From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Willem de Bruijn <willemb@google.com>,
Mahesh Bandewar <maheshb@google.com>
Cc: netdev <netdev@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>
Subject: [PATCH net-next 2/8] net/packet: constify packet_lookup_frame() and __tpacket_has_room()
Date: Wed, 12 Jun 2019 09:52:27 -0700 [thread overview]
Message-ID: <20190612165233.109749-3-edumazet@google.com> (raw)
In-Reply-To: <20190612165233.109749-1-edumazet@google.com>
Goal is to be able to use __tpacket_has_room() without holding a lock.
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
net/packet/af_packet.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 66fcfd5b51f82a861795e002e91d3cbc69ab545a..273bffd2130d36cceb9947540a8511a51895874a 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -460,10 +460,10 @@ static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
return ts_status;
}
-static void *packet_lookup_frame(struct packet_sock *po,
- struct packet_ring_buffer *rb,
- unsigned int position,
- int status)
+static void *packet_lookup_frame(const struct packet_sock *po,
+ const struct packet_ring_buffer *rb,
+ unsigned int position,
+ int status)
{
unsigned int pg_vec_pos, frame_offset;
union tpacket_uhdr h;
@@ -1198,12 +1198,12 @@ static void packet_free_pending(struct packet_sock *po)
#define ROOM_LOW 0x1
#define ROOM_NORMAL 0x2
-static bool __tpacket_has_room(struct packet_sock *po, int pow_off)
+static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
{
int idx, len;
- len = po->rx_ring.frame_max + 1;
- idx = po->rx_ring.head;
+ len = READ_ONCE(po->rx_ring.frame_max) + 1;
+ idx = READ_ONCE(po->rx_ring.head);
if (pow_off)
idx += len >> pow_off;
if (idx >= len)
--
2.22.0.rc2.383.gf4fbbf30c2-goog
next prev parent reply other threads:[~2019-06-12 16:52 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 16:52 [PATCH net-next 0/8] net/packet: better behavior under DDOS Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 1/8] net/packet: constify __packet_get_status() argument Eric Dumazet
2019-06-12 16:52 ` Eric Dumazet [this message]
2019-06-12 16:52 ` [PATCH net-next 3/8] net/packet: constify prb_lookup_block() and __tpacket_v3_has_room() Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 4/8] net/packet: constify __packet_rcv_has_room() Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 5/8] net/packet: make tp_drops atomic Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 6/8] net/packet: implement shortcut in tpacket_rcv() Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 7/8] net/packet: remove locking from packet_rcv_has_room() Eric Dumazet
2019-06-12 16:52 ` [PATCH net-next 8/8] net/packet: introduce packet_rcv_try_clear_pressure() helper Eric Dumazet
2019-06-13 0:11 ` Vinicius Costa Gomes
2019-06-12 17:15 ` [PATCH net-next 0/8] net/packet: better behavior under DDOS Willem de Bruijn
2019-06-15 1:53 ` David Miller
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