[PATCH bpf-next 1/2] selftests/bpf: fix an unused-but-set-variable compiler warning

[PATCH bpf-next 1/2] selftests/bpf: fix an unused-but-set-variable compiler warning

[Yonghong Song]

When using clang to build selftests with LLVM=1 in make commandline,
I hit the following compiler warning:
  xdpxceiver.c:747:6: warning: variable 'total' set but not used [-Wunused-but-set-variable]
          u32 total = 0;
              ^

This patch fixed the issue by removing that declaration and its
assocatied unused operation.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/xdpxceiver.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/xdpxceiver.c b/tools/testing/selftests/bpf/xdpxceiver.c
index 6c7cf8aadc79..fe7f423b8c3f 100644
--- a/tools/testing/selftests/bpf/xdpxceiver.c
+++ b/tools/testing/selftests/bpf/xdpxceiver.c
@@ -744,7 +744,6 @@ static void receive_pkts(struct pkt_stream *pkt_stream, struct xsk_socket_info *
 	struct pkt *pkt = pkt_stream_get_next_rx_pkt(pkt_stream);
 	struct xsk_umem_info *umem = xsk->umem;
 	u32 idx_rx = 0, idx_fq = 0, rcvd, i;
-	u32 total = 0;
 	int ret;
 
 	while (pkt) {
@@ -799,7 +798,6 @@ static void receive_pkts(struct pkt_stream *pkt_stream, struct xsk_socket_info *
 
 		pthread_mutex_lock(&pacing_mutex);
 		pkts_in_flight -= rcvd;
-		total += rcvd;
 		if (pkts_in_flight < umem->num_frames)
 			pthread_cond_signal(&pacing_cond);
 		pthread_mutex_unlock(&pacing_mutex);
-- 
2.30.2

[PATCH bpf-next 2/2] selftests/bpf: fix a tautological-constant-out-of-range-compare compiler warning

[Yonghong Song]

When using clang to build selftests with LLVM=1 in make commandline,
I hit the following compiler warning:

  benchs/bench_bloom_filter_map.c:84:46: warning: result of comparison of constant 256
    with expression of type '__u8' (aka 'unsigned char') is always false
    [-Wtautological-constant-out-of-range-compare]
                if (args.value_size < 2 || args.value_size > 256) {
                                           ~~~~~~~~~~~~~~~ ^ ~~~

The reason is arg.vaue_size has type __u8, so comparison "args.value_size > 256"
is always false.

This patch fixed the issue by doing proper comparison before assigning the
value to args.value_size. The patch also fixed the same issue in two
other places.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 .../bpf/benchs/bench_bloom_filter_map.c         | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/bpf/benchs/bench_bloom_filter_map.c b/tools/testing/selftests/bpf/benchs/bench_bloom_filter_map.c
index 6eeeed2913e6..5bcb8a8cdeb2 100644
--- a/tools/testing/selftests/bpf/benchs/bench_bloom_filter_map.c
+++ b/tools/testing/selftests/bpf/benchs/bench_bloom_filter_map.c
@@ -63,29 +63,34 @@ static const struct argp_option opts[] = {
 
 static error_t parse_arg(int key, char *arg, struct argp_state *state)
 {
+	long ret;
+
 	switch (key) {
 	case ARG_NR_ENTRIES:
-		args.nr_entries = strtol(arg, NULL, 10);
-		if (args.nr_entries == 0) {
+		ret = strtol(arg, NULL, 10);
+		if (ret < 1 || ret > UINT_MAX) {
 			fprintf(stderr, "Invalid nr_entries count.");
 			argp_usage(state);
 		}
+		args.nr_entries = ret;
 		break;
 	case ARG_NR_HASH_FUNCS:
-		args.nr_hash_funcs = strtol(arg, NULL, 10);
-		if (args.nr_hash_funcs == 0 || args.nr_hash_funcs > 15) {
+		ret = strtol(arg, NULL, 10);
+		if (ret < 1 || ret > 15) {
 			fprintf(stderr,
 				"The bloom filter must use 1 to 15 hash functions.");
 			argp_usage(state);
 		}
+		args.nr_hash_funcs = ret;
 		break;
 	case ARG_VALUE_SIZE:
-		args.value_size = strtol(arg, NULL, 10);
-		if (args.value_size < 2 || args.value_size > 256) {
+		ret = strtol(arg, NULL, 10);
+		if (ret < 2 || ret > 256) {
 			fprintf(stderr,
 				"Invalid value size. Must be between 2 and 256 bytes");
 			argp_usage(state);
 		}
+		args.value_size = ret;
 		break;
 	default:
 		return ARGP_ERR_UNKNOWN;
-- 
2.30.2