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| author | Willem de Bruijn <willemb@google.com> | 2018-04-23 17:37:03 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-04-24 13:17:08 -0400 |
| commit | a6361f0ca4b25460f2cdf3235ebe8115f622901e (patch) | |
| tree | f57888c07419a06a85caa62d73717363d86b15b7 /net/packet/internal.h | |
| parent | 9cf2f437ca5b39828984064fad213e68fc17ef11 (diff) | |
| download | lwn-a6361f0ca4b25460f2cdf3235ebe8115f622901e.tar.gz lwn-a6361f0ca4b25460f2cdf3235ebe8115f622901e.zip | |
packet: fix bitfield update race
Updates to the bitfields in struct packet_sock are not atomic.
Serialize these read-modify-write cycles.
Move po->running into a separate variable. Its writes are protected by
po->bind_lock (except for one startup case at packet_create). Also
replace a textual precondition warning with lockdep annotation.
All others are set only in packet_setsockopt. Serialize these
updates by holding the socket lock. Analogous to other field updates,
also hold the lock when testing whether a ring is active (pg_vec).
Fixes: 8dc419447415 ("[PACKET]: Add optional checksum computation for recvmsg")
Reported-by: DaeRyong Jeong <threeearcat@gmail.com>
Reported-by: Byoungyoung Lee <byoungyoung@purdue.edu>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/packet/internal.h')
| -rw-r--r-- | net/packet/internal.h | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/net/packet/internal.h b/net/packet/internal.h index a1d2b2319ae9..3bb7c5fb3bff 100644 --- a/net/packet/internal.h +++ b/net/packet/internal.h @@ -112,10 +112,12 @@ struct packet_sock { int copy_thresh; spinlock_t bind_lock; struct mutex pg_vec_lock; - unsigned int running:1, /* prot_hook is attached*/ - auxdata:1, + unsigned int running; /* bind_lock must be held */ + unsigned int auxdata:1, /* writer must hold sock lock */ origdev:1, - has_vnet_hdr:1; + has_vnet_hdr:1, + tp_loss:1, + tp_tx_has_off:1; int pressure; int ifindex; /* bound device */ __be16 num; @@ -125,8 +127,6 @@ struct packet_sock { enum tpacket_versions tp_version; unsigned int tp_hdrlen; unsigned int tp_reserve; - unsigned int tp_loss:1; - unsigned int tp_tx_has_off:1; unsigned int tp_tstamp; struct net_device __rcu *cached_dev; int (*xmit)(struct sk_buff *skb); |