Adjust LOAD segment to generate GNU_RELRO segment

This patch fixes 2 GNU_RELRO segment bugs:

1. lang_size_sections didn't properly align base to the maximum
alignment power of sections between DATA_SEGMENT_ALIGN and
DATA_SEGMENT_RELRO_END.
2. ld failed to adjust LOAD segment to generate GNU_RELRO segment
when LOAD segment doesn't fit GNU_RELRO segment.  This is

https://sourceware.org/bugzilla/show_bug.cgi?id=14207

We "fixed" ld by not generating GNU_RELRO segment.  This patch
adjusts LOAD segment to generate GNU_RELRO segment.  It fixes
PR ld/16322 and at the same time it also fixes PR binutils/16323
since now we can adjust LOAD segment if it is too small.

bfd/

	PR ld/14207
	PR ld/16322
	PR binutils/16323
	* elf.c (_bfd_elf_map_sections_to_segments): Don't check section
	size for PT_GNU_RELRO segment.
	(assign_file_positions_for_load_sections): If PT_LOAD segment
	doesn't fit PT_GNU_RELRO segment, adjust its p_filesz and p_memsz.

ld/

	PR ld/14207
	PR ld/16322
	PR binutils/16323
	* ldlang.c (lang_size_sections): Properly align RELRO base.

ld/testsuite/

	PR ld/14207
	PR ld/16322
	PR binutils/16323
	* ld-elf/pr16322.d: New file.
	* ld-elf/pr16322.s: Likewise.

	* ld-x86-64/pr14207.d: Expect PT_GNU_RELRO segment.

2 files changed, 46 insertions, 5 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 7ea72c0..c2053be 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,13 @@
+2014-01-08  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/14207
+	PR ld/16322
+	PR binutils/16323
+	* elf.c (_bfd_elf_map_sections_to_segments): Don't check section
+	size for PT_GNU_RELRO segment.
+	(assign_file_positions_for_load_sections): If PT_LOAD segment
+	doesn't fit PT_GNU_RELRO segment, adjust its p_filesz and p_memsz.
+
 2014-01-07  Tom Tromey  <tromey@redhat.com>
 
 	* elf32-xtensa.c (vsprint_msg): Don't use old VA_* compatibility
diff --git a/bfd/elf.c b/bfd/elf.c
index ede51e9..870e281 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -4184,11 +4184,7 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info)
 			== (SEC_LOAD | SEC_HAS_CONTENTS))
 		      break;
 
-		  if (i == (unsigned) -1)
-		    continue;
-
-		  if (m->sections[i]->vma + m->sections[i]->size
-		      >= info->relro_end)
+		  if (i != (unsigned) -1)
 		    break;
 		}
 	    }
@@ -4380,6 +4376,7 @@ assign_file_positions_for_load_sections (bfd *abfd,
   unsigned int alloc;
   unsigned int i, j;
   bfd_vma header_pad = 0;
+  bfd_vma relro_start = 0, relro_end = 0;
 
   if (link_info == NULL
       && !_bfd_elf_map_sections_to_segments (abfd, link_info))
@@ -4450,6 +4447,23 @@ assign_file_positions_for_load_sections (bfd *abfd,
     header_pad -= off;
   off += header_pad;
 
+  /* Get start and end of PT_GNU_RELRO segment.  */
+  if (link_info != NULL)
+    {
+      relro_start = link_info->relro_start;
+      relro_end = link_info->relro_end;
+    }
+  else
+    {
+      for (m = elf_seg_map (abfd); m != NULL; m = m->next)
+	if (m->p_type == PT_GNU_RELRO)
+	  {
+	    relro_start = m->p_paddr;
+	    relro_end = relro_start + m->p_size;
+	    break;
+	  }
+    }
+
   for (m = elf_seg_map (abfd), p = phdrs, j = 0;
        m != NULL;
        m = m->next, p++, j++)
@@ -4792,6 +4806,23 @@ assign_file_positions_for_load_sections (bfd *abfd,
 		p->p_flags |= PF_W;
 	    }
 	}
+
+      if (relro_start != 0
+	  && p->p_type == PT_LOAD
+	  && p->p_vaddr >= relro_start)
+	{
+	  /* If PT_LOAD segment doesn't fit PT_GNU_RELRO segment,
+	     adjust its p_filesz and p_memsz.  */
+	  if (p->p_vaddr + p->p_filesz < relro_end)
+	    {
+	      bfd_vma adjust = relro_end - (p->p_vaddr + p->p_filesz);
+	      p->p_filesz += adjust;
+	      off += adjust;
+	    }
+	  if (p->p_vaddr + p->p_memsz < relro_end)
+	    p->p_memsz += relro_end - (p->p_vaddr + p->p_memsz);
+	}
+
       off -= off_adjust;
 
       /* Check that all sections are in a PT_LOAD segment.