Alan Maguire ac5a72ea5c bpf: Use dedicated bpf_trace_printk event instead of trace_printk()
The bpf helper bpf_trace_printk() uses trace_printk() under the hood.
This leads to an alarming warning message originating from trace
buffer allocation which occurs the first time a program using
bpf_trace_printk() is loaded.

We can instead create a trace event for bpf_trace_printk() and enable
it in-kernel when/if we encounter a program using the
bpf_trace_printk() helper.  With this approach, trace_printk()
is not used directly and no warning message appears.

This work was started by Steven (see Link) and finished by Alan; added
Steven's Signed-off-by with his permission.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/r/20200628194334.6238b933@oasis.local.home
Link: https://lore.kernel.org/bpf/1594641154-18897-2-git-send-email-alan.maguire@oracle.com
2020-07-13 16:55:49 -07:00
..
2020-06-07 09:52:36 -07:00
\n
2020-04-06 08:58:42 -07:00
2020-06-02 17:13:37 -07:00
2020-06-03 13:06:42 -07:00
2020-01-08 16:32:55 +00:00
2020-06-03 13:06:42 -07:00
2020-06-14 11:39:31 -07:00
2019-12-04 15:18:39 +01:00
2020-03-30 18:06:39 -07:00
2019-12-18 18:07:31 +01:00
2020-05-09 13:57:12 +02:00
2020-06-04 19:06:24 -07:00
2020-05-09 13:57:12 +02:00