Cure a number of segfaults caused by /DISCARD/ of dynamic sections.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 3347191d75f743e1389db921243fa752e18232b1..c683b4d9071568f32135060cb5e1f6ac5ee003a9 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,12 @@
 2000-10-07  Alan Modra  <alan@linuxcare.com.au>
 
+       * elflink.h (size_dynamic_sections): Don't create various tags if
+       .dynstr is excluded from the link.  Don't set first dynsym entry
+       if dynsymcount is zero.
+       (elf_bfd_final_link): Don't try to swap out dynamic syms if
+       .dynsym excluded from the link.  Don't try to write any dynamic
+       sections excluded from the link.
+
        * elf.c (swap_out_syms): Handle global section symbols.
 
 2000-10-05  DJ Delorie  <dj@redhat.com>

diff --git a/bfd/elflink.h b/bfd/elflink.h
index 80c5b1c8fdec51bb245fd5344fd9200cc3211f36..9e543a7c8d08355a9e2cf7bc289b48f431c98713 100644 (file)
--- a/bfd/elflink.h
+++ b/bfd/elflink.h
@@ -2897,7 +2897,7 @@ NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
     {
       struct elf_info_failed eif;
       struct elf_link_hash_entry *h;
-      bfd_size_type strsize;
+      asection *dynstr;
 
       *sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
       BFD_ASSERT (*sinterpptr != NULL || info->shared);
@@ -3026,14 +3026,24 @@ NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
            return false;
        }
 
-      strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
-      if (! elf_add_dynamic_entry (info, DT_HASH, 0)
-         || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
-         || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
-         || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
-         || ! elf_add_dynamic_entry (info, DT_SYMENT,
-                                     sizeof (Elf_External_Sym)))
-       return false;
+      dynstr = bfd_get_section_by_name (dynobj, ".dynstr");
+      /* If .dynstr is excluded from the link, we don't want any of
+        these tags.  Strictly, we should be checking each section
+        individually;  This quick check covers for the case where
+        someone does a /DISCARD/ : { *(*) }.  */
+      if (dynstr != NULL && dynstr->output_section != bfd_abs_section_ptr)
+       {
+         bfd_size_type strsize;
+
+         strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
+         if (! elf_add_dynamic_entry (info, DT_HASH, 0)
+             || ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
+             || ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
+             || ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
+             || ! elf_add_dynamic_entry (info, DT_SYMENT,
+                                         sizeof (Elf_External_Sym)))
+           return false;
+       }
     }
 
   /* The backend must work out the sizes of all the other dynamic
@@ -3047,7 +3057,6 @@ NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
       size_t dynsymcount;
       asection *s;
       size_t bucketcount = 0;
-      Elf_Internal_Sym isym;
       size_t hash_entry_size;
 
       /* Set up the version definition section.  */
@@ -3384,15 +3393,20 @@ NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
       if (s->contents == NULL && s->_raw_size != 0)
        return false;
 
-      /* The first entry in .dynsym is a dummy symbol.  */
-      isym.st_value = 0;
-      isym.st_size = 0;
-      isym.st_name = 0;
-      isym.st_info = 0;
-      isym.st_other = 0;
-      isym.st_shndx = 0;
-      elf_swap_symbol_out (output_bfd, &isym,
-                          (PTR) (Elf_External_Sym *) s->contents);
+      if (dynsymcount != 0)
+       {
+         Elf_Internal_Sym isym;
+
+         /* The first entry in .dynsym is a dummy symbol.  */
+         isym.st_value = 0;
+         isym.st_size = 0;
+         isym.st_name = 0;
+         isym.st_info = 0;
+         isym.st_other = 0;
+         isym.st_shndx = 0;
+         elf_swap_symbol_out (output_bfd, &isym,
+                              (PTR) (Elf_External_Sym *) s->contents);
+       }
 
       /* Compute the size of the hashing table.  As a side effect this
         computes the hash values for all the names we export.  */
@@ -4602,7 +4616,8 @@ elf_bfd_final_link (abfd, info)
   /* The sh_info field records the index of the first non local symbol.  */
   symtab_hdr->sh_info = bfd_get_symcount (abfd);
 
-  if (dynamic)
+  if (dynamic
+      && finfo.dynsym_sec->output_section != bfd_abs_section_ptr)
     {
       Elf_Internal_Sym sym;
       Elf_External_Sym *dynsym =
@@ -4867,7 +4882,8 @@ elf_bfd_final_link (abfd, info)
       for (o = dynobj->sections; o != NULL; o = o->next)
        {
          if ((o->flags & SEC_HAS_CONTENTS) == 0
-             || o->_raw_size == 0)
+             || o->_raw_size == 0
+             || o->output_section == bfd_abs_section_ptr)
            continue;
          if ((o->flags & SEC_LINKER_CREATED) == 0)
            {