[SCSI] bnx2fc: Fix NULL pointer deref during arm_cq.
There exists a race condition between CQ doorbell unmap and IO completion path
that arms the CQ which causes a NULL dereference. Protect the ctx_base with
cq_lock to avoid this. Also, wait for the CQ doorbell to be successfully mapped
before arming the CQ.
Also, do not count uncolicited CQ completions for free_sqes.
Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/bnx2fc/bnx2fc_hwi.c b/drivers/scsi/bnx2fc/bnx2fc_hwi.c
index 72cfb14..b241f3d 100644
--- a/drivers/scsi/bnx2fc/bnx2fc_hwi.c
+++ b/drivers/scsi/bnx2fc/bnx2fc_hwi.c
@@ -1009,6 +1009,7 @@
u32 cq_cons;
struct fcoe_cqe *cqe;
u32 num_free_sqes = 0;
+ u32 num_cqes = 0;
u16 wqe;
/*
@@ -1058,10 +1059,11 @@
wake_up_process(fps->iothread);
else
bnx2fc_process_cq_compl(tgt, wqe);
+ num_free_sqes++;
}
cqe++;
tgt->cq_cons_idx++;
- num_free_sqes++;
+ num_cqes++;
if (tgt->cq_cons_idx == BNX2FC_CQ_WQES_MAX) {
tgt->cq_cons_idx = 0;
@@ -1070,8 +1072,10 @@
1 - tgt->cq_curr_toggle_bit;
}
}
- if (num_free_sqes) {
- bnx2fc_arm_cq(tgt);
+ if (num_cqes) {
+ /* Arm CQ only if doorbell is mapped */
+ if (tgt->ctx_base)
+ bnx2fc_arm_cq(tgt);
atomic_add(num_free_sqes, &tgt->free_sqes);
}
spin_unlock_bh(&tgt->cq_lock);
