3.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Stanislaw Gruszka <[email protected]> commit e5851dac2c95af7159716832300b9f50c62c648e upstream. Remove spinlock as atomic_t can be used instead. Note we use only 16 lower bits, upper bits are changed but we impilcilty cast to u16. This fix possible deadlock on IBSS mode reproted by lockdep: ================================= [ INFO: inconsistent lock state ] 3.4.0-wl+ #4 Not tainted --------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. kworker/u:2/30374 [HC0[0]:SC0[0]:HE1:SE1] takes: (&(&intf->seqlock)->rlock){+.?...}, at: [<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] {IN-SOFTIRQ-W} state was registered at: [<c04978ab>] __lock_acquire+0x47b/0x1050 [<c0498504>] lock_acquire+0x84/0xf0 [<c0835733>] _raw_spin_lock+0x33/0x40 [<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [<f9979f2a>] rt2x00queue_write_tx_frame+0x1a/0x300 [rt2x00lib] [<f997834f>] rt2x00mac_tx+0x7f/0x380 [rt2x00lib] [<f98fe363>] __ieee80211_tx+0x1b3/0x300 [mac80211] [<f98ffdf5>] ieee80211_tx+0x105/0x130 [mac80211] [<f99000dd>] ieee80211_xmit+0xad/0x100 [mac80211] [<f9900519>] ieee80211_subif_start_xmit+0x2d9/0x930 [mac80211] [<c0782e87>] dev_hard_start_xmit+0x307/0x660 [<c079bb71>] sch_direct_xmit+0xa1/0x1e0 [<c0784bb3>] dev_queue_xmit+0x183/0x730 [<c078c27a>] neigh_resolve_output+0xfa/0x1e0 [<c07b436a>] ip_finish_output+0x24a/0x460 [<c07b4897>] ip_output+0xb7/0x100 [<c07b2d60>] ip_local_out+0x20/0x60 [<c07e01ff>] igmpv3_sendpack+0x4f/0x60 [<c07e108f>] igmp_ifc_timer_expire+0x29f/0x330 [<c04520fc>] run_timer_softirq+0x15c/0x2f0 [<c0449e3e>] __do_softirq+0xae/0x1e0 irq event stamp: 18380437 hardirqs last enabled at (18380437): [<c0526027>] __slab_alloc.clone.3+0x67/0x5f0 hardirqs last disabled at (18380436): [<c0525ff3>] __slab_alloc.clone.3+0x33/0x5f0 softirqs last enabled at (18377616): [<c0449eb3>] __do_softirq+0x123/0x1e0 softirqs last disabled at (18377611): [<c041278d>] do_softirq+0x9d/0xe0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&intf->seqlock)->rlock); <Interrupt> lock(&(&intf->seqlock)->rlock); *** DEADLOCK *** 4 locks held by kworker/u:2/30374: #0: (wiphy_name(local->hw.wiphy)){++++.+}, at: [<c045cf99>] process_one_work+0x109/0x3f0 #1: ((&sdata->work)){+.+.+.}, at: [<c045cf99>] process_one_work+0x109/0x3f0 #2: (&ifibss->mtx){+.+.+.}, at: [<f98f005b>] ieee80211_ibss_work+0x1b/0x470 [mac80211] #3: (&intf->beacon_skb_mutex){+.+...}, at: [<f997a644>] rt2x00queue_update_beacon+0x24/0x50 [rt2x00lib] stack backtrace: Pid: 30374, comm: kworker/u:2 Not tainted 3.4.0-wl+ #4 Call Trace: [<c04962a6>] print_usage_bug+0x1f6/0x220 [<c0496a12>] mark_lock+0x2c2/0x300 [<c0495ff0>] ? check_usage_forwards+0xc0/0xc0 [<c04978ec>] __lock_acquire+0x4bc/0x1050 [<c0527890>] ? __kmalloc_track_caller+0x1c0/0x1d0 [<c0777fb6>] ? copy_skb_header+0x26/0x90 [<c0498504>] lock_acquire+0x84/0xf0 [<f9979a20>] ? rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [<c0835733>] _raw_spin_lock+0x33/0x40 [<f9979a20>] ? rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [<f9979a20>] rt2x00queue_create_tx_descriptor+0x380/0x490 [rt2x00lib] [<f997a5cf>] rt2x00queue_update_beacon_locked+0x5f/0xb0 [rt2x00lib] [<f997a64d>] rt2x00queue_update_beacon+0x2d/0x50 [rt2x00lib] [<f9977e3a>] rt2x00mac_bss_info_changed+0x1ca/0x200 [rt2x00lib] [<f9977c70>] ? rt2x00mac_remove_interface+0x70/0x70 [rt2x00lib] [<f98e4dd0>] ieee80211_bss_info_change_notify+0xe0/0x1d0 [mac80211] [<f98ef7b8>] __ieee80211_sta_join_ibss+0x3b8/0x610 [mac80211] [<c0496ab4>] ? mark_held_locks+0x64/0xc0 [<c0440012>] ? virt_efi_query_capsule_caps+0x12/0x50 [<f98efb09>] ieee80211_sta_join_ibss+0xf9/0x140 [mac80211] [<f98f0456>] ieee80211_ibss_work+0x416/0x470 [mac80211] [<c0496d8b>] ? trace_hardirqs_on+0xb/0x10 [<c077683b>] ? skb_dequeue+0x4b/0x70 [<f98f207f>] ieee80211_iface_work+0x13f/0x230 [mac80211] [<c045cf99>] ? process_one_work+0x109/0x3f0 [<c045d015>] process_one_work+0x185/0x3f0 [<c045cf99>] ? process_one_work+0x109/0x3f0 [<f98f1f40>] ? ieee80211_teardown_sdata+0xa0/0xa0 [mac80211] [<c045ed86>] worker_thread+0x116/0x270 [<c045ec70>] ? manage_workers+0x1e0/0x1e0 [<c0462f64>] kthread+0x84/0x90 [<c0462ee0>] ? __init_kthread_worker+0x60/0x60 [<c083d382>] kernel_thread_helper+0x6/0x10 Signed-off-by: Stanislaw Gruszka <[email protected]> Acked-by: Helmut Schaa <[email protected]> Acked-by: Gertjan van Wingerde <[email protected]> Signed-off-by: John W. Linville <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/net/wireless/rt2x00/rt2x00.h | 3 +-- drivers/net/wireless/rt2x00/rt2x00mac.c | 1 - drivers/net/wireless/rt2x00/rt2x00queue.c | 13 ++++++------- 3 files changed, 7 insertions(+), 10 deletions(-) --- a/drivers/net/wireless/rt2x00/rt2x00.h +++ b/drivers/net/wireless/rt2x00/rt2x00.h @@ -396,8 +396,7 @@ struct rt2x00_intf { * for hardware which doesn't support hardware * sequence counting. */ - spinlock_t seqlock; - u16 seqno; + atomic_t seqno; }; static inline struct rt2x00_intf* vif_to_intf(struct ieee80211_vif *vif) --- a/drivers/net/wireless/rt2x00/rt2x00mac.c +++ b/drivers/net/wireless/rt2x00/rt2x00mac.c @@ -277,7 +277,6 @@ int rt2x00mac_add_interface(struct ieee8 else rt2x00dev->intf_sta_count++; - spin_lock_init(&intf->seqlock); mutex_init(&intf->beacon_skb_mutex); intf->beacon = entry; --- a/drivers/net/wireless/rt2x00/rt2x00queue.c +++ b/drivers/net/wireless/rt2x00/rt2x00queue.c @@ -207,6 +207,7 @@ static void rt2x00queue_create_tx_descri struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb); struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; struct rt2x00_intf *intf = vif_to_intf(tx_info->control.vif); + u16 seqno; if (!(tx_info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ)) return; @@ -227,15 +228,13 @@ static void rt2x00queue_create_tx_descri * sequence counting per-frame, since those will override the * sequence counter given by mac80211. */ - spin_lock(&intf->seqlock); - if (test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags)) - intf->seqno += 0x10; - hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG); - hdr->seq_ctrl |= cpu_to_le16(intf->seqno); - - spin_unlock(&intf->seqlock); + seqno = atomic_add_return(0x10, &intf->seqno); + else + seqno = atomic_read(&intf->seqno); + hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG); + hdr->seq_ctrl |= cpu_to_le16(seqno); } static void rt2x00queue_create_tx_descriptor_plcp(struct rt2x00_dev *rt2x00dev, -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
