Re: [RESEND PATCH bpf-next v4 1/2] bpf, sockmap: Introduce tracing capability for sockmap

[Martin KaFai Lau <martin.lau@linux.dev>]

On 5/5/25 7:51 PM, Jiayuan Chen wrote:
> Sockmap has the same high-performance forwarding capability as XDP, but
> operates at Layer 7.
> 
> Introduce tracing capability for sockmap, to trace the execution results
> of BPF programs without modifying the programs themselves, similar to
> the existing trace_xdp_redirect{_map}.

There were advancements in bpf tracing since the trace_xdp_xxx additions.

Have you considered the fexit bpf prog and why it is not sufficient ?

> 
> It is crucial for debugging sockmap programs, especially in production
> environments.
> 
> Additionally, the new header file has to be added to bpf_trace.h to
> automatically generate tracepoints.
> 
> Test results:
> $ echo "1" > /sys/kernel/tracing/events/sockmap/enable
> 
> msg/skb:
> '''
> sockmap_redirect: sk=000000000ec02a93, netns=4026531840, inode=318, \
> family=2, protocol=6, prog_id=59, len=8192, type=msg, action=REDIRECT, \
> redirect_type=ingress
> 
> sockmap_redirect: sk=00000000d5d9c931, netns=4026531840, inode=64731, \
> family=2, protocol=6, prog_id=91, len=8221, type=skb, action=REDIRECT, \
> redirect_type=egress
> 
> sockmap_redirect: sk=00000000106fc281, netns=4026531840, inode=64729, \
> family=2, protocol=6, prog_id=94, len=8192, type=msg, action=PASS, \
> redirect_type=none
> '''
> 
> strparser:
> '''
> sockmap_strparser: sk=00000000f15fc1c8, netns=4026531840, inode=52396, \
> family=2, protocol=6, prog_id=143, in_len=1000, full_len=10
> '''
> 
> Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
> Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
> Suggested-by: Cong Wang <xiyou.wangcong@gmail.com>
> Suggested-by: Steven Rostedt <rostedt@goodmis.org>
> Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
> 
> ---
> v3 -> v4: Resending this patch as v3 was incorrectly closed by Patchwork.
>            Additionally, carrying the Reviewed-by tag.

John and JakubS, please take a look.