On 29/02/2024 15.39, Zhao Liu wrote:
From: Zhao Liu <[email protected]>As the comment in qapi/error, passing @errp to error_prepend() requires ERRP_GUARD(): * = Why, when and how to use ERRP_GUARD() = * * Without ERRP_GUARD(), use of the @errp parameter is restricted: ... * - It should not be passed to error_prepend(), error_vprepend() or * error_append_hint(), because that doesn't work with &error_fatal. * ERRP_GUARD() lifts these restrictions. * * To use ERRP_GUARD(), add it right at the beginning of the function. * @errp can then be used without worrying about the argument being * NULL or &error_fatal. ERRP_GUARD() could avoid the case when @errp is the pointer of error_fatal, the user can't see this additional information, because exit() happens in error_setg earlier than information is added [1]. The vfio_ap_realize() passes @errp to error_prepend(), and as a DeviceClass.realize method, its @errp is so widely sourced that it is necessary to protect it with ERRP_GUARD(). To avoid the issue like [1] said, add missing ERRP_GUARD() at the beginning of this function. [1]: Issue description in the commit message of commit ae7c80a7bd73 ("error: New macro ERRP_GUARD()"). Cc: Alex Williamson <[email protected]> Cc: "Cédric Le Goater" <[email protected]> Cc: Thomas Huth <[email protected]> Cc: Tony Krowiak <[email protected]> Cc: Halil Pasic <[email protected]> Cc: Jason Herne <[email protected]> Signed-off-by: Zhao Liu <[email protected]> --- hw/vfio/ap.c | 1 + 1 file changed, 1 insertion(+) diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c index e157aa1ff79c..7c4caa593863 100644 --- a/hw/vfio/ap.c +++ b/hw/vfio/ap.c @@ -155,6 +155,7 @@ static void vfio_ap_unregister_irq_notifier(VFIOAPDevice *vapdev,static void vfio_ap_realize(DeviceState *dev, Error **errp){ + ERRP_GUARD(); int ret; Error *err = NULL;
Now this function looks like we need both, ERRP_GUARD and the local "err" variable? ... patch looks ok to me, but maybe Markus has an idea how this could be done in a nicer way?
Thomas
