* [PATCH v3 net-next] tcp: Remove use of daddr_cache in tracepoint
@ 2017-10-17 20:09 David Ahern
2017-10-17 20:34 ` Cong Wang
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: David Ahern @ 2017-10-17 20:09 UTC (permalink / raw)
To: netdev; +Cc: xiyou.wangcong, eric.dumazet, David Ahern
Running perf in one window to capture tcp_retransmit_skb tracepoint:
$ perf record -e tcp:tcp_retransmit_skb -a
And causing a retransmission on an active TCP session (e.g., dropping
packets in the receiver, changing MTU on the interface to 500 and back
to 1500) triggers a panic:
[ 58.543144] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 58.545300] IP: perf_trace_tcp_retransmit_skb+0xd0/0x145
[ 58.546770] PGD 0 P4D 0
[ 58.547472] Oops: 0000 [#1] SMP
[ 58.548328] Modules linked in: vrf
[ 58.549262] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-rc4+ #26
[ 58.551004] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 58.554560] task: ffffffff81a0e540 task.stack: ffffffff81a00000
[ 58.555817] RIP: 0010:perf_trace_tcp_retransmit_skb+0xd0/0x145
[ 58.557137] RSP: 0018:ffff88003fc03d68 EFLAGS: 00010282
[ 58.558292] RAX: 0000000000000000 RBX: ffffe8ffffc0ec80 RCX: ffff880038543098
[ 58.559850] RDX: 0400000000000000 RSI: ffff88003fc03d70 RDI: ffff88003fc14b68
[ 58.561099] RBP: ffff88003fc03da8 R08: 0000000000000000 R09: ffffea0000d3224a
[ 58.562005] R10: ffff88003fc03db8 R11: 0000000000000010 R12: ffff8800385428c0
[ 58.562930] R13: ffffe8ffffc0e478 R14: ffffffff81a93a40 R15: ffff88003d4f0c00
[ 58.563845] FS: 0000000000000000(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
[ 58.564873] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 58.565613] CR2: 0000000000000008 CR3: 000000003d68f004 CR4: 00000000000606f0
[ 58.566538] Call Trace:
[ 58.566865] <IRQ>
[ 58.567140] __tcp_retransmit_skb+0x4ab/0x4c6
[ 58.567704] ? tcp_set_ca_state+0x22/0x3f
[ 58.568231] tcp_retransmit_skb+0x14/0xa3
[ 58.568754] tcp_retransmit_timer+0x472/0x5e3
[ 58.569324] ? tcp_write_timer_handler+0x1e9/0x1e9
[ 58.569946] tcp_write_timer_handler+0x95/0x1e9
[ 58.570548] tcp_write_timer+0x2a/0x58
Remove use of ipv6_pinfo in favor of data in sock_common.
Fixes: e086101b150a ("tcp: add a tracepoint for tcp retransmission")
Signed-off-by: David Ahern <dsahern@gmail.com>
---
v3
- remove use of inet6_sk and check sk_family (requested by Eric)
- Add IS_ENABLED(CONFIG_IPV6) around use of sk_v6_rcv_saddr and
sk_v6_daddr as done in sock_common (noted by Cong)
v2
- remove np and get addresses from sock_common
include/trace/events/tcp.h | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h
index 3d1cbd072b7e..271812216ce3 100644
--- a/include/trace/events/tcp.h
+++ b/include/trace/events/tcp.h
@@ -27,7 +27,6 @@ TRACE_EVENT(tcp_retransmit_skb,
),
TP_fast_assign(
- struct ipv6_pinfo *np = inet6_sk(sk);
struct inet_sock *inet = inet_sk(sk);
struct in6_addr *pin6;
__be32 *p32;
@@ -44,12 +43,15 @@ TRACE_EVENT(tcp_retransmit_skb,
p32 = (__be32 *) __entry->daddr;
