From db2424c58e5962a87888d25d29ceb0873eef6348 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 10 May 2013 19:07:52 +0200 Subject: [PATCH] regulatory: use RCU in regulatory_hint_11d() Since it just does a quick check of the last regulatory request, the function doesn't have to hold the reg mutex but can use RCU instead. Signed-off-by: Johannes Berg --- net/wireless/reg.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) diff --git a/net/wireless/reg.c b/net/wireless/reg.c index e7655961858..17e5eccb42c 100644 --- a/net/wireless/reg.c +++ b/net/wireless/reg.c @@ -1715,20 +1715,18 @@ void regulatory_hint_11d(struct wiphy *wiphy, enum ieee80211_band band, { char alpha2[2]; enum environment_cap env = ENVIRON_ANY; - struct regulatory_request *request, *lr; - - mutex_lock(®_mutex); - lr = get_last_request(); - - if (unlikely(!lr)) - goto out; + struct regulatory_request *request = NULL, *lr; /* IE len must be evenly divisible by 2 */ if (country_ie_len & 0x01) - goto out; + return; if (country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN) - goto out; + return; + + request = kzalloc(sizeof(*request), GFP_KERNEL); + if (!request) + return; alpha2[0] = country_ie[0]; alpha2[1] = country_ie[1]; @@ -1738,6 +1736,12 @@ void regulatory_hint_11d(struct wiphy *wiphy, enum ieee80211_band band, else if (country_ie[2] == 'O') env = ENVIRON_OUTDOOR; + rcu_read_lock(); + lr = get_last_request(); + + if (unlikely(!lr)) + goto out; + /* * We will run this only upon a successful connection on cfg80211. * We leave conflict resolution to the workqueue, where can hold @@ -1747,10 +1751,6 @@ void regulatory_hint_11d(struct wiphy *wiphy, enum ieee80211_band band, lr->wiphy_idx != WIPHY_IDX_INVALID) goto out; - request = kzalloc(sizeof(struct regulatory_request), GFP_KERNEL); - if (!request) - goto out; - request->wiphy_idx = get_wiphy_idx(wiphy); request->alpha2[0] = alpha2[0]; request->alpha2[1] = alpha2[1]; @@ -1758,8 +1758,10 @@ void regulatory_hint_11d(struct wiphy *wiphy, enum ieee80211_band band, request->country_ie_env = env; queue_regulatory_request(request); + request = NULL; out: - mutex_unlock(®_mutex); + kfree(request); + rcu_read_unlock(); } static void restore_alpha2(char *alpha2, bool reset_user) -- 2.43.2