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From: Calvin Owens <jcalvinowens@gmail.com>
To: johannes@sipsolutions.com
Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
	jcalvinowens@gmail.com
Subject: [PATCH] mac80211: Fix bogus RCU warning from ieee80211_get_tx_rates (Was: Re: rcu)
Date: Sun, 9 Jun 2013 23:29:59 -0500	[thread overview]
Message-ID: <20130610042959.GA1902@gmail.com> (raw)
In-Reply-To: <20130609225120.GA2789@gmail.com>

rate_control_fill_sta_table(), whose sole caller is ieee80211_get_tx_rates(),
is guaranteed by mac80211 not to be called concurrently with
rate_control_set_rates() [1], the sole function that touches the rate table
pointer/data in struct ieee80211_sta. The RCU dereference is therefore safe.

[1]: See commit f6b3d85f7f6d6

Signed-off-by: Calvin Owens <jcalvinowens@gmail.com>
---
 net/mac80211/rate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index d3f414f..585297d 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -539,7 +539,7 @@ static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 	int i;
 
 	if (sta && !info->control.skip_table)
-		ratetbl = rcu_dereference(sta->rates);
+		ratetbl = rcu_dereference_protected(sta->rates, true);
 
 	/* Fill remaining rate slots with data from the sta rate table. */
 	max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
-- 
1.8.2.1


  reply	other threads:[~2013-06-10  4:30 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-09 22:51 rcu Calvin Owens
2013-06-10  4:29 ` Calvin Owens [this message]
2013-06-11 11:42   ` [PATCH] mac80211: Fix bogus RCU warning from ieee80211_get_tx_rates (Was: Re: rcu) Johannes Berg
2013-06-11 17:13     ` [PATCH] mac80211: ath9k: Use RCU protection calling ieee80211_get_tx_rates Calvin Owens
2013-06-11 19:55       ` Johannes Berg
2013-06-12  6:37         ` Kalle Valo
2013-06-12  7:56         ` Calvin Owens
2013-06-12  8:00           ` [PATCH] mac80211: Use RCU protection in ieee80211_get_tx_rates() Calvin Owens
2013-06-12  9:47             ` Felix Fietkau
2013-06-13 15:27               ` Calvin Owens

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