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[SCSI] bnx2fc: Fix NULL pointer deref during arm_cq.

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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>
This commit is contained in:
Bhanu Prakash Gollapudi 2011-08-04 17:38:46 -07:00 committed by James Bottomley
parent 8121401313
commit b338c785c5
2 changed files with 18 additions and 11 deletions
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8
drivers/scsi/bnx2fc/bnx2fc_hwi.c
View File

@ -1009,6 +1009,7 @@ int bnx2fc_process_new_cqes(struct bnx2fc_rport *tgt)
u32 cq_cons;
struct fcoe_cqe *cqe;
u32 num_free_sqes = 0;
u32 num_cqes = 0;
u16 wqe;
/*
@ -1058,10 +1059,11 @@ unlock:
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;
@ -1070,7 +1072,9 @@ unlock:
1 - tgt->cq_curr_toggle_bit;
}
}
if (num_free_sqes) {
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);
}

15
drivers/scsi/bnx2fc/bnx2fc_tgt.c
View File

@ -133,7 +133,7 @@ retry_ofld:
printk(KERN_ERR PFX "map doorbell failed - no mem\n");
/* upload will take care of cleaning up sess resc */
lport->tt.rport_logoff(rdata);
}
} else
/* Arm CQ */
bnx2fc_arm_cq(tgt);
return;
@ -806,14 +806,14 @@ mem_alloc_failure:
static void bnx2fc_free_session_resc(struct bnx2fc_hba *hba,
struct bnx2fc_rport *tgt)
{
void __iomem *ctx_base_ptr;
BNX2FC_TGT_DBG(tgt, "Freeing up session resources\n");
if (tgt->ctx_base) {
iounmap(tgt->ctx_base);
tgt->ctx_base = NULL;
}
spin_lock_bh(&tgt->cq_lock);
ctx_base_ptr = tgt->ctx_base;
tgt->ctx_base = NULL;
/* Free LCQ */
if (tgt->lcq) {
dma_free_coherent(&hba->pcidev->dev, tgt->lcq_mem_size,
@ -867,4 +867,7 @@ static void bnx2fc_free_session_resc(struct bnx2fc_hba *hba,
tgt->sq = NULL;
}
spin_unlock_bh(&tgt->cq_lock);
if (ctx_base_ptr)
iounmap(ctx_base_ptr);
}