From cc69950864954cd0d1c801eb5058ec5b2fbd545f Mon Sep 17 00:00:00 2001
From: Gunther Nikl <gnikl@baltic.net>
Date: Wed, 29 Apr 2015 17:03:03 +0000
Subject: [PATCH] Make reading HUNK_EXT data robust.

* bfd/amigaos.c (howto_for_reloc): New helper function to select a relocation
  howto entry.
  (amiga_slurp_relocs): Use it.
---
 bfd/amigaos.c | 51 ++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 36 insertions(+), 15 deletions(-)

diff --git a/bfd/amigaos.c b/bfd/amigaos.c
index e44be70..453c1ac 100644
--- a/bfd/amigaos.c
+++ b/bfd/amigaos.c
@@ -161,6 +161,7 @@ typedef struct amiga_ardata_struct {
 #define MAX_NAME_SIZE 124
 
 static reloc_howto_type *howto_for_raw_reloc PARAMS ((unsigned long type));
+static reloc_howto_type *howto_for_reloc PARAMS ((unsigned long type));
 static bfd_boolean get_long PARAMS ((bfd *, unsigned long *));
 static bfd_boolean get_word PARAMS ((bfd *, unsigned long *));
 static const struct bfd_target *amiga_object_p PARAMS ((bfd *));
@@ -293,6 +294,37 @@ howto_for_raw_reloc (type)
   }
 }
 
+static reloc_howto_type *
+howto_for_reloc (type)
+     unsigned long type;
+{
+  switch (type)
+  {
+  case EXT_ABSREF32:
+  case EXT_ABSCOMMON:
+    return &howto_table[R_ABS32];
+  case EXT_RELREF32:
+    return &howto_table[R_PC32];
+  case EXT_RELREF16:
+    return &howto_table[R_PC16];
+  case EXT_RELREF8:
+    return &howto_table[R_PC8];
+  case EXT_DEXT32:
+  case EXT_DEXT32COMMON:
+    return &howto_table[R_SD32];
+  case EXT_DEXT16:
+  case EXT_DEXT16COMMON:
+    return &howto_table[R_SD16];
+  case EXT_DEXT8:
+  case EXT_DEXT8COMMON:
+    return &howto_table[R_SD8];
+  case EXT_RELREF26:
+    return &howto_table[R_PC26];
+  default:
+    return NULL;
+  }
+}
+
 /* The following are gross hacks that need to be fixed.  The problem is
    that the linker unconditionally references these values without
    going through any of bfd's standard interface.  Thus they need to
@@ -2653,7 +2685,6 @@ amiga_slurp_relocs (abfd, section, symbols)
 	case EXT_DEXT32COMMON:
 	case EXT_DEXT16COMMON:
 	case EXT_DEXT8COMMON:
-	  type -= 75; /* convert to EXT_DEXT */
 	case EXT_ABSCOMMON:
 	  if (bfd_seek (abfd, 4, SEEK_CUR))
 	    return FALSE;
@@ -2662,21 +2693,11 @@ amiga_slurp_relocs (abfd, section, symbols)
 	  /* points to num of refs to hunk */
 	  if (!get_long (abfd, &n))
 	    return FALSE;
+	  /* determine howto */
+	  howto = howto_for_reloc (type);
+	  if (howto == NULL)
+	    return FALSE;
 	  /* Add relocs to this section, relative to asp */
-	  /* determine howto first */
-	  if (type==EXT_ABSCOMMON) /* 32 bit ref */
-	    howto=&howto_table[R_ABS32];
-	  else if (type==EXT_RELREF32)
-	    howto=&howto_table[R_PC32];
-	  else if (type==EXT_RELREF26)
-	    howto=&howto_table[R_PC26];
-	  else
-	    {
-	      type -= EXT_ABSREF32;
-	      if (type)
-		type--; /* skip EXT_ABSCOMMON gap */
-	      howto=&howto_table[R_ABS32+type];
-	    }/* of else */
 	  for (i=0;i<n;i++) /* refs follow */
 	    {
 	      if (!get_long (abfd, &offset))