toolchain/binutils/patches/2.28/002-PR-ld-21334-Always-call-_bfd_elf_link_renumber_dynsy.patch

   1 From 51ffcfc2c67b4c4aa1620fb4c9834c38d150e1c5 Mon Sep 17 00:00:00 2001
   2 From: "Maciej W. Rozycki" <macro@imgtec.com>
   3 Date: Wed, 26 Apr 2017 22:23:44 +0100
   4 Subject: PR ld/21334: Always call `_bfd_elf_link_renumber_dynsyms' if required
   5
   6 Complement commit e17b0c351f0b ("MIPS/BFD: Respect the ELF gABI dynamic
   7 symbol table sort requirement") and correct an inconsistency in dynamic
   8 symbol accounting data causing an assertion failure in the MIPS backend:
   9
  10 ld: BFD (GNU Binutils) 2.28.51.20170330 assertion fail
  11 ../../binutils-gdb/bfd/elfxx-mips.c:3860
  12
  13 in the course of making a GOT entry in a static binary to satisfy a GOT
  14 relocation present in input, due to the local dynamic symbol count not
  15 having been established.
  16
  17 To do so let backends request `_bfd_elf_link_renumber_dynsyms' to be
  18 always called, rather than where a dynamic binary is linked only, and
  19 then make this request in the MIPS backend.
  20
  21         bfd/
  22         PR ld/21334
  23         * elf-bfd.h (elf_backend_data): Add `always_renumber_dynsyms'
  24         member.
  25         * elfxx-target.h [!elf_backend_always_renumber_dynsyms]
  26         (elf_backend_always_renumber_dynsyms): Define.
  27         (elfNN_bed): Initialize `always_renumber_dynsyms' member.
  28         * elfxx-mips.h (elf_backend_always_renumber_dynsyms): Define.
  29         * elflink.c (bfd_elf_size_dynsym_hash_dynstr): Also call
  30         `_bfd_elf_link_renumber_dynsyms' if the backend has requested
  31         it.
  32         (elf_gc_sweep): Likewise.
  33
  34 (backported from commit 23ec1e32b1ab714649a7c25e49b5d721fe3bd3db)
  35 ---
  36  bfd/ChangeLog      | 14 ++++++++++++++
  37  bfd/elf-bfd.h      |  4 ++++
  38  bfd/elflink.c      | 34 +++++++++++++++++++++++-----------
  39  bfd/elfxx-mips.h   |  1 +
  40  bfd/elfxx-target.h |  6 +++++-
  41  5 files changed, 47 insertions(+), 12 deletions(-)
  42
  43 diff --git a/bfd/ChangeLog b/bfd/ChangeLog
  44 index 537ebb5e2c..3f10bc55f2 100644
  45 --- a/bfd/ChangeLog
  46 +++ b/bfd/ChangeLog
  47 @@ -1,5 +1,19 @@
  48  2017-04-26  Maciej W. Rozycki  <macro@imgtec.com>
  49
  50 +       PR ld/21334
  51 +       * elf-bfd.h (elf_backend_data): Add `always_renumber_dynsyms'
  52 +       member.
  53 +       * elfxx-target.h [!elf_backend_always_renumber_dynsyms]
  54 +       (elf_backend_always_renumber_dynsyms): Define.
  55 +       (elfNN_bed): Initialize `always_renumber_dynsyms' member.
  56 +       * elfxx-mips.h (elf_backend_always_renumber_dynsyms): Define.
  57 +       * elflink.c (bfd_elf_size_dynsym_hash_dynstr): Also call
  58 +       `_bfd_elf_link_renumber_dynsyms' if the backend has requested
  59 +       it.
  60 +       (elf_gc_sweep): Likewise.
  61 +
  62 +2017-04-26  Maciej W. Rozycki  <macro@imgtec.com>
  63 +
  64         * elflink.c (elf_gc_sweep): Only call
  65         `_bfd_elf_link_renumber_dynsyms' if dynamic sections have been
  66         created.
  67 diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
  68 index 5de9ab6ca6..dc4bd87f89 100644
  69 --- a/bfd/elf-bfd.h
  70 +++ b/bfd/elf-bfd.h
  71 @@ -1478,6 +1478,10 @@ struct elf_backend_data
  72    /* Address of protected data defined in the shared library may be
  73       external, i.e., due to copy relocation.   */
  74    unsigned extern_protected_data : 1;
  75 +
  76 +  /* True if `_bfd_elf_link_renumber_dynsyms' must be called even for
  77 +     static binaries.  */
  78 +  unsigned always_renumber_dynsyms : 1;
  79  };
  80
  81  /* Information about reloc sections associated with a bfd_elf_section_data
  82 diff --git a/bfd/elflink.c b/bfd/elflink.c
  83 index 75d6543dcc..507f2b6259 100644
  84 --- a/bfd/elflink.c
  85 +++ b/bfd/elflink.c
  86 @@ -6710,6 +6710,8 @@ bfd_boolean
  87  bfd_elf_size_dynsym_hash_dynstr (bfd *output_bfd, struct bfd_link_info *info)
  88  {
  89    const struct elf_backend_data *bed;
  90 +  unsigned long section_sym_count;
  91 +  bfd_size_type dynsymcount;
  92
  93    if (!is_elf_hash_table (info->hash))
  94      return TRUE;
  95 @@ -6717,24 +6719,30 @@ bfd_elf_size_dynsym_hash_dynstr (bfd *output_bfd, struct bfd_link_info *info)
  96    bed = get_elf_backend_data (output_bfd);
  97    (*bed->elf_backend_init_index_section) (output_bfd, info);
  98
  99 +  /* Assign dynsym indices.  In a shared library we generate a section
 100 +     symbol for each output section, which come first.  Next come all
 101 +     of the back-end allocated local dynamic syms, followed by the rest
 102 +     of the global symbols.