*p32 = inet->inet_daddr;
- if (np) {
+#if IS_ENABLED(CONFIG_IPV6)
+ if (sk->sk_family == AF_INET6) {
pin6 = (struct in6_addr *)__entry->saddr_v6;
- *pin6 = np->saddr;
+ *pin6 = sk->sk_v6_rcv_saddr;
pin6 = (struct in6_addr *)__entry->daddr_v6;
- *pin6 = *(np->daddr_cache);
- } else {
+ *pin6 = sk->sk_v6_daddr;
+ } else
+#endif
+ {
pin6 = (struct in6_addr *)__entry->saddr_v6;
ipv6_addr_set_v4mapped(inet->inet_saddr, pin6);
pin6 = (struct in6_addr *)__entry->daddr_v6;
--
2.1.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v3 net-next] tcp: Remove use of daddr_cache in tracepoint
2017-10-17 20:09 [PATCH v3 net-next] tcp: Remove use of daddr_cache in tracepoint David Ahern
@ 2017-10-17 20:34 ` Cong Wang
2017-10-17 21:44 ` Eric Dumazet
2017-10-19 12:32 ` David Miller
2 siblings, 0 replies; 5+ messages in thread
From: Cong Wang @ 2017-10-17 20:34 UTC (permalink / raw)
To: David Ahern; +Cc: Linux Kernel Network Developers, Eric Dumazet
On Tue, Oct 17, 2017 at 1:09 PM, David Ahern <dsahern@gmail.com> wrote:
> Running perf in one window to capture tcp_retransmit_skb tracepoint:
> $ perf record -e tcp:tcp_retransmit_skb -a
>
> And causing a retransmission on an active TCP session (e.g., dropping
> packets in the receiver, changing MTU on the interface to 500 and back
> to 1500) triggers a panic:
>
> [ 58.543144] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
> [ 58.545300] IP: perf_trace_tcp_retransmit_skb+0xd0/0x145
> [ 58.546770] PGD 0 P4D 0
> [ 58.547472] Oops: 0000 [#1] SMP
> [ 58.548328] Modules linked in: vrf
> [ 58.549262] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-rc4+ #26
> [ 58.551004] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
> [ 58.554560] task: ffffffff81a0e540 task.stack: ffffffff81a00000
> [ 58.555817] RIP: 0010:perf_trace_tcp_retransmit_skb+0xd0/0x145
> [ 58.557137] RSP: 0018:ffff88003fc03d68 EFLAGS: 00010282
> [ 58.558292] RAX: 0000000000000000 RBX: ffffe8ffffc0ec80 RCX: ffff880038543098
> [ 58.559850] RDX: 0400000000000000 RSI: ffff88003fc03d70 RDI: ffff88003fc14b68
> [ 58.561099] RBP: ffff88003fc03da8 R08: 0000000000000000 R09: ffffea0000d3224a
> [ 58.562005] R10: ffff88003fc03db8 R11: 0000000000000010 R12: ffff8800385428c0
> [ 58.562930] R13: ffffe8ffffc0e478 R14: ffffffff81a93a40 R15: ffff88003d4f0c00
> [ 58.563845] FS: 0000000000000000(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
> [ 58.564873] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 58.565613] CR2: 0000000000000008 CR3: 000000003d68f004 CR4: 00000000000606f0
> [ 58.566538] Call Trace:
> [ 58.566865] <IRQ>
> [ 58.567140] __tcp_retransmit_skb+0x4ab/0x4c6
> [ 58.567704] ? tcp_set_ca_state+0x22/0x3f
> [ 58.568231] tcp_retransmit_skb+0x14/0xa3
> [ 58.568754] tcp_retransmit_timer+0x472/0x5e3
> [ 58.569324] ? tcp_write_timer_handler+0x1e9/0x1e9
> [ 58.569946] tcp_write_timer_handler+0x95/0x1e9
> [ 58.570548] tcp_write_timer+0x2a/0x58
>
> Remove use of ipv6_pinfo in favor of data in sock_common.
