[PATCH] Fix segfault relocating debugging sections on powerpc-*-linux-gnu

[Daniel Jacobowitz <drow@false.org>]

When the attached testcase is compiled on powerpc-linux with 'c++ -fPIC
-shared -g segvtest.cc' it causes a SEGV in the linker.  Franz Sirl
noticed that elf32-i386.c specifically avoids relocations in sections
with SEC_DEBUGGING set; this patch adds the same to elf32-ppc.c.  It
also copies the warning from elf32-i386.c in the same situation; the if
condition here (here being elf32-ppc.c:3000 or so) does not obviously
guarantee that output_section will not be NULL, and there could be
other cases it misses.  I see no reason to have ld segfault
mysteriously :)

I would have added a testcase, but the organization of ld/testsuite/
eludes me.

[Please CC: me in any list replies, I'm not on this list]

Dan

/--------------------------------\  /--------------------------------\
|       Daniel Jacobowitz        |__|        SCS Class of 2002       |
|   Debian GNU/Linux Developer    __    Carnegie Mellon University   |
|         dan@debian.org         |  |       dmj+@andrew.cmu.edu      |
\--------------------------------/  \--------------------------------/
/* $Id: pathname.cc,v 1.1 1999/07/25 19:59:49 drow Exp $ */

#include <sys/param.h>
#include <string.h>
#include <stack>

struct PathName {
  stack<int> dirOffsets;
  int        curDirOffset;

  void Push();
};

void PathName::Push()
{
  dirOffsets.push(curDirOffset);
}
Index: bfd/elf32-ppc.c
===================================================================
RCS file: /cvs/binutils/binutils/bfd/elf32-ppc.c,v
retrieving revision 1.6
diff -c -p -r1.6 elf32-ppc.c
*** elf32-ppc.c	1999/07/13 18:21:22	1.6
--- elf32-ppc.c	1999/07/29 23:32:10
*************** ppc_elf_relocate_section (output_bfd, in
*** 3038,3044 ****
  		      && ((! info->symbolic && h->dynindx != -1)
  			  || (h->elf_link_hash_flags
  			      & ELF_LINK_HASH_DEF_REGULAR) == 0)
! 		      && (input_section->flags & SEC_ALLOC) != 0
  		      && (r_type == R_PPC_ADDR32
  			  || r_type == R_PPC_ADDR24
  			  || r_type == R_PPC_ADDR16
--- 3038,3045 ----
  		      && ((! info->symbolic && h->dynindx != -1)
  			  || (h->elf_link_hash_flags
  			      & ELF_LINK_HASH_DEF_REGULAR) == 0)
! 		      && ((input_section->flags & SEC_ALLOC) != 0
! 		          || (input_section->flags & SEC_DEBUGGING) != 0)
  		      && (r_type == R_PPC_ADDR32
  			  || r_type == R_PPC_ADDR24
  			  || r_type == R_PPC_ADDR16
*************** ppc_elf_relocate_section (output_bfd, in
*** 3081,3086 ****
--- 3082,3095 ----
                       obscure cases sec->output_section will be NULL.  */
  		  relocation = 0;
  		}
+ 	      else if (sec->output_section == NULL)
+ 	        {
+                   (*_bfd_error_handler)
+                     (_("%s: warning: unresolvable relocation against symbol `%s' from %s section"),
+                      bfd_get_filename (input_bfd), h->root.root.string,
+                      bfd_get_section_name (input_bfd, input_section));
+ 		  relocation = 0;
+ 	        }
  	      else
  		relocation = (h->root.u.def.value
  			      + sec->output_section->vma