gold: Get alignment of uncompressed section from ch_addralign

The ELF compression header has a field (ch_addralign) that is set to
the alignment of the uncompressed section. This way the section itself
can have a different alignment than the decompressed section.  Update
decompress_input_section to get alignment of the decompressed section
and use it when merging decompressed strings.

	PR binutils/23919
	* merge.cc (Output_merge_string<Char_type>::do_add_input_section):
	Get addralign from decompressed_section_contents.
	* object.cc (build_compressed_section_map): Set info.addralign.
	(Object::decompressed_section_contents): Add a palign
	argument and store p->second.addralign in *palign if it isn't
	NULL.
	* object.h (Compressed_section_info): Add addralign.
	(section_is_compressed): Add a palign argument, default it
	to NULL, store p->second.addralign in *palign if it isn't NULL.
	(Object::decompressed_section_contents): Likewise.
	* output.cc (Output_section::add_input_section): Get addralign
	from section_is_compressed.

diff --git a/gold/ChangeLog b/gold/ChangeLog
index 9d10dc83eea448fce5a616650dbc882ea5d5a42f..f42e4863fd5f3cc565bea9187ad93851fd314db1 100644 (file)
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,19 @@
+2018-12-02  H.J. Lu  <hongjiu.lu@intel.com>
+
+       PR binutils/23919
+       * merge.cc (Output_merge_string<Char_type>::do_add_input_section):
+       Get addralign from decompressed_section_contents.
+       * object.cc (build_compressed_section_map): Set info.addralign.
+       (Object::decompressed_section_contents): Add a palign
+       argument and store p->second.addralign in *palign if it isn't
+       NULL.
+       * object.h (Compressed_section_info): Add addralign.
+       (section_is_compressed): Add a palign argument, default it
+       to NULL, store p->second.addralign in *palign if it isn't NULL.
+       (Object::decompressed_section_contents): Likewise.
+       * output.cc (Output_section::add_input_section): Get addralign
+       from section_is_compressed.
+
 2018-11-26  Alan Modra  <amodra@gmail.com>
 
        * testsuite/Makefile.am (justsyms_lib): Link with -z norelro.

diff --git a/gold/merge.cc b/gold/merge.cc
index de00ee9ae9c0f90c6327bcda7d4665530f1c0ee1..d7de11789f762a6643c883c46996baac03081a22 100644 (file)
--- a/gold/merge.cc
+++ b/gold/merge.cc
@@ -440,9 +440,11 @@ Output_merge_string<Char_type>::do_add_input_section(Relobj* object,
 {
   section_size_type sec_len;
   bool is_new;
+  uint64_t addralign = this->addralign();
   const unsigned char* pdata = object->decompressed_section_contents(shndx,
                                                                     &sec_len,
-                                                                    &is_new);
+                                                                    &is_new,
+                                                                    &addralign);
 
   const Char_type* p = reinterpret_cast<const Char_type*>(pdata);
   const Char_type* pend = p + sec_len / sizeof(Char_type);
@@ -494,7 +496,7 @@ Output_merge_string<Char_type>::do_add_input_section(Relobj* object,
   // aligned, so each string within the section must retain the same
   // modulo.
   uintptr_t init_align_modulo = (reinterpret_cast<uintptr_t>(pdata)
-                                & (this->addralign() - 1));
+                                & (addralign - 1));
   bool has_misaligned_strings = false;
 
   while (p < pend)
@@ -503,7 +505,7 @@ Output_merge_string<Char_type>::do_add_input_section(Relobj* object,
 
       // Within merge input section each string must be aligned.
       if (len != 0
-         && ((reinterpret_cast<uintptr_t>(p) & (this->addralign() - 1))
+         && ((reinterpret_cast<uintptr_t>(p) & (addralign - 1))
              != init_align_modulo))
          has_misaligned_strings = true;
 

