Put IRELATIVE relocations after JUMP_SLOT.

bfd/ 2011-10-21 H.J. Lu <hongjiu.lu@intel.com> PR ld/13302 * elf32-i386.c (elf_i386_link_hash_table): Add next_jump_slot_index and next_irelative_index. (elf_i386_link_hash_table_create): Initialize next_jump_slot_index and next_irelative_index. (elf_i386_allocate_dynrelocs): Increment reloc_count instead of next_tls_desc_index. (elf_i386_size_dynamic_sections): Set next_tls_desc_index and next_irelative_index from reloc_count. (elf_i386_finish_dynamic_symbol): Put R_386_IRELATIVE after R_386_JUMP_SLOT. * elf64-x86-64.c (elf_x86_64_link_hash_table): Add next_jump_slot_index and next_irelative_index. (elf_x86_64_link_hash_table_create): Initialize next_jump_slot_index and next_irelative_index. (elf_x86_64_size_dynamic_sections): Set next_irelative_index from reloc_count. (elf_x86_64_finish_dynamic_symbol): Put R_X86_64_IRELATIVE after R_X86_64_JUMP_SLOT. ld/testsuite/ 2011-10-21 H.J. Lu <hongjiu.lu@intel.com> PR ld/13302 * ld-ifunc/ifunc-16-i386.d: New. * ld-ifunc/ifunc-16-x86-64.d: Likewise. * ld-ifunc/ifunc-16-x86.s: Likewise.
2011-10-21 15:13:37 +00:00 · 2011-10-21 15:13:37 +00:00 · e1f987424b
parent f8e24652cb
commit e1f987424b
7 changed files with 146 additions and 38 deletions
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@ -1,3 +1,26 @@
+2011-10-21  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/13302
+	* elf32-i386.c (elf_i386_link_hash_table): Add next_jump_slot_index
+	and next_irelative_index.
+	(elf_i386_link_hash_table_create): Initialize next_jump_slot_index
+	and next_irelative_index.
+	(elf_i386_allocate_dynrelocs): Increment reloc_count instead of
+	next_tls_desc_index.
+	(elf_i386_size_dynamic_sections): Set next_tls_desc_index and
+	next_irelative_index from reloc_count.
+	(elf_i386_finish_dynamic_symbol): Put R_386_IRELATIVE after
+	R_386_JUMP_SLOT.
+
+	* elf64-x86-64.c (elf_x86_64_link_hash_table): Add
+	next_jump_slot_index and next_irelative_index.
+	(elf_x86_64_link_hash_table_create): Initialize
+	next_jump_slot_index and next_irelative_index.
+	(elf_x86_64_size_dynamic_sections): Set next_irelative_index
+	from reloc_count.
+	(elf_x86_64_finish_dynamic_symbol): Put R_X86_64_IRELATIVE after
+	R_X86_64_JUMP_SLOT.
+
 2011-10-20  Nick Clifton  <nickc@redhat.com>

 	PR ld/13049
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@ -806,6 +806,12 @@ struct elf_i386_link_hash_table

  /* The index of the next unused R_386_TLS_DESC slot in .rel.plt.  */
  bfd_vma next_tls_desc_index;
+
+  /* The index of the next unused R_386_JUMP_SLOT slot in .rel.plt.  */
+  bfd_vma next_jump_slot_index;
+
+  /* The index of the next unused R_386_IRELATIVE slot in .rel.plt.  */
+  bfd_vma next_irelative_index;
 };

 /* Get the i386 ELF linker hash table from a link_info structure.  */
@ -946,6 +952,8 @@ elf_i386_link_hash_table_create (bfd *abfd)
  ret->sym_cache.abfd = NULL;
  ret->srelplt2 = NULL;
  ret->tls_module_base = NULL;
+  ret->next_jump_slot_index = 0;
+  ret->next_irelative_index = 0;

  ret->loc_hash_table = htab_try_create (1024,
 					 elf_i386_local_htab_hash,
@ -2275,7 +2283,7 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)

 	  /* We also need to make an entry in the .rel.plt section.  */
 	  htab->elf.srelplt->size += sizeof (Elf32_External_Rel);
-	  htab->next_tls_desc_index++;
+	  htab->elf.srelplt->reloc_count++;

 	  if (get_elf_i386_backend_data (info->output_bfd)->is_vxworks
              && !info->shared)
@ -2700,9 +2708,19 @@ elf_i386_size_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info)
     incremented.  However, when we reserve space for TLS descriptors,
     it's not incremented, so in order to compute the space reserved
     for them, it suffices to multiply the reloc count by the jump
-     slot size.  */
+     slot size.
+     
+     PR ld/13302: We start next_irelative_index at the end of .rela.plt
+     so that R_386_IRELATIVE entries come last.  */
  if (htab->elf.srelplt)
-    htab->sgotplt_jump_table_size = htab->next_tls_desc_index * 4;
+    {
+      htab->next_tls_desc_index = htab->elf.srelplt->reloc_count;
+      htab->sgotplt_jump_table_size = htab->next_tls_desc_index * 4;
+      htab->next_irelative_index = htab->elf.srelplt->reloc_count - 1;
+    }
+  else if (htab->elf.irelplt)
+    htab->next_irelative_index = htab->elf.irelplt->reloc_count - 1;
+

