[BZ,#19178] ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA conflict
Commit Message
On Wed, Oct 28, 2015 at 6:42 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Wed, Oct 28, 2015 at 4:49 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> _dl_debug_bindings updates relocation type class with 4 and 8. But
>> ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA may be defined to 4. This patch
>> adds ELF_RTYPE_CLASS_TLS/ELF_RTYPE_CLASS_IFUNC and use them in
>> _dl_debug_bindings.
>>
>> Tested on i686 and x86-64. OK for master and 2.22 branch?
>>
>>
>> H.J.
>> --
>> [BZ #19178]
>> * dl-lookup.c (_dl_debug_bindings): Replace 4 and 8 with
>> ELF_RTYPE_CLASS_TLS and ELF_RTYPE_CLASS_IFUNC.
>> * sysdeps/generic/ldsodefs.h (ELF_RTYPE_CLASS_TLS): New.
>> (ELF_RTYPE_CLASS_IFUNC): Likewise.
>
>
> It doesn't work with prelink.
>
Here is the correct patch. Verified with prelink. OK for master
and 2.22 branch?
From 1ed43952877eb3183a8093849e33c8dab0cf7ddf Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Wed, 28 Oct 2015 07:49:44 -0700
Subject: [PATCH] Clear ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA for prelink
prelink runs ld.so with the environment variable LD_TRACE_PRELINKING
set to dump the relocation type class from _dl_debug_bindings. prelink
has the following relocation type classes:
where ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA has a conflict with
RTYPE_CLASS_TLS.
Since prelink doesn't use ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA, we
should clear the ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA bit when the
DL_DEBUG_PRELINK bit is set.
[BZ #19178]
* elf/dl-lookup.c (RTYPE_CLASS_VALID): New.
(RTYPE_CLASS_PLT): Likewise.
(RTYPE_CLASS_COPY): Likewise.
(RTYPE_CLASS_TLS): Likewise.
(_dl_debug_bindings): Use RTYPE_CLASS_TLS and RTYPE_CLASS_VALID
to set relocation type class for DL_DEBUG_PRELINK. Clear the
ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA bit for DL_DEBUG_PRELINK.
---
elf/dl-lookup.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
@@ -1016,6 +1016,18 @@ _dl_debug_bindings (const char *undef_name, struct link_map *undef_map,
#ifdef SHARED
if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK)
{
+/* ELF_RTYPE_CLASS_XXX must match RTYPE_CLASS_XXX used by prelink with
+ LD_TRACE_PRELINKING. */
+#define RTYPE_CLASS_VALID 8
+#define RTYPE_CLASS_PLT (8|1)
+#define RTYPE_CLASS_COPY (8|2)
+#define RTYPE_CLASS_TLS (8|4)
+#if ELF_RTYPE_CLASS_PLT != 0 && ELF_RTYPE_CLASS_PLT != 1
+# error ELF_RTYPE_CLASS_PLT must be 0 or 1!
+#endif
+#if ELF_RTYPE_CLASS_COPY != 0 && ELF_RTYPE_CLASS_COPY != 2
+# error ELF_RTYPE_CLASS_COPY must be 0 or 2!
+#endif
int conflict = 0;
struct sym_val val = { NULL, NULL };
@@ -1071,12 +1083,17 @@ _dl_debug_bindings (const char *undef_name, struct link_map *undef_map,
if (value->s)
{
+ /* Clear the ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA bit since
+ it isn't used by prelink. */
+ type_class &= ~ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA;
if (__glibc_unlikely (ELFW(ST_TYPE) (value->s->st_info)
== STT_TLS))
- type_class = 4;
+ /* Clear the RTYPE_CLASS_VALID bit in RTYPE_CLASS_TLS. */
+ type_class = RTYPE_CLASS_TLS & ~RTYPE_CLASS_VALID;
else if (__glibc_unlikely (ELFW(ST_TYPE) (value->s->st_info)
== STT_GNU_IFUNC))
- type_class |= 8;
+ /* Set the RTYPE_CLASS_VALID bit. */
+ type_class |= RTYPE_CLASS_VALID;
}
if (conflict
--
2.4.3