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.

1 files changed, 1 insertions, 0 deletions

diff --git a/ld/testsuite/ld-discard/discard.ld b/ld/testsuite/ld-discard/discard.ld
index a7ff4a5..64f3350 100644
--- a/ld/testsuite/ld-discard/discard.ld
+++ b/ld/testsuite/ld-discard/discard.ld
@@ -1,6 +1,7 @@
 ENTRY(_start)
 SECTIONS
 {
+  . = SIZEOF_HEADERS;
   /* Sections to be discarded */
   /DISCARD/ : {
 	*(.data.exit)