Fix the linker so that it will not silently generate ELF binaries with invalid program headers. Fix readelf to report such invalid binaries.

	PR ld/20815
bfd	* elf.c (elf_modify_segment_map): Allow empty LOAD segments if
	they contain the program headers.
	(_bfd_elf_map_sections_to_segments): If the linker created the
	PHDR segment then always attempt to include it in a LOAD segment.
	(assign_file_positions_for_non_load_sections): Allow LOAD segments
	to overlap PHDR segments.
	(phdr_sorter): New function.  Sorts program headers.
	(assign_file_positions_except_relocs): Sort the program headers
	before writing them out.  Issue an error if the PHDR segment is
	not covered by a LOAD segment, unless the backend allows it.
	* elf-bfd.h (struct elf_backend_data): Add
	elf_backend_allow_non_load_phdr.
	* elfxx-target.h (elf_backend_allow_non_load_phdr): Provide
	default definition that returns FALSE.
	(elfNN_bed): Initialise the elf_backend_allow_non_load_phdr
	field.
	* elf64-hppa.c (elf64_hppa_allow_non_load_phdr): New function.
	Returns TRUE.
	(elf_backend_allow_non_load_phdr): Define.
	* elf-m10300.c (_bfd_mn10300_elf_size_dynamic_sections): Do not
	place the interpreter string into the .interp section if the
	nointerp flag is set in the link info structure.
	* elf32-arc.c (elf_arc_size_dynamic_sections): Likewise.
	* elf32-score7.c (score_elf_final_link_relocate): Allow for the
	_gp symbol not being part of the output.

binutils* readelf.c (process_program_headers): Check PT_LOAD and PT_PHDR
	segments for validity.

ld	* ld.texinfo: Note that PT_TLS can be used as a segment type.
	* testsuite/ld-discard/discard.ld: Add space for program headers.
	* testsuite/ld-elf/flags1.ld: Likewise.
	* testsuite/ld-elf/maxpage3.t: Likewise.
	* testsuite/ld-elf/noload-1.t: Likewise.
	* testsuite/ld-elf/orphan.ld: Likewise.
	* testsuite/ld-elf/overlay.t: Likewise.
	* testsuite/ld-elf/pr14052.t: Likewise.
	* testsuite/ld-elf/pr19539.t: Likewise.
	* testsuite/ld-elf/provide-hidden-1.ld: Likewise.
	* testsuite/ld-elf/provide-hidden-s.ld: Likewise.
	* testsuite/ld-elf/weak-dyn-1.ld: Likewise.
	* testsuite/ld-i386/pr19539.t: Likewise.
	* testsuite/ld-scripts/defined.t: Likewise.
	* testsuite/ld-scripts/defined6.t: Likewise.
	* testsuite/ld-scripts/dynamic-sections.t: Likewise.
	* testsuite/ld-scripts/empty-aligned.t: Likewise.
	* testsuite/ld-scripts/provide-2.t: Likewise.
	* testsuite/ld-scripts/provide-4.t: Likewise.
	* testsuite/ld-vax-elf/plt-local.ld: Likewise.
	* testsuite/ld-x86-64/pr19539.t: Likewise.
	* testsuite/ld-elf/ehdr_start-missing.d: Do not initialise the
	dynamic linker.
	* testsuite/ld-elf/ehdr_start-weak.d: Likewise.
	* testsuite/ld-elf/elf.exp (pr14170, pr17068): Likewise.
	* testsuite/ld-elf/loadaddr1.d: Update expected readelf output.
	* testsuite/ld-elf/noload-2.d: Likewise.
	* testsuite/ld-powerpc/vxworks2.sd: Likewise.
	* testsuite/ld-scripts/phdrs3a.d: Likewise.
	* testsuite/ld-scripts/size-2.d: Likewise.
	* testsuite/ld-elf/group.ld: Add program headers.
	* testsuite/ld-elf/overlay.d: Skip for SPU.
	* testsuite/ld-elf/flags1.d: Skip for RX.
	* testsuite/ld-elf/pr19162.d: Skip for HPPA64.
	* testsuite/ld-elf/pr19539.d: Skip for ALPHA.
	* testsuite/ld-scripts/empty-orphan.t: Update program headers.
	* testsuite/ld-scripts/size-2.t: Likewise.

