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  1. 13 May, 2014 34 commits
  3. 12 May, 2014 2 commits
  5. 11 May, 2014 1 commit
    • Emmanuel Grumbach's avatar
      iwlwifi: mvm: fix setting channel in monitor mode · 1c4abec0
      Emmanuel Grumbach authored 
      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

Cc: <stable@vger.kernel.org> [3.13+]
Reviewed-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
      1c4abec0
  7. 09 May, 2014 2 commits
    • Eliad Peller's avatar
      mac80211: fix vif name tracing · f9ac71bf
      Eliad Peller authored 
      If sdata doesn't have a valid dev (e.g. in case of monitor
vif), the vif_name field was initialized with (a length of)
some short string, but later was set to a different,
potentially larger one.

This resulted in out-of-bounds write, which usually
appeared as garbage in the trace log.

Simply trace sdata->name, as it should always have the
correct name for both cases.
Signed-off-by: default avatarEliad Peller <eliadx.peller@intel.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      f9ac71bf
    • Johannes Berg's avatar
      mac80211: allow VHT with peers not capable of 40MHz · 4a817aa7
      Johannes Berg authored 
      There are two (related) issues with this.

One case, reported by Michal, is related to hostap: it unsets the
20/40 capability bit for stations that associate when it's in 20
MHz mode.

The other case, reported by Eyal, is that some APs like Netgear
R6300v2 and probably others based on the BCM4360 chipset can be
configured for doing VHT at 20Mhz. In this case the beacon has
a VHT IE but the HT cap indicates transmitter only support 20Mhz.

In both of these cases, we currently avoid VHT and use only HT
this means we can't use the highest rates (MCS8), so fixing this
leads to throughput improvements.
Reported-by: default avatarMichal Kazior <michal.kazior@tieto.com>
Reported-by: default avatarEyal Shapira <eyal@wizery.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      4a817aa7
  9. 08 May, 2014 1 commit
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