[binutils-gdb] xtensa: fix relaxation of undefined weak references in shared objects

[Max Filippov]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=5d3a462f05cba5b0c0c96de899b84fb84155c760

commit 5d3a462f05cba5b0c0c96de899b84fb84155c760
Author: Max Filippov <jcmvbkbc@gmail.com>
Date:   Sun Jul 22 13:52:28 2018 -0700

    xtensa: fix relaxation of undefined weak references in shared objects
    
    The change c451bb34ae8b ("xtensa: don't emit dynamic relocation for weak
    undefined symbol") didn't properly handle shrinking of relocation
    sections due to coalescing of references to a dynamic undefined weak
    symbol in a shared object, which resulted in the following assertion
    failure in ld when linking uClibc-ng libthread_db for xtensa:
    
      BFD (GNU Binutils) 2.31 internal error, aborting at elf32-xtensa.c:3269
      in elf_xtensa_finish_dynamic_sections
    
    Shrink dynamic relocations section for dynamic undefined weak symbols
    when linking a shared object.
    
    bfd/
    2018-07-23  Max Filippov  <jcmvbkbc@gmail.com>
    
    	* elf32-xtensa.c (shrink_dynamic_reloc_sections): Shrink dynamic
    	relocations section for dynamic undefined weak symbols when
    	linking a shared object.

Diff:
---
 bfd/ChangeLog      | 6 ++++++
 bfd/elf32-xtensa.c | 3 ++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 19fd9df..3bdd2aa 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2018-07-23  Max Filippov  <jcmvbkbc@gmail.com>
+
+	* elf32-xtensa.c (shrink_dynamic_reloc_sections): Shrink dynamic
+	relocations section for dynamic undefined weak symbols when
+	linking a shared object.
+
 2018-07-23  Tom Tromey  <tom@tromey.com>
 
 	* elf.c (bfd_get_elf_phdrs): Don't call memcpy with size 0.
diff --git a/bfd/elf32-xtensa.c b/bfd/elf32-xtensa.c
index f7f569d..a4b046e 100644
--- a/bfd/elf32-xtensa.c
+++ b/bfd/elf32-xtensa.c
@@ -10022,7 +10022,8 @@ shrink_dynamic_reloc_sections (struct bfd_link_info *info,
   if ((r_type == R_XTENSA_32 || r_type == R_XTENSA_PLT)
       && (input_section->flags & SEC_ALLOC) != 0
       && (dynamic_symbol || bfd_link_pic (info))
-      && (!h || h->root.type != bfd_link_hash_undefweak))
+      && (!h || h->root.type != bfd_link_hash_undefweak
+	  || (dynamic_symbol && bfd_link_dll (info))))
     {
       asection *srel;
       bfd_boolean is_plt = FALSE;