On Thu, Jul 25, 2024 at 3:39 AM Tony Ambardar <[email protected]> wrote:
>
> From: Tony Ambardar <[email protected]>
>
> Current code parses arguments with strtok_r() using a construct like
>
> char *state = NULL;
> while ((next = strtok_r(state ? NULL : input, ",", &state))) {
> ...
> }
>
> where logic assumes the 'state' var can distinguish between first and
> subsequent strtok_r() calls, and adjusts parameters accordingly. However,
> 'state' is strictly internal context for strtok_r() and no such assumptions
> are supported in the man page. Moreover, the exact behaviour of 'state'
> depends on the libc implementation, making the above code fragile.
>
> Indeed, invoking "./test_progs -t <test_name>" on mips64el/musl will hang,
> with the above code in an infinite loop.
>
> Similarly, we see strange behaviour running 'veristat' on mips64el/musl:
>
> $ ./veristat -e file,prog,verdict,insns -C two-ok add-failure
> Can't specify more than 9 stats
>
> Rewrite code using a 'for' loop without logic dependent on var 'state', the
> same approach already used in cgroup_helpers.c.
>
> Fixes: 61ddff373ffa ("selftests/bpf: Improve by-name subtest selection logic
> in prog_tests")
> Fixes: 394169b079b5 ("selftests/bpf: add comparison mode to veristat")
> Fixes: c8bc5e050976 ("selftests/bpf: Add veristat tool for mass-verifying BPF
> object files")
> Signed-off-by: Tony Ambardar <[email protected]>
> ---
> tools/testing/selftests/bpf/testing_helpers.c | 2 +-
> tools/testing/selftests/bpf/veristat.c | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/testing_helpers.c
> b/tools/testing/selftests/bpf/testing_helpers.c
> index ac7c66f4fc7b..2a73b72feb18 100644
> --- a/tools/testing/selftests/bpf/testing_helpers.c
> +++ b/tools/testing/selftests/bpf/testing_helpers.c
> @@ -227,7 +227,7 @@ int parse_test_list(const char *s,
> if (!input)
> return -ENOMEM;
>
> - while ((test_spec = strtok_r(state ? NULL : input, ",", &state))) {
> + for (test_spec = strtok_r(input, ",", &state); test_spec; test_spec =
> strtok_r(NULL, ",", &state)) {
oh, this is so long and verