[PATCH] bfd: Mark symbols with mismatching types

[Egeyar Bagcioglu]

Introduce flag for defined symbols whose type is mismatched with a
dynamic definition. Mark such symbols. Prevent such symbols from being
made dynamic in sparc.

Sparc makes use of dynamic symbols during relocations. Unless detected,
above-mentioned symbols are confused with library symbols by the dynamic
linker.

This change is tested for sparc64-unknown-linux-gnu.

bfd/ChangeLog:

2017-04-11  Egeyar Bagcioglu  <egeyar.bagcioglu@oracle.com>

        * elf-bfd.h (elf_link_hash_entry): Add conflict_with_library.
        * elflink.c (_bfd_elf_merge_symbol): Set conflict_with_library.
        * elfxx-sparc.c (allocate_dynrelocs): Avoid the call to
        bfd_elf_link_record_dynamic_symbol in case of conflict_with_library.
---
 bfd/elf-bfd.h     |    2 ++
 bfd/elflink.c     |    1 +
 bfd/elfxx-sparc.c |    6 ++++--
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
index af377ee..150f038 100644
--- a/bfd/elf-bfd.h
+++ b/bfd/elf-bfd.h
@@ -213,6 +213,8 @@ struct elf_link_hash_entry
   /* Symbol is defined by a shared library with non-default visibility
      in a read/write section.  */
   unsigned int protected_def : 1;
+  /* Symbol is defined also with a different type in a shared library */
+  unsigned int conflict_with_library : 1;
 
   /* String table index in .dynstr if this is a dynamic symbol.  */
   unsigned long dynstr_index;
diff --git a/bfd/elflink.c b/bfd/elflink.c
index c00d712..7a9979a 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -1257,6 +1257,7 @@ _bfd_elf_merge_symbol (bfd *abfd,
       && h->type != STT_NOTYPE
       && !(newfunc && oldfunc))
     {
+      h->conflict_with_library = 1;
       *skip = TRUE;
       return TRUE;
     }
diff --git a/bfd/elfxx-sparc.c b/bfd/elfxx-sparc.c
index c978aad..c4e7b7c 100644
--- a/bfd/elfxx-sparc.c
+++ b/bfd/elfxx-sparc.c
@@ -2310,7 +2310,8 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
 	 Undefined weak syms won't yet be marked as dynamic.  */
       if (h->dynindx == -1
 	  && !h->forced_local
-          && !resolved_to_zero)
+          && !resolved_to_zero
+          && !h->conflict_with_library)
 	{
 	  if (! bfd_elf_link_record_dynamic_symbol (info, h))
 	    return FALSE;
@@ -2422,7 +2423,8 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
 	 Undefined weak syms won't yet be marked as dynamic.  */
       if (h->dynindx == -1
 	  && !h->forced_local
-          && !resolved_to_zero)
+          && !resolved_to_zero
+          && !h->conflict_with_library)
 	{
 	  if (! bfd_elf_link_record_dynamic_symbol (info, h))
 	    return FALSE;
-- 
1.7.1