net: embed nr_ids in the xps maps

Embed nr_ids (the number of cpu for the xps cpus map, and the number of
rxqs for the xps cpus map) in dev_maps. That will help not accessing out
of bound memory if those values change after dev_maps was allocated.

Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Antoine Tenart 2021-03-18 19:37:44 +01:00 committed by David S. Miller
parent 255c04a87f
commit 5478fcd0f4
3 changed files with 51 additions and 44 deletions

View File

@ -772,6 +772,9 @@ struct xps_map {
/*
* This structure holds all XPS maps for device. Maps are indexed by CPU.
*
* We keep track of the number of cpus/rxqs used when the struct is allocated,
* in nr_ids. This will help not accessing out-of-bound memory.
*
* We keep track of the number of traffic classes used when the struct is
* allocated, in num_tc. This will be used to navigate the maps, to ensure we're
* not crossing its upper bound, as the original dev->num_tc can be updated in
@ -779,6 +782,7 @@ struct xps_map {
*/
struct xps_dev_maps {
struct rcu_head rcu;
unsigned int nr_ids;
s16 num_tc;
struct xps_map __rcu *attr_map[]; /* Either CPUs map or RXQs map */
};

View File

@ -2524,14 +2524,14 @@ static void reset_xps_maps(struct net_device *dev,
}
static void clean_xps_maps(struct net_device *dev, const unsigned long *mask,
struct xps_dev_maps *dev_maps, unsigned int nr_ids,
u16 offset, u16 count, bool is_rxqs_map)
struct xps_dev_maps *dev_maps, u16 offset, u16 count,
bool is_rxqs_map)
{
unsigned int nr_ids = dev_maps->nr_ids;
bool active = false;
int i, j;
for (j = -1; j = netif_attrmask_next(j, mask, nr_ids),
j < nr_ids;)
for (j = -1; j = netif_attrmask_next(j, mask, nr_ids), j < nr_ids;)
active |= remove_xps_queue_cpu(dev, dev_maps, j, offset,
count);
if (!active)
@ -2551,7 +2551,6 @@ static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
{
const unsigned long *possible_mask = NULL;
struct xps_dev_maps *dev_maps;
unsigned int nr_ids;
if (!static_key_false(&xps_needed))
return;
@ -2561,11 +2560,9 @@ static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
if (static_key_false(&xps_rxqs_needed)) {
dev_maps = xmap_dereference(dev->xps_rxqs_map);
if (dev_maps) {
nr_ids = dev->num_rx_queues;
clean_xps_maps(dev, possible_mask, dev_maps, nr_ids,
offset, count, true);
}
if (dev_maps)
clean_xps_maps(dev, possible_mask, dev_maps, offset,
count, true);
}
dev_maps = xmap_dereference(dev->xps_cpus_map);
@ -2574,9 +2571,7 @@ static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
if (num_possible_cpus() > 1)
possible_mask = cpumask_bits(cpu_possible_mask);
nr_ids = nr_cpu_ids;
clean_xps_maps(dev, possible_mask, dev_maps, nr_ids, offset, count,
false);
clean_xps_maps(dev, possible_mask, dev_maps, offset, count, false);
out_no_maps:
mutex_unlock(&xps_map_mutex);
@ -2673,11 +2668,12 @@ int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
maps_sz = L1_CACHE_BYTES;
/* The old dev_maps could be larger or smaller than the one we're
* setting up now, as dev->num_tc could have been updated in between. We
* could try to be smart, but let's be safe instead and only copy
* foreign traffic classes if the two map sizes match.
* setting up now, as dev->num_tc or nr_ids could have been updated in
* between. We could try to be smart, but let's be safe instead and only
* copy foreign traffic classes if the two map sizes match.
*/
if (dev_maps && dev_maps->num_tc == num_tc)
if (dev_maps &&
dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
copy = true;
/* allocate memory for queue storage */
@ -2690,6 +2686,7 @@ int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
return -ENOMEM;
}
new_dev_maps->nr_ids = nr_ids;
new_dev_maps->num_tc = num_tc;
}
@ -2770,7 +2767,7 @@ int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
goto out_no_old_maps;
for (j = -1; j = netif_attrmask_next(j, possible_mask, nr_ids),
j < nr_ids;) {
j < dev_maps->nr_ids;) {
for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
map = xmap_dereference(dev_maps->attr_map[tci]);
if (!map)
@ -2804,12 +2801,12 @@ out_no_new_maps:
goto out_no_maps;
/* removes tx-queue from unused CPUs/rx-queues */
for (j = -1; j = netif_attrmask_next(j, possible_mask, nr_ids),
j < nr_ids;) {
for (j = -1; j = netif_attrmask_next(j, possible_mask, dev_maps->nr_ids),
j < dev_maps->nr_ids;) {
for (i = tc, tci = j * dev_maps->num_tc; i--; tci++)
active |= remove_xps_queue(dev_maps, tci, index);
if (!netif_attr_test_mask(j, mask, nr_ids) ||
!netif_attr_test_online(j, online_mask, nr_ids))
if (!netif_attr_test_mask(j, mask, dev_maps->nr_ids) ||
!netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
active |= remove_xps_queue(dev_maps, tci, index);
for (i = dev_maps->num_tc - tc, tci++; --i; tci++)
active |= remove_xps_queue(dev_maps, tci, index);
@ -3965,7 +3962,7 @@ static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
struct xps_map *map;
int queue_index = -1;
if (tc >= dev_maps->num_tc)
if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
return queue_index;
tci *= dev_maps->num_tc;
@ -4004,7 +4001,7 @@ static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
if (dev_maps) {
int tci = sk_rx_queue_get(sk);
if (tci >= 0 && tci < dev->num_rx_queues)
if (tci >= 0)
queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
tci);
}

