From a6af384b19c63bab4a1803c09592c5b5bd8674c2 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Mon, 26 Oct 2015 06:10:23 -0700
Subject: Properly convert address load of __start_XXX/__stop_XXX

Since __start_XXX and __stop_XXX symbols aren't defined when address
load is being converted, we need to check if there is an XXX output
section to get their section and value.  This patch adds a new function,
bfd_link_get_defined_symbol, to search for the XXX output section to
check if __start_XXX and __stop_XXX symbols are defined.

bfd/

	PR ld/19171
	* elf32-i386.c (elf_i386_convert_load): Call
	bfd_link_get_defined_symbol to check if a symbol is defined.
	* elf64-x86-64.c (elf_x86_64_convert_load): Call
	bfd_link_get_defined_symbol to get defined symbol section and
	value.
	* linker.c (bfd_link_get_defined_symbol): New function.
	* bfd-in2.h: Regenerated.

ld/testsuite/

	PR ld/19171
	* ld-i386/lea1.s: Add tests for address load of __start_XXX
	and __stop_XXX.
	* ld-i386/mov1.s: Likewise.
	* ld-x86-64/lea1.s: Likewise.
	* ld-x86-64/mov1.s: Likewise.
	* ld-i386/lea1a.d: Updated.
	* ld-i386/lea1b.d: Likewise.
	* ld-i386/lea1c.d: Likewise.
	* ld-i386/mov1a.d: Likewise.
	* ld-i386/mov1b.d: Likewise.
	* ld-x86-64/lea1a.d: Likewise.
	* ld-x86-64/lea1b.d: Likewise.
	* ld-x86-64/lea1c.d: Likewise.
	* ld-x86-64/lea1d.d: Likewise.
	* ld-x86-64/lea1e.d: Likewise.
	* ld-x86-64/lea1f.d: Likewise.
	* ld-x86-64/mov1a.d: Likewise.
	* ld-x86-64/mov1b.d: Likewise.
	* ld-x86-64/mov1c.d: Likewise.
	* ld-x86-64/mov1d.d: Likewise.
---
 bfd/linker.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)

(limited to 'bfd/linker.c')

diff --git a/bfd/linker.c b/bfd/linker.c
index 86a7a19..f2290e0 100644
--- a/bfd/linker.c
+++ b/bfd/linker.c
@@ -3303,3 +3303,92 @@ bfd_hide_sym_by_version (struct bfd_elf_version_tree *verdefs,
   bfd_find_version_for_sym (verdefs, sym_name, &hidden);
   return hidden;
 }
+
+/*
+FUNCTION
+	bfd_link_get_defined_symbol
+
+SYNOPSIS
+	bfd_boolean bfd_link_get_defined_symbol
+	  (struct bfd_link_info *info, struct bfd_link_hash_entry *h,
+	   asection **sec, bfd_vma *value);
+
+DESCRIPTION
+	Return TRUE, store symbol section and value in @var{*sec} and
+	@var{*value} if symbol @var{h} is defined during a final link.
+*/
+
+bfd_boolean
+bfd_link_get_defined_symbol (struct bfd_link_info *info,
+			     struct bfd_link_hash_entry *h,
+			     asection **sec, bfd_vma *value)
+{
+  if (h->type == bfd_link_hash_defined
+      || h->type == bfd_link_hash_defweak)
+    {
+      if (sec)
+	*sec = h->u.def.section;
+      if (value)
+	*value = h->u.def.value;
+      return TRUE;
+    }
+
+  if (h->type == bfd_link_hash_new
+      || h->type == bfd_link_hash_undefined
+      || h->type == bfd_link_hash_undefweak)
+    {
+      /* Check yet undefined reference to __start_XXX or __stop_XXX
+	 symbols.  The linker will later define such symbols for output
+	 sections that have a name representable as a C identifier.  */
+      const char *sec_name;
+      if (strncmp (h->root.string, "__start_", 8) == 0)
+	sec_name = h->root.string + 8;
+      else if (strncmp (h->root.string, "__stop_", 7) == 0)
+	sec_name = h->root.string + 7;
+      else
+	sec_name = NULL;
+
+      if (sec_name != NULL && *sec_name != '\0')
+	{
+	  bfd *i;
+
+	  for (i = info->input_bfds; i != NULL; i = i->link.next)
+	    {
+	      asection *s = bfd_get_section_by_name (i, sec_name);
+	      if (s != NULL)
+		{
+		  asection *asect;
+		  bfd_vma size;
+
+		  if (sec)
+		    *sec = s;
+
+		  if (!value)
+		    return TRUE;
+		  if (sec_name == (h->root.string + 8))
+		    {
+		      /* Set __start_XXX symbol value.  */
+		      *value = 0;
+		      return TRUE;
+		    }
+
+		  /* Get the size of the output XXX section for
+		     __stop_XXX symbol value.  */
+		  size = 0;
+		  for (asect = s->output_section->map_head.s;
+		       asect != NULL;
+		       asect = asect->map_head.s)
+		    {
+		      size = align_power (size, asect->alignment_power);
+		      size += asect->size;
+		    }
+
+		  *value = size;
+		  return TRUE;
+		}
+	    }
+	}
+    }
+
+  return FALSE;
+}
-- 
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