From ac5a72ea5c8989871e61f6bb0852e0f91de51ebe Mon Sep 17 00:00:00 2001 From: Alan Maguire Date: Mon, 13 Jul 2020 12:52:33 +0100 Subject: 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) Signed-off-by: Alan Maguire Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko 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 --- kernel/trace/Makefile | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/trace/Makefile') diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 6575bb0a0434..aeba5ee7325a 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -31,6 +31,8 @@ ifdef CONFIG_GCOV_PROFILE_FTRACE GCOV_PROFILE := y endif +CFLAGS_bpf_trace.o := -I$(src) + CFLAGS_trace_benchmark.o := -I$(src) CFLAGS_trace_events_filter.o := -I$(src) -- cgit v1.2.3