Finish IFUNC support for x86 and x86-64.

Add support for the IRELAIVE relocation and IFUNC in static executables.

2 files changed, 68 insertions, 0 deletions

diff --git a/sysdeps/i386/dl-irel.h b/sysdeps/i386/dl-irel.h
new file mode 100644
index 0000000000..4acb862c69
--- /dev/null
+++ b/sysdeps/i386/dl-irel.h
@@ -0,0 +1,44 @@
+/* Machine-dependent ELF indirect relocation inline functions.
+   i386 version.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _DL_IREL_H
+#define _DL_IREL_H
+
+#include <unistd.h>
+
+#define ELF_MACHINE_IREL	1
+
+static inline void
+__attribute ((always_inline))
+elf_irel (const Elf32_Rel *reloc)
+{
+  Elf32_Addr *const reloc_addr = (void *) reloc->r_offset;
+  const unsigned long int r_type = ELF32_R_TYPE (reloc->r_info);
+
+  if (__builtin_expect (r_type == R_386_IRELATIVE, 1))
+    {
+      Elf64_Addr value = ((Elf32_Addr (*) (void)) (*reloc_addr)) ();
+      *reloc_addr = value;
+    }
+  else
+    _exit (-1);
+}
+
+#endif /* dl-irel.h */
diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
index 0e15878d4e..efa929e57f 100644
--- a/sysdeps/i386/dl-machine.h
+++ b/sysdeps/i386/dl-machine.h
@@ -345,6 +345,7 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc,
       Elf32_Addr value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
 
       if (sym != NULL
+	  && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
 	  && __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC,
 			       0))
 	value = ((Elf32_Addr (*) (void)) value) ();
@@ -471,6 +472,11 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc,
 	  memcpy (reloc_addr_arg, (void *) value,
 		  MIN (sym->st_size, refsym->st_size));
 	  break;
+	case R_386_IRELATIVE:
+	  value = map->l_addr + *reloc_addr;
+	  value = ((Elf32_Addr (*) (void)) value) ();
+	  *reloc_addr = value;
+	  break;
 	default:
 	  _dl_reloc_bad_type (map, r_type, 0);
 	  break;
@@ -500,6 +506,7 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
       Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value;
 
       if (sym != NULL
+	  && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
 	  && __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC,
 			       0))
 	value = ((Elf32_Addr (*) (void)) value) ();
@@ -609,6 +616,11 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
 		  MIN (sym->st_size, refsym->st_size));
 	  break;
 #  endif /* !RESOLVE_CONFLICT_FIND_MAP */
+	case R_386_IRELATIVE:
+	  value = map->l_addr + reloc->r_addend;
+	  value = ((Elf32_Addr (*) (void)) value) ();
+	  *reloc_addr = value;
+	  break;
 	default:
 	  /* We add these checks in the version to relocate ld.so only
 	     if we are still debugging.  */
@@ -703,6 +715,12 @@ elf_machine_lazy_rel (struct link_map *map,
 # endif
 	}
     }
+  else if (__builtin_expect (r_type == R_386_IRELATIVE, 0))
+    {
+      Elf32_Addr value = map->l_addr + *reloc_addr;
+      value = ((Elf32_Addr (*) (void)) value) ();
+      *reloc_addr = value;
+    }
   else
     _dl_reloc_bad_type (map, r_type, 1);
 }
@@ -726,6 +744,12 @@ elf_machine_lazy_rela (struct link_map *map,
       td->arg = (void*)reloc;
       td->entry = _dl_tlsdesc_resolve_rela;
     }
+  else if (__builtin_expect (r_type == R_386_IRELATIVE, 0))
+    {
+      Elf32_Addr value = map->l_addr + reloc->r_addend;
+      value = ((Elf32_Addr (*) (void)) value) ();
+      *reloc_addr = value;
+    }
   else
     _dl_reloc_bad_type (map, r_type, 1);
 }