Commit d4b5bd98 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net/packet: constify packet_lookup_frame() and __tpacket_has_room() 



Goal is to be able to use __tpacket_has_room() without holding a lock.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 96f657e6

net/packet/af_packet.c

+7 −7
Original line number Diff line number Diff line
@@ -460,8 +460,8 @@ 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,

static void *packet_lookup_frame(const struct packet_sock *po,

				 const struct packet_ring_buffer *rb,

				 unsigned int position,

				 int status)

{
@@ -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)