commit dffecd133e0bde443315bbd8b8615752ef3d0ed2
Author: Egor Kochetov <egor.kochetov@intel.com>
Date:   Sat Feb 20 14:56:24 2016 +0300

    Added filtering of FDEs with empty PC range
    
    Change-Id: Ie3e1adf5ad8441015dad1239fb41ffb4e37091a9
    Signed-off-by: Egor Kochetov <egor.kochetov@intel.com>

diff --git a/binutils-2.25/gold/ehframe.cc b/binutils-2.25/gold/ehframe.cc
index 4f92618..08c5fc8 100644
--- a/binutils-2.25/gold/ehframe.cc
+++ b/binutils-2.25/gold/ehframe.cc
@@ -656,6 +656,7 @@ Eh_frame::do_add_ehframe_input_section(
   // Keep track of which CIEs are at which offsets.
   Offsets_to_cie cies;
 
+  int fde_pc_encoding;
   while (p < pend)
     {
       if (pend - p < 4)
@@ -697,14 +698,15 @@ Eh_frame::do_add_ehframe_input_section(
 	  if (!this->read_cie(object, shndx, symbols, symbols_size,
 			      symbol_names, symbol_names_size,
 			      pcontents, p, pentend, &relocs, &cies,
-			      new_cies))
+			      new_cies, fde_pc_encoding))
 	    return false;
 	}
       else
 	{
 	  // FDE.
 	  if (!this->read_fde(object, shndx, symbols, symbols_size,
-			      pcontents, id, p, pentend, &relocs, &cies))
+			      pcontents, id, p, pentend, &relocs, &cies,
+                  fde_pc_encoding))
 	    return false;
 	}
 
@@ -729,7 +731,8 @@ Eh_frame::read_cie(Sized_relobj_file<size, big_endian>* object,
 		   const unsigned char* pcieend,
 		   Track_relocs<size, big_endian>* relocs,
 		   Offsets_to_cie* cies,
-		   New_cies* new_cies)
+		   New_cies* new_cies,
+		   int& fde_pc_encoding)
 {
   bool mergeable = true;
 
@@ -811,7 +814,7 @@ Eh_frame::read_cie(Sized_relobj_file<size, big_endian>* object,
 	  if (pcieend - p < 1)
 	    return false;
 	  fde_encoding = *p;
-	  switch (fde_encoding & 7)
+	  switch ((fde_pc_encoding = fde_encoding & 7))
 	    {
 	    case elfcpp::DW_EH_PE_absptr:
 	    case elfcpp::DW_EH_PE_udata2:
@@ -981,7 +984,8 @@ Eh_frame::read_fde(Sized_relobj_file<size, big_endian>* object,
 		   const unsigned char* pfde,
 		   const unsigned char* pfdeend,
 		   Track_relocs<size, big_endian>* relocs,
-		   Offsets_to_cie* cies)
+		   Offsets_to_cie* cies,
+		   int fde_pc_encoding)
 {
   // OFFSET is the distance between the 4 bytes before PFDE to the
   // start of the CIE.  The offset we recorded for the CIE is 8 bytes
@@ -1019,10 +1023,21 @@ Eh_frame::read_fde(Sized_relobj_file<size, big_endian>* object,
   fde_shndx = object->adjust_sym_shndx(symndx, sym.get_st_shndx(),
 				       &is_ordinary);
 
-  if (is_ordinary
+  bool is_zero_range = false;
+  switch (fde_pc_encoding) {
+      case elfcpp::DW_EH_PE_udata2: is_zero_range = *(uint16_t*)(pfde + 2) == 0; break;
+      case elfcpp::DW_EH_PE_udata4: is_zero_range = *(uint32_t*)(pfde + 4) == 0; break;
+      case elfcpp::DW_EH_PE_udata8: is_zero_range = *(uint64_t*)(pfde + 8) == 0; break;
+      default:
+        // All other cases were rejected in Eh_frame::read_cie.
+        gold_unreachable();
+  }
+
+  if (is_zero_range
+      || (is_ordinary
       && fde_shndx != elfcpp::SHN_UNDEF
       && fde_shndx < object->shnum()
-      && !object->is_section_included(fde_shndx))
+      && !object->is_section_included(fde_shndx)))
     {
       // This FDE applies to a section which we are discarding.  We
       // can discard this FDE.
diff --git a/binutils-2.25/gold/ehframe.h b/binutils-2.25/gold/ehframe.h
index e9c9da8..e50689c 100644
--- a/binutils-2.25/gold/ehframe.h
+++ b/binutils-2.25/gold/ehframe.h
@@ -470,6 +470,8 @@ class Eh_frame : public Output_section_data
 			       New_cies*);
 
   // Read a CIE.
+  // Fill the fde_pc_encoding parameter if it can be parsed.
+  // Returns false if the CIE is unreadable.
   template<int size, bool big_endian>
   bool
   read_cie(Sized_relobj_file<size, big_endian>* object,
@@ -483,7 +485,8 @@ class Eh_frame : public Output_section_data
 	   const unsigned char* pcieend,
 	   Track_relocs<size, big_endian>* relocs,
 	   Offsets_to_cie* cies,
-	   New_cies* new_cies);
+	   New_cies* new_cies,
+	   int& fde_pc_encoding);
 
   // Read an FDE.
   template<int size, bool big_endian>
@@ -497,7 +500,8 @@ class Eh_frame : public Output_section_data
 	   const unsigned char* pfde,
 	   const unsigned char* pfdeend,
 	   Track_relocs<size, big_endian>* relocs,
-	   Offsets_to_cie* cies);
+	   Offsets_to_cie* cies,
+	   int fde_pc_encoding);
 
   // Template version of write function.
   template<int size, bool big_endian>