chardev/char-mux.c | 3 ++- stubs/qmp-quit.c | 8 ++++++++ stubs/meson.build | 1 + 3 files changed, 11 insertions(+), 1 deletion(-) create mode 100644 stubs/qmp-quit.c
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 qmp_quit() instead which takes care of some housekeeping before
triggering the shutdown.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reported-by: Lukas Jünger <lukas.junger@greensocs.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20211018140226.838137-1-alex.bennee@linaro.org>
---
v2
- use qmp_quit instead of direct qemu_system_shutdown_request
- g_assert_not_reached() for the stub definition
---
chardev/char-mux.c | 3 ++-
stubs/qmp-quit.c | 8 ++++++++
stubs/meson.build | 1 +
3 files changed, 11 insertions(+), 1 deletion(-)
create mode 100644 stubs/qmp-quit.c
diff --git a/chardev/char-mux.c b/chardev/char-mux.c
index ada0c6866f..ee2d47b20d 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 "qapi/qapi-commands-control.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);
+ qmp_quit(NULL);
break;
}
case 's':
diff --git a/stubs/qmp-quit.c b/stubs/qmp-quit.c
new file mode 100644
index 0000000000..a3ff47f7bd
--- /dev/null
+++ b/stubs/qmp-quit.c
@@ -0,0 +1,8 @@
+#include "qemu/osdep.h"
+#include "qapi/qapi-commands-control.h"
+#include "qapi/qmp/dispatch.h"
+
+void qmp_quit(Error **errp)
+{
+ g_assert_not_reached();
+}
diff --git a/stubs/meson.build b/stubs/meson.build
index f6aa3aa94f..71469c1d50 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -31,6 +31,7 @@ stub_ss.add(files('pci-bus.c'))
stub_ss.add(files('qemu-timer-notify-cb.c'))
stub_ss.add(files('qmp_memory_device.c'))
stub_ss.add(files('qmp-command-available.c'))
+stub_ss.add(files('qmp-quit.c'))
stub_ss.add(files('qtest.c'))
stub_ss.add(files('ram-block.c'))
stub_ss.add(files('ramfb.c'))
--
2.30.2
On 19/10/21 11:29, Alex Bennée wrote: > 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 qmp_quit() instead which takes care of some housekeeping before > triggering the shutdown. > > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > Reported-by: Lukas Jünger <lukas.junger@greensocs.com> > Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> > Message-Id: <20211018140226.838137-1-alex.bennee@linaro.org> > > --- > v2 > - use qmp_quit instead of direct qemu_system_shutdown_request > - g_assert_not_reached() for the stub definition Either g_assert_not_reached() or exit(0) should be okay, so Acked-by: Paolo Bonzini <pbonzini@redhat.com> Thanks, Paolo > --- > chardev/char-mux.c | 3 ++- > stubs/qmp-quit.c | 8 ++++++++ > stubs/meson.build | 1 + > 3 files changed, 11 insertions(+), 1 deletion(-) > create mode 100644 stubs/qmp-quit.c > > diff --git a/chardev/char-mux.c b/chardev/char-mux.c > index ada0c6866f..ee2d47b20d 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 "qapi/qapi-commands-control.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); > + qmp_quit(NULL); > break; > } > case 's': > diff --git a/stubs/qmp-quit.c b/stubs/qmp-quit.c > new file mode 100644 > index 0000000000..a3ff47f7bd > --- /dev/null > +++ b/stubs/qmp-quit.c > @@ -0,0 +1,8 @@ > +#include "qemu/osdep.h" > +#include "qapi/qapi-commands-control.h" > +#include "qapi/qmp/dispatch.h" > + > +void qmp_quit(Error **errp) > +{ > + g_assert_not_reached(); > +} > diff --git a/stubs/meson.build b/stubs/meson.build > index f6aa3aa94f..71469c1d50 100644 > --- a/stubs/meson.build > +++ b/stubs/meson.build > @@ -31,6 +31,7 @@ stub_ss.add(files('pci-bus.c')) > stub_ss.add(files('qemu-timer-notify-cb.c')) > stub_ss.add(files('qmp_memory_device.c')) > stub_ss.add(files('qmp-command-available.c')) > +stub_ss.add(files('qmp-quit.c')) > stub_ss.add(files('qtest.c')) > stub_ss.add(files('ram-block.c')) > stub_ss.add(files('ramfb.c')) >
On 10/19/21 11:29, Alex Bennée wrote: > 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 qmp_quit() instead which takes care of some housekeeping before > triggering the shutdown. > > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > Reported-by: Lukas Jünger <lukas.junger@greensocs.com> > Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> > Message-Id: <20211018140226.838137-1-alex.bennee@linaro.org> > > --- > v2 > - use qmp_quit instead of direct qemu_system_shutdown_request > - g_assert_not_reached() for the stub definition > --- > chardev/char-mux.c | 3 ++- > stubs/qmp-quit.c | 8 ++++++++ > stubs/meson.build | 1 + > 3 files changed, 11 insertions(+), 1 deletion(-) > create mode 100644 stubs/qmp-quit.c Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
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