From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Denis Kenzior , Johannes Berg , Sasha Levin Subject: [PATCH 4.17 142/324] mac80211: disable BHs/preemption in ieee80211_tx_control_port() Date: Thu, 23 Aug 2018 09:53:28 +0200 Message-Id: <20180823075003.047550058@linuxfoundation.org> In-Reply-To: <20180823074955.885811006@linuxfoundation.org> References: <20180823074955.885811006@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Denis Kenzior [ Upstream commit e7441c9274a6a5453e06f4c2b8b5f72eca0a3f17 ] On pre-emption enabled kernels the following print was being seen due to missing local_bh_disable/local_bh_enable calls. mac80211 assumes that pre-emption is disabled in the data path. BUG: using smp_processor_id() in preemptible [00000000] code: iwd/517 caller is __ieee80211_subif_start_xmit+0x144/0x210 [mac80211] [...] Call Trace: dump_stack+0x5c/0x80 check_preemption_disabled.cold.0+0x46/0x51 __ieee80211_subif_start_xmit+0x144/0x210 [mac80211] Fixes: 911806491425 ("mac80211: Add support for tx_control_port") Signed-off-by: Denis Kenzior [commit message rewrite, fixes tag] Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/mac80211/tx.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -4800,7 +4800,9 @@ int ieee80211_tx_control_port(struct wip skb_reset_network_header(skb); skb_reset_mac_header(skb); + local_bh_disable(); __ieee80211_subif_start_xmit(skb, skb->dev, flags); + local_bh_enable(); return 0; }