynsyms' to be
always called, rather than where a dynamic binary is linked only, and
then make this request in the MIPS backend.
bfd/
PR ld/21334
* elf-bfd.h (elf_backend_data): Add `always_renumber_dynsyms'
member.
* elfxx-target.h [!elf_backend_always_renumber_dynsyms]
(elf_backend_always_renumber_dynsyms): Define.
(elfNN_bed): Initialize `always_renumber_dynsyms' member.
* elfxx-mips.h (elf_backend_always_renumber_dynsyms): Define.
* elflink.c (bfd_elf_size_dynsym_hash_dynstr): Also call
`_bfd_elf_link_renumber_dynsyms' if the backend has requested
it.
(elf_gc_sweep): Likewise.
(backported from commit 23ec1e32b1ab714649a7c25e49b5d721fe3bd3db)
---
bfd/ChangeLog | 14 ++++++++++++++
bfd/elf-bfd.h | 4 ++++
bfd/elflink.c | 34 +++++++++++++++++++++++-----------
bfd/elfxx-mips.h | 1 +
bfd/elfxx-target.h | 6 +++++-
5 files changed, 47 insertions(+), 12 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 537ebb5e2c..3f10bc55f2 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,19 @@
2017-04-26 Maciej W. Rozycki <macro@imgtec.com>
+ PR ld/21334
+ * elf-bfd.h (elf_backend_data): Add `always_renumber_dynsyms'
+ member.
+ * elfxx-target.h [!elf_backend_always_renumber_dynsyms]
+ (elf_backend_always_renumber_dynsyms): Define.
+ (elfNN_bed): Initialize `always_renumber_dynsyms' member.
+ * elfxx-mips.h (elf_backend_always_renumber_dynsyms): Define.
+ * elflink.c (bfd_elf_size_dynsym_hash_dynstr): Also call
+ `_bfd_elf_link_renumber_dynsyms' if the backend has requested
+ it.
+ (elf_gc_sweep): Likewise.
+
+2017-04-26 Maciej W. Rozycki <macro@imgtec.com>
+
* elflink.c (elf_gc_sweep): Only call
`_bfd_elf_link_renumber_dynsyms' if dynamic sections have been
created.
diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
index 5de9ab6ca6..dc4bd87f89 100644
--- a/bfd/elf-bfd.h
+++ b/bfd/elf-bfd.h
@@ -1478,6 +1478,10 @@ struct elf_backend_data
/* Address of protected data defined in the shared library may be
external, i.e., due to copy relocation. */
unsigned extern_protected_data : 1;
+
+ /* True if `_bfd_elf_link_renumber_dynsyms' must be called even for
+ static binaries. */
+ unsigned always_renumber_dynsyms : 1;
};
/* Information about reloc sections associated with a bfd_elf_section_data
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 75d6543dcc..507f2b6259 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -6710,6 +6710,8 @@ bfd_boolean
bfd_elf_size_dynsym_hash_dynstr (bfd *output_bfd, struct bfd_link_info *info)
{
const struct elf_backend_data *bed;
+ unsigned long section_sym_count;
+ bfd_size_type dynsymcount;
if (!is_elf_hash_table (info->hash))
return TRUE;
@@ -6717,24 +6719,30 @@ bfd_elf_size_dynsym_hash_dynstr (bfd *output_bfd, struct bfd_link_info *info)
bed = get_elf_backend_data (output_bfd);
(*bed->elf_backend_init_index_section) (output_bfd, info);
+ /* Assign dynsym indices. In a shared library we generate a section
+ symbol for each output section, which come first. Next come all
+ of the back-end allocated local dynamic syms, followed by the rest
+ of the global symbols.
+
+ This is usually not needed for static binaries, however backends
+ can request to always do it, e.g. the MIPS backend uses dynamic
+ symbol counts to lay out GOT, which will be produced in the
+ presence of GOT relocations even in static binaries (holding fixed
+ data in that case, to satisfy those relocations). */
+
+ if (elf_hash_table (info)->dynamic_sections_created
+ || bed->always_renumber_dynsyms)
+ dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info,
+ §ion_sym_count);
+
if (elf_hash_table (info)->dynamic_sections_created)
{
bfd *dynobj;
asection *s;
- bfd_size_type dynsymcount;
- unsigned long section_sym_count;
unsigned int dtagcount;
dynobj = elf_hash_table (info)->dynobj;
- /* Assign dynsym indicies. In a shared library we generate a
- section symbol for each output section, which come first.
- Next come all of the back-end allocated local dynamic syms,
- followed by the rest of the global symbols. */
-
- dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info,
- §ion_sym_count);
-
/* Work out the size of the symbol version section. */
s = bfd_get_linker_section (dynobj, ".gnu.version");
BFD_ASSERT (s != NULL);
@@ -12986,7 +12994,11 @@ elf_gc_sweep (bfd *abfd, struct bfd_link_info *info)
elf_link_hash_traverse (elf_hash_table (info), elf_gc_sweep_symbol,
&sweep_info);
- if (elf_hash_table (info)->dynamic_sections_created)
+ /* We need to reassign dynsym indices now that symbols may have
+ been removed. See the call in `bfd_elf_size_dynsym_hash_dynstr'
+ for the details of the conditions used here. */
+ if (elf_hash_table (info)->dynamic_sections_created
+ || bed->always_renumber_dynsyms)
_bfd_elf_link_renumber_dynsyms (abfd, info, §ion_sym_count);
return TRUE;
}
diff --git a/bfd/elfxx-mips.h b/bfd/elfxx-mips.h
index fa5b5d2de9..274129b2e5 100644
--- a/bfd/elfxx-mips.h
+++ b/bfd/elfxx-mips.h
@@ -196,3 +196,4 @@ literal_reloc_p (int r_type)
#define elf_backend_post_process_headers _bfd_mips_post_process_headers
#define elf_backend_compact_eh_encoding _bfd_mips_elf_compact_eh_encoding
#define elf_backend_cant_unwind_opcode _bfd_mips_elf_cant_unwind_opcode
+#define elf_backend_always_renumber_dynsyms TRUE
diff --git a/bfd/elfxx-target.h b/bfd/elfxx-target.h
index d063fb7f1b..d07600c15d 100644
--- a/bfd/elfxx-target.h
+++ b/bfd/elfxx-target.h
@@ -126,6 +126,9 @@
#ifndef elf_backend_extern_protected_data
#define elf_backend_extern_protected_data 0
#endif
+#ifndef elf_backend_always_renumber_dynsyms
+#define elf_backend_always_renumber_dynsyms FALSE
+#endif
#ifndef elf_backend_stack_align
#define elf_backend_stack_align 16
#endif
@@ -866,7 +869,8 @@ static struct elf_backend_data elfNN_bed =
elf_backend_no_page_alias,
elf_backend_default_execstack,
elf_backend_caches_rawsize,
- elf_backend_extern_protected_data
+ elf_backend_extern_protected_data,
+ elf_backend_always_renumber_dynsyms
};
/* Forward declaration for use when initialising alternative_target field. */
--
2.11.0
|
