[PATCH v2 3/3] gdbstub: replace exit(0) with proper shutdown

[Clément Chigot]

This replaces the exit(0) call by a shutdown request, ensuring a proper
cleanup of Qemu. Otherwise, some connections could be broken without
being correctly flushed.

Signed-off-by: Clément Chigot <chigot@adacore.com>
---
 gdbstub/gdbstub.c |  3 +--
 gdbstub/softmmu.c | 13 +++++++++++++
 gdbstub/user.c    |  2 ++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 5f28d5cf57..358eed1935 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -1298,7 +1298,6 @@ static void handle_v_kill(GArray *params, void *user_ctx)
     gdb_put_packet("OK");
     error_report("QEMU: Terminated via GDBstub");
     gdb_exit(0);
-    exit(0);
 }
 
 static const GdbCmdParseEntry gdb_v_commands_table[] = {
@@ -1818,7 +1817,7 @@ static int gdb_handle_packet(const char *line_buf)
         /* Kill the target */
         error_report("QEMU: Terminated via GDBstub");
         gdb_exit(0);
-        exit(0);
+        break;
     case 'D':
         {
             static const GdbCmdParseEntry detach_cmd_desc = {
diff --git a/gdbstub/softmmu.c b/gdbstub/softmmu.c
index f509b7285d..fa9b09537d 100644
--- a/gdbstub/softmmu.c
+++ b/gdbstub/softmmu.c
@@ -434,6 +434,19 @@ void gdb_exit(int code)
     }
 
     qemu_chr_fe_deinit(&gdbserver_system_state.chr, true);
+
+    /*
+     * Shutdown request is a clean way to stop the QEMU, compared
+     * to a direct call to exit(). But we can't pass the exit code
+     * through it so avoid doing that when it can matter.
+     * As this function is also called during the cleanup process,
+     * avoid sending the request if one is already set.
+     */
+    if (code) {
+        exit(code);
+    } else if (!qemu_shutdown_requested_get()) {
+        qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
+    }
 }
 
 /*
diff --git a/gdbstub/user.c b/gdbstub/user.c
index 5b375be1d9..f3d97d621f 100644
--- a/gdbstub/user.c
+++ b/gdbstub/user.c
@@ -113,6 +113,8 @@ void gdb_exit(int code)
         gdb_put_packet(buf);
         gdbserver_state.allow_stop_reply = false;
     }
+
+    exit(code);
 }
 
 int gdb_handlesig(CPUState *cpu, int sig)
-- 
2.25.1