Make qemu_shutdown_requested signal-safe
qemu_shutdown_requested may be interrupted by qemu_system_killed. If the
latter sets shutdown_requested after qemu_shutdown_requested has read it
but before it was cleared, the shutdown event is lost. Fix this by using
atomic_xchg.
This provides a different fix for the problem which commit 15124e142
attempts to deal with. That commit breaks use of ^C to drop into gdb,
and so this approach is better (and 15124e142 can be reverted).
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
[PMM: commit message tweak]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/vl.c b/vl.c
index 2f81384..f6b3546 100644
--- a/vl.c
+++ b/vl.c
@@ -1609,9 +1609,7 @@
static int qemu_shutdown_requested(void)
{
- int r = shutdown_requested;
- shutdown_requested = 0;
- return r;
+ return atomic_xchg(&shutdown_requested, 0);
}
static void qemu_kill_report(void)
