[DTrace-devel] [PATCH 05/22] Set the ERROR PRID in BPF code

[eugene.loh at oracle.com]

From: Eugene Loh <eugene.loh at oracle.com>

We use the fact that the ERROR PRID is always 3.

Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
---
 bpf/probe_error.c                         |  3 +++
 test/unittest/builtinvar/tst.id_ERROR.d   | 32 +++++++++++++++++++++++
 test/unittest/builtinvar/tst.id_ERROR.r   |  3 +++
 test/unittest/builtinvar/tst.id_ERROR.r.p |  4 +++
 4 files changed, 42 insertions(+)
 create mode 100644 test/unittest/builtinvar/tst.id_ERROR.d
 create mode 100644 test/unittest/builtinvar/tst.id_ERROR.r
 create mode 100755 test/unittest/builtinvar/tst.id_ERROR.r.p

diff --git a/bpf/probe_error.c b/bpf/probe_error.c
index c8ddcdfa..ee1a1793 100644
--- a/bpf/probe_error.c
+++ b/bpf/probe_error.c
@@ -26,6 +26,7 @@ noinline void dt_probe_error(const dt_dctx_t *dctx, uint64_t pc, uint64_t fault,
 			     uint64_t illval)
 {
 	dt_mstate_t	*mst = dctx->mst;
+	int		oldprid = mst->prid;
 
 	mst->argv[0] = 0;
 	mst->argv[1] = mst->epid;
@@ -34,7 +35,9 @@ noinline void dt_probe_error(const dt_dctx_t *dctx, uint64_t pc, uint64_t fault,
 	mst->argv[4] = fault;
 	mst->argv[5] = illval;
 
+	mst->prid = 3;
 	dt_error(dctx);
+	mst->prid = oldprid;
 
 	mst->fault = fault;
 }
diff --git a/test/unittest/builtinvar/tst.id_ERROR.d b/test/unittest/builtinvar/tst.id_ERROR.d
new file mode 100644
index 00000000..59021c60
--- /dev/null
+++ b/test/unittest/builtinvar/tst.id_ERROR.d
@@ -0,0 +1,32 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2024, 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.
+ */
+
+/*
+ * ASSERTION:
+ * The id in the ERROR probe is 3.
+ *
+ * SECTION: Variables/Built-in Variables
+ */
+
+#pragma D option quiet
+
+tick-1s
+{
+	/* trigger the ERROR probe */
+	trace(*((int*)0));
+}
+
+tick-2s
+{
+	exit(1);
+}
+
+ERROR
+{
+	printf("id of the ERROR probe = %d\n", id);
+	exit(0);
+}
diff --git a/test/unittest/builtinvar/tst.id_ERROR.r b/test/unittest/builtinvar/tst.id_ERROR.r
new file mode 100644
index 00000000..95974abe
--- /dev/null
+++ b/test/unittest/builtinvar/tst.id_ERROR.r
@@ -0,0 +1,3 @@
+id of the ERROR probe = 3
+
+-- @@stderr --
diff --git a/test/unittest/builtinvar/tst.id_ERROR.r.p b/test/unittest/builtinvar/tst.id_ERROR.r.p
new file mode 100755
index 00000000..884b43f4
--- /dev/null
+++ b/test/unittest/builtinvar/tst.id_ERROR.r.p
@@ -0,0 +1,4 @@
+#!/usr/bin/gawk -f
+
+# Drop the line with run-dependent PRID for profile probe.
+!/error on enabled probe ID/ { print }
-- 
2.43.5