On Mon, Feb 16, 2009 at 12:49 AM, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > On Mon, 2009-02-16 at 00:13 -0800, Luis R. Rodriguez wrote: > >> >> + if (!cfg80211_regdomain) >> >> + return -EINPROGRESS; >> >> + >> > >> > But that variable access here is racy too. >> >> Right. >> >> > It might be ok anyway because >> > the variable can never be NULL again after the first assignment >> >> That's what I was going for. >> >> > but in >> > that case the assignment needs to take care to assign something fully >> > created ... >> >> Can you elaborate on what you mean? > > It'd have to be done in a RCU-like fashion, I see what you're saying. > unless we only ever use it > as a bool here? Its only used as a bool here, mind you __regulatory_hint() does do mucking with cfg80211 but my patches move the hint to a workqueue so that locking is now done later through the workqueue so under this new patch series -- yes cfg80211_regdomain will only be used as a bool. But come to think of it this is still racy -- think of the cases where reset_regdomains() is called and the small race between the end of of those calls and another CPU getting a new user reg hint. So we should just lock. Luis -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
