Zhao Liu <[email protected]> writes: > 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 migrate_params_check() passes @errp to error_prepend() without > ERRP_GUARD(), and it could be called from migration_object_init(), > where the passed @errp points to @error_fatal. > > Therefore, the error message echoed in error_prepend() will be lost > because of the above issue. > > To fix this, 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: Peter Xu <[email protected]> > Cc: Fabiano Rosas <[email protected]> > Signed-off-by: Zhao Liu <[email protected]>
Reviewed-by: Fabiano Rosas <[email protected]>
