Subject: Re: [PATCH v11 tip 6/9] samples: bpf: simple non-portable kprobe filter example

From: Alexei Starovoitov <ast-uqk4Ao+rVK5Wk0Htik3J/[email-masked]>
Date: Sun, 29 Mar 2015 17:59:54 -0700

On 3/29/15 5:34 PM, Jovi Zhangwei wrote:
>> +               snprintf(buf, sizeof(buf),
>> +                        "echo '%c:%s %s' >> /sys/kernel/debug/tracing/kprobe_events",
>> +                        is_kprobe ? 'p' : 'r', event, event);
>> +               err = system(buf);
>
> Maybe we need to remember cleanup the kprobe_events in debugfs?

the real tracing tool should be cleaning it up. This is sample code.
I didn't want to overcomplicate it with a chain of ctrl-c handlers.
Notice patch 7 is simply doing signal(SIGINT, int_exit) and prints
histogram when process is terminated. The kprobe cleaning logic would
have interfere with this and overall would have made these samples
unnecessary complex.