 103 +
 104 +     This is usually not needed for static binaries, however backends
 105 +     can request to always do it, e.g. the MIPS backend uses dynamic
 106 +     symbol counts to lay out GOT, which will be produced in the
 107 +     presence of GOT relocations even in static binaries (holding fixed
 108 +     data in that case, to satisfy those relocations).  */
 109 +
 110 +  if (elf_hash_table (info)->dynamic_sections_created
 111 +      || bed->always_renumber_dynsyms)
 112 +    dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info,
 113 +                                                 &section_sym_count);
 114 +
 115    if (elf_hash_table (info)->dynamic_sections_created)
 116      {
 117        bfd *dynobj;
 118        asection *s;
 119 -      bfd_size_type dynsymcount;
 120 -      unsigned long section_sym_count;
 121        unsigned int dtagcount;
 122
 123        dynobj = elf_hash_table (info)->dynobj;
 124
 125 -      /* Assign dynsym indicies.  In a shared library we generate a
 126 -        section symbol for each output section, which come first.
 127 -        Next come all of the back-end allocated local dynamic syms,
 128 -        followed by the rest of the global symbols.  */
 129 -
 130 -      dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info,
 131 -                                                   &section_sym_count);
 132 -
 133        /* Work out the size of the symbol version section.  */
 134        s = bfd_get_linker_section (dynobj, ".gnu.version");
 135        BFD_ASSERT (s != NULL);
 136 @@ -12986,7 +12994,11 @@ elf_gc_sweep (bfd *abfd, struct bfd_link_info *info)
 137    elf_link_hash_traverse (elf_hash_table (info), elf_gc_sweep_symbol,
 138                           &sweep_info);
 139
 140 -  if (elf_hash_table (info)->dynamic_sections_created)
 141 +  /* We need to reassign dynsym indices now that symbols may have
 142 +     been removed.  See the call in `bfd_elf_size_dynsym_hash_dynstr'
 143 +     for the details of the conditions used here.  */
 144 +  if (elf_hash_table (info)->dynamic_sections_created
 145 +      || bed->always_renumber_dynsyms)
 146      _bfd_elf_link_renumber_dynsyms (abfd, info, &section_sym_count);
 147    return TRUE;
 148  }
 149 diff --git a/bfd/elfxx-mips.h b/bfd/elfxx-mips.h
 150 index fa5b5d2de9..274129b2e5 100644
 151 --- a/bfd/elfxx-mips.h
 152 +++ b/bfd/elfxx-mips.h
 153 @@ -196,3 +196,4 @@ literal_reloc_p (int r_type)
 154  #define elf_backend_post_process_headers _bfd_mips_post_process_headers
 155  #define elf_backend_compact_eh_encoding _bfd_mips_elf_compact_eh_encoding
 156  #define elf_backend_cant_unwind_opcode _bfd_mips_elf_cant_unwind_opcode
 157 +#define elf_backend_always_renumber_dynsyms TRUE
 158 diff --git a/bfd/elfxx-target.h b/bfd/elfxx-target.h
 159 index d063fb7f1b..d07600c15d 100644
 160 --- a/bfd/elfxx-target.h
 161 +++ b/bfd/elfxx-target.h
 162 @@ -126,6 +126,9 @@
 163  #ifndef elf_backend_extern_protected_data
 164  #define elf_backend_extern_protected_data 0
 165  #endif
 166 +#ifndef elf_backend_always_renumber_dynsyms
 167 +#define elf_backend_always_renumber_dynsyms FALSE
 168 +#endif
 169  #ifndef elf_backend_stack_align
 170  #define elf_backend_stack_align 16
 171  #endif
 172 @@ -866,7 +869,8 @@ static struct elf_backend_data elfNN_bed =
 173    elf_backend_no_page_alias,
 174    elf_backend_default_execstack,
 175    elf_backend_caches_rawsize,
 176 -  elf_backend_extern_protected_data
 177 +  elf_backend_extern_protected_data,
 178 +  elf_backend_always_renumber_dynsyms
 179  };
 180
 181  /* Forward declaration for use when initialising alternative_target field.  */
 182 --
 183 2.11.0
 184