linux_dsm_epyc7002/drivers/net/ethernet/cisco/enic/enic_clsf.c
Govindarajulu Varadarajan b6931c9ba7 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:
  [<ffffffff810a25af>] __lock_acquire+0x83f/0x21c0
  [<ffffffff810a45f2>] lock_acquire+0xa2/0xd0
  [<ffffffff814913fc>] _raw_spin_lock+0x3c/0x80
  [<ffffffffa029c3d5>] enic_flow_may_expire+0x25/0x130[enic]
  [<ffffffff810bcd07>] call_timer_fn+0x77/0x100
  [<ffffffff810bd8e3>] run_timer_softirq+0x1e3/0x270
  [<ffffffff8105f9ae>] __do_softirq+0x14e/0x280
  [<ffffffff8105fdae>] irq_exit+0x8e/0xb0
  [<ffffffff8103da0f>] smp_apic_timer_interrupt+0x3f/0x50
  [<ffffffff81493742>] apic_timer_interrupt+0x72/0x80
  [<ffffffff81018143>] default_idle+0x13/0x20
  [<ffffffff81018a6a>] arch_cpu_idle+0xa/0x10
  [<ffffffff81097676>] cpu_startup_entry+0x2c6/0x330
  [<ffffffff8103b7ad>] start_secondary+0x21d/0x290
irq event stamp: 2997
hardirqs last  enabled at (2997): [<ffffffff81491865>] _raw_spin_unlock_irqrestore+0x65/0x90
hardirqs last disabled at (2996): [<ffffffff814915e6>] _raw_spin_lock_irqsave+0x26/0x90
softirqs last  enabled at (2968): [<ffffffff813b57a3>] dev_deactivate_many+0x213/0x260
softirqs last disabled at (2966): [<ffffffff813b5783>] dev_deactivate_many+0x1f3/0x260

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&enic->rfs_h.lock)->rlock);
  <Interrupt>
    lock(&(&enic->rfs_h.lock)->rlock);

