From b6931c9ba728d60c542c39ff037fe6f595c074a2 Mon Sep 17 00:00:00 2001 From: Govindarajulu Varadarajan <_govind@gmx.com> Date: Sun, 19 Oct 2014 14:20:27 +0530 Subject: [PATCH] enic: fix possible deadlock in enic_stop/ enic_rfs_flw_tbl_free The following warning is shown when spinlock debug is enabled. This occurs when enic_flow_may_expire timer function is running and enic_stop is called on same CPU. Fix this by using spink_lock_bh(). ================================= [ INFO: inconsistent lock state ] 3.17.0-netnext-05504-g59f35b8 #268 Not tainted --------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. ifconfig/443 [HC0[0]:SC0[0]:HE1:SE1] takes: (&(&enic->rfs_h.lock)->rlock){+.?...}, at: enic_rfs_flw_tbl_free+0x34/0xd0 [enic] {IN-SOFTIRQ-W} state was registered at: [] __lock_acquire+0x83f/0x21c0 [] lock_acquire+0xa2/0xd0 [] _raw_spin_lock+0x3c/0x80 [] enic_flow_may_expire+0x25/0x130[enic] [] call_timer_fn+0x77/0x100 [] run_timer_softirq+0x1e3/0x270 [] __do_softirq+0x14e/0x280 [] irq_exit+0x8e/0xb0 [] smp_apic_timer_interrupt+0x3f/0x50 [] apic_timer_interrupt+0x72/0x80 [] default_idle+0x13/0x20 [] arch_cpu_idle+0xa/0x10 [] cpu_startup_entry+0x2c6/0x330 [] start_secondary+0x21d/0x290 irq event stamp: 2997 hardirqs last enabled at (2997): [] _raw_spin_unlock_irqrestore+0x65/0x90 hardirqs last disabled at (2996): [] _raw_spin_lock_irqsave+0x26/0x90 softirqs last enabled at (2968): [] dev_deactivate_many+0x213/0x260 softirqs last disabled at (2966): [] dev_deactivate_many+0x1f3/0x260 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&enic->rfs_h.lock)->rlock); lock(&(&enic->rfs_h.lock)->rlock); *** DEADLOCK *** Reported-by: Jan Stancek Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com> Signed-off-by: David S. Miller --- drivers/net/ethernet/cisco/enic/enic_clsf.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/cisco/enic/enic_clsf.c b/drivers/net/ethernet/cisco/enic/enic_clsf.c index 69dfd3c9e529..0be6850be8a2 100644 --- a/drivers/net/ethernet/cisco/enic/enic_clsf.c +++ b/drivers/net/ethernet/cisco/enic/enic_clsf.c @@ -86,7 +86,7 @@ void enic_rfs_flw_tbl_free(struct enic *enic) int i; enic_rfs_timer_stop(enic); - spin_lock(&enic->rfs_h.lock); + spin_lock_bh(&enic->rfs_h.lock); enic->rfs_h.free = 0; for (i = 0; i < (1 << ENIC_RFS_FLW_BITSHIFT); i++) { struct hlist_head *hhead; @@ -100,7 +100,7 @@ void enic_rfs_flw_tbl_free(struct enic *enic) kfree(n); } } - spin_unlock(&enic->rfs_h.lock); + spin_unlock_bh(&enic->rfs_h.lock); } struct enic_rfs_fltr_node *htbl_fltr_search(struct enic *enic, u16 fltr_id) @@ -128,7 +128,7 @@ void enic_flow_may_expire(unsigned long data) bool res; int j; - spin_lock(&enic->rfs_h.lock); + spin_lock_bh(&enic->rfs_h.lock); for (j = 0; j < ENIC_CLSF_EXPIRE_COUNT; j++) { struct hlist_head *hhead; struct hlist_node *tmp; @@ -148,7 +148,7 @@ void enic_flow_may_expire(unsigned long data) } } } - spin_unlock(&enic->rfs_h.lock); + spin_unlock_bh(&enic->rfs_h.lock); mod_timer(&enic->rfs_h.rfs_may_expire, jiffies + HZ/4); } @@ -183,7 +183,7 @@ int enic_rx_flow_steer(struct net_device *dev, const struct sk_buff *skb, return -EPROTONOSUPPORT; tbl_idx = skb_get_hash_raw(skb) & ENIC_RFS_FLW_MASK; - spin_lock(&enic->rfs_h.lock); + spin_lock_bh(&enic->rfs_h.lock); n = htbl_key_search(&enic->rfs_h.ht_head[tbl_idx], &keys); if (n) { /* entry already present */ @@ -277,7 +277,7 @@ int enic_rx_flow_steer(struct net_device *dev, const struct sk_buff *skb, } ret_unlock: - spin_unlock(&enic->rfs_h.lock); + spin_unlock_bh(&enic->rfs_h.lock); return res; } -- 2.20.1