gdbstub: Send a reply to the vKill packet.

Per the GDB remote protocol documentation

https://sourceware.org/gdb/current/onlinedocs/gdb/Packets.html#index-vKill-packet

the debug stub is expected to send a reply to the 'vKill' packet.  At
least some versions of GDB crash if the gdb stub simply exits without
sending a reply.  This patch fixes QEMU's gdb stub to conform to the
expected behavior.

Note that QEMU's existing handling of the legacy 'k' packet is
correct: in that case GDB does not expect a reply, and QEMU does not
send one.

Signed-off-by: Sandra Loosemore <sandra@codesourcery.com>
Message-id: 1550008033-26540-1-git-send-email-sandra@codesourcery.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/gdbstub.c b/gdbstub.c
index ff19579..bc774ae 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -1361,6 +1361,7 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
             break;
         } else if (strncmp(p, "Kill;", 5) == 0) {
             /* Kill the target */
+            put_packet(s, "OK");
             error_report("QEMU: Terminated via GDBstub");
             exit(0);
         } else {