S/390: Add support for pgste marker

This patch adds a new S/390 specific segment type: PT_S390_PGSTE.  For
binaries marked with that segment the kernel will allocate 4k page
tables.  The only user so far will be qemu.

ld/ChangeLog:

2017-06-23  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* Makefile.in: Add s390.em as build dependency.
	* emulparams/elf64_s390.sh (EXTRA_EM_FILE): Add s390.em.
	* emultempl/s390.em: New file.
	* gen-doc.texi: Add documentation for --s390-pgste option.
	* ld.texinfo: Likewise.

include/ChangeLog:

2017-06-23  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* elf/s390.h (PT_S390_PGSTE): Define macro.

binutils/ChangeLog:

2017-06-23  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* readelf.c (get_s390_segment_type): Add support for the new
	segment type PT_S390_PGSTE.
	(get_segment_type): Call get_s390_segment_type.

elfcpp/ChangeLog:

2017-06-23  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* elfcpp.h (enum PT): Add PT_S390_PGSTE to enum.

bfd/ChangeLog:

2017-06-23  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* elf-s390.h: New file.
	* elf64-s390.c (struct elf_s390_link_hash_table): Add params
	field.
	(elf_s390_additional_program_headers): New function.
	(elf_s390_modify_segment_map): New function.
	(bfd_elf_s390_set_options): New function.
	(elf_backend_additional_program_headers)
	(elf_backend_modify_segment_map): Add macro definitions.

5 files changed, 98 insertions, 0 deletions

diff --git a/ld/Makefile.in b/ld/Makefile.in
index 5e66e02..ba25177 100644
--- a/ld/Makefile.in
+++ b/ld/Makefile.in
@@ -3502,6 +3502,7 @@ eelf64_ia64_vms.c: $(srcdir)/emulparams/elf64_ia64_vms.sh \
   $(srcdir)/scripttempl/ia64vms.sc ${GEN_DEPENDS}
 
 eelf64_s390.c: $(srcdir)/emulparams/elf64_s390.sh \
+  $(srcdir)/emultempl/s390.em \
   $(ELF_DEPS) $(srcdir)/scripttempl/elf.sc ${GEN_DEPENDS}
 
 eelf64_sparc.c: $(srcdir)/emulparams/elf64_sparc.sh \
diff --git a/ld/emulparams/elf64_s390.sh b/ld/emulparams/elf64_s390.sh
index fc9f06a..5309774 100644
--- a/ld/emulparams/elf64_s390.sh
+++ b/ld/emulparams/elf64_s390.sh
@@ -12,6 +12,7 @@ TEMPLATE_NAME=elf32
 GENERATE_SHLIB_SCRIPT=yes
 GENERATE_PIE_SCRIPT=yes
 NO_SMALL_DATA=yes
+EXTRA_EM_FILE=s390
 IREL_IN_PLT=
 
 # Treat a host that matches the target with the possible exception of "x"
diff --git a/ld/emultempl/s390.em b/ld/emultempl/s390.em
new file mode 100644
index 0000000..536104e
--- /dev/null
+++ b/ld/emultempl/s390.em
@@ -0,0 +1,64 @@
+# This shell script emits a C file. -*- C -*-
+# Copyright (C) 2017 Free Software Foundation, Inc.
+#
+# This file is part of the GNU Binutils.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the license, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; see the file COPYING3. If not,
+# see <http://www.gnu.org/licenses/>.
+#
+
+# This file is sourced from elf-generic.em, and defines S/390
+# specific routines.
+#
+fragment <<EOF
+
+#include "ldctor.h"
+#include "elf-s390.h"
+
+static struct s390_elf_params params = { 0 };
+
+/* This is a convenient point to tell BFD about target specific flags.
+   After the output has been created, but before inputs are read.  */
+static void
+s390_elf_create_output_section_statements (void)
+{
+  if (!bfd_elf_s390_set_options (&link_info, &params))
+    einfo ("%F%P: can not init BFD: %E\n");
+}
+
+EOF
+
+# Define some shell vars to insert bits of code into the standard elf
+# parse_args and list_options functions.
+#
+PARSE_AND_LIST_PROLOGUE='
+#define OPTION_PGSTE	301
+'
+
+PARSE_AND_LIST_LONGOPTS='
+  { "s390-pgste", no_argument, NULL, OPTION_PGSTE},
+'
+
+PARSE_AND_LIST_OPTIONS='
+  fprintf (file, _("  --s390-pgste                Tell the kernel to "
+		   "allocate 4k page tables\n"));
+'
+
+PARSE_AND_LIST_ARGS_CASES='
+    case OPTION_PGSTE:
+      params.pgste = 1;
+      break;
+'
+
+LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=s390_elf_create_output_section_statements
diff --git a/ld/gen-doc.texi b/ld/gen-doc.texi
index 27b8198..6b31a6b 100644
--- a/ld/gen-doc.texi
+++ b/ld/gen-doc.texi
@@ -21,6 +21,7 @@
 @set POWERPC
 @set POWERPC64
 @set Renesas
+@set S/390
 @set SPU
 @set TICOFF
 @set WIN32
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index 77b5d3e..bb5f719 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -34,6 +34,7 @@
 @set POWERPC
 @set POWERPC64
 @set Renesas
+@set S/390
 @set SPU
 @set TICOFF
 @set WIN32
@@ -158,6 +159,9 @@ in the section entitled ``GNU Free Documentation License''.
 @ifset POWERPC64
 * PowerPC64 ELF64::             ld and PowerPC64 64-bit ELF Support
 @end ifset
+@ifset S/390
+* S/390 ELF::			ld and S/390 ELF Support
+@end ifset
 @ifset SPU
 * SPU ELF::			ld and SPU ELF Support
 @end ifset
@@ -6565,6 +6569,9 @@ functionality are not listed.
 @ifset POWERPC64
 * PowerPC64 ELF64::		@command{ld} and PowerPC64 64-bit ELF Support
 @end ifset
+@ifset S/390
+* S/390 ELF::			@command{ld} and S/390 ELF Support
+@end ifset
 @ifset SPU
 * SPU ELF::			@command{ld} and SPU ELF Support
 @end ifset
@@ -7600,6 +7607,30 @@ default behaviour.
 @end ifclear
 @end ifset
 
+@ifset S/390
+@ifclear GENERIC
+@raisesections
+@end ifclear
+
+@node S/390 ELF
+@section @command{ld} and S/390 ELF Support
+
+@cindex S/390 ELF options
+@table @option
+
+@cindex S/390
+@kindex --s390-pgste
+@item --s390-pgste
+This option marks the result file with a @code{PT_S390_PGSTE}
+segment.  The Linux kernel is supposed to allocate 4k page tables for
+binaries marked that way.
+@end table
+
+@ifclear GENERIC
+@lowersections
+@end ifclear
+@end ifset
+
 @ifset SPU
 @ifclear GENERIC
 @raisesections