1 files changed, 43 insertions, 0 deletions
diff --git a/usr/src/cmd/mdb/common/modules/genunix/refstr.c b/usr/src/cmd/mdb/common/modules/genunix/refstr.c
new file mode 100644
index 0000000000..5b5fcec14c
--- /dev/null
+++ b/usr/src/cmd/mdb/common/modules/genunix/refstr.c
@@ -0,0 +1,43 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright 2019 Joyent, Inc.
+ */
+
+#include <mdb/mdb_modapi.h>
+#include <mdb/mdb_ks.h>
+#include <sys/refstr.h>
+
+#define	REFSTR_LEN (1024)
+
+int
+cmd_refstr(uintptr_t addr, uint_t flags __unused,
+    int argc, const mdb_arg_t *argv)
+{
+	if (!(flags & DCMD_ADDRSPEC)) {
+		mdb_warn("address is required\n");
+		return (DCMD_ERR);
+	}
+
+	if (mdb_getopts(argc, argv, NULL) != argc)
+		return (DCMD_USAGE);
+
+	char *buf = mdb_alloc(REFSTR_LEN, UM_SLEEP | UM_GC);
+
+	if (mdb_read_refstr(addr, buf, REFSTR_LEN) < 0) {
+		mdb_warn("couldn't read refstr from %p", addr);
+		return (DCMD_ERR);
+	}
+
+	mdb_printf("%s\n", buf);
+	return (DCMD_OK);
+}