This is a note to let you know that I've just added the patch titled iwlwifi: mvm: fix setting channel in monitor mode to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: iwlwifi-mvm-fix-setting-channel-in-monitor-mode.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 1c4abec0baf25ffb92a28cc99d4231feeaa4d3f3 Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx> Date: Thu, 8 May 2014 09:48:10 +0300 Subject: iwlwifi: mvm: fix setting channel in monitor mode From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx> commit 1c4abec0baf25ffb92a28cc99d4231feeaa4d3f3 upstream. There was a deadlock in monitor mode when we were setting the channel if the channel was not 1. ====================================================== [ INFO: possible circular locking dependency detected ] 3.14.3 #4 Not tainted ------------------------------------------------------- iw/3323 is trying to acquire lock: (&local->chanctx_mtx){+.+.+.}, at: [<ffffffffa062e2f2>] ieee80211_vif_release_channel+0x42/0xb0 [mac80211] but task is already holding lock: (&local->iflist_mtx){+.+...}, at: [<ffffffffa0609e0a>] ieee80211_set_monitor_channel+0x5a/0x1b0 [mac80211] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&local->iflist_mtx){+.+...}: [<ffffffff810d95bb>] __lock_acquire+0xb3b/0x13b0 [<ffffffff810d9ee0>] lock_acquire+0xb0/0x1f0 [<ffffffff817eb9c8>] mutex_lock_nested+0x78/0x4f0 [<ffffffffa06225cf>] ieee80211_iterate_active_interfaces+0x2f/0x60 [mac80211] [<ffffffffa0518189>] iwl_mvm_recalc_multicast+0x49/0xa0 [iwlmvm] [<ffffffffa051822e>] iwl_mvm_configure_filter+0x4e/0x70 [iwlmvm] [<ffffffffa05e6d43>] ieee80211_configure_filter+0x153/0x5f0 [mac80211] [<ffffffffa05e71f5>] ieee80211_reconfig_filter+0x15/0x20 [mac80211] [snip] -> #1 (&mvm->mutex){+.+.+.}: [<ffffffff810d95bb>] __lock_acquire+0xb3b/0x13b0 [<ffffffff810d9ee0>] lock_acquire+0xb0/0x1f0 [<ffffffff817eb9c8>] mutex_lock_nested+0x78/0x4f0 [<ffffffffa0517246>] iwl_mvm_add_chanctx+0x56/0xe0 [iwlmvm] [<ffffffffa062ca1e>] ieee80211_new_chanctx+0x13e/0x410 [mac80211] [<ffffffffa062d953>] ieee80211_vif_use_channel+0x1c3/0x5a0 [mac80211] [<ffffffffa06035ab>] ieee80211_add_virtual_monitor+0x1ab/0x6b0 [mac80211] [<ffffffffa06052ea>] ieee80211_do_open+0xe6a/0x15a0 [mac80211] [<ffffffffa0605a79>] ieee80211_open+0x59/0x60 [mac80211] [snip] -> #0 (&local->chanctx_mtx){+.+.+.}: [<ffffffff810d6cb7>] check_prevs_add+0x977/0x980 [<ffffffff810d95bb>] __lock_acquire+0xb3b/0x13b0 [<ffffffff810d9ee0>] lock_acquire+0xb0/0x1f0 [<ffffffff817eb9c8>] mutex_lock_nested+0x78/0x4f0 [<ffffffffa062e2f2>] ieee80211_vif_release_channel+0x42/0xb0 [mac80211] [<ffffffffa0609ec3>] ieee80211_set_monitor_channel+0x113/0x1b0 [mac80211] [<ffffffffa058fb37>] cfg80211_set_monitor_channel+0x77/0x2b0 [cfg80211] [<ffffffffa056e0b2>] __nl80211_set_channel+0x122/0x140 [cfg80211] [<ffffffffa0581374>] nl80211_set_wiphy+0x284/0xaf0 [cfg80211] [snip] other info that might help us debug this: Chain exists of: &local->chanctx_mtx --> &mvm->mutex --> &local->iflist_mtx Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&local->iflist_mtx); lock(&mvm->mutex); lock(&local->iflist_mtx); lock(&local->chanctx_mtx); *** DEADLOCK *** This