On Wed, Mar 25, 2020 at 06:35:22PM +0100, Jessica Yu wrote: > +++ Peter Zijlstra [24/03/20 14:56 +0100]: > > Now that notifiers got unbroken; use the proper interface to handle > > notifier errors and propagate them. > > > > There were already MODULE_STATE_COMING notifiers that failed; notably: > > > > - jump_label_module_notifier() > > - tracepoint_module_notify() > > - bpf_event_notify() > > > > By propagating this error, we fix those users. > > > > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > > Cc: jeyu@xxxxxxxxxx > > --- > > kernel/module.c | 10 +++++++--- > > 1 file changed, 7 insertions(+), 3 deletions(-) > > > > --- a/kernel/module.c > > +++ b/kernel/module.c > > @@ -3751,9 +3751,13 @@ static int prepare_coming_module(struct > > if (err) > > return err; > > > > - blocking_notifier_call_chain(&module_notify_list, > > - MODULE_STATE_COMING, mod); > > - return 0; > > + err = blocking_notifier_call_chain_robust(&module_notify_list, > > + MODULE_STATE_COMING, MODULE_STATE_GOING, mod); > > + err = notifier_to_errno(err); > > + if (err) > > + klp_module_going(mod); > > + > > + return err; > > } > > > > static int unknown_module_param_cb(char *param, char *val, const char *modname, > > > > This looks fine to me - klp_module_going() is only called after > successful klp_module_coming(), and klp_module_going() is fine with > mod->state still being MODULE_STATE_COMING here. Would be good to have > livepatch folks double check. Which reminds me - Miroslav had pointed > out in the past that if there is an error when calling the COMING > notifiers, the GOING notifiers will be called while the mod->state is > still MODULE_STATE_COMING. I've briefly looked through all the module > notifiers and it looks like nobody is looking at mod->state directly > at least. > > Acked-by: Jessica Yu <jeyu@xxxxxxxxxx> Looks good to me. klp_module_going() is already called in other load_module() error scenarios so this should be fine from a livepatch standpoint. Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> -- Josh
