Revert x86: Allow undefined _DYNAMIC in static executable

This code is used in non-PIE static executable and static PIE.  It checks
if _DYNAMIC is undefined before using it to compute load address.  But
not all targets can convert access _DYNAMIC via GOT, which needs dynamic
relocation, to PC-relative at link-time.

	* sysdeps/i386/dl-machine.h (elf_machine_load_address): Don't
	allow undefined _DYNAMIC in PIE libc.a.
	* sysdeps/x86_64/dl-machine.h (elf_machine_load_address):
	Likewse.

diff --git a/ChangeLog b/ChangeLog
index 581a926106cd0aa4ec74072628b44752c942e5b2..01517c5514df2b9c0215fe2c0f184943720a9cb9 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2017-10-03  H.J. Lu  <hongjiu.lu@intel.com>
+
+       * sysdeps/i386/dl-machine.h (elf_machine_load_address): Don't
+       allow undefined _DYNAMIC in PIE libc.a.
+       * sysdeps/x86_64/dl-machine.h (elf_machine_load_address):
+       Likewse.
+
 2017-10-03  H.J. Lu  <hongjiu.lu@intel.com>
 
        * sysdeps/mips/dl-machine.h (elf_machine_load_address): Don't

diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
index 242c692c17ac2b138a78b6d4f3b1140d48891f94..2e17eba5c08042ac5cad563afa6078fe70dc3222 100644 (file)
--- a/sysdeps/i386/dl-machine.h
+++ b/sysdeps/i386/dl-machine.h
@@ -54,15 +54,8 @@ elf_machine_load_address (void)
   /* Compute the difference between the runtime address of _DYNAMIC as seen
      by a GOTOFF reference, and the link-time address found in the special
      unrelocated first GOT entry.  */
-#ifndef SHARED
-  extern Elf32_Dyn _DYNAMIC[] __attribute__((weak, visibility ("hidden")));
-  if (!_DYNAMIC)
-    return 0;
-#endif
-  /* The address of dynamic must be taken as non-weak to avoid dynamic
-     relocation.  */
-  extern Elf32_Dyn dynamic[] asm ("_DYNAMIC") attribute_hidden;
-  return (Elf32_Addr) &dynamic - elf_machine_dynamic ();
+  extern Elf32_Dyn bygotoff[] asm ("_DYNAMIC") attribute_hidden;
+  return (Elf32_Addr) &bygotoff - elf_machine_dynamic ();
 }
 
 /* Set up the loaded object described by L so its unrelocated PLT

diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h
index a79e5ca2f9e1eb112bad1bb9511ff47e9296dba3..6a04cbcdc98da4363719892bde060b5e7adb97d4 100644 (file)
--- a/sysdeps/x86_64/dl-machine.h
+++ b/sysdeps/x86_64/dl-machine.h
@@ -55,15 +55,8 @@ elf_machine_load_address (void)
   /* Compute the difference between the runtime address of _DYNAMIC as seen
      by an IP-relative reference, and the link-time address found in the
      special unrelocated first GOT entry.  */
-#ifndef SHARED
-  extern ElfW(Dyn) _DYNAMIC[] __attribute__((weak, visibility ("hidden")));
-  if (!_DYNAMIC)
-    return 0;
-#endif
-  /* The address of dynamic must be taken as non-weak to avoid dynamic
-     relocation.  */
-  extern ElfW(Dyn) dynamic[] asm ("_DYNAMIC") attribute_hidden;
-  return (ElfW(Addr)) &dynamic - elf_machine_dynamic ();
+  extern ElfW(Dyn) _DYNAMIC[] attribute_hidden;
+  return (ElfW(Addr)) &_DYNAMIC - elf_machine_dynamic ();
 }
 
 /* Set up the loaded object described by L so its unrelocated PLT