Sandro/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-09-18 23:19:34 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

net: add READ_ONCE()/WRITE_ONCE() annotations for dev->prio_tc_map

Browse Source 
Concurrent fast-path readers access dev->prio_tc_map (e.g. via
skb_tx_hash(), netdev_get_prio_tc_map(), and qdiscs) while writers
update entries in dev->prio_tc_map or reset/clear the map via
netdev_reset_tc() and netdev_unbind_sb_channel().

Furthermore, memset() in netdev_reset_tc() and
netdev_unbind_sb_channel() provides no guarantee of performing
atomic word/byte stores.

Add READ_ONCE() and WRITE_ONCE() annotations to netdev_get_prio_tc_map()
and netdev_set_prio_tc_map(), replace memset() in dev.c with explicit
WRITE_ONCE() loops, and update direct array accesses in qdiscs to use
netdev_get_prio_tc_map().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260812085440.3917924-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Dumazet
2026-08-17 10:27:48 -07:00
committed by Jakub Kicinski
parent 0c6c32a8c8
commit 51b0aaafd9
4 changed files with 9 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files
include/linux/netdevice.h
+2 -2
View File
@@ -2672,7 +2672,7 @@ static inline bool netif_elide_gro(const struct net_device *dev)
static inline
int netdev_get_prio_tc_map(const struct net_device *dev, u32 prio)
{
return dev->prio_tc_map[prio & TC_BITMASK];
return READ_ONCE(dev->prio_tc_map[prio & TC_BITMASK]);
}
static inline
@@ -2681,7 +2681,7 @@ int netdev_set_prio_tc_map(struct net_device *dev, u8 prio, u8 tc)
if (tc >= READ_ONCE(dev->num_tc))
return -EINVAL;
dev->prio_tc_map[prio & TC_BITMASK] = tc & TC_BITMASK;
WRITE_ONCE(dev->prio_tc_map[prio & TC_BITMASK], tc & TC_BITMASK);
return 0;
}
net/core/dev.c
+4 -2
View File
@@ -3120,7 +3120,8 @@ void netdev_reset_tc(struct net_device *dev)
WRITE_ONCE(dev->num_tc, 0);
for (i = 0; i < TC_MAX_QUEUE; i++)
WRITE_ONCE(dev->tc_to_txq[i].combined, 0);
memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
for (i = 0; i <= TC_BITMASK; i++)
WRITE_ONCE(dev->prio_tc_map[i], 0);
}
EXPORT_SYMBOL(netdev_reset_tc);
@@ -3168,7 +3169,8 @@ void netdev_unbind_sb_channel(struct net_device *dev,
#endif
for (i = 0; i < TC_MAX_QUEUE; i++)
WRITE_ONCE(sb_dev->tc_to_txq[i].combined, 0);
memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
for (i = 0; i <= TC_BITMASK; i++)
WRITE_ONCE(sb_dev->prio_tc_map[i], 0);
while (txq-- != &dev->_tx[0]) {
if (txq->sb_dev == sb_dev)
net/sched/sch_mqprio_lib.c
+2 -1
View File
@@ -105,7 +105,8 @@ void mqprio_qopt_reconstruct(struct net_device *dev, struct tc_mqprio_qopt *qopt
int tc, num_tc = netdev_get_num_tc(dev);
qopt->num_tc = num_tc;
memcpy(qopt->prio_tc_map, dev->prio_tc_map, sizeof(qopt->prio_tc_map));
for (tc = 0; tc <= TC_BITMASK; tc++)
qopt->prio_tc_map[tc] = netdev_get_prio_tc_map(dev, tc);
for (tc = 0; tc < num_tc; tc++) {
struct netdev_tc_txq res;
net/sched/sch_taprio.c
+1 -1
View File
@@ -1813,7 +1813,7 @@ static int taprio_mqprio_cmp(const struct net_device *dev,
}
for (i = 0; i <= TC_BITMASK; i++)
if (dev->prio_tc_map[i] != mqprio->prio_tc_map[i])
if (netdev_get_prio_tc_map(dev, i) != mqprio->prio_tc_map[i])
return -1;
return 0;