>
> Fixes: e086101b150a ("tcp: add a tracepoint for tcp retransmission")
> Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v3 net-next] tcp: Remove use of daddr_cache in tracepoint
2017-10-17 20:09 [PATCH v3 net-next] tcp: Remove use of daddr_cache in tracepoint David Ahern
2017-10-17 20:34 ` Cong Wang
@ 2017-10-17 21:44 ` Eric Dumazet
2017-10-19 12:32 ` David Miller
2 siblings, 0 replies; 5+ messages in thread
From: Eric Dumazet @ 2017-10-17 21:44 UTC (permalink / raw)
To: David Ahern; +Cc: netdev, xiyou.wangcong
On Tue, 2017-10-17 at 13:09 -0700, David Ahern wrote:
> Running perf in one window to capture tcp_retransmit_skb tracepoint:
> $ perf record -e tcp:tcp_retransmit_skb -a
>
> And causing a retransmission on an active TCP session (e.g., dropping
> packets in the receiver, changing MTU on the interface to 500 and back
> to 1500) triggers a panic:
> Remove use of ipv6_pinfo in favor of data in sock_common.
>
> Fixes: e086101b150a ("tcp: add a tracepoint for tcp retransmission")
> Signed-off-by: David Ahern <dsahern@gmail.com>
> ---
Reviewed-by: Eric Dumazet <edumazet@google.com>
Thanks David !
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v3 net-next] tcp: Remove use of daddr_cache in tracepoint
[not found] <1508276678.31614.118.camel.edumazet-glaptop3.roam.corp.google.com>
@ 2017-10-18 0:25 ` Song Liu
0 siblings, 0 replies; 5+ messages in thread
From: Song Liu @ 2017-10-18 0:25 UTC (permalink / raw)
To: netdev; +Cc: eric.dumazet, xiyou.wangcong, dsahern, Song Liu
> > Remove use of ipv6_pinfo in favor of data in sock_common.
> >
> > Fixes: e086101b150a ("tcp: add a tracepoint for tcp retransmission")
> > Signed-off-by: David Ahern <dsahern@gmail.com>
> > ---
>
> Reviewed-by: Eric Dumazet <edumazet@google.com>
> Thanks David !
Tested-by: Song Liu <songliubraving@fb.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v3 net-next] tcp: Remove use of daddr_cache in tracepoint
2017-10-17 20:09 [PATCH v3 net-next] tcp: Remove use of daddr_cache in tracepoint David Ahern
2017-10-17 20:34 ` Cong Wang
2017-10-17 21:44 ` Eric Dumazet
@ 2017-10-19 12:32 ` David Miller
2 siblings, 0 replies; 5+ messages in thread
From: David Miller @ 2017-10-19 12:32 UTC (permalink / raw)
To: dsahern; +Cc: netdev, xiyou.wangcong, eric.dumazet
From: David Ahern <dsahern@gmail.com>
Date: Tue, 17 Oct 2017 13:09:33 -0700
> Running perf in one window to capture tcp_retransmit_skb tracepoint:
> $ perf record -e tcp:tcp_retransmit_skb -a
>
> And causing a retransmission on an active TCP session (e.g., dropping
> packets in the receiver, changing MTU on the interface to 500 and back
> to 1500) triggers a panic:
...
> Remove use of ipv6_pinfo in favor of data in sock_common.
>
> Fixes: e086101b150a ("tcp: add a tracepoint for tcp retransmission")
> Signed-off-by: David Ahern <dsahern@gmail.com>
This doesn't apply to net-next, please respin.
Thanks.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2017-10-19 12:32 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2017-10-17 20:09 [PATCH v3 net-next] tcp: Remove use of daddr_cache in tracepoint David Ahern
2017-10-17 20:34 ` Cong Wang
2017-10-17 21:44 ` Eric Dumazet
2017-10-19 12:32 ` David Miller
[not found] <1508276678.31614.118.camel.edumazet-glaptop3.roam.corp.google.com>
2017-10-18 0:25 ` Song Liu
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