From: Arend Van Spriel Date: Tue, 23 May 2017 08:58:07 +0000 (+0100) Subject: cfg80211: make cfg80211_sched_scan_results() work from atomic context X-Git-Tag: MMI-PSA29.97-13-9~5530^2~17^2 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1b57b6210f4e52904393be97c62122aae69bc8aa;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git cfg80211: make cfg80211_sched_scan_results() work from atomic context Drivers should be able to call cfg80211_sched_scan_results() from atomic context. However, with the introduction of multiple scheduled scan feature this requirement was not taken into account resulting in regression shown below. [ 119.021594] BUG: scheduling while atomic: irq/47-iwlwifi/517/0x00000200 [ 119.021604] Modules linked in: [...] [ 119.021759] CPU: 1 PID: 517 Comm: irq/47-iwlwifi Not tainted 4.12.0-rc2-t440s-20170522+ #1 [ 119.021763] Hardware name: LENOVO 20AQS03H00/20AQS03H00, BIOS GJET91WW (2.41 ) 09/21/2016 [ 119.021766] Call Trace: [ 119.021778] ? dump_stack+0x5c/0x84 [ 119.021784] ? __schedule_bug+0x4c/0x70 [ 119.021792] ? __schedule+0x496/0x5c0 [ 119.021798] ? schedule+0x2d/0x80 [ 119.021804] ? schedule_preempt_disabled+0x5/0x10 [ 119.021810] ? __mutex_lock.isra.0+0x18e/0x4c0 [ 119.021817] ? __wake_up+0x2f/0x50 [ 119.021833] ? cfg80211_sched_scan_results+0x19/0x60 [cfg80211] [ 119.021844] ? cfg80211_sched_scan_results+0x19/0x60 [cfg80211] [ 119.021859] ? iwl_mvm_rx_lmac_scan_iter_complete_notif+0x17/0x30 [iwlmvm] [ 119.021869] ? iwl_pcie_rx_handle+0x2a9/0x7e0 [iwlwifi] [ 119.021878] ? iwl_pcie_irq_handler+0x17c/0x730 [iwlwifi] [ 119.021884] ? irq_forced_thread_fn+0x60/0x60 [ 119.021887] ? irq_thread_fn+0x16/0x40 [ 119.021892] ? irq_thread+0x109/0x180 [ 119.021896] ? wake_threads_waitq+0x30/0x30 [ 119.021901] ? kthread+0xf2/0x130 [ 119.021905] ? irq_thread_dtor+0x90/0x90 [ 119.021910] ? kthread_create_on_node+0x40/0x40 [ 119.021915] ? ret_from_fork+0x26/0x40 Fixes: b34939b98369 ("cfg80211: add request id to cfg80211_sched_scan_*() api") Reported-by: Sander Eikelenboom Signed-off-by: Arend van Spriel Signed-off-by: Johannes Berg --- diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 14d5f0c8c45f..9f0901f3e42b 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -322,9 +322,9 @@ cfg80211_find_sched_scan_req(struct cfg80211_registered_device *rdev, u64 reqid) { struct cfg80211_sched_scan_request *pos; - ASSERT_RTNL(); + WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held()); - list_for_each_entry(pos, &rdev->sched_scan_req_list, list) { + list_for_each_entry_rcu(pos, &rdev->sched_scan_req_list, list) { if (pos->reqid == reqid) return pos; } @@ -398,13 +398,13 @@ void cfg80211_sched_scan_results(struct wiphy *wiphy, u64 reqid) trace_cfg80211_sched_scan_results(wiphy, reqid); /* ignore if we're not scanning */ - rtnl_lock(); + rcu_read_lock(); request = cfg80211_find_sched_scan_req(rdev, reqid); if (request) { request->report_results = true; queue_work(cfg80211_wq, &rdev->sched_scan_res_wk); } - rtnl_unlock(); + rcu_read_unlock(); } EXPORT_SYMBOL(cfg80211_sched_scan_results);