From 325d956d67178af92b5b12ff950a2f93a433f2c4 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Fri, 12 Nov 2021 12:48:38 -0800 Subject: [PATCH] selftests/bpf: Fix a tautological-constant-out-of-range-compare compiler warning 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 Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20211112204838.3579953-1-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 6eeeed2913e62..5bcb8a8cdeb20 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;