linux.git/include/trace/events/sock.h, branch v6.2

net: sock: tracing: Fix sock_exceed_buf_limit not to dereference stale pointer

2022-07-08T11:06:17+00:00

The trace event sock_exceed_buf_limit saves the prot->sysctl_mem pointer
and then dereferences it in the TP_printk() portion. This is unsafe as the
TP_printk() portion is executed at the time the buffer is read. That is,
it can be seconds, minutes, days, months, even years later. If the proto
is freed, then this dereference will can also lead to a kernel crash.

Instead, save the sysctl_mem array into the ring buffer and have the
TP_printk() reference that instead. This is the proper and safe way to
read pointers in trace events.

Link: https://lore.kernel.org/all/20220706052130.16368-12-kuniyu@amazon.com/

Cc: stable@vger.kernel.org
Fixes: 3847ce32aea9f ("core: add tracepoints for queueing skb to rcvbuf")
Signed-off-by: Steven Rostedt (Google) 
Acked-by: Kuniyuki Iwashima 
Signed-off-by: David S. Miller

net: sock: add trace for socket errors

2021-06-29T18:28:21+00:00

This patch will add tracers to trace inet socket errors only. A user
space monitor application can track connection errors indepedent from
socket lifetime and do additional handling. For example a cluster
manager can fence a node if errors occurs in a specific heuristic.

Signed-off-by: Alexander Aring 
Signed-off-by: David S. Miller

tcp: Define IPPROTO_MPTCP

2020-01-10T02:41:41+00:00

To open a MPTCP socket with socket(AF_INET, SOCK_STREAM, IPPROTO_MPTCP),
IPPROTO_MPTCP needs a value that differs from IPPROTO_TCP. The existing
IPPROTO numbers mostly map directly to IANA-specified protocol numbers.
MPTCP does not have a protocol number allocated because MPTCP packets
use the TCP protocol number. Use private number not used OTA.

Reviewed-by: Eric Dumazet 
Signed-off-by: Mat Martineau 
Signed-off-by: David S. Miller

sock: Make sk_protocol a 16-bit value

2020-01-10T02:41:41+00:00

Match the 16-bit width of skbuff->protocol. Fills an 8-bit hole so
sizeof(struct sock) does not change.

Also take care of BPF field access for sk_type/sk_protocol. Both of them
are now outside the bitfield, so we can use load instructions without
further shifting/masking.

v5 -> v6:
 - update eBPF accessors, too (Intel's kbuild test robot)
v2 -> v3:
 - keep 'sk_type' 2 bytes aligned (Eric)
v1 -> v2:
 - preserve sk_pacing_shift as bit field (Eric)

Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: bpf@vger.kernel.org
Co-developed-by: Paolo Abeni 
Signed-off-by: Paolo Abeni 
Co-developed-by: Matthieu Baerts 
Signed-off-by: Matthieu Baerts 
Signed-off-by: Mat Martineau 
Signed-off-by: David S. Miller

tcp: annotate sk->sk_wmem_queued lockless reads

2019-10-13T17:13:08+00:00

For the sake of tcp_poll(), there are few places where we fetch
sk->sk_wmem_queued while this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make sure write
sides use corresponding WRITE_ONCE() to avoid store-tearing.

sk_wmem_queued_add() helper is added so that we can in
the future convert to ADD_ONCE() or equivalent if/when
available.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

tcp: annotate sk->sk_rcvbuf lockless reads

2019-10-13T17:13:08+00:00

For the sake of tcp_poll(), there are few places where we fetch
sk->sk_rcvbuf while this field can change from IRQ or other cpu.

We need to add READ_ONCE() annotations, and also make sure write
sides use corresponding WRITE_ONCE() to avoid store-tearing.

Note that other transports probably need similar fixes.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: expose sk wmem in sock_exceed_buf_limit tracepoint

2018-07-02T13:40:56+00:00

Currently trace_sock_exceed_buf_limit() only show rmem info,
but wmem limit may also be hit.
So expose wmem info in this tracepoint as well.

Regarding memcg, I think it is better to introduce a new tracepoint(if
that is needed), i.e. trace_memcg_limit_hit other than show memcg info in
trace_sock_exceed_buf_limit.

Signed-off-by: Yafang Shao 
Signed-off-by: David S. Miller

net: tracepoint: exposing sk_faimily in tracepoint inet_sock_set_state

2018-01-08T19:32:45+00:00

As of now, there're two sk_family are traced with sock:inet_sock_set_state,
which are AF_INET and AF_INET6.
So the sk_family are exposed as well.
Then we can conveniently use it to do the filter.

Both sk_family and sk_protocol are showed in the printk message, so we need
not expose them as tracepoint arguments.

Suggested-by: Brendan Gregg 
Suggested-by: Song Liu 
Signed-off-by: Yafang Shao 
Reviewed-by: Song Liu 
Signed-off-by: David S. Miller

net/trace: fix printk format in inet_sock_set_state

2017-12-27T22:03:44+00:00

There's a space character missed in the printk messages.

Put the message into one line could simplify searching for
the messages in the kernel source.

Fixes: 563e0bb0dc74("net: tracepoint: replace tcp_set_state tracepoint with inet_sock_set_state tracepoint")
Cc: Sergei Shtylyov 
Signed-off-by: Yafang Shao 
Signed-off-by: David S. Miller

net: tracepoint: replace tcp_set_state tracepoint with inet_sock_set_state tracepoint

2017-12-20T19:00:25+00:00

As sk_state is a common field for struct sock, so the state
transition tracepoint should not be a TCP specific feature.
Currently it traces all AF_INET state transition, so I rename this
tracepoint to inet_sock_set_state tracepoint with some minor changes and move it
into trace/events/sock.h.
We dont need to create a file named trace/events/inet_sock.h for this one single
tracepoint.

Two helpers are introduced to trace sk_state transition
    - void inet_sk_state_store(struct sock *sk, int newstate);
    - void inet_sk_set_state(struct sock *sk, int state);
As trace header should not be included in other header files,
so they are defined in sock.c.

The protocol such as SCTP maybe compiled as a ko, hence export
inet_sk_set_state().

Signed-off-by: Yafang Shao 
Signed-off-by: David S. Miller