[RFC PATCH] chardev: don't exit() straight away on C-a x

[Alex Bennée]

While there are a number of uses in the code-base of the exit(0)
pattern it gets in the way of clean exit which can do all of it's
house-keeping. In particular it was reported that you can crash
plugins this way because TCG can still be running on other threads
when the atexit callback is called.

Use qemu_system_shutdown_request() instead. I did a gentle rename of
the runstate stub seeing as it now contains two functions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reported-by: Lukas Jünger <lukas.junger@greensocs.com>
---
 chardev/char-mux.c                     | 3 ++-
 stubs/{runstate-check.c => runstate.c} | 5 +++++
 stubs/meson.build                      | 2 +-
 3 files changed, 8 insertions(+), 2 deletions(-)
 rename stubs/{runstate-check.c => runstate.c} (64%)

diff --git a/chardev/char-mux.c b/chardev/char-mux.c
index ada0c6866f..a46897fcd5 100644
--- a/chardev/char-mux.c
+++ b/chardev/char-mux.c
@@ -28,6 +28,7 @@
 #include "qemu/option.h"
 #include "chardev/char.h"
 #include "sysemu/block-backend.h"
+#include "sysemu/runstate.h"
 #include "chardev-internal.h"
 
 /* MUX driver for serial I/O splitting */
@@ -157,7 +158,7 @@ static int mux_proc_byte(Chardev *chr, MuxChardev *d, int 
ch)
             {
                  const char *term =  "QEMU: Terminated\n\r";
                  qemu_chr_write_all(chr, (uint8_t *)term, strlen(term));
-                 exit(0);
+                 qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
                  break;
             }
         case 's':
diff --git a/stubs/runstate-check.c b/stubs/runstate.c
similarity index 64%
rename from stubs/runstate-check.c
rename to stubs/runstate.c
index 2ccda2b70f..f47dbcd3e0 100644
--- a/stubs/runstate-check.c
+++ b/stubs/runstate.c
@@ -5,3 +5,8 @@ bool runstate_check(RunState state)
 {
     return state == RUN_STATE_PRELAUNCH;
 }
+
+void qemu_system_shutdown_request(ShutdownCause reason)
+{
+    return;
+}
diff --git a/stubs/meson.build b/stubs/meson.build
index f6aa3aa94f..8f6a9f17e5 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -35,7 +35,7 @@ stub_ss.add(files('qtest.c'))
 stub_ss.add(files('ram-block.c'))
 stub_ss.add(files('ramfb.c'))
 stub_ss.add(files('replay.c'))
-stub_ss.add(files('runstate-check.c'))
+stub_ss.add(files('runstate.c'))
 stub_ss.add(files('sysbus.c'))
 stub_ss.add(files('target-get-monitor-def.c'))
 stub_ss.add(files('target-monitor-defs.c'))
-- 
2.30.2