[binutils-gdb/binutils-2_29-branch] relocs_compatible test for gc-sections

[Alan Modra <amodra at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=5e769a82c35d580ed81a52e6fbd072841530d3f6

commit 5e769a82c35d580ed81a52e6fbd072841530d3f6
Author: Alan Modra <amodra@gmail.com>
Date:   Mon Oct 30 10:20:29 2017 +1030

    relocs_compatible test for gc-sections
    
    I noticed when looking at pr22300 that before calling check_relocs we
    have an elf_object_id test (added for pr11933) as well as the
    relocs_compatible test.  I believe backend gc_mark_hook and
    gc_sweep_hook ought to be protected similarly from being confused by
    unexpected relocations (for example, both elf64-ppc.c and elf32-ppc.c
    use _bfd_elf_relocs_compatible, so I think it would be possible for
    the ppc64 gc_mark_hook to be presented with a ppc32 relocatable
    object).
    
    	* elflink.c (elf_gc_sweep): Test elf_object_id in addition to
    	relocs_compatible.
    	(bfd_elf_gc_sections): Likewise.

Diff:
---
 bfd/ChangeLog | 5 +++++
 bfd/elflink.c | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index ea035e7..a86ad61 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,6 +1,11 @@
 2017-11-01  Alan Modra  <amodra@gmail.com>
 
 	Apply from master
+	2017-10-30  Alan Modra  <amodra@gmail.com>
+	* elflink.c (elf_gc_sweep): Test elf_object_id in addition to
+	relocs_compatible.
+	(bfd_elf_gc_sections): Likewise.
+
 	2017-10-28  Alan Modra  <amodra@gmail.com>
 	PR 22300
 	* elflink.c (_bfd_elf_merge_symbol): Remove relocs_compatible check.
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 245d89c..9e0c1bb 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -13023,6 +13023,7 @@ elf_gc_sweep (bfd *abfd, struct bfd_link_info *info)
       asection *o;
 
       if (bfd_get_flavour (sub) != bfd_target_elf_flavour
+	  || elf_object_id (sub) != elf_hash_table_id (elf_hash_table (info))
 	  || !(*bed->relocs_compatible) (sub->xvec, abfd->xvec))
 	continue;
       o = sub->sections;
@@ -13351,6 +13352,7 @@ bfd_elf_gc_sections (bfd *abfd, struct bfd_link_info *info)
       asection *o;
 
       if (bfd_get_flavour (sub) != bfd_target_elf_flavour
+	  || elf_object_id (sub) != elf_hash_table_id (htab)
 	  || !(*bed->relocs_compatible) (sub->xvec, abfd->xvec))
 	continue;