2 files changed, 41 insertions, 6 deletions

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index 0f3d167..f625a26 100644
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,9 @@
+2016-11-23  Nick Clifton  <nickc@redhat.com>
+
+	PR ld/20815
+	* readelf.c (process_program_headers): Check PT_LOAD and PT_PHDR
+	segments for validity.
+
 2016-11-22  Ambrogino Modigliani  <ambrogino.modigliani@gmail.com>
 
         * configure: Regenerate.
diff --git a/binutils/readelf.c b/binutils/readelf.c
index e782e95..ee55852 100644
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -3797,7 +3797,7 @@ get_segment_type (unsigned long p_type)
 	  if (result != NULL)
 	    return result;
 
-	  sprintf (buff, "LOPROC+%lx", p_type - PT_LOPROC);
+	  sprintf (buff, "LOPROC+%#lx", p_type - PT_LOPROC);
 	}
       else if ((p_type >= PT_LOOS) && (p_type <= PT_HIOS))
 	{
@@ -3822,7 +3822,7 @@ get_segment_type (unsigned long p_type)
 	  if (result != NULL)
 	    return result;
 
-	  sprintf (buff, "LOOS+%lx", p_type - PT_LOOS);
+	  sprintf (buff, "LOOS+%#lx", p_type - PT_LOOS);
 	}
       else
 	snprintf (buff, sizeof (buff), _("<unknown>: %lx"), p_type);
@@ -4770,6 +4770,7 @@ process_program_headers (FILE * file)
 {
   Elf_Internal_Phdr * segment;
   unsigned int i;
+  Elf_Internal_Phdr * previous_load = NULL;
 
   if (elf_header.e_phnum == 0)
     {
@@ -4901,13 +4902,39 @@ process_program_headers (FILE * file)
 		      (segment->p_flags & PF_X ? 'E' : ' '));
 	      print_vma (segment->p_align, HEX);
 	    }
-	}
 
-      if (do_segments)
-	putc ('\n', stdout);
+	  putc ('\n', stdout);
+	}
 
       switch (segment->p_type)
 	{
+	case PT_LOAD:
+	  if (previous_load
+	      && previous_load->p_vaddr > segment->p_vaddr)
+	    error (_("LOAD segments must be sorted in order of increasing VirtAddr\n"));
+	  if (segment->p_memsz < segment->p_filesz)
+	    error (_("the segment's file size is larger than its memory size\n"));
+	  previous_load = segment;
+	  break;
+
+	case PT_PHDR:
+	  /* PR 20815 - Verify that the program header is loaded into memory.  */
+	  if (i > 0 && previous_load != NULL)
+	    error (_("the PHDR segment must occur before any LOAD segment\n"));
+	  if (elf_header.e_machine != EM_PARISC)
+	    {
+	      unsigned int j;
+
+	      for (j = 1; j < elf_header.e_phnum; j++)
+		if (program_headers[j].p_vaddr <= segment->p_vaddr
+		    && (program_headers[j].p_vaddr + program_headers[j].p_memsz)
+		    >= (segment->p_vaddr + segment->p_filesz))
+		  break;
+	      if (j == elf_header.e_phnum)
+		error (_("the PHDR segment is not covered by a LOAD segment\n"));
+	    }
+	  break;
+
 	case PT_DYNAMIC:
 	  if (dynamic_addr)
 	    error (_("more than one dynamic segment\n"));
@@ -6068,7 +6095,9 @@ process_section_headers (FILE * file)
 	  if (section->sh_type == SHT_NOBITS)
 	    /* NOBITS section headers with non-zero sh_info fields can be
 	       created when a binary is stripped of everything but its debug
-	       information.  The stripped sections have their headers preserved but their types set to SHT_NOBITS.  so do not check this type of section.  */
+	       information.  The stripped sections have their headers
+	       preserved but their types set to SHT_NOBITS.  So do not check
+	       this type of section.  */
 	    ;
 	  else if (section->sh_flags & SHF_INFO_LINK)
 	    {