  if (htab->elf.sgotplt)
    {
@ -4364,13 +4382,13 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd,

      if (plt == htab->elf.splt)
 	{
-	  plt_index = h->plt.offset / plt_entry_size - 1;
-	  got_offset = (plt_index + 3) * 4;
+	  got_offset = h->plt.offset / plt_entry_size - 1;
+	  got_offset = (got_offset + 3) * 4;
 	}
      else
 	{
-	  plt_index = h->plt.offset / plt_entry_size;
-	  got_offset = plt_index * 4;
+	  got_offset = h->plt.offset / plt_entry_size;
+	  got_offset = got_offset * 4;
 	}

      /* Fill in the entry in the procedure linkage table.  */
@ -4431,18 +4449,6 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd,
                      + abed->plt->plt_got_offset);
 	}

-      /* Don't fill PLT entry for static executables.  */
-      if (plt == htab->elf.splt)
-	{
-	  bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rel),
-		      plt->contents + h->plt.offset
-                      + abed->plt->plt_reloc_offset);
-	  bfd_put_32 (output_bfd, - (h->plt.offset
-                                     + abed->plt->plt_plt_offset + 4),
-		      plt->contents + h->plt.offset
-                      + abed->plt->plt_plt_offset);
-	}
-
      /* Fill in the entry in the global offset table.  */
      bfd_put_32 (output_bfd,
 		  (plt->output_section->vma
@ -4470,12 +4476,29 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd,
 		       + h->root.u.def.section->output_offset),
 		      gotplt->contents + got_offset);
 	  rel.r_info = ELF32_R_INFO (0, R_386_IRELATIVE);
+	  /* R_386_IRELATIVE comes last.  */
+	  plt_index = htab->next_irelative_index--;
 	}
      else
-	rel.r_info = ELF32_R_INFO (h->dynindx, R_386_JUMP_SLOT);
+	{
+	  rel.r_info = ELF32_R_INFO (h->dynindx, R_386_JUMP_SLOT);
+	  plt_index = htab->next_jump_slot_index++;
+	}
      loc = relplt->contents + plt_index * sizeof (Elf32_External_Rel);
      bfd_elf32_swap_reloc_out (output_bfd, &rel, loc);

+      /* Don't fill PLT entry for static executables.  */
+      if (plt == htab->elf.splt)
+	{
+	  bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rel),
+		      plt->contents + h->plt.offset
+                      + abed->plt->plt_reloc_offset);
+	  bfd_put_32 (output_bfd, - (h->plt.offset
+                                     + abed->plt->plt_plt_offset + 4),
+		      plt->contents + h->plt.offset
+                      + abed->plt->plt_plt_offset);
+	}
+
      if (!h->def_regular)
 	{
 	  /* Mark the symbol as undefined, rather than as defined in
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@ -698,6 +698,11 @@ struct elf_x86_64_link_hash_table
  /* The offset into sgot of the GOT entry used by the PLT entry
     above.  */
  bfd_vma tlsdesc_got;
+
+  /* The index of the next R_X86_64_JUMP_SLOT entry in .rela.plt.  */
+  bfd_vma next_jump_slot_index;
+  /* The index of the next R_X86_64_IRELATIVE entry in .rela.plt.  */
+  bfd_vma next_irelative_index;
 };

 /* Get the x86-64 ELF linker hash table from a link_info structure.  */
@ -839,6 +844,8 @@ elf_x86_64_link_hash_table_create (bfd *abfd)
  ret->tls_ld_got.refcount = 0;
  ret->sgotplt_jump_table_size = 0;
  ret->tls_module_base = NULL;
+  ret->next_jump_slot_index = 0; 
+  ret->next_irelative_index = 0;

  if (ABI_64_P (abfd))
    {
@ -2667,10 +2674,18 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd,
     incremented.  However, when we reserve space for TLS descriptors,
     it's not incremented, so in order to compute the space reserved
     for them, it suffices to multiply the reloc count by the jump
-     slot size.  */
+     slot size.
+
+     PR ld/13302: We start next_irelative_index at the end of .rela.plt
+     so that R_X86_64_IRELATIVE entries come last.  */
  if (htab->elf.srelplt)
-    htab->sgotplt_jump_table_size
-      = elf_x86_64_compute_jump_table_size (htab);
+    {
+      htab->sgotplt_jump_table_size
+	= elf_x86_64_compute_jump_table_size (htab);
+      htab->next_irelative_index = htab->elf.srelplt->reloc_count - 1;
+    }
+  else if (htab->elf.irelplt)
+    htab->next_irelative_index = htab->elf.irelplt->reloc_count - 1;

