Properly match PLT entry against .got.plt relocation

Relocations against .got.plt section may not be in the same order as
entries in PLT section.  It is incorrect to assume that the Ith reloction
index against .got.plt section always maps to the (I + 1)th entry in PLT
section.  This patch matches the .got.plt relocation offset/index in PLT
entry against the index in .got.plt relocation table.  It only checks
R_*_JUMP_SLOT and R_*_IRELATIVE relocations.  It ignores R_*_TLS_DESC
and R_*_TLSDESC relocations since they have different PLT entries.

bfd/

	PR binutils/17154
	* elf32-i386.c (elf_i386_plt_sym_val): Only match R_*_JUMP_SLOT
	and R_*_IRELATIVE relocation offset with PLT entry.
	* elf64-x86-64.c (elf_x86_64_plt_sym_val): Likewise.
	(elf_x86_64_plt_sym_val_offset_plt_bnd): New.
	(elf_x86_64_get_synthetic_symtab): Use it.

ld/testsuite/

	PR binutils/17154
	* ld-ifunc/pr17154-i386.d: New file.
	* ld-ifunc/pr17154-x86-64.d: Likewise.
	* ld-ifunc/pr17154-x86.s: Likewise.
	* ld-x86-64/bnd-ifunc-2.d: Likewise.
	* ld-x86-64/bnd-ifunc-2.s: Likewise.
	* ld-x86-64/mpx.exp: Run bnd-ifunc-2.
	* ld-x86-64/tlsdesc-nacl.pd: Updated.
	* ld-x86-64/tlsdesc.pd: Likewise.

1 files changed, 80 insertions, 9 deletions

diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 894ab98..5eea810 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -5292,14 +5292,77 @@ elf_x86_64_finish_dynamic_sections (bfd *output_bfd,
   return TRUE;
 }
 
-/* Return address for Ith PLT stub in section PLT, for relocation REL
-   or (bfd_vma) -1 if it should not be included.  */
+/* Return address in section PLT for the Ith GOTPLT relocation, for
+   relocation REL or (bfd_vma) -1 if it should not be included.  */
 
 static bfd_vma
 elf_x86_64_plt_sym_val (bfd_vma i, const asection *plt,
-			const arelent *rel ATTRIBUTE_UNUSED)
+			const arelent *rel)
 {
-  return plt->vma + (i + 1) * GET_PLT_ENTRY_SIZE (plt->owner);
+  bfd *abfd;
+  const struct elf_x86_64_backend_data *bed;
+  bfd_vma plt_offset;
+
+  /* Only match R_X86_64_JUMP_SLOT and R_X86_64_IRELATIVE.  */
+  if (rel->howto->type != R_X86_64_JUMP_SLOT
+      && rel->howto->type != R_X86_64_IRELATIVE)
+    return (bfd_vma) -1;
+
+  abfd = plt->owner;
+  bed = get_elf_x86_64_backend_data (abfd);
+  plt_offset = bed->plt_entry_size;
+  while (plt_offset < plt->size)
+    {
+      bfd_vma reloc_index;
+      bfd_byte reloc_index_raw[4];
+
+      if (!bfd_get_section_contents (abfd, (asection *) plt,
+				     reloc_index_raw,
+				     plt_offset + bed->plt_reloc_offset,
+				     sizeof (reloc_index_raw)))
+	return (bfd_vma) -1;
+
+      reloc_index = H_GET_32 (abfd, reloc_index_raw);
+      if (reloc_index == i)
+	return plt->vma + plt_offset;
+      plt_offset += bed->plt_entry_size;
+    }
+
+  abort ();
+}
+
+/* Return offset in .plt.bnd section for the Ith GOTPLT relocation with
+   PLT section, or (bfd_vma) -1 if it should not be included.  */
+
+static bfd_vma
+elf_x86_64_plt_sym_val_offset_plt_bnd (bfd_vma i, const asection *plt)
+{
+  const struct elf_x86_64_backend_data *bed = &elf_x86_64_bnd_arch_bed;
+  bfd *abfd = plt->owner;
+  bfd_vma plt_offset = bed->plt_entry_size;
+  while (plt_offset < plt->size)
+    {
+      bfd_vma reloc_index;
+      bfd_byte reloc_index_raw[4];
+
+      if (!bfd_get_section_contents (abfd, (asection *) plt,
+				     reloc_index_raw,
+				     plt_offset + bed->plt_reloc_offset,
+				     sizeof (reloc_index_raw)))
+	return (bfd_vma) -1;
+
+      reloc_index = H_GET_32 (abfd, reloc_index_raw);
+      if (reloc_index == i)
+	{
+	  /* This is the index in .plt section.  */
+	  long plt_index = plt_offset / bed->plt_entry_size;
+	  /* Return the offset in .plt.bnd section.  */
+	  return (plt_index - 1) * sizeof (elf_x86_64_legacy_plt2_entry);
+	}
+      plt_offset += bed->plt_entry_size;
+    }
+
+  abort ();
 }
 
 /* Similar to _bfd_elf_get_synthetic_symtab, with .plt.bnd section
@@ -5322,8 +5385,11 @@ elf_x86_64_get_synthetic_symtab (bfd *abfd,
   size_t size;
   Elf_Internal_Shdr *hdr;
   char *names;
-  asection *plt;
-  bfd_vma addr;
+  asection *plt, *plt_push;
+
+  plt_push = bfd_get_section_by_name (abfd, ".plt");
+  if (plt_push == NULL)
+    return 0;
 
   plt = bfd_get_section_by_name (abfd, ".plt.bnd");
   /* Use the generic ELF version if there is no .plt.bnd section.  */
@@ -5369,11 +5435,17 @@ elf_x86_64_get_synthetic_symtab (bfd *abfd,
   names = (char *) (s + count);
   p = relplt->relocation;
   n = 0;
-  addr = 0;
   for (i = 0; i < count; i++, p++)
     {
+      bfd_vma offset;
       size_t len;
 
+      if (p->howto->type != R_X86_64_JUMP_SLOT
+	  && p->howto->type != R_X86_64_IRELATIVE)
+	continue;
+
+      offset = elf_x86_64_plt_sym_val_offset_plt_bnd (i, plt_push);
+
       *s = **p->sym_ptr_ptr;
       /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL set.  Since
 	 we are defining a symbol, ensure one of them is set.  */
@@ -5381,7 +5453,7 @@ elf_x86_64_get_synthetic_symtab (bfd *abfd,
 	s->flags |= BSF_GLOBAL;
       s->flags |= BSF_SYNTHETIC;
       s->section = plt;
-      s->value = addr;
+      s->value = offset;
       s->name = names;
       s->udata.p = NULL;
       len = strlen ((*p->sym_ptr_ptr)->name);
@@ -5403,7 +5475,6 @@ elf_x86_64_get_synthetic_symtab (bfd *abfd,
       memcpy (names, "@plt", sizeof ("@plt"));
       names += sizeof ("@plt");
       ++s, ++n;
-      addr += sizeof (elf_x86_64_legacy_plt2_entry);
     }
 
   return n;