ld: add support for eBPF

This patch adds support to the linker for the Linux eBPF architecture.
A minimal testsuite is included.

ld/ChangeLog:

2019-05-23  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* Makefile.am (ALL_64_EMULATION_SOURCES): Add eelf64bpf.c.
	* Makefile.in (prefix): Regenerate.
	* configure.tgt (targ_extra_ofiles): Add case for bpf-*-* targets.
	* emulparams/elf64bpf.sh: New file.
	* testsuite/lib/ld-lib.exp (check_gc_sections_available): Add
	bpf-*-* to the list of targets not supporting gc-sections.
	* testsuite/ld-bpf/bar.s: New file.
	* testsuite/ld-bpf/jump-1.d: Likewise.
	* testsuite/ld-bpf/foo.s: Likewise.
	* testsuite/ld-bpf/call-1.d: Likewise.
	* testsuite/ld-bpf/bpf.exp: Likewise.
	* testsuite/ld-bpf/baz.s: Likewise.

7 files changed, 91 insertions, 0 deletions

diff --git a/ld/testsuite/ld-bpf/bar.s b/ld/testsuite/ld-bpf/bar.s
new file mode 100644
index 0000000..b577d87
--- /dev/null
+++ b/ld/testsuite/ld-bpf/bar.s
@@ -0,0 +1,5 @@
+        .global bar
+bar:
+        mov	%r1,%r2
+        mov	%r3,%r1
+        exit
diff --git a/ld/testsuite/ld-bpf/baz.s b/ld/testsuite/ld-bpf/baz.s
new file mode 100644
index 0000000..2e159a8
--- /dev/null
+++ b/ld/testsuite/ld-bpf/baz.s
@@ -0,0 +1,5 @@
+        mov %r1,1
+        mov %r2,2
+        mov %r3,3
+        ja bar
+        exit
diff --git a/ld/testsuite/ld-bpf/bpf.exp b/ld/testsuite/ld-bpf/bpf.exp
new file mode 100644
index 0000000..02b2e03
--- /dev/null
+++ b/ld/testsuite/ld-bpf/bpf.exp
@@ -0,0 +1,29 @@
+# Copyright (C) 2019 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.
+#
+
+if { ![istarget bpf*-*-*] } {
+    return
+}
+
+set bpf_test_list [lsort [glob -nocomplain $srcdir/$subdir/*.d]]
+foreach bpf_test $bpf_test_list {
+    verbose [file rootname $bpf_test]
+    run_dump_test [file rootname $bpf_test]
+}
diff --git a/ld/testsuite/ld-bpf/call-1.d b/ld/testsuite/ld-bpf/call-1.d
new file mode 100644
index 0000000..f408cd4
--- /dev/null
+++ b/ld/testsuite/ld-bpf/call-1.d
@@ -0,0 +1,23 @@
+#as: --EL
+#source: foo.s
+#source: bar.s
+#objdump: -dr
+#ld: -EL
+#warning: .*cannot find entry symbol _start.*
+#name: CALL with disp32 reloc
+
+.*: +file format .*bpf.*
+
+Disassembly of section .text:
+
+[0-9a-f]+ <.*>:
+ *[0-9a-f]+:	b7 01 00 00 01 00 00 00 	mov %r1,1
+ *[0-9a-f]+:	b7 02 00 00 02 00 00 00 	mov %r2,2
+ *[0-9a-f]+:	b7 03 00 00 03 00 00 00 	mov %r3,3
+ *[0-9a-f]+:	85 10 00 00 01 00 00 00 	call 1
+ *[0-9a-f]+:	95 00 00 00 00 00 00 00 	exit
+
+[0-9a-f]+ <bar>:
+ *[0-9a-f]+:	bf 21 00 00 00 00 00 00 	mov %r1,%r2
+ *[0-9a-f]+:	bf 13 00 00 00 00 00 00 	mov %r3,%r1
+ *[0-9a-f]+:	95 00 00 00 00 00 00 00 	exit
diff --git a/ld/testsuite/ld-bpf/foo.s b/ld/testsuite/ld-bpf/foo.s
new file mode 100644
index 0000000..0958bbf
--- /dev/null
+++ b/ld/testsuite/ld-bpf/foo.s
@@ -0,0 +1,5 @@
+        mov %r1,1
+        mov %r2,2
+        mov %r3,3
+        call bar
+        exit
diff --git a/ld/testsuite/ld-bpf/jump-1.d b/ld/testsuite/ld-bpf/jump-1.d
new file mode 100644
index 0000000..b57bcf1
--- /dev/null
+++ b/ld/testsuite/ld-bpf/jump-1.d
@@ -0,0 +1,23 @@
+#as: --EL
+#source: baz.s
+#source: bar.s
+#objdump: -dr
+#ld: -EL
+#warning: .*cannot find entry symbol _start.*
+#name: jump with disp16 reloc
+
+.*: +file format .*bpf.*
+
+Disassembly of section .text:
+
+[0-9a-f]+ <.*>:
+ *[0-9a-f]+:	b7 01 00 00 01 00 00 00 	mov %r1,1
+ *[0-9a-f]+:	b7 02 00 00 02 00 00 00 	mov %r2,2
+ *[0-9a-f]+:	b7 03 00 00 03 00 00 00 	mov %r3,3
+ *[0-9a-f]+:	05 00 01 00 00 00 00 00 	ja 1
+ *[0-9a-f]+:	95 00 00 00 00 00 00 00 	exit
+
+[0-9a-f]+ <bar>:
+ *[0-9a-f]+:	bf 21 00 00 00 00 00 00 	mov %r1,%r2
+ *[0-9a-f]+:	bf 13 00 00 00 00 00 00 	mov %r3,%r1
+ *[0-9a-f]+:	95 00 00 00 00 00 00 00 	exit
diff --git a/ld/testsuite/lib/ld-lib.exp b/ld/testsuite/lib/ld-lib.exp
index 0ff51c9..5ebb7fa 100644
--- a/ld/testsuite/lib/ld-lib.exp
+++ b/ld/testsuite/lib/ld-lib.exp
@@ -1045,6 +1045,7 @@ proc check_gc_sections_available { } {
 	# Some targets don't support gc-sections despite whatever's
 	# advertised by ld's options.
 	if {   [istarget alpha-*-*]
+            || [istarget bpf-*-*]
 	    || [istarget d30v-*-*]
 	    || [istarget dlx-*-*]
 	    || [istarget hppa*64-*-*]