From 55e241079c05ca6798450f82b5d9a95718f84cbd Mon Sep 17 00:00:00 2001
From: cem <cem@FreeBSD.org>
Date: Mon, 19 Aug 2019 22:58:30 +0000
Subject: [PATCH] gdb(4): Support "qC" query

Sometimes GDB gets confused about what the current thread is.  When it does,
it asks the remote: "Who am I?"

Answer it.
---
 sys/gdb/gdb_main.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/sys/gdb/gdb_main.c b/sys/gdb/gdb_main.c
index aabbf983ba25..20d9fcc3bc97 100644
--- a/sys/gdb/gdb_main.c
+++ b/sys/gdb/gdb_main.c
@@ -305,7 +305,13 @@ gdb_trap(int type, int code)
 			break;
 		}
 		case 'q':	/* General query. */
-			if (gdb_rx_equal("fThreadInfo")) {
+			if (gdb_rx_equal("C")) {
+				gdb_tx_begin('Q');
+				gdb_tx_char('C');
+				gdb_tx_varhex((long)kdb_thread->td_tid);
+				gdb_tx_end();
+				break;
+			} else if (gdb_rx_equal("fThreadInfo")) {
 				thr_iter = kdb_thr_first();
 				gdb_do_threadinfo(&thr_iter);
 			} else if (gdb_rx_equal("sThreadInfo")) {