Messages in this thread | | | Date | Wed, 19 Jun 2019 14:01:31 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC][PATCH] module: Propagate MODULE_STATE_COMING notifier errors |
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On Wed, Jun 19, 2019 at 01:35:08PM +0200, Peter Zijlstra wrote: > On Wed, Jun 19, 2019 at 01:33:24PM +0200, Peter Zijlstra wrote: > > How's something like so: > > > > diff --git a/kernel/module.c b/kernel/module.c > > index 80c7c09584cf..eba6560c89da 100644 > > --- a/kernel/module.c > > +++ b/kernel/module.c > > @@ -3631,16 +3631,28 @@ static int complete_formation(struct module *mod, struct load_info *info) > > > > static int prepare_coming_module(struct module *mod) > > { > > - int err; > > + struct blocking_notifier_head *nh = &module_notify_list; > > + int err, nr; > > > > ftrace_module_enable(mod); > > err = klp_module_coming(mod); > > if (err) > > return err; > > > > - blocking_notifier_call_chain(&module_notify_list, > > - MODULE_STATE_COMING, mod); > > - return 0; > > + if (!rcu_access_pointer(nh->head)) > > + return 0; > > + > > + down_read(&nh->rwsem); > > + ret = notifier_call_chain(&nh->head, MODULE_STATE_COMING, mod, -1, &nr); > > + if (ret & NOTIFIER_STOP_MASK) > > It compiles _lots_ better with s/ret/err/ on. > > > + notifier_call_chain(&nh->head, MODULE_STATE_GOING, mod, nr, NULL); > > + up_read(&nh->rwsem); > > + > > + err = notifier_to_err(err); > > + if (err) > > + klp_module_going(mod); > > + > > + return err; > > } > > > > static int unknown_module_param_cb(char *param, char *val, const char *modname,
Rafael, how is kernel/power/user.c snapshot_open() not broken (any any other __pm_notifier_call_chain() user)?
afaict the __pm_notifier_call_chain() thing is broken in two ways:
- there can be a change to the notifier list between the PREPARE and POST iteration
- the error value isn't put through notifier_to_errno().
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