[binutils-gdb] Don't clear output_has_begun

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=a4dd3cb4252e42e5af9490abf3558a284bf45619

commit a4dd3cb4252e42e5af9490abf3558a284bf45619
Author: Alan Modra <amodra@gmail.com>
Date:   Fri Aug 21 13:12:23 2026 +0930

    Don't clear output_has_begun
    
    I think all the other uses of this flag are on an output bfd, and the
    flag is initialised to false.  Removing the loop that clears this
    flag exposes the fact that as far as the compiler is concerned,
    _bfd_default_link_order could modify p->type or any other field of
    struct bfd_link_orfer, and thus there is a potentially uninitialised
    use of "sub".
    
            * elflink.c (_bfd_elf_final_link): Don't clear output_has_begun.
            Reassign "sub" from link_order.

Diff:
---
 bfd/elflink.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/bfd/elflink.c b/bfd/elflink.c
index df9c698d874..09eaacc8497 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -13180,8 +13180,6 @@ _bfd_elf_final_link (bfd *obfd, struct bfd_link_info *info)
      we could write the relocs out and then read them again; I don't
      know how bad the memory loss will be.  */
 
-  for (sub = info->input_bfds; sub != NULL; sub = sub->link.next)
-    sub->output_has_begun = false;
   for (o = obfd->sections; o != NULL; o = o->next)
     {
       for (p = o->map_head.link_order; p != NULL; p = p->next)
@@ -13193,10 +13191,10 @@ _bfd_elf_final_link (bfd *obfd, struct bfd_link_info *info)
 	    {
 	      if (! sub->output_has_begun)
 		{
+		  sub->output_has_begun = true;
 		  if ((sub->flags & BFD_LINKER_CREATED) == 0
 		      && !elf_link_input_bfd (&flinfo, sub))
 		    goto error_return;
-		  sub->output_has_begun = true;
 		}
 	    }
 	  else if (p->type == bfd_section_reloc_link_order
@@ -13210,7 +13208,7 @@ _bfd_elf_final_link (bfd *obfd, struct bfd_link_info *info)
 	      if (! _bfd_default_link_order (obfd, info, o, p))
 		{
 		  if (p->type == bfd_indirect_link_order
-		      && (bfd_get_flavour (sub)
+		      && (bfd_get_flavour ((sub = p->u.indirect.section->owner))
 			  == bfd_target_elf_flavour)
 		      && (elf_elfheader (sub)->e_ident[EI_CLASS]
 			  != obed->s->elfclass))
@@ -13251,10 +13249,8 @@ _bfd_elf_final_link (bfd *obfd, struct bfd_link_info *info)
   for (sub = info->input_bfds; sub != NULL; sub = sub->link.next)
     if (sub->output_has_begun && (sub->flags & BFD_LINKER_CREATED) != 0)
       {
-	sub->output_has_begun = false;
 	if (!elf_link_input_bfd (&flinfo, sub))
 	  goto error_return;
-	sub->output_has_begun = true;
       }
 
   /* Free symbol buffer if needed.  */