From dfee325ad23ff4714981c9d2a4df6386493a4475 Mon Sep 17 00:00:00 2001 From: Rasesh Mody Date: Tue, 30 Aug 2011 15:27:45 +0000 Subject: [PATCH] bna: MBOX IRQ Flag Check after Locking Change details: - Check the BNAD_RF_MBOX_IRQ_DISABLED flag after acquiring the bna_lock, since checking the flag and executing bna_mbox_handler needs to be atomic. If not, it opens up window where flag is reset when it was checked, but got set while spinning on the lock by the other thread which is actually holding the lock Signed-off-by: Gurunatha Karaje Signed-off-by: Rasesh Mody Signed-off-by: David S. Miller --- drivers/net/ethernet/brocade/bna/bnad.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/brocade/bna/bnad.c b/drivers/net/ethernet/brocade/bna/bnad.c index c81550b076ad..11990cf0a265 100644 --- a/drivers/net/ethernet/brocade/bna/bnad.c +++ b/drivers/net/ethernet/brocade/bna/bnad.c @@ -586,10 +586,11 @@ bnad_msix_mbox_handler(int irq, void *data) unsigned long flags; struct bnad *bnad = (struct bnad *)data; - if (unlikely(test_bit(BNAD_RF_MBOX_IRQ_DISABLED, &bnad->run_flags))) - return IRQ_HANDLED; - spin_lock_irqsave(&bnad->bna_lock, flags); + if (unlikely(test_bit(BNAD_RF_MBOX_IRQ_DISABLED, &bnad->run_flags))) { + spin_unlock_irqrestore(&bnad->bna_lock, flags); + return IRQ_HANDLED; + } bna_intr_status_get(&bnad->bna, intr_status); @@ -612,15 +613,18 @@ bnad_isr(int irq, void *data) struct bnad_rx_ctrl *rx_ctrl; struct bna_tcb *tcb = NULL; - if (unlikely(test_bit(BNAD_RF_MBOX_IRQ_DISABLED, &bnad->run_flags))) + spin_lock_irqsave(&bnad->bna_lock, flags); + if (unlikely(test_bit(BNAD_RF_MBOX_IRQ_DISABLED, &bnad->run_flags))) { + spin_unlock_irqrestore(&bnad->bna_lock, flags); return IRQ_NONE; + } bna_intr_status_get(&bnad->bna, intr_status); - if (unlikely(!intr_status)) + if (unlikely(!intr_status)) { + spin_unlock_irqrestore(&bnad->bna_lock, flags); return IRQ_NONE; - - spin_lock_irqsave(&bnad->bna_lock, flags); + } if (BNA_IS_MBOX_ERR_INTR(&bnad->bna, intr_status)) bna_mbox_handler(&bnad->bna, intr_status); -- 2.20.1