[Bug binutils/135] New: bfd crashes when processing nested archives.

[mikulas at artax dot karlin dot mff dot cuni dot cz]

BFD 2.14 crashes when program is opening and operating on archives containing
other archives (with bfd_openr_next_archived_file).

The problems arise usually when there are too many open files and open file
caching takes effect.

At many places in code, there are constructs like
if (bfd->my_archive) offset += bfd->origin;
and similar.

The problem with these is that if bfd->my_archive is contained in some archive
too, you add only offset of inner archive, not offset of outer
archive. Similarly, in bfd_cache_lookup_worker you do
if (abfd->my_archive) abfd = abfd->my_archive; --- now if archives are nested,
you need to get to the topmost archive.

The crash becomes because of this and other bug --- bfd cache doesn't check if
files was reopened succesfully --- see my next bug report.

The attached patch fixes the problems with nested archives --- it modifies
archive creating so that bfd->my_archive always points to the topmost
archive, not to the immediate descendant. With the patch, i can link large
programs with nested archives flawlessly.

--- bfd/archive.c_      Wed Apr 21 19:28:07 2004
+++ bfd/archive.c       Wed Apr 21 20:54:25 2004
@@ -498,6 +498,11 @@
   struct areltdata *new_areldata;
   bfd *n_nfd;

+  if (archive->my_archive) {
+    filepos += archive->origin;
+    archive = archive->my_archive;
+  }
+
   n_nfd = _bfd_look_for_bfd_in_cache (archive, filepos);
   if (n_nfd)
     return n_nfd;
@@ -593,6 +598,7 @@
         BSD-4.4-style element with a long odd size.  */
       filestart = last_file->origin + size;
       filestart += filestart % 2;
+      if (archive->my_archive) filestart -= archive->origin;
     }

   return _bfd_get_elt_at_filepos (archive, filestart);

-- 
           Summary: bfd crashes when processing nested archives.
           Product: binutils
           Version: 2.14
            Status: NEW
          Severity: critical
          Priority: P2
         Component: binutils
        AssignedTo: unassigned at sources dot redhat dot com
        ReportedBy: mikulas at artax dot karlin dot mff dot cuni dot cz
                CC: bug-binutils at gnu dot org
 GCC build triplet: i586-pc-linux-gnu
  GCC host triplet: i486-pc-spad
GCC target triplet: i486-pc-spad


http://sources.redhat.com/bugzilla/show_bug.cgi?id=135

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