Fix ld --gc-section segfault with ARMv8-M entry function in absolute section

[deliverable/binutils-gdb.git] / bfd / merge.c

diff --git a/bfd/merge.c b/bfd/merge.c
index aef3cf35a554ab4bbdc553d7729a4b9d1d6172fe..a892dde11dac8052e513c53e6ca8863c20b3fa57 100644 (file)
--- a/bfd/merge.c
+++ b/bfd/merge.c
@@ -1,6 +1,5 @@
 /* SEC_MERGE support.
-   Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
-   Free Software Foundation, Inc.
+   Copyright (C) 2001-2016 Free Software Foundation, Inc.
    Written by Jakub Jelinek <jakub@redhat.com>.
 
    This file is part of BFD, the Binary File Descriptor library.
@@ -26,6 +25,7 @@
 
 #include "sysdep.h"
 #include "bfd.h"
+#include "elf-bfd.h"
 #include "libbfd.h"
 #include "hashtab.h"
 #include "libiberty.h"
@@ -284,7 +284,8 @@ sec_merge_add (struct sec_merge_hash *tab, const char *str,
 }
 
 static bfd_boolean
-sec_merge_emit (bfd *abfd, struct sec_merge_hash_entry *entry)
+sec_merge_emit (bfd *abfd, struct sec_merge_hash_entry *entry,
+               unsigned char *contents, file_ptr offset)
 {
   struct sec_merge_sec_info *secinfo = entry->secinfo;
   asection *sec = secinfo->sec;
@@ -307,7 +308,12 @@ sec_merge_emit (bfd *abfd, struct sec_merge_hash_entry *entry)
       len = -off & (entry->alignment - 1);
       if (len != 0)
        {
-         if (bfd_bwrite (pad, len, abfd) != len)
+         if (contents)
+           {
+             memcpy (contents + offset, pad, len);
+             offset += len;
+           }
+         else if (bfd_bwrite (pad, len, abfd) != len)
            goto err;
          off += len;
        }
@@ -315,7 +321,12 @@ sec_merge_emit (bfd *abfd, struct sec_merge_hash_entry *entry)
       str = entry->root.string;
       len = entry->len;
 
-      if (bfd_bwrite (str, len, abfd) != len)
+      if (contents)
+       {
+         memcpy (contents + offset, str, len);
+         offset += len;
+       }
+      else if (bfd_bwrite (str, len, abfd) != len)
        goto err;
 
       off += len;
@@ -323,9 +334,13 @@ sec_merge_emit (bfd *abfd, struct sec_merge_hash_entry *entry)
 
   /* Trailing alignment needed?  */
   off = sec->size - off;
-  if (off != 0
-      && bfd_bwrite (pad, off, abfd) != off)
-    goto err;
+  if (off != 0)
+    {
+      if (contents)
+       memcpy (contents + offset, pad, off);
+      else if (bfd_bwrite (pad, off, abfd) != off)
+       goto err;
+    }
 
   if (pad != NULL)
     free (pad);
@@ -786,6 +801,8 @@ _bfd_write_merged_section (bfd *output_bfd, asection *sec, void *psecinfo)
 {
   struct sec_merge_sec_info *secinfo;
   file_ptr pos;
+  unsigned char *contents;
+  Elf_Internal_Shdr *hdr;
 
   secinfo = (struct sec_merge_sec_info *) psecinfo;
 
@@ -796,11 +813,26 @@ _bfd_write_merged_section (bfd *output_bfd, asection *sec, void *psecinfo)
     return TRUE;
 
   /* FIXME: octets_per_byte.  */
-  pos = sec->output_section->filepos + sec->output_offset;
-  if (bfd_seek (output_bfd, pos, SEEK_SET) != 0)
-    return FALSE;
+  hdr = &elf_section_data (sec->output_section)->this_hdr;
+  if (hdr->sh_offset == (file_ptr) -1)
+    {
+      /* We must compress this section.  Write output to the
+        buffer.  */
+      contents = hdr->contents;
+      if ((sec->output_section->flags & SEC_ELF_COMPRESS) == 0
+         || contents == NULL)
+       abort ();
+    }
+  else
+    {
+      contents = NULL;
+      pos = sec->output_section->filepos + sec->output_offset;
+      if (bfd_seek (output_bfd, pos, SEEK_SET) != 0)
+       return FALSE;
+    }
 
-  if (! sec_merge_emit (output_bfd, secinfo->first_str))
+  if (! sec_merge_emit (output_bfd, secinfo->first_str, contents,
+                       sec->output_offset))
     return FALSE;
 
   return TRUE;
@@ -885,3 +917,17 @@ _bfd_merged_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, asection **psec,
   *psec = entry->secinfo->sec;
   return entry->u.index + (secinfo->contents + offset - p);
 }
+
+/* Tidy up when done.  */
+
+void
+_bfd_merge_sections_free (void *xsinfo)
+{
+  struct sec_merge_info *sinfo;
+
+  for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next)
+    {
+      bfd_hash_table_free (&sinfo->htab->table);
+      free (sinfo->htab);
+    }
+}