ARM: Fix R_ARM_IRELATIVE RELA relocations.

This patch fixes what I believe to be a bug in the handling of
R_ARM_IRELATIVE RELA relocations. At present, these are handled the
same as REL relocations: i.e. the addend is loaded from the relocation
address. Most of the time this isn't a problem because RELA relocations
aren't used on ARM (GNU/Linux at least) anyway, but it causes problems
with prelink, which uses RELA on all targets for its conflict table.
(Support for ifunc prelinking requires a prelink patch, not yet posted.)

Anyway, this patch works, though I'm not 100% sure if it is correct: I
notice that this code path received attention last year:

https://sourceware.org/ml/libc-ports/2013-07/msg00000.html

I'm not sure under what circumstances that patch would have had an
effect, nor if my patch conflicts with that case.

No regressions using Mentor's usual glibc cross-testing infrastructure.

	[BZ #16888]
	* sysdeps/arm/dl-machine.h (elf_machine_rela): Fix R_ARM_IRELATIVE
	handling.

diff --git a/ChangeLog b/ChangeLog
index e0d131d9ca51d135151393bdd629f8bb61c55219..1e6dda8586b3471c149cba90019d4328d1f98655 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-04-30  Julian Brown  <julian@codesourcery.com>
+
+       [BZ #16888]
+       * sysdeps/arm/dl-machine.h (elf_machine_rela): Fix R_ARM_IRELATIVE
+       handling.
+
 2014-04-30  Joseph Myers  <joseph@codesourcery.com>
 
        [BZ #9894]

diff --git a/NEWS b/NEWS
index 9d4db05d42ee0e4ce0447050eba4719ef39a8ffa..445acab17d3d998accb32a9f0b5b0d35e3bc1f19 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -15,7 +15,7 @@ Version 2.20
   16632, 16634, 16639, 16642, 16648, 16649, 16670, 16674, 16677, 16680,
   16683, 16689, 16695, 16701, 16706, 16707, 16712, 16713, 16714, 16731,
   16739, 16740, 16743, 16754, 16758, 16759, 16760, 16770, 16786, 16789,
-  16791, 16799, 16800, 16815, 16823, 16824, 16831, 16838, 16854.
+  16791, 16799, 16800, 16815, 16823, 16824, 16831, 16838, 16854, 16888.
 
 * The minimum Linux kernel version that this version of the GNU C Library
   can be used with is 2.6.32.

diff --git a/sysdeps/arm/dl-machine.h b/sysdeps/arm/dl-machine.h
index 02d1a5ebdf85706875084b049973c574c994ce44..899b2568f3c27dd46f7fbb5bd2ba036d199aad5c 100644 (file)
--- a/sysdeps/arm/dl-machine.h
+++ b/sysdeps/arm/dl-machine.h
@@ -594,7 +594,7 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
            }
          break;
        case R_ARM_IRELATIVE:
-         value = map->l_addr + *reloc_addr;
+         value = map->l_addr + reloc->r_addend;
          value = ((Elf32_Addr (*) (int)) value) (GLRO(dl_hwcap));
          *reloc_addr = value;
          break;