[PATCH 5.6 192/194] selftests/bpf: Enforce returning 0 for fentry/fexit programs

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Yonghong Song <yhs@xxxxxx>

commit 6d74f64b922b8394dccc52576659cb0dc0a1da7b upstream.

There are a few fentry/fexit programs returning non-0.
The tests with these programs will break with the previous
patch which enfoced return-0 rules. Fix them properly.

Fixes: ac065870d928 ("selftests/bpf: Add BPF_PROG, BPF_KPROBE, and BPF_KRETPROBE macros")
Signed-off-by: Yonghong Song <yhs@xxxxxx>
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Acked-by: Andrii Nakryiko <andriin@xxxxxx>
Link: https://lore.kernel.org/bpf/20200514053207.1298479-1-yhs@xxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 tools/testing/selftests/bpf/progs/test_overhead.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/tools/testing/selftests/bpf/progs/test_overhead.c
+++ b/tools/testing/selftests/bpf/progs/test_overhead.c
@@ -33,13 +33,13 @@ int prog3(struct bpf_raw_tracepoint_args
 SEC("fentry/__set_task_comm")
 int BPF_PROG(prog4, struct task_struct *tsk, const char *buf, bool exec)
 {
-	return !tsk;
+	return 0;
 }
 
 SEC("fexit/__set_task_comm")
 int BPF_PROG(prog5, struct task_struct *tsk, const char *buf, bool exec)
 {
-	return !tsk;
+	return 0;
 }
 
 char _license[] SEC("license") = "GPL";