deadlock actually occurs: INFO: task iw:3323 blocked for more than 120 seconds. Not tainted 3.14.3 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. iw D ffff8800c8afcd80 4192 3323 3322 0x00000000 ffff880078fdb7e0 0000000000000046 ffff8800c8afcd80 ffff880078fdbfd8 00000000001d5540 00000000001d5540 ffff8801141b0000 ffff8800c8afcd80 ffff880078ff9e38 ffff880078ff9e38 ffff880078ff9e40 0000000000000246 Call Trace: [<ffffffff817ea841>] schedule_preempt_disabled+0x31/0x80 [<ffffffff817ebaed>] mutex_lock_nested+0x19d/0x4f0 [<ffffffffa06225cf>] ? ieee80211_iterate_active_interfaces+0x2f/0x60 [mac80211] [<ffffffffa06225cf>] ? ieee80211_iterate_active_interfaces+0x2f/0x60 [mac80211] [<ffffffffa052a680>] ? iwl_mvm_power_mac_update_mode+0xc0/0xc0 [iwlmvm] [<ffffffffa06225cf>] ieee80211_iterate_active_interfaces+0x2f/0x60 [mac80211] [<ffffffffa0529357>] _iwl_mvm_power_update_binding+0x27/0x80 [iwlmvm] [<ffffffffa0516eb1>] iwl_mvm_unassign_vif_chanctx+0x81/0xc0 [iwlmvm] [<ffffffffa062d3ff>] __ieee80211_vif_release_channel+0xdf/0x470 [mac80211] [<ffffffffa062e2fa>] ieee80211_vif_release_channel+0x4a/0xb0 [mac80211] [<ffffffffa0609ec3>] ieee80211_set_monitor_channel+0x113/0x1b0 [mac80211] [<ffffffffa058fb37>] cfg80211_set_monitor_channel+0x77/0x2b0 [cfg80211] [<ffffffffa056e0b2>] __nl80211_set_channel+0x122/0x140 [cfg80211] [<ffffffffa0581374>] nl80211_set_wiphy+0x284/0xaf0 [cfg80211] This fixes https://bugzilla.kernel.org/show_bug.cgi?id=75541 Reviewed-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/iwlwifi/mvm/mac80211.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c +++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c @@ -796,7 +796,7 @@ static void iwl_mvm_mc_iface_iterator(vo memcpy(cmd->bssid, vif->bss_conf.bssid, ETH_ALEN); len = roundup(sizeof(*cmd) + cmd->count * ETH_ALEN, 4); - ret = iwl_mvm_send_cmd_pdu(mvm, MCAST_FILTER_CMD, CMD_SYNC, len, cmd); + ret = iwl_mvm_send_cmd_pdu(mvm, MCAST_FILTER_CMD, CMD_ASYNC, len, cmd); if (ret) IWL_ERR(mvm, "mcast filter cmd error. ret=%d\n", ret); } @@ -812,7 +812,7 @@ static void iwl_mvm_recalc_multicast(str if (WARN_ON_ONCE(!mvm->mcast_filter_cmd)) return; - ieee80211_iterate_active_interfaces( + ieee80211_iterate_active_interfaces_atomic( mvm->hw, IEEE80211_IFACE_ITER_NORMAL, iwl_mvm_mc_iface_iterator, &iter_data); } Patches currently in stable-queue which might be from emmanuel.grumbach@xxxxxxxxx are queue-3.14/iwlwifi-add-module_firmware-for-7265.patch queue-3.14/iwlwifi-mvm-fix-setting-channel-in-monitor-mode.patch queue-3.14/iwlwifi-pcie-disable-interrupts-upon-pcie-alloc.patch queue-3.14/iwlwifi-7000-bump-api-to-9.patch queue-3.14/iwlwifi-mvm-avoid-searching-unnecessary-columns.patch queue-3.14/iwlwifi-mvm-rs-fix-and-cleanup-rs_get_rate_action.patch queue-3.14/iwlwifi-mvm-rs-fallback-to-legacy-tx-columns.patch queue-3.14/iwlwifi-add-new-7265-hw-ids.patch queue-3.14/iwlwifi-mvm-rs-fix-mimo-delimiter-in-lq-cmd.patch queue-3.14/iwlwifi-mvm-rs-reinit-rs-if-no-tx-for-a-long-time.patch queue-3.14/iwlwifi-mvm-delay-enabling-smart-fifo-until-after-beacon-rx.patch queue-3.14/mac80211-fix-suspend-vs.-association-race.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html