[PATCH] sample/bpf: Make perf_event_read() static

From: Arnaldo Carvalho de Melo
Date: Thu Dec 15 2016 - 10:29:46 EST

While testing Joe's conversion of samples/bpf/ to use tools/lib/bpf/ I
noticed some warnings, do you guys mind if I put patches like the one
below in my tree, pushing to Ingo soon?

Or is there anything subtle against doing so?


While building samples/bpf/ on a Fedora Rawhide container, with
clang/llvm 3.9 I noticed this:

root@1e797fdfbf4f linux]# make -j4 O=/tmp/build/linux/ samples/bpf/
make[1]: Entering directory '/tmp/build/linux'
CHK include/config/kernel.release
GEN ./Makefile
CHK include/generated/uapi/linux/version.h
Using /git/linux as source for kernel
HOSTCC samples/bpf/trace_output_user.o
/git/linux/samples/bpf/trace_output_user.c:64:6: warning: no previous
prototype for 'perf_event_read' [-Wmissing-prototypes]
void perf_event_read(print_fn fn)
HOSTLD samples/bpf/trace_output
make[1]: Leaving directory '/tmp/build/linux'

Shutup the compiler by setting that function as static.

Cc: Alexei Starovoitov <ast@xxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>,
Cc: Joe Stringer <joe@xxxxxxx>
Link: http://lkml.kernel.org/n/tip-2wkr4ymwhdie0stbkbiyplt5@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>


diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c
index 3bedd945def1..1a1da7bddb93 100644
--- a/samples/bpf/trace_output_user.c
+++ b/samples/bpf/trace_output_user.c
@@ -61,7 +61,7 @@ struct perf_event_sample {
char data[];

-void perf_event_read(print_fn fn)
+static void perf_event_read(print_fn fn)
__u64 data_tail = header->data_tail;
__u64 data_head = header->data_head;