selftests/bpf: fix lots of silly mistakes pointed out by compiler

Once we enable -Wall for BPF sources, compiler will complain about lots
of unused variables, variables that are set but never read, etc.

Fix all these issues first before enabling -Wall in Makefile.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230309054015.4068562-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf3.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf3.c
index 7fab39a3bb12..99c8d1d8a187 100644
--- a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf3.c
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf3.c
@@ -2,6 +2,7 @@
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 #include "bpf_legacy.h"
+#include "bpf_misc.h"
 
 struct {
 	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
@@ -20,6 +21,8 @@ int subprog_tail2(struct __sk_buff *skb)
 	else
 		bpf_tail_call_static(skb, &jmp_table, 1);
 
+	__sink(arr[sizeof(arr) - 1]);
+
 	return skb->len;
 }
 
@@ -30,6 +33,8 @@ int subprog_tail(struct __sk_buff *skb)
 
 	bpf_tail_call_static(skb, &jmp_table, 0);
 
+	__sink(arr[sizeof(arr) - 1]);
+
 	return skb->len * 2;
 }
 
@@ -38,6 +43,8 @@ int classifier_0(struct __sk_buff *skb)
 {
 	volatile char arr[128] = {};
 
+	__sink(arr[sizeof(arr) - 1]);
+
 	return subprog_tail2(skb);
 }
 
@@ -46,6 +53,8 @@ int classifier_1(struct __sk_buff *skb)
 {
 	volatile char arr[128] = {};
 
+	__sink(arr[sizeof(arr) - 1]);
+
 	return skb->len * 3;
 }
 
@@ -54,6 +63,8 @@ int entry(struct __sk_buff *skb)
 {
 	volatile char arr[128] = {};
 
+	__sink(arr[sizeof(arr) - 1]);
+
 	return subprog_tail(skb);
 }