x86: Add a GNU_PROPERTY_X86_ISA_1_USED note if needed

When -z separate-code, which is enabled by default for Linux/x86, is
used to create executable, ld won't place any data in the code-only
PT_LOAD segment.  If there are no data sections placed before the
code-only PT_LOAD segment, the program headers won't be mapped into
any PT_LOAD segment.  When the executable tries to access it (based
on the program header address passed in AT_PHDR), it will lead to
segfault.  This patch inserts a GNU_PROPERTY_X86_ISA_1_USED note if
there may be no data sections before the text section so that the
first PT_LOAD segment won't be code-only and will contain the program
header.

Testcases are adjusted to either pass "-z noseparate-code" to ld or
discard the .note.gnu.property section.  A Linux/x86 run-time test is
added.

bfd/

	PR ld/23428
	* elfxx-x86.c (_bfd_x86_elf_link_setup_gnu_properties): If the
	separate code program header is needed, make sure that the first
	read-only PT_LOAD segment has no code by adding a
	GNU_PROPERTY_X86_ISA_1_USED note.

ld/

	PR ld/23428
	* testsuite/ld-elf/linux-x86.S: New file.
	* testsuite/ld-elf/linux-x86.exp: Likewise.
	* testsuite/ld-elf/pr23428.c: Likewise.
	* testsuite/ld-elf/sec64k.exp: Pass "-z noseparate-code" to ld
	for Linux/x86 targets.
	* testsuite/ld-i386/abs-iamcu.d: Likewise.
	* testsuite/ld-i386/abs.d: Likewise.
	* testsuite/ld-i386/pr12718.d: Likewise.
	* testsuite/ld-i386/pr12921.d: Likewise.
	* testsuite/ld-x86-64/abs-k1om.d: Likewise.
	* testsuite/ld-x86-64/abs-l1om.d: Likewise.
	* testsuite/ld-x86-64/abs.d: Likewise.
	* testsuite/ld-x86-64/pr12718.d: Likewise.
	* testsuite/ld-x86-64/pr12921.d: Likewise.
	* testsuite/ld-linkonce/zeroeh.ld: Discard .note.gnu.property
	section.
	* testsuite/ld-scripts/print-memory-usage.t: Likewise.
	* testsuite/ld-scripts/size-2.t: Likewise.
	* testsuite/lib/ld-lib.exp (run_ld_link_exec_tests): Use ld
	to create executable if language is "asm".

1 files changed, 46 insertions, 0 deletions

diff --git a/ld/testsuite/ld-elf/linux-x86.exp b/ld/testsuite/ld-elf/linux-x86.exp
new file mode 100644
index 0000000000..36217c6fb4
--- /dev/null
+++ b/ld/testsuite/ld-elf/linux-x86.exp
@@ -0,0 +1,46 @@
+# Expect script for simple native Linux/x86 tests.
+#   Copyright (C) 2018 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; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+# MA 02110-1301, USA.
+#
+
+# Test very simple native Linux/x86 programs with linux-x86.S.
+if { ![isnative] || [which $CC] == 0 \
+     || (![istarget "i?86-*-linux*"] \
+         && ![istarget "x86_64-*-linux*"] \
+         && ![istarget "amd64-*-linux*"]) } {
+    return
+}
+
+# Add $PLT_CFLAGS if PLT is expected.
+global PLT_CFLAGS
+# Add $NOPIE_CFLAGS and $NOPIE_LDFLAGS if non-PIE is required.
+global NOPIE_CFLAGS NOPIE_LDFLAGS
+
+run_ld_link_exec_tests [list \
+    [list \
+	"Run PR ld/23428 test" \
+	"--no-dynamic-linker -z separate-code" \
+	"" \
+	{ linux-x86.S pr23428.c } \
+	"pr23428" \
+	"pass.out" \
+	"$NOPIE_CFLAGS -fno-asynchronous-unwind-tables" \
+	"asm" \
+    ] \
+]