Add support for mod() and sym()

Also add a new test, since existing tests do not yet work.  (They depend
on indexed aggregations.)  Further, the sym() tests are very weak.

Signed-off-by: Eugene Loh <eugene.loh@oracle.com>
Reviewed-by: Kris Van Hees <kris.van.hees@oracle.com>

libdtrace/dt_cg.c

@@ -1415,6 +1415,10 @@ dt_cg_act_stop(dt_pcb_t *pcb, dt_node_t *dnp, dtrace_actkind_t kind)
 static void
 dt_cg_act_symmod(dt_pcb_t *pcb, dt_node_t *dnp, dtrace_actkind_t kind)
 {
+	dt_node_t	*arg = dnp->dn_args;
+
+	assert(arg != NULL);
+	dt_cg_store_val(pcb, arg, kind, NULL, 0);
 }
 
 static void

libdtrace/dt_consume.c

@@ -2084,6 +2084,14 @@ dt_consume_one(dtrace_hdl_t *dtp, FILE *fp, char *buf,
 					return -1;
 				continue;
 			}
+			case DTRACEACT_SYM:
+				if (dt_print_sym(dtp, fp, NULL, recdata) < 0)
+					return -1;
+				continue;
+			case DTRACEACT_MOD:
+				if (dt_print_mod(dtp, fp, NULL, recdata) < 0)
+					return -1;
+				continue;
 			case DTRACEACT_PRINTF:
 				func = dtrace_fprintf;
 				break;

test/unittest/actions/symmod/tst.symmod.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+#
+# Oracle Linux DTrace.
+# Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+# Licensed under the Universal Permissive License v 1.0 as shown at
+# http://oss.oracle.com/licenses/upl.
+#
+
+dtrace=$1
+
+# pick a test symbol from /proc/kallmodsyms
+read ADD NAM MOD <<< `awk '/ksys_write/ {print $1, $4, $5}' /proc/kallmodsyms`
+
+# a blank module means the module is vmlinux
+if [ x$MOD == x ]; then
+	MOD=vmlinux
+fi
+
+# add the module to the name
+NAM=$MOD'`'$NAM
+
+# run DTrace to test mod() and sym()
+read MYMOD MYNAM <<< `$dtrace -qn 'BEGIN {mod(0x'$ADD'); sym(0x'$ADD'); exit(0) }'`
+if [ $? -ne 0 ]; then
+	exit 1
+fi
+
+# reporting
+echo test $ADD $MOD   $NAM
+echo expect    $MOD   $NAM
+echo actual  $MYMOD $MYNAM
+
+if [ $MOD != $MYMOD ]; then
+	echo fail: $MOD does not match $MYMOD
+	exit 1
+fi
+if [ $NAM != $MYNAM ]; then
+	echo fail: $NAM does not match $MYNAM
+	exit 1
+fi
+
+exit 0