glibc: Fix ld.so / prelink interface for ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA

A bug in glibc 2.22's ld.so interface for the prelink support causes
the displayed values to be incorrect.  The included path fixes this
issue.

   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.

(From OE-Core rev: 12c86bdcc60c54e587a896b0dceb8bb6cc9ff7e3)

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 85 insertions, 0 deletions

diff --git a/meta/recipes-core/glibc/glibc/0028-Clear-ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA-for-prel.patch b/meta/recipes-core/glibc/glibc/0028-Clear-ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA-for-prel.patch
new file mode 100644
index 0000000000..3455df1cff
--- /dev/null
+++ b/meta/recipes-core/glibc/glibc/0028-Clear-ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA-for-prel.patch
@@ -0,0 +1,84 @@
+From cadaf1336332ca7bcdfe4a400776e5782a20e26d 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] Keep only ELF_RTYPE_CLASS_{PLT|COPY} bits 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:
+
+ #define RTYPE_CLASS_VALID       8
+ #define RTYPE_CLASS_PLT         (8|1)
+ #define RTYPE_CLASS_COPY        (8|2)
+ #define RTYPE_CLASS_TLS         (8|4)
+
+where ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA has a conflict with
+RTYPE_CLASS_TLS.
+
+Since prelink only uses ELF_RTYPE_CLASS_PLT and ELF_RTYPE_CLASS_COPY
+bits, we should clear the other bits 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.  Keep only
+        ELF_RTYPE_CLASS_PLT and ELF_RTYPE_CLASS_COPY bits for
+        DL_DEBUG_PRELINK.
+
+Upstream-Status: submitted (https://sourceware.org/bugzilla/show_bug.cgi?id=19178)
+
+Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
+---
+ elf/dl-lookup.c | 21 +++++++++++++++++++--
+ 1 file changed, 19 insertions(+), 2 deletions(-)
+
+diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c
+index 581fb20..6ae6cc3 100644
+--- a/elf/dl-lookup.c
++++ b/elf/dl-lookup.c
+@@ -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)
+        {
++         /* Keep only ELF_RTYPE_CLASS_PLT and ELF_RTYPE_CLASS_COPY
++            bits since since prelink only uses them.  */
++         type_class &= ELF_RTYPE_CLASS_PLT | ELF_RTYPE_CLASS_COPY;
+          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
+-- 
+1.9.3
+
diff --git a/meta/recipes-core/glibc/glibc_2.22.bb b/meta/recipes-core/glibc/glibc_2.22.bb
index 2494ad7d97..1b23597ef7 100644
--- a/meta/recipes-core/glibc/glibc_2.22.bb
+++ b/meta/recipes-core/glibc/glibc_2.22.bb
@@ -39,6 +39,7 @@ SRC_URI = "${GLIBC_GIT_URI};branch=${SRCBRANCH};name=glibc \
            file://0026-eglibc-dl_debug_mask-is-controlled-by-__OPTION_EGLIB.patch \
            file://0027-eglibc-use-option-groups-Conditionally-exclude-c-tes.patch \
            file://nscd-no-bash.patch \
+           file://0028-Clear-ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA-for-prel.patch \
 "
 
 SRC_URI += "\