POWER10: Add Return-Oriented Programming instructions

POWER10 adds some return-oriented programming (ROP) instructions and
this patch adds support for them.  You will notice that they are enabled
for POWER8 and later, not just POWER10 and later.  This is on purpose.
This allows the instructions to be added to POWER8 binaries that can be
run on POWER8, POWER9 and POWER10 cpus.  On POWER8 and POWER9, these
instructions just act as nop's.

opcodes/
	* ppc-opc.c (insert_dw, (extract_dw): New functions.
	(DW, (XRC_MASK): Define.
	(powerpc_opcodes) <hashchk, hashchkp, hashst, haststp>: New mnemonics.
gas/
	* testsuite/gas/ppc/rop-checks.d,
	* testsuite/gas/ppc/rop-checks.l,
	* testsuite/gas/ppc/rop-checks.s,
	* testsuite/gas/ppc/rop.d,
	* testsuite/gas/ppc/rop.s: New tests.
	* testsuite/gas/ppc/ppc.exp: Run them.

7 files changed, 97 insertions, 0 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index a2cdeda..cb38110 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,12 @@
+2021-01-08  Peter Bergner  <bergner@linux.ibm.com>
+
+	* testsuite/gas/ppc/rop-checks.d,
+	* testsuite/gas/ppc/rop-checks.l,
+	* testsuite/gas/ppc/rop-checks.s,
+	* testsuite/gas/ppc/rop.d,
+	* testsuite/gas/ppc/rop.s: New tests.
+	* testsuite/gas/ppc/ppc.exp: Run them.
+
 2021-01-09  Alan Modra  <amodra@gmail.com>
 
 	* configure: Regenerate.
diff --git a/gas/testsuite/gas/ppc/ppc.exp b/gas/testsuite/gas/ppc/ppc.exp
index bec3151..6f61ad0 100644
--- a/gas/testsuite/gas/ppc/ppc.exp
+++ b/gas/testsuite/gas/ppc/ppc.exp
@@ -146,5 +146,7 @@ run_dump_test "stringop"
 run_dump_test "xvtlsbb"
 run_dump_test "rightmost"
 run_dump_test "scalarquad"
+run_dump_test "rop"
+run_dump_test "rop-checks"
 
 run_dump_test "dcbt"
diff --git a/gas/testsuite/gas/ppc/rop-checks.d b/gas/testsuite/gas/ppc/rop-checks.d
new file mode 100644
index 0000000..b7ef25e
--- /dev/null
+++ b/gas/testsuite/gas/ppc/rop-checks.d
@@ -0,0 +1,3 @@
+#as: -mpower10
+#name: Test Return-Oriented Programming checks
+#error_output: rop-checks.l
diff --git a/gas/testsuite/gas/ppc/rop-checks.l b/gas/testsuite/gas/ppc/rop-checks.l
new file mode 100644
index 0000000..83ffbee
--- /dev/null
+++ b/gas/testsuite/gas/ppc/rop-checks.l
@@ -0,0 +1,17 @@
+[^:]*: Assembler messages:
+[^:]*:3: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:4: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:5: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:6: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:7: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:8: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:9: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:10: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:11: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:12: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:13: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:14: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:15: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:16: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:17: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
+[^:]*:18: Error: invalid offset: must be in the range \[-512, -8\] and be a multiple of 8
diff --git a/gas/testsuite/gas/ppc/rop-checks.s b/gas/testsuite/gas/ppc/rop-checks.s
new file mode 100644
index 0000000..83ca35a
--- /dev/null
+++ b/gas/testsuite/gas/ppc/rop-checks.s
@@ -0,0 +1,18 @@
+	.text
+_start:
+	hashst   20,8(1)
+	hashst   21,0(1)
+	hashst   22,-12(1)
+	hashst   23,-520(1)
+	hashchk  20,8(1)
+	hashchk  21,0(1)
+	hashchk  22,-12(1)
+	hashchk  23,-520(1)
+	hashstp  20,8(1)
+	hashstp  21,0(1)
+	hashstp  22,-12(1)
+	hashstp  23,-520(1)
+	hashchkp 20,8(1)
+	hashchkp 21,0(1)
+	hashchkp 22,-12(1)
+	hashchkp 23,-520(1)
diff --git a/gas/testsuite/gas/ppc/rop.d b/gas/testsuite/gas/ppc/rop.d
new file mode 100644
index 0000000..2671dd6
--- /dev/null
+++ b/gas/testsuite/gas/ppc/rop.d
@@ -0,0 +1,27 @@
+#as: -mpower8
+#objdump: -d -Mpower8
+#name: Return-Oriented Programming tests
+
+.*
+
+
+Disassembly of section \.text:
+
+0+0 <_start>:
+.*:	(7f e1 a5 a5|a5 a5 e1 7f) 	hashst  r20,-8\(r1\)
+.*:	(7f c1 ad a5|a5 ad c1 7f) 	hashst  r21,-16\(r1\)
+.*:	(7c 01 b5 a5|a5 b5 01 7c) 	hashst  r22,-256\(r1\)
+.*:	(7c 01 bd a4|a4 bd 01 7c) 	hashst  r23,-512\(r1\)
+.*:	(7f e1 a5 e5|e5 a5 e1 7f) 	hashchk r20,-8\(r1\)
+.*:	(7f c1 ad e5|e5 ad c1 7f) 	hashchk r21,-16\(r1\)
+.*:	(7c 01 b5 e5|e5 b5 01 7c) 	hashchk r22,-256\(r1\)
+.*:	(7c 01 bd e4|e4 bd 01 7c) 	hashchk r23,-512\(r1\)
+.*:	(7f e1 a5 25|25 a5 e1 7f) 	hashstp r20,-8\(r1\)
+.*:	(7f c1 ad 25|25 ad c1 7f) 	hashstp r21,-16\(r1\)
+.*:	(7c 01 b5 25|25 b5 01 7c) 	hashstp r22,-256\(r1\)
+.*:	(7c 01 bd 24|24 bd 01 7c) 	hashstp r23,-512\(r1\)
+.*:	(7f e1 a5 65|65 a5 e1 7f) 	hashchkp r20,-8\(r1\)
+.*:	(7f c1 ad 65|65 ad c1 7f) 	hashchkp r21,-16\(r1\)
+.*:	(7c 01 b5 65|65 b5 01 7c) 	hashchkp r22,-256\(r1\)
+.*:	(7c 01 bd 64|64 bd 01 7c) 	hashchkp r23,-512\(r1\)
+#pass
diff --git a/gas/testsuite/gas/ppc/rop.s b/gas/testsuite/gas/ppc/rop.s
new file mode 100644
index 0000000..22e45f4
--- /dev/null
+++ b/gas/testsuite/gas/ppc/rop.s
@@ -0,0 +1,21 @@
+# These instructions are new in POWER10, but enabled for POWER8 and
+# later cpus.  On POWER8 and POWER9, these instructions behave as
+# nop's.
+	.text
+_start:
+	hashst   20,-8(1)
+	hashst   21,-16(1)
+	hashst   22,-256(1)
+	hashst   23,-512(1)
+	hashchk  20,-8(1)
+	hashchk  21,-16(1)
+	hashchk  22,-256(1)
+	hashchk  23,-512(1)
+	hashstp  20,-8(1)
+	hashstp  21,-16(1)
+	hashstp  22,-256(1)
+	hashstp  23,-512(1)
+	hashchkp 20,-8(1)
+	hashchkp 21,-16(1)
+	hashchkp 22,-256(1)
+	hashchkp 23,-512(1)