stop bogus dwarf killing objdump

[Nick Clifton]

Hi Nathan,

> I had the misfortune to have an executable with bogus dwarf information. 

Just to check - how did readelf cope with this corrupt binary ?


> !   while (stash->info_ptr < stash->info_ptr_end)
>       {
>         bfd_vma length;
>         unsigned int offset_size = addr_size;
> --- 3023,3029 ----
>     BFD_ASSERT (addr_size == 4 || addr_size == 8);
>   
>     /* Read each remaining comp. units checking each as they are read.  */
> !   while (stash->info_ptr != stash->info_ptr_end)
>       {
>         bfd_vma length;
>         unsigned int offset_size = addr_size;

I do not like this change.  A corrupt value in the length field of a 
comp unit could cause stash->info_ptr to be set beyond 
stash->info_ptr_end which could lead to all kinds of problems.  Besides 
it is not needed because...

>   	  each = parse_comp_unit (stash, length, info_ptr_unit,
>   				  offset_size);
> + 	  if (!each)
> + 	    {
> + 	      /* The dwarf information is damaged, don't trust it any
> + 		 more.  */
> + 	      stash->info_ptr = stash->info_ptr_end;
> + 	      break;
> + 	    }

The break here will exit the while loop without ever testing 
stash->info_ptr (and so setting it to stash->info_ptr_end is redundant).

Please could you modify your patch to just check the return value from 
parse_comp_unit and break the loop if it is NULL ?

Cheers
   Nick