On Thu, 2017-01-05 at 02:34 +0100, Daniel Borkmann wrote:
> When TX timestamping is in use with TPACKET_V3's TX ring, then we'll
> hit the BUG() in __packet_set_timestamp() when ring buffer slot is
> returned to user space via tpacket_destruct_skb(). This is due to v3
> being assumed as unreachable here, but since 7f953ab2ba46 ("af_packet:
> TX_RING support for TPACKET_V3") it's not anymore. Fix it by filling
> the timestamp back into the ring slot.
>
> Fixes: 7f953ab2ba46 ("af_packet: TX_RING support for TPACKET_V3")
> Signed-off-by: Daniel Borkmann <[email protected]>
> ---
> net/packet/af_packet.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
> index 7e39087..ddbda25 100644
> --- a/net/packet/af_packet.c
> +++ b/net/packet/af_packet.c
> @@ -481,6 +481,9 @@ static __u32 __packet_set_timestamp(struct packet_sock
> *po, void *frame,
> h.h2->tp_nsec = ts.tv_nsec;
> break;
> case TPACKET_V3:
> + h.h3->tp_sec = ts.tv_sec;
> + h.h3->tp_nsec = ts.tv_nsec;
> + break;
> default:
> WARN(1, "TPACKET version not supported.\n");
> BUG();
Gosh. Can we also replace this BUG() into something less aggressive ?
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index
b9e1a13b4ba36a0bc7edf6a8c2c116c7d48c970c..0c0d268544787dcbef6601c5014e7d3836d16f96
100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -476,9 +476,11 @@ static __u32 __packet_set_timestamp(struct packet_sock
*po, void *frame,
h.h2->tp_nsec = ts.tv_nsec;
break;
case TPACKET_V3:
+ h.h3->tp_sec = ts.tv_sec;
+ h.h3->tp_nsec = ts.tv_nsec;
+ break;
default:
- WARN(1, "TPACKET version not supported.\n");
- BUG();
+ pr_err_once("TPACKET version %u not supported.\n",
po->tp_version);
}
/* one flush is safe, as both fields always lie on the same cacheline */