  if (htab->tlsdesc_plt)
    {
@ -4205,13 +4220,13 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd,

      if (plt == htab->elf.splt)
 	{
-	  plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1;
-	  got_offset = (plt_index + 3) * GOT_ENTRY_SIZE;
+	  got_offset = h->plt.offset / PLT_ENTRY_SIZE - 1;
+	  got_offset = (got_offset + 3) * GOT_ENTRY_SIZE;
 	}
      else
 	{
-	  plt_index = h->plt.offset / PLT_ENTRY_SIZE;
-	  got_offset = plt_index * GOT_ENTRY_SIZE;
+	  got_offset = h->plt.offset / PLT_ENTRY_SIZE;
+	  got_offset = got_offset * GOT_ENTRY_SIZE;
 	}

      /* Fill in the entry in the procedure linkage table.  */
@ -4233,17 +4248,6 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd,
 		       - 6),
 		  plt->contents + h->plt.offset + 2);

-      /* Don't fill PLT entry for static executables.  */
-      if (plt == htab->elf.splt)
-	{
-	  /* Put relocation index.  */
-	  bfd_put_32 (output_bfd, plt_index,
-		      plt->contents + h->plt.offset + 7);
-	  /* Put offset for jmp .PLT0.  */
-	  bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE),
-		      plt->contents + h->plt.offset + 12);
-	}
-
      /* Fill in the entry in the global offset table, initially this
 	 points to the pushq instruction in the PLT which is at offset 6.  */
      bfd_put_64 (output_bfd, (plt->output_section->vma
@ -4267,11 +4271,25 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd,
 	  rela.r_addend = (h->root.u.def.value
 			   + h->root.u.def.section->output_section->vma
 			   + h->root.u.def.section->output_offset);
+	  /* R_X86_64_IRELATIVE comes last.  */
+	  plt_index = htab->next_irelative_index--;
 	}
      else
 	{
 	  rela.r_info = htab->r_info (h->dynindx, R_X86_64_JUMP_SLOT);
 	  rela.r_addend = 0;
+	  plt_index = htab->next_jump_slot_index++;
+	}
+
+      /* Don't fill PLT entry for static executables.  */
+      if (plt == htab->elf.splt)
+	{
+	  /* Put relocation index.  */
+	  bfd_put_32 (output_bfd, plt_index,
+		      plt->contents + h->plt.offset + 7);
+	  /* Put offset for jmp .PLT0.  */
+	  bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE),
+		      plt->contents + h->plt.offset + 12);
 	}

      bed = get_elf_backend_data (output_bfd);
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@ -1,3 +1,10 @@
+2011-10-21  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/13302
+	* ld-ifunc/ifunc-16-i386.d: New.
+	* ld-ifunc/ifunc-16-x86-64.d: Likewise.
+	* ld-ifunc/ifunc-16-x86.s: Likewise.
+
 2011-10-20  Alan Modra  <amodra@gmail.com>

 	* ld-selective/selective.exp: Use check_gc_sections_available.
--- a/ld/testsuite/ld-ifunc/ifunc-16-i386.d
+++ b/ld/testsuite/ld-ifunc/ifunc-16-i386.d
@ -0,0 +1,10 @@
+#source: ifunc-16-x86.s
+#ld: -shared -m elf_i386
+#as: --32
+#readelf: -r --wide
+#target: x86_64-*-* i?86-*-*
+
+Relocation section '.rel.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_JUMP_SLOT[ ]+0+[ ]+ifunc
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_386_IRELATIVE[ ]*
--- a/ld/testsuite/ld-ifunc/ifunc-16-x86-64.d
+++ b/ld/testsuite/ld-ifunc/ifunc-16-x86-64.d
@ -0,0 +1,10 @@
+#source: ifunc-16-x86.s
+#as: --64
+#ld: -shared -melf_x86_64
+#readelf: -r --wide
+#target: x86_64-*-*
+
+Relocation section '.rela.plt' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_JUMP_SLOT[ ]+0+[ ]+ifunc \+ 0
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_X86_64_IRELATIVE[ ]+[0-9a-f]*
--- a/ld/testsuite/ld-ifunc/ifunc-16-x86.s
+++ b/ld/testsuite/ld-ifunc/ifunc-16-x86.s
@ -0,0 +1,17 @@
+	.text
+	.globl	fct
+	.type	fct, @gnu_indirect_function
+	.set	fct,resolve
+	.hidden int_fct
+	.globl	int_fct
+	.set	int_fct,fct
+	.p2align 4,,15
+	.type	resolve, @function
+resolve:
+	call	ifunc@PLT
+	.size	resolve, .-resolve
+	.globl	g
+	.type	g, @function
+g:
+	jmp	int_fct@PLT
+	.size	g, .-g