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cnic: Fix occasional NULL pointer dereference during reboot.

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We register with bnx2x before we allocate ctx_tbl structure, so it is
possible for bnx2x to call cnic_ctl before the structure is allocated.
This can sometimes cause NULL pointer dereference of cp->ctx_tbl.  We
fix this by adding simple checking for valid state before proceeding.
The cnic_ctl call is RCU protected so we don't have to deal with race
conditions.

Because of the additional checking, we need to finish the shutdown
before clearing the CNIC_UP flag.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Michael Chan 2012-06-27 15:08:19 +00:00 committed by David S. Miller
parent c10237e077
commit a2028b2376
1 changed files with 7 additions and 2 deletions
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9
drivers/net/ethernet/broadcom/cnic.c
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@ -291,6 +291,9 @@ static int cnic_get_l5_cid(struct cnic_local *cp, u32 cid, u32 *l5_cid)
{
u32 i;
if (!cp->ctx_tbl)
return -EINVAL;
for (i = 0; i < cp->max_cid_space; i++) {
if (cp->ctx_tbl[i].cid == cid) {
*l5_cid = i;
@ -3220,6 +3223,9 @@ static int cnic_ctl(void *data, struct cnic_ctl_info *info)
u32 l5_cid;
struct cnic_local *cp = dev->cnic_priv;
if (!test_bit(CNIC_F_CNIC_UP, &dev->flags))
break;
if (cnic_get_l5_cid(cp, cid, &l5_cid) == 0) {
struct cnic_context *ctx = &cp->ctx_tbl[l5_cid];
@ -4253,8 +4259,6 @@ static int cnic_cm_shutdown(struct cnic_dev *dev)
struct cnic_local *cp = dev->cnic_priv;
int i;
cp->stop_cm(dev);
if (!cp->csk_tbl)
return 0;
@ -5290,6 +5294,7 @@ static void cnic_stop_hw(struct cnic_dev *dev)
i++;
}
cnic_shutdown_rings(dev);
cp->stop_cm(dev);
clear_bit(CNIC_F_CNIC_UP, &dev->flags);
RCU_INIT_POINTER(cp->ulp_ops[CNIC_ULP_L4], NULL);
synchronize_rcu();