third_party/binutils/unlock-thin.patch

   1 commit 2cfbf2fece582c29df348104b28677c38a8301f4
   2 Author: Cary Coutant <ccoutant@google.com>
   3 Date:   Tue Feb 3 19:54:57 2015 -0800
   4
   5     Fix a file descriptor leak in gold.
   6
   7     When an LTO linker plugin claims an external member of a thin archive, gold
   8     does not properly unlock the file and make its file descriptor available for
   9     reuse. This patch fixes the problem by modifying Archive::include_member to
  10     unlock the object file via an RAII class instance, ensuring that it will be
  11     unlocked no matter what path is taken through the function.
  12
  13     gold/
  14         PR gold/15660
  15         * archive.cc (Thin_archive_object_unlocker): New class.
  16         (Archive::include_member): Unlock external members of thin archives.
  17         * testsuite/Makefile.am (plugin_test_1): Rename .syms files.
  18         (plugin_test_2): Likewise.
  19         (plugin_test_3): Likewise.
  20         (plugin_test_4): Likewise.
  21         (plugin_test_5): Likewise.
  22         (plugin_test_6): Likewise.
  23         (plugin_test_7): Likewise.
  24         (plugin_test_8): Likewise.
  25         (plugin_test_9): Likewise.
  26         (plugin_test_10): Likewise.
  27         (plugin_test_11): New test case.
  28         * testsuite/Makefile.in: Regenerate.
  29         * testsuite/plugin_test.c (claim_file_hook): Check for parallel .syms
  30         file to decide whether to claim file.
  31         (all_symbols_read_hook): Likewise.
  32         * testsuite/plugin_test_1.sh: Adjust expected output.
  33         * testsuite/plugin_test_2.sh: Likewise.
  34         * testsuite/plugin_test_3.sh: Likewise.
  35         * testsuite/plugin_test_6.sh: Likewise.
  36         * testsuite/plugin_test_tls.sh: Likewise.
  37         * testsuite/plugin_test_11.sh: New testcase.
  38
  39 diff --git a/gold/archive.cc b/gold/archive.cc
  40 index 69107f5..6d25980 100644
  41 --- a/gold/archive.cc
  42 +++ b/gold/archive.cc
  43 @@ -930,6 +930,32 @@ Archive::count_members()
  44    return ret;
  45  }
  46
  47 +// RAII class to ensure we unlock the object if it's a member of a
  48 +// thin archive. We can't use Task_lock_obj in Archive::include_member
  49 +// because the object file is already locked when it's opened by
  50 +// get_elf_object_for_member.
  51 +
  52 +class Thin_archive_object_unlocker
  53 +{
  54 + public:
  55 +  Thin_archive_object_unlocker(const Task *task, Object* obj)
  56 +    : task_(task), obj_(obj)
  57 +  { }
  58 +
  59 +  ~Thin_archive_object_unlocker()
  60 +  {
  61 +    if (this->obj_->offset() == 0)
  62 +      this->obj_->unlock(this->task_);
  63 +  }
  64 +
  65 + private:
  66 +  Thin_archive_object_unlocker(const Thin_archive_object_unlocker&);
  67 +  Thin_archive_object_unlocker& operator=(const Thin_archive_object_unlocker&);
  68 +
  69 +  const Task* task_;
  70 +  Object* obj_;
  71 +};
  72 +
  73  // Include an archive member in the link.  OFF is the file offset of
  74  // the member header.  WHY is the reason we are including this member.
  75  // Return true if we added the member or if we had an error, return
  76 @@ -978,6 +1004,10 @@ Archive::include_member(Symbol_table* symtab, Layout* layout,
  77        return unconfigured ? false : true;
  78      }
  79
  80 +  // If the object is an external member of a thin archive,
  81 +  // unlock it when we're done here.
  82 +  Thin_archive_object_unlocker unlocker(this->task_, obj);
  83 +
  84    if (mapfile != NULL)
  85      mapfile->report_include_archive_member(obj->name(), sym, why);
  86
  87 @@ -991,31 +1021,21 @@ Archive::include_member(Symbol_table* symtab, Layout* layout,
  88
  89    if (!input_objects->add_object(obj))
  90      {
  91 -      // If this is an external member of a thin archive, unlock the
  92 -      // file.
  93 -      if (obj->offset() == 0)
  94 -       obj->unlock(this->task_);
  95        delete obj;
  96 +      return true;
  97      }
  98 -  else
  99 -    {
 100 -      {
 101 -       if (layout->incremental_inputs() != NULL)
 102 -         layout->incremental_inputs()->report_object(obj, 0, this, NULL);
 103 -       Read_symbols_data sd;
 104 -       obj->read_symbols(&sd);
 105 -       obj->layout(symtab, layout, &sd);
 106 -       obj->add_symbols(symtab, &sd, layout);
 107 -      }
 108 -
 109 -      // If this is an external member of a thin archive, unlock the file
 110 -      // for the next task.
 111 -      if (obj->offset() == 0)
 112 -        obj->unlock(this->task_);
 113
 114 -      this->included_member_ = true;
 115 -    }
 116 +  if (layout->incremental_inputs() != NULL)
 117 +    layout->incremental_inputs()->report_object(obj, 0, this, NULL);
 118 +
 119 +  {
 120 +    Read_symbols_data sd;
 121 +    obj->read_symbols(&sd);
 122 +    obj->layout(symtab, layout, &sd);
 123 +    obj->add_symbols(symtab, &sd, layout);
 124 +  }
 125
 126 +  this->included_member_ = true;
 127    return true;
 128  }
 129