 *** DEADLOCK ***

Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-21 15:24:25 -04:00

285 lines
6.8 KiB
C

#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_link.h>
#include <linux/netdevice.h>
#include <linux/in.h>
#include <linux/types.h>
#include <linux/skbuff.h>
#include <net/flow_keys.h>
#include "enic_res.h"
#include "enic_clsf.h"
/* enic_addfltr_5t - Add ipv4 5tuple filter
* @enic: enic struct of vnic
* @keys: flow_keys of ipv4 5tuple
* @rq: rq number to steer to
*
* This function returns filter_id(hardware_id) of the filter
* added. In case of error it returns an negative number.
*/
int enic_addfltr_5t(struct enic *enic, struct flow_keys *keys, u16 rq)
{
int res;
struct filter data;
switch (keys->ip_proto) {
case IPPROTO_TCP:
data.u.ipv4.protocol = PROTO_TCP;
break;
case IPPROTO_UDP:
data.u.ipv4.protocol = PROTO_UDP;
break;
default:
return -EPROTONOSUPPORT;
};
data.type = FILTER_IPV4_5TUPLE;
data.u.ipv4.src_addr = ntohl(keys->src);
data.u.ipv4.dst_addr = ntohl(keys->dst);
data.u.ipv4.src_port = ntohs(keys->port16[0]);
data.u.ipv4.dst_port = ntohs(keys->port16[1]);
data.u.ipv4.flags = FILTER_FIELDS_IPV4_5TUPLE;
spin_lock_bh(&enic->devcmd_lock);
res = vnic_dev_classifier(enic->vdev, CLSF_ADD, &rq, &data);
spin_unlock_bh(&enic->devcmd_lock);
res = (res == 0) ? rq : res;
return res;
}
/* enic_delfltr - Delete clsf filter
* @enic: enic struct of vnic
* @filter_id: filter_is(hardware_id) of filter to be deleted
*
* This function returns zero in case of success, negative number incase of
* error.
*/
int enic_delfltr(struct enic *enic, u16 filter_id)
{
int ret;
spin_lock_bh(&enic->devcmd_lock);
ret = vnic_dev_classifier(enic->vdev, CLSF_DEL, &filter_id, NULL);
spin_unlock_bh(&enic->devcmd_lock);
return ret;
}
/* enic_rfs_flw_tbl_init - initialize enic->rfs_h members
* @enic: enic data
*/
void enic_rfs_flw_tbl_init(struct enic *enic)
{
int i;
spin_lock_init(&enic->rfs_h.lock);
for (i = 0; i <= ENIC_RFS_FLW_MASK; i++)
INIT_HLIST_HEAD(&enic->rfs_h.ht_head[i]);
enic->rfs_h.max = enic->config.num_arfs;
enic->rfs_h.free = enic->rfs_h.max;
enic->rfs_h.toclean = 0;
enic_rfs_timer_start(enic);
}
void enic_rfs_flw_tbl_free(struct enic *enic)
{
int i;
enic_rfs_timer_stop(enic);
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;
struct hlist_node *tmp;
struct enic_rfs_fltr_node *n;
hhead = &enic->rfs_h.ht_head[i];
hlist_for_each_entry_safe(n, tmp, hhead, node) {
enic_delfltr(enic, n->fltr_id);
hlist_del(&n->node);
kfree(n);
}
}
spin_unlock_bh(&enic->rfs_h.lock);
}
struct enic_rfs_fltr_node *htbl_fltr_search(struct enic *enic, u16 fltr_id)
{
int i;
for (i = 0; i < (1 << ENIC_RFS_FLW_BITSHIFT); i++) {
struct hlist_head *hhead;
struct hlist_node *tmp;
struct enic_rfs_fltr_node *n;
hhead = &enic->rfs_h.ht_head[i];
hlist_for_each_entry_safe(n, tmp, hhead, node)
if (n->fltr_id == fltr_id)
return n;
}
return NULL;
}
#ifdef CONFIG_RFS_ACCEL
void enic_flow_may_expire(unsigned long data)
{
struct enic *enic = (struct enic *)data;
bool res;
int j;
spin_lock_bh(&enic->rfs_h.lock);
for (j = 0; j < ENIC_CLSF_EXPIRE_COUNT; j++) {
struct hlist_head *hhead;
struct hlist_node *tmp;
struct enic_rfs_fltr_node *n;
hhead = &enic->rfs_h.ht_head[enic->rfs_h.toclean++];
hlist_for_each_entry_safe(n, tmp, hhead, node) {
res = rps_may_expire_flow(enic->netdev, n->rq_id,
n->flow_id, n->fltr_id);
if (res) {
res = enic_delfltr(enic, n->fltr_id);
if (unlikely(res))
continue;
hlist_del(&n->node);
kfree(n);
enic->rfs_h.free++;
}
}
}
spin_unlock_bh(&enic->rfs_h.lock);
mod_timer(&enic->rfs_h.rfs_may_expire, jiffies + HZ/4);
}
static struct enic_rfs_fltr_node *htbl_key_search(struct hlist_head *h,
struct flow_keys *k)
{
struct enic_rfs_fltr_node *tpos;
hlist_for_each_entry(tpos, h, node)
if (tpos->keys.src == k->src &&
tpos->keys.dst == k->dst &&
tpos->keys.ports == k->ports &&
tpos->keys.ip_proto == k->ip_proto &&
tpos->keys.n_proto == k->n_proto)
return tpos;
return NULL;
}
int enic_rx_flow_steer(struct net_device *dev, const struct sk_buff *skb,
u16 rxq_index, u32 flow_id)
{
struct flow_keys keys;
struct enic_rfs_fltr_node *n;
struct enic *enic;
u16 tbl_idx;
int res, i;
enic = netdev_priv(dev);
res = skb_flow_dissect(skb, &keys);
if (!res || keys.n_proto != htons(ETH_P_IP) ||
(keys.ip_proto != IPPROTO_TCP && keys.ip_proto != IPPROTO_UDP))
return -EPROTONOSUPPORT;
tbl_idx = skb_get_hash_raw(skb) & ENIC_RFS_FLW_MASK;
spin_lock_bh(&enic->rfs_h.lock);
n = htbl_key_search(&enic->rfs_h.ht_head[tbl_idx], &keys);
if (n) { /* entry already present */
if (rxq_index == n->rq_id) {
res = -EEXIST;
goto ret_unlock;
}
/* desired rq changed for the flow, we need to delete
* old fltr and add new one
*
* The moment we delete the fltr, the upcoming pkts
* are put it default rq based on rss. When we add
* new filter, upcoming pkts are put in desired queue.
* This could cause ooo pkts.
*
* Lets 1st try adding new fltr and then del old one.
*/
i = --enic->rfs_h.free;
/* clsf tbl is full, we have to del old fltr first*/
if (unlikely(i < 0)) {
enic->rfs_h.free++;
res = enic_delfltr(enic, n->fltr_id);
if (unlikely(res < 0))
goto ret_unlock;
res = enic_addfltr_5t(enic, &keys, rxq_index);
if (res < 0) {
hlist_del(&n->node);
enic->rfs_h.free++;
goto ret_unlock;
}
/* add new fltr 1st then del old fltr */
} else {
int ret;
res = enic_addfltr_5t(enic, &keys, rxq_index);
if (res < 0) {
enic->rfs_h.free++;
goto ret_unlock;
}
ret = enic_delfltr(enic, n->fltr_id);
/* deleting old fltr failed. Add old fltr to list.
* enic_flow_may_expire() will try to delete it later.
*/
if (unlikely(ret < 0)) {
struct enic_rfs_fltr_node *d;
struct hlist_head *head;
head = &enic->rfs_h.ht_head[tbl_idx];
d = kmalloc(sizeof(*d), GFP_ATOMIC);
if (d) {
d->fltr_id = n->fltr_id;
INIT_HLIST_NODE(&d->node);
hlist_add_head(&d->node, head);
}
} else {
enic->rfs_h.free++;
}
}
n->rq_id = rxq_index;
n->fltr_id = res;
n->flow_id = flow_id;
/* entry not present */
} else {
i = --enic->rfs_h.free;
if (i <= 0) {
enic->rfs_h.free++;
res = -EBUSY;
goto ret_unlock;
}
n = kmalloc(sizeof(*n), GFP_ATOMIC);
if (!n) {
res = -ENOMEM;
enic->rfs_h.free++;
goto ret_unlock;
}
res = enic_addfltr_5t(enic, &keys, rxq_index);
if (res < 0) {
kfree(n);
enic->rfs_h.free++;
goto ret_unlock;
}
n->rq_id = rxq_index;
n->fltr_id = res;
n->flow_id = flow_id;
n->keys = keys;
INIT_HLIST_NODE(&n->node);
hlist_add_head(&n->node, &enic->rfs_h.ht_head[tbl_idx]);
}
ret_unlock:
spin_unlock_bh(&enic->rfs_h.lock);
return res;
}
#endif /* CONFIG_RFS_ACCEL */