ELF: Group PT_NOTE segments by section alignments
authorH.J. Lu <hjl.tools@gmail.com>
Wed, 3 Oct 2018 20:22:26 +0000 (13:22 -0700)
committerH.J. Lu <hjl.tools@gmail.com>
Wed, 3 Oct 2018 20:22:40 +0000 (13:22 -0700)
Alignments of SHT_NOTE sections can be 8 bytes for 64-bit ELF files.  We
should put all adjacent SHT_NOTE sections with the same section alignment
into a single PT_NOTE segment even when the section alignment != 4 bytes.
Also check SHT_NOTE section type instead of section name.

PR ld/23658
* elf.c (get_program_header_size): Put all adjacent SHT_NOTE
sections with the same section alignment into a single PT_NOTE
segment.  Check SHT_NOTE section type instead of section name.
(_bfd_elf_map_sections_to_segments): Likewise.

bfd/ChangeLog
bfd/elf.c

index 122983cb18b7a152a25695be0cb80bdfca3842aa..d2b5a57fe78e3baebe508c844f9867ecc5492879 100644 (file)
@@ -1,3 +1,11 @@
+2018-10-03  H.J. Lu  <hongjiu.lu@intel.com>
+
+       PR ld/23658
+       * elf.c (get_program_header_size): Put all adjacent SHT_NOTE
+       sections with the same section alignment into a single PT_NOTE
+       segment.  Check SHT_NOTE section type instead of section name.
+       (_bfd_elf_map_sections_to_segments): Likewise.
+
 2018-10-03  Millan Wolff  <mail@milianw.de>
 
        PR 23715
index 5320ae2237fcb67e39c7fd9f47a8ce81338d2aa1..8850efe20e9ea5c9f59bac839cf453790594b6af 100644 (file)
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -4371,23 +4371,22 @@ get_program_header_size (bfd *abfd, struct bfd_link_info *info)
   for (s = abfd->sections; s != NULL; s = s->next)
     {
       if ((s->flags & SEC_LOAD) != 0
-         && CONST_STRNEQ (s->name, ".note"))
+         && elf_section_type (s) == SHT_NOTE)
        {
+         unsigned int alignment_power;
          /* We need a PT_NOTE segment.  */
          ++segs;
-         /* Try to create just one PT_NOTE segment
-            for all adjacent loadable .note* sections.
-            gABI requires that within a PT_NOTE segment
-            (and also inside of each SHT_NOTE section)
-            each note is padded to a multiple of 4 size,
-            so we check whether the sections are correctly
-            aligned.  */
-         if (s->alignment_power == 2)
-           while (s->next != NULL
-                  && s->next->alignment_power == 2
-                  && (s->next->flags & SEC_LOAD) != 0
-                  && CONST_STRNEQ (s->next->name, ".note"))
-             s = s->next;
+         /* Try to create just one PT_NOTE segment for all adjacent
+            loadable SHT_NOTE sections.  gABI requires that within a
+            PT_NOTE segment (and also inside of each SHT_NOTE section)
+            each note should have the same alignment.  So we check
+            whether the sections are correctly aligned.  */
+         alignment_power = s->alignment_power;
+         while (s->next != NULL
+                && s->next->alignment_power == alignment_power
+                && (s->next->flags & SEC_LOAD) != 0
+                && elf_section_type (s->next) == SHT_NOTE)
+           s = s->next;
        }
     }
 
@@ -4885,33 +4884,33 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info)
          pm = &m->next;
        }
 
-      /* For each batch of consecutive loadable .note sections,
+      /* For each batch of consecutive loadable SHT_NOTE  sections,
         add a PT_NOTE segment.  We don't use bfd_get_section_by_name,
         because if we link together nonloadable .note sections and
         loadable .note sections, we will generate two .note sections
-        in the output file.  FIXME: Using names for section types is
-        bogus anyhow.  */
+        in the output file.  */
       for (s = abfd->sections; s != NULL; s = s->next)
        {
          if ((s->flags & SEC_LOAD) != 0
-             && CONST_STRNEQ (s->name, ".note"))
+             && elf_section_type (s) == SHT_NOTE)
            {
              asection *s2;
+             unsigned int alignment_power = s->alignment_power;
 
              count = 1;
              amt = sizeof (struct elf_segment_map);
-             if (s->alignment_power == 2)
-               for (s2 = s; s2->next != NULL; s2 = s2->next)
-                 {
-                   if (s2->next->alignment_power == 2
-                       && (s2->next->flags & SEC_LOAD) != 0
-                       && CONST_STRNEQ (s2->next->name, ".note")
-                       && align_power (s2->lma + s2->size, 2)
-                          == s2->next->lma)
-                     count++;
-                   else
-                     break;
-                 }
+             for (s2 = s; s2->next != NULL; s2 = s2->next)
+               {
+                 if (s2->next->alignment_power == alignment_power
+                     && (s2->next->flags & SEC_LOAD) != 0
+                     && elf_section_type (s2->next) == SHT_NOTE
+                     && align_power (s2->lma + s2->size,
+                                     alignment_power)
+                     == s2->next->lma)
+                   count++;
+                 else
+                   break;
+               }
              amt += (count - 1) * sizeof (asection *);
              m = (struct elf_segment_map *) bfd_zalloc (abfd, amt);
              if (m == NULL)
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