View File

@ -1366,9 +1366,9 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue,
{
struct net_device *dev = queue->dev;
struct xps_dev_maps *dev_maps;
unsigned int index, nr_ids;
int j, len, ret, tc = 0;
unsigned long *mask;
unsigned int index;
if (!netif_is_multiqueue(dev))
return -ENOENT;
@ -1387,19 +1387,20 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue,
goto err_rtnl_unlock;
}
mask = bitmap_zalloc(nr_cpu_ids, GFP_KERNEL);
if (!mask) {
ret = -ENOMEM;
goto err_rtnl_unlock;
}
rcu_read_lock();
dev_maps = rcu_dereference(dev->xps_cpus_map);
nr_ids = dev_maps ? dev_maps->nr_ids : nr_cpu_ids;
mask = bitmap_zalloc(nr_ids, GFP_KERNEL);
if (!mask) {
ret = -ENOMEM;
goto err_rcu_unlock;
}
if (!dev_maps || tc >= dev_maps->num_tc)
goto out_no_maps;
for (j = -1; j = netif_attrmask_next(j, NULL, nr_cpu_ids),
j < nr_cpu_ids;) {
for (j = -1; j = netif_attrmask_next(j, NULL, nr_ids), j < nr_ids;) {
int i, tci = j * dev_maps->num_tc + tc;
struct xps_map *map;
@ -1419,10 +1420,12 @@ out_no_maps:
rtnl_unlock();
len = bitmap_print_to_pagebuf(false, buf, mask, nr_cpu_ids);
len = bitmap_print_to_pagebuf(false, buf, mask, nr_ids);
bitmap_free(mask);
return len < PAGE_SIZE ? len : -EINVAL;
err_rcu_unlock:
rcu_read_unlock();
err_rtnl_unlock:
rtnl_unlock();
return ret;
@ -1473,9 +1476,9 @@ static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf)
{
struct net_device *dev = queue->dev;
struct xps_dev_maps *dev_maps;
unsigned int index, nr_ids;
int j, len, ret, tc = 0;
unsigned long *mask;
unsigned int index;
index = get_netdev_queue_index(queue);
@ -1488,19 +1491,20 @@ static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf)
goto err_rtnl_unlock;
}
mask = bitmap_zalloc(dev->num_rx_queues, GFP_KERNEL);
if (!mask) {
ret = -ENOMEM;
goto err_rtnl_unlock;
}
rcu_read_lock();
dev_maps = rcu_dereference(dev->xps_rxqs_map);
nr_ids = dev_maps ? dev_maps->nr_ids : dev->num_rx_queues;
mask = bitmap_zalloc(nr_ids, GFP_KERNEL);
if (!mask) {
ret = -ENOMEM;
goto err_rcu_unlock;
}
if (!dev_maps || tc >= dev_maps->num_tc)
goto out_no_maps;
for (j = -1; j = netif_attrmask_next(j, NULL, dev->num_rx_queues),
j < dev->num_rx_queues;) {
for (j = -1; j = netif_attrmask_next(j, NULL, nr_ids), j < nr_ids;) {
int i, tci = j * dev_maps->num_tc + tc;
struct xps_map *map;
@ -1520,11 +1524,13 @@ out_no_maps:
rtnl_unlock();
len = bitmap_print_to_pagebuf(false, buf, mask, dev->num_rx_queues);
len = bitmap_print_to_pagebuf(false, buf, mask, nr_ids);
bitmap_free(mask);
return len < PAGE_SIZE ? len : -EINVAL;
err_rcu_unlock:
rcu_read_unlock();
err_rtnl_unlock:
rtnl_unlock();
return ret;