[PATCH v5 3/9] test: add systemwide stapsdt note test

[Alan Maguire <alan.maguire@oracle.com>]

Add test verifying that systemwide stapsdt probe firing
is detected and we retrieve arguments correctly.

We launch multiple instances of the program:

- one before DTrace starts
- one with -c
- two via system() when DTrace is already running

We ensure that we see 4 sets of firings for 4 different
probes to ensure we catch previously-running programs
and programs run after DTrace starts.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
---
 .../usdt/tst.stapsdt-notes-systemwide.r       |  5 ++
 .../usdt/tst.stapsdt-notes-systemwide.sh      | 89 +++++++++++++++++++
 2 files changed, 94 insertions(+)
 create mode 100644 test/unittest/usdt/tst.stapsdt-notes-systemwide.r
 create mode 100755 test/unittest/usdt/tst.stapsdt-notes-systemwide.sh

diff --git a/test/unittest/usdt/tst.stapsdt-notes-systemwide.r b/test/unittest/usdt/tst.stapsdt-notes-systemwide.r
new file mode 100644
index 00000000..679d835c
--- /dev/null
+++ b/test/unittest/usdt/tst.stapsdt-notes-systemwide.r
@@ -0,0 +1,5 @@
+test:args:2:./test:val:18
+test:args:2:./test:val:18
+test:args:2:./test:val:18
+test:args:2:./test:val:18
+
diff --git a/test/unittest/usdt/tst.stapsdt-notes-systemwide.sh b/test/unittest/usdt/tst.stapsdt-notes-systemwide.sh
new file mode 100755
index 00000000..5d5c6f09
--- /dev/null
+++ b/test/unittest/usdt/tst.stapsdt-notes-systemwide.sh
@@ -0,0 +1,89 @@
+#!/bin/bash
+#
+# Oracle Linux DTrace.
+# Copyright (c) 2026, 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.
+
+# This test covers stapsdt probes fired by the STAP_PROBEn macros,
+# testing various argument forms (constant, register, deref etc).
+
+if [ $# != 1 ]; then
+	echo expected one argument: '<'dtrace-path'>'
+	exit 2
+fi
+
+dtrace=$1
+CC=/usr/bin/gcc
+CFLAGS="-I${PWD}/test/unittest/usdt"
+
+DIRNAME="$tmpdir/usdt-notes.$$.$RANDOM"
+mkdir -p $DIRNAME
+cd $DIRNAME
+
+cat > test.c <<EOF
+#include <unistd.h>
+#include <sdt_notes.h>
+
+int
+main(int argc, char **argv)
+{
+	int i;
+
+	for (i = 0; i < 20; i++) {
+		STAP_PROBE4(test_prov, args, argc, argv[0], argv[1] + 4, 18);
+		sleep(1);
+	}
+	return 0;
+}
+EOF
+
+${CC} ${CFLAGS} -o test test.c
+if [ $? -ne 0 ]; then
+	echo "failed to compile test.c" >& 2
+	exit 1
+fi
+export PATH=.:$PATH
+
+# Launch one program before DTrace starts
+
+./test arg1val &
+
+sleep 1
+
+# Launch another with dtrace -c
+$dtrace -w -c './test arg1val' -qs /dev/stdin <<EOF
+
+BEGIN
+{
+	pids = 0;
+	afters = 0;
+}
+
+test_prov*:test::args
+/ !done[pid] /
+{
+	printf("%s:%s:%li:%s:%s:%li\n", probemod, probename,
+	       arg0, copyinstr(arg1), copyinstr(arg2), arg3);
+	done[pid] = 1;  
+	pids++;
+}
+
+/* And launch two more with system() */
+profile:::tick-1s
+/ afters < 2 /
+{
+	system("./test arg1val &");
+	afters++;
+}
+
+profile:::tick-1s
+/ pids == 4 && afters == 2 /
+{
+	exit(0);
+}
+
+EOF
+status=$?
+
+exit $status
-- 
2.43.5