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[PATCH v2] arm: handle unaligned ABS relocs
- From: Mike Frysinger <vapier at gentoo dot org>
- To: libc-ports at sourceware dot org
- Cc: Richard Henderson <rth at twiddle dot net>, "Joseph S. Myers" <joseph at codesourcery dot com>
- Date: Sun, 12 Aug 2012 01:50:18 -0400
- Subject: [PATCH v2] arm: handle unaligned ABS relocs
- References: <201112121920.17908.vapier@gentoo.org>
When relocating a misaligned R_ARM_ABS32, glibc currently crashes.
URL: https://bugs.gentoo.org/394237
URL: http://gcc.gnu.org/PR51456
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2012-08-12 Mike Frysinger <vapier@gentoo.org>
* sysdeps/arm/dl-machine.h (elf_machine_rel) [R_ARM_ABS32]: Declare
a new unaligned struct. Cast reloc_addr to that when updating the
value it points to.
---
ports/sysdeps/arm/dl-machine.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/ports/sysdeps/arm/dl-machine.h b/ports/sysdeps/arm/dl-machine.h
index fe39a5e..ca66e83 100644
--- a/ports/sysdeps/arm/dl-machine.h
+++ b/ports/sysdeps/arm/dl-machine.h
@@ -413,6 +413,10 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc,
break;
case R_ARM_ABS32:
{
+ struct unaligned
+ {
+ Elf32_Addr x;
+ } __attribute__((packed, may_alias));
# ifndef RTLD_BOOTSTRAP
/* This is defined in rtld.c, but nowhere in the static
libc.a; make the reference weak so static programs can
@@ -431,7 +435,8 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc,
used while loading those libraries. */
value -= map->l_addr + refsym->st_value;
# endif
- *reloc_addr += value;
+ /* Support relocations on mis-aligned offsets. */
+ ((struct unaligned *) reloc_addr)->x += value;
break;
}
case R_ARM_TLS_DESC:
--
1.7.9.7