Re: [PATCH-bfd] i386-mingw32-ld crash on x86_64 linux

[Alan Modra <amodra at bigpond dot net dot au>]

On Thu, Apr 16, 2009 at 09:41:35PM -0500, Peter O'Gorman wrote:
> Index: bfd/peXXigen.c
> ===================================================================
> --- bfd/peXXigen.c.orig	2008-07-30 04:34:56.000000000 +0000
> +++ bfd/peXXigen.c	2009-04-17 02:19:12.221139740 +0000
> @@ -138,7 +138,7 @@
>  
>  	  for (sec = abfd->sections; sec; sec = sec->next)
>  	    {
> -	      if (strcmp (sec->name, in->n_name) == 0)
> +	      if (strncmp (sec->name, in->n_name, SYMNMLEN) == 0)

This isn't quite right.  If in->n_name is not 0 terminated then you
could match the wrong section.

>  		{
>  		  in->n_scnum = sec->target_index;
>  		  break;
> @@ -157,10 +157,10 @@
>  	    if (unused_section_number <= sec->target_index)
>  	      unused_section_number = sec->target_index + 1;
>  
> -	  name = bfd_alloc (abfd, (bfd_size_type) strlen (in->n_name) + 10);
> +	  name = bfd_alloc (abfd, (bfd_size_type) SYMNMLEN + 1);

Better to use char[SYMNMLEN + 1] rather than bfd_alloc.

>  	  if (name == NULL)
>  	    return;
> -	  strcpy (name, in->n_name);
> +	  strncpy (name, in->n_name, SYMNMLEN);

This also isn't quite correct.  You want

	  strncpy (name, in->n_name, SYMNMLEN);
	  name[SYMNMLEN] = '\0';

So, something like the following.  I won't commit this as it's
untested, and I'm not sure whether the ext->e.e_name[0] == 0 case
ought to be handled.

Index: bfd/peXXigen.c
===================================================================
RCS file: /cvs/src/src/bfd/peXXigen.c,v
retrieving revision 1.49
diff -u -p -r1.49 peXXigen.c
--- bfd/peXXigen.c	6 Apr 2009 16:48:36 -0000	1.49
+++ bfd/peXXigen.c	17 Apr 2009 03:59:32 -0000
@@ -129,6 +129,8 @@ _bfd_XXi_swap_sym_in (bfd * abfd, void *
      they will be handled somewhat correctly in the bfd code.  */
   if (in->n_sclass == C_SECTION)
     {
+      char name[SYMNMLEN + 1];
+
       in->n_value = 0x0;
 
       /* Create synthetic empty sections as needed.  DJ */
@@ -136,31 +138,23 @@ _bfd_XXi_swap_sym_in (bfd * abfd, void *
 	{
 	  asection *sec;
 
-	  for (sec = abfd->sections; sec; sec = sec->next)
-	    {
-	      if (strcmp (sec->name, in->n_name) == 0)
-		{
-		  in->n_scnum = sec->target_index;
-		  break;
-		}
-	    }
+	  strncpy (name, in->n_name, SYMNMLEN);
+	  name[SYMNMLEN] = '\0';
+	  sec = bfd_get_section_by_name (abfd, name);
+	  if (sec != NULL)
+	    in->n_scnum = sec->target_index;
 	}
 
       if (in->n_scnum == 0)
 	{
 	  int unused_section_number = 0;
 	  asection *sec;
-	  char *name;
 	  flagword flags;
 
 	  for (sec = abfd->sections; sec; sec = sec->next)
 	    if (unused_section_number <= sec->target_index)
 	      unused_section_number = sec->target_index + 1;
 
-	  name = bfd_alloc (abfd, (bfd_size_type) strlen (in->n_name) + 10);
-	  if (name == NULL)
-	    return;
-	  strcpy (name, in->n_name);
 	  flags = SEC_HAS_CONTENTS | SEC_ALLOC | SEC_DATA | SEC_LOAD;
 	  sec = bfd_make_section_anyway_with_flags (abfd, name, flags);
 

-- 
Alan Modra
Australia Development Lab, IBM