On Thu, Feb 29, 2024 at 12:37:21AM +0800, 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 xen_console_connect() passes @errp to error_prepend() without > ERRP_GUARD(). > > There're 2 places will call xen_console_connect(): > - xen_console_realize(): the @errp is from DeviceClass.realize()'s > parameter. > - xen_console_frontend_changed(): the @errp points its caller's > @local_err. > > To avoid the issue like [1] said, add missing ERRP_GUARD() at the > beginning of xen_console_connect(). > > [1]: Issue description in the commit message of commit ae7c80a7bd73 > ("error: New macro ERRP_GUARD()"). > > Cc: Stefano Stabellini <[email protected]> > Cc: Anthony Perard <[email protected]> > Cc: Paul Durrant <[email protected]> > Cc: "Marc-André Lureau" <[email protected]> > Cc: Paolo Bonzini <[email protected]> > Signed-off-by: Zhao Liu <[email protected]>
Acked-by: Anthony PERARD <[email protected]> Thanks, -- Anthony PERARD
