[AArch64] Reject invalid immediate operands to MSR PAN

The support for accessing the ARMv8.1 PSTATE field PAN allows
instructions of the form MSR PAN, #<imm> with <imm> any unsigned 4-bit
integer. However, the architecture specification requires that the
immediate is either 0 or 1.

This patch implements the constraint on the immediate, generating an
error if the immediate operand is invalid, and adds tests for the
illegal forms.

opcodes/
2015-11-19  Matthew Wahab  <matthew.wahab@arm.com>

	* aarch64-opc.c (operand_general_constraint_met_p): Check validity
	of MSR PAN immediate operand.

gas/testsuite/
2015-11-19  Matthew Wahab  <matthew.wahab@arm.com>

	* gas/aarch64/pan-illegal.d: New.
	* gas/aarch64/pan-illegal.l: New.
	* gas/aarch64/pan.s: Add tests for invalid immediates.

Change-Id: Ibb3056c975eb792104da138d94594224f56a993e

6 files changed, 43 insertions, 0 deletions

diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog
index 51a622e..3d2b948 100644
--- a/gas/testsuite/ChangeLog
+++ b/gas/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2015-11-19  Matthew Wahab  <matthew.wahab@arm.com>
+
+	* gas/aarch64/pan-illegal.d: New.
+	* gas/aarch64/pan-illegal.l: New.
+	* gas/aarch64/pan.s: Add tests for invalid immediates.
+
 2015-11-19  Alan Modra  <amodra@gmail.com>
 
 	* gas/ppc/altivec3.d: Allow for padding at end of section.
diff --git a/gas/testsuite/gas/aarch64/pan-illegal.d b/gas/testsuite/gas/aarch64/pan-illegal.d
new file mode 100644
index 0000000..372b9d7
--- /dev/null
+++ b/gas/testsuite/gas/aarch64/pan-illegal.d
@@ -0,0 +1,3 @@
+#as: -march=armv8.1-a --defsym ERROR=1
+#source: pan.s
+#error-output: pan-illegal.l
diff --git a/gas/testsuite/gas/aarch64/pan-illegal.l b/gas/testsuite/gas/aarch64/pan-illegal.l
new file mode 100644
index 0000000..f620ab0
--- /dev/null
+++ b/gas/testsuite/gas/aarch64/pan-illegal.l
@@ -0,0 +1,15 @@
+[^:]*: Assembler messages:
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#2'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#3'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#4'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#5'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#6'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#7'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#8'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#9'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#10'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#11'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#12'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#13'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#14'
+[^:]*:[0-9]+: Error: immediate value out of range 0 to 1 at operand 1 -- `msr pan,#15'
diff --git a/gas/testsuite/gas/aarch64/pan.s b/gas/testsuite/gas/aarch64/pan.s
index 059046c..4144e2b 100644
--- a/gas/testsuite/gas/aarch64/pan.s
+++ b/gas/testsuite/gas/aarch64/pan.s
@@ -31,4 +31,10 @@
 	msr pan, x0
 	mrs x1, pan
 
+	.ifdef ERROR
+	.irp N,2,3,4,5,6,7,8,9,10,11,12,13,14,15
+	msr pan, #\N
+	.endr
+	.endif
+
 	.arch_extension nopan
diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index edec363..5333c48 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,8 @@
+2015-11-19  Matthew Wahab  <matthew.wahab@arm.com>
+
+	* aarch64-opc.c (operand_general_constraint_met_p): Check validity
+	of MSR PAN immediate operand.
+
 2015-11-16  Nick Clifton  <nickc@redhat.com>
 
 	* rx-dis.c (condition_names): Replace always and never with
diff --git a/opcodes/aarch64-opc.c b/opcodes/aarch64-opc.c
index c6ab4b2..50dbd36 100644
--- a/opcodes/aarch64-opc.c
+++ b/opcodes/aarch64-opc.c
@@ -1862,6 +1862,14 @@ operand_general_constraint_met_p (const aarch64_opnd_info *opnds, int idx,
 	{
 	case AARCH64_OPND_PSTATEFIELD:
 	  assert (idx == 0 && opnds[1].type == AARCH64_OPND_UIMM4);
+	  /* MSR PAN, #uimm4
+	     The immediate must be #0 or #1.  */
+	  if (opnd->pstatefield == 0x04 /* PAN.  */
+	      && opnds[1].imm.value > 1)
+	    {
+	      set_imm_out_of_range_error (mismatch_detail, idx, 0, 1);
+	      return 0;
+	    }
 	  /* MSR SPSel, #uimm4
 	     Uses uimm4 as a control value to select the stack pointer: if
 	     bit 0 is set it selects the current exception level's stack