diff options
author | Olaf Kirch <olaf.kirch@oracle.com> | 2007-07-11 22:32:02 -0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2007-07-11 22:32:02 -0400 |
commit | 29578624e354f56143d92510fff33a8b2aaa2c03 (patch) | |
tree | 67d0f28264dbeacedde4882f1e76157894ba33ba /net/core | |
parent | 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9 (diff) |
[NET]: Fix races in net_rx_action vs netpoll.
Keep netpoll/poll_napi from messing with the poll_list.
Only net_rx_action is allowed to manipulate the list.
Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r-- | net/core/netpoll.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/net/core/netpoll.c b/net/core/netpoll.c index de1b26aa5720..d1264e9a50a8 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c | |||
@@ -124,6 +124,13 @@ static void poll_napi(struct netpoll *np) | |||
124 | if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && | 124 | if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) && |
125 | npinfo->poll_owner != smp_processor_id() && | 125 | npinfo->poll_owner != smp_processor_id() && |
126 | spin_trylock(&npinfo->poll_lock)) { | 126 | spin_trylock(&npinfo->poll_lock)) { |
127 | /* When calling dev->poll from poll_napi, we may end up in | ||
128 | * netif_rx_complete. However, only the CPU to which the | ||
129 | * device was queued is allowed to remove it from poll_list. | ||
130 | * Setting POLL_LIST_FROZEN tells netif_rx_complete | ||
131 | * to leave the NAPI state alone. | ||
132 | */ | ||
133 | set_bit(__LINK_STATE_POLL_LIST_FROZEN, &np->dev->state); | ||
127 | npinfo->rx_flags |= NETPOLL_RX_DROP; | 134 | npinfo->rx_flags |= NETPOLL_RX_DROP; |
128 | atomic_inc(&trapped); | 135 | atomic_inc(&trapped); |
129 | 136 | ||
@@ -131,6 +138,7 @@ static void poll_napi(struct netpoll *np) | |||
131 | 138 | ||
132 | atomic_dec(&trapped); | 139 | atomic_dec(&trapped); |
133 | npinfo->rx_flags &= ~NETPOLL_RX_DROP; | 140 | npinfo->rx_flags &= ~NETPOLL_RX_DROP; |
141 | clear_bit(__LINK_STATE_POLL_LIST_FROZEN, &np->dev->state); | ||
134 | spin_unlock(&npinfo->poll_lock); | 142 | spin_unlock(&npinfo->poll_lock); |
135 | } | 143 | } |
136 | } | 144 | } |