diff --git a/gold/object.cc b/gold/object.cc
index cbeddb9158b91afcbf30c060009f81f880f5f19f..7930de66fe630f3f689297c307e004c23392c9e4 100644 (file)
--- a/gold/object.cc
+++ b/gold/object.cc
@@ -751,11 +751,13 @@ build_compressed_section_map(
              const unsigned char* contents =
                  obj->section_contents(i, &len, false);
              uint64_t uncompressed_size;
+             Compressed_section_info info;
              if (is_zcompressed)
                {
                  // Skip over the ".zdebug" prefix.
                  name += 7;
                  uncompressed_size = get_uncompressed_size(contents, len);
+                 info.addralign = shdr.get_sh_addralign();
                }
              else
                {
@@ -763,8 +765,8 @@ build_compressed_section_map(
                  name += 6;
                  elfcpp::Chdr<size, big_endian> chdr(contents);
                  uncompressed_size = chdr.get_ch_size();
+                 info.addralign = chdr.get_ch_addralign();
                }
-             Compressed_section_info info;
              info.size = convert_to_section_size_type(uncompressed_size);
              info.flag = shdr.get_sh_flags();
              info.contents = NULL;
@@ -3064,7 +3066,8 @@ const unsigned char*
 Object::decompressed_section_contents(
     unsigned int shndx,
     section_size_type* plen,
-    bool* is_new)
+    bool* is_new,
+    uint64_t* palign)
 {
   section_size_type buffer_size;
   const unsigned char* buffer = this->do_section_contents(shndx, &buffer_size,
@@ -3091,6 +3094,8 @@ Object::decompressed_section_contents(
     {
       *plen = uncompressed_size;
       *is_new = false;
+      if (palign != NULL)
+       *palign = p->second.addralign;
       return p->second.contents;
     }
 
@@ -3112,6 +3117,8 @@ Object::decompressed_section_contents(
   // once in this pass.
   *plen = uncompressed_size;
   *is_new = true;
+  if (palign != NULL)
+    *palign = p->second.addralign;
   return uncompressed_data;
 }
 

diff --git a/gold/object.h b/gold/object.h
index 0b786a5471ed84cc8586f2096af8175a717f453f..b99548463d726e61854849135699c652ec5b2253 100644 (file)
--- a/gold/object.h
+++ b/gold/object.h
@@ -373,6 +373,7 @@ struct Compressed_section_info
 {
   section_size_type size;
   elfcpp::Elf_Xword flag;
+  uint64_t addralign;
   const unsigned char* contents;
 };
 typedef std::map<unsigned int, Compressed_section_info> Compressed_section_map;
@@ -808,7 +809,8 @@ class Object
 
   bool
   section_is_compressed(unsigned int shndx,
-                       section_size_type* uncompressed_size) const
+                       section_size_type* uncompressed_size,
+                       elfcpp::Elf_Xword* palign = NULL) const
   {
     if (this->compressed_sections_ == NULL)
       return false;
@@ -818,6 +820,8 @@ class Object
       {
        if (uncompressed_size != NULL)
          *uncompressed_size = p->second.size;
+       if (palign != NULL)
+         *palign = p->second.addralign;
        return true;
       }
     return false;
@@ -828,7 +832,7 @@ class Object
   // by the caller.
   const unsigned char*
   decompressed_section_contents(unsigned int shndx, section_size_type* plen,
-                               bool* is_cached);
+                               bool* is_cached, uint64_t* palign = NULL);
 
   // Discard any buffers of decompressed sections.  This is done
   // at the end of the Add_symbols task.

diff --git a/gold/output.cc b/gold/output.cc
index 1701db1c99f18f5a0f8645ff2d548d7961098cc5..75ac3bcf977eb99498bebb949e21038dc222aefe 100644 (file)
--- a/gold/output.cc
+++ b/gold/output.cc
@@ -2448,7 +2448,13 @@ Output_section::add_input_section(Layout* layout,
                                  unsigned int reloc_shndx,
                                  bool have_sections_script)
 {
+  section_size_type input_section_size = shdr.get_sh_size();
+  section_size_type uncompressed_size;
   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
+  if (object->section_is_compressed(shndx, &uncompressed_size,
+                                   &addralign))
+    input_section_size = uncompressed_size;
+
   if ((addralign & (addralign - 1)) != 0)
     {
       object->error(_("invalid alignment %lu for section \"%s\""),
@@ -2498,11 +2504,6 @@ Output_section::add_input_section(Layout* layout,
        }
     }
 
-  section_size_type input_section_size = shdr.get_sh_size();
-  section_size_type uncompressed_size;
-  if (object->section_is_compressed(shndx, &uncompressed_size))
-    input_section_size = uncompressed_size;
-
   off_t offset_in_section;
 
   if (this->has_fixed_layout())