| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.17 142/324] mac80211: disable BHs/preemption in ieee80211_tx_control_port() | Date | Thu, 23 Aug 2018 09:53:28 +0200 |
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4.17-stable review patch. If anyone has any objections, please let me know.
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From: Denis Kenzior <denkenz@gmail.com>
[ 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 <denkenz@gmail.com> [commit message rewrite, fixes tag] Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- 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; }
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