diff options
| author | Remi Pommarel <repk@triplefau.lt> | 2024-09-24 21:28:05 +0200 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2024-10-08 21:24:19 +0200 |
| commit | 4cc6f3e5e5765abad9c091989970d67d8c1d2204 (patch) | |
| tree | 6cb1a89c99806eaf3c0aa378facd14cb1afd45ed /net/mac80211/cfg.c | |
| parent | 68d0021fe7231eec0fb84cd110cf62a6e782b72d (diff) | |
wifi: mac80211: Convert color collision detection to wiphy work
Call to ieee80211_color_collision_detection_work() needs wiphy lock to
be held (see lockdep assert in cfg80211_bss_color_notify()). Not locking
wiphy causes the following lockdep error:
WARNING: CPU: 2 PID: 42 at net/wireless/nl80211.c:19505 cfg80211_bss_color_notify+0x1a4/0x25c
Modules linked in:
CPU: 2 PID: 42 Comm: kworker/u8:3 Tainted: G W 6.4.0-02327-g36c6cb260481 #1048
Hardware name:
Workqueue: phy1 ieee80211_color_collision_detection_work
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : cfg80211_bss_color_notify+0x1a4/0x25c
lr : cfg80211_bss_color_notify+0x1a0/0x25c
sp : ffff000002947d00
x29: ffff000002947d00 x28: ffff800008e1a000 x27: ffff000002bd4705
x26: ffff00000d034000 x25: ffff80000903cf40 x24: 0000000000000000
x23: ffff00000cb70720 x22: 0000000000800000 x21: ffff800008dfb008
x20: 000000000000008d x19: ffff00000d035fa8 x18: 0000000000000010
x17: 0000000000000001 x16: 000003564b1ce96a x15: 000d69696d057970
x14: 000000000000003b x13: 0000000000000001 x12: 0000000000040000
x11: 0000000000000001 x10: ffff80000978f9c0 x9 : ffff0000028d3174
x8 : ffff800008e30000 x7 : 0000000000000000 x6 : 0000000000000028
x5 : 000000000002f498 x4 : ffff00000d034a80 x3 : 0000000000800000
x2 : ffff800016143000 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
cfg80211_bss_color_notify+0x1a4/0x25c
ieee80211_color_collision_detection_work+0x20/0x118
process_one_work+0x294/0x554
worker_thread+0x70/0x440
kthread+0xf4/0xf8
ret_from_fork+0x10/0x20
irq event stamp: 77372
hardirqs last enabled at (77371): [<ffff800008a346fc>] _raw_spin_unlock_irq+0x2c/0x4c
hardirqs last disabled at (77372): [<ffff800008a28754>] el1_dbg+0x20/0x48
softirqs last enabled at (77350): [<ffff8000089e120c>] batadv_send_outstanding_bcast_packet+0xb8/0x120
softirqs last disabled at (77348): [<ffff8000089e11d4>] batadv_send_outstanding_bcast_packet+0x80/0x120
The wiphy lock cannot be taken directly from color collision detection
delayed work (ieee80211_color_collision_detection_work()) because this
work is cancel_delayed_work_sync() under this wiphy lock causing a
potential deadlock( see [0] for details).
To fix that ieee80211_color_collision_detection_work() could be
converted to a wiphy work and cancel_delayed_work_sync() can be simply
replaced by wiphy_delayed_work_cancel() serving the same purpose under
wiphy lock.
This could potentially fix [1].
[0]: https://lore.kernel.org/linux-wireless/D4A40Q44OAY2.W3SIF6UEPBUN@freebox.fr/
[1]: https://lore.kernel.org/lkml/000000000000612f290618eee3e5@google.com/
Reported-by: Nicolas Escande <nescande@freebox.fr>
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Link: https://patch.msgid.link/20240924192805.13859-3-repk@triplefau.lt
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211/cfg.c')
| -rw-r--r-- | net/mac80211/cfg.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 7cefe763b772..13294cc20a9b 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -4831,12 +4831,12 @@ void ieee80211_color_change_finalize_work(struct wiphy *wiphy, ieee80211_color_change_finalize(link); } -void ieee80211_color_collision_detection_work(struct work_struct *work) +void ieee80211_color_collision_detection_work(struct wiphy *wiphy, + struct wiphy_work *work) { - struct delayed_work *delayed_work = to_delayed_work(work); struct ieee80211_link_data *link = - container_of(delayed_work, struct ieee80211_link_data, - color_collision_detect_work); + container_of(work, struct ieee80211_link_data, + color_collision_detect_work.work); struct ieee80211_sub_if_data *sdata = link->sdata; cfg80211_obss_color_collision_notify(sdata->dev, link->color_bitmap, @@ -4889,7 +4889,8 @@ ieee80211_obss_color_collision_notify(struct ieee80211_vif *vif, return; } - if (delayed_work_pending(&link->color_collision_detect_work)) { + if (wiphy_delayed_work_pending(sdata->local->hw.wiphy, + &link->color_collision_detect_work)) { rcu_read_unlock(); return; } @@ -4898,9 +4899,9 @@ ieee80211_obss_color_collision_notify(struct ieee80211_vif *vif, /* queue the color collision detection event every 500 ms in order to * avoid sending too much netlink messages to userspace. */ - ieee80211_queue_delayed_work(&sdata->local->hw, - &link->color_collision_detect_work, - msecs_to_jiffies(500)); + wiphy_delayed_work_queue(sdata->local->hw.wiphy, + &link->color_collision_detect_work, + msecs_to_jiffies(500)); rcu_read_unlock(); } |