On 04/02/2017 04:21, Ashijeet Acharya wrote:
> Commit a3a3d8c7 introduced a segfault bug while checking for
> 'dc->vmsd->unmigratable' which caused QEMU to crash when trying to add
> devices which do no set their 'dc->vmsd' yet while initialization.
> Place a 'dc->vmsd' check prior to it so that we do not segfault for
> such devices.
>
> NOTE: This doesn't compromise the functioning of --only-migratable
> option as all the unmigratable devices do set their 'dc->vmsd'.
>
> Also, move the only_migratable check inside device_set_realized() to avoid
> code duplication and fix the bug to display only_migratable error message
> only if the device constructuon is right.
>
> Signed-off-by: Ashijeet Acharya <ashijeetacha...@gmail.com>
> ---
> Changes is v3:
> - move only_migratable check inside device_set_realized() to avoid code
> - duplication
> - I have dropped Juan's R-b tag for this one
> Changes in v2:
> - place dc->vmsd check in hw/usb/bus.c as well
> ---
> hw/core/qdev.c | 10 ++++++++++
> hw/usb/bus.c | 19 -------------------
> qdev-monitor.c | 9 ---------
> 3 files changed, 10 insertions(+), 28 deletions(-)
>
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index 5783442..4438cbf 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -37,6 +37,7 @@
> #include "hw/boards.h"
> #include "hw/sysbus.h"
> #include "qapi-event.h"
> +#include "migration/migration.h"
>
> int qdev_hotplug = 0;
> static bool qdev_hot_added = false;
> @@ -896,6 +897,15 @@ static void device_set_realized(Object *obj, bool value,
> Error **errp)
> }
>
> if (value && !dev->realized) {
> + if (only_migratable && dc->vmsd) {
> + if (dc->vmsd->unmigratable) {
> + error_setg(&local_err, "Device %s is not migratable, but "
> + "--only-migratable was specified",
> + object_get_typename(obj));
> + goto fail;
> + }
> + }
> +
> if (!obj->parent) {
> gchar *name = g_strdup_printf("device[%d]", unattached_count++);
>
> diff --git a/hw/usb/bus.c b/hw/usb/bus.c
> index 1dcc35c..25913ad 100644
> --- a/hw/usb/bus.c
> +++ b/hw/usb/bus.c
> @@ -8,7 +8,6 @@
> #include "monitor/monitor.h"
> #include "trace.h"
> #include "qemu/cutils.h"
> -#include "migration/migration.h"
>
> static void usb_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
>
> @@ -687,8 +686,6 @@ USBDevice *usbdevice_create(const char *cmdline)
> const char *params;
> int len;
> USBDevice *dev;
> - ObjectClass *klass;
> - DeviceClass *dc;
>
> params = strchr(cmdline,':');
> if (params) {
> @@ -723,22 +720,6 @@ USBDevice *usbdevice_create(const char *cmdline)
> return NULL;
> }
>
> - klass = object_class_by_name(f->name);
> - if (klass == NULL) {
> - error_report("Device '%s' not found", f->name);
> - return NULL;
> - }
> -
> - dc = DEVICE_CLASS(klass);
> -
> - if (only_migratable) {
> - if (dc->vmsd->unmigratable) {
> - error_report("Device %s is not migratable, but --only-migratable
> "
> - "was specified", f->name);
> - return NULL;
> - }
> - }
> -
> if (f->usbdevice_init) {
> dev = f->usbdevice_init(bus, params);
> } else {
> diff --git a/qdev-monitor.c b/qdev-monitor.c
> index 549f45f..5f2fcdf 100644
> --- a/qdev-monitor.c
> +++ b/qdev-monitor.c
> @@ -29,7 +29,6 @@
> #include "qemu/error-report.h"
> #include "qemu/help_option.h"
> #include "sysemu/block-backend.h"
> -#include "migration/migration.h"
>
> /*
> * Aliases were a bad idea from the start. Let's keep them
> @@ -579,14 +578,6 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error
> **errp)
> return NULL;
> }
>
> - if (only_migratable) {
> - if (dc->vmsd->unmigratable) {
> - error_setg(errp, "Device %s is not migratable, but "
> - "--only-migratable was specified", driver);
> - return NULL;
> - }
> - }
> -
> /* find bus */
> path = qemu_opt_get(opts, "bus");
> if (path != NULL) {
>
Reviewed-bv: Paolo Bonzini <pbonz...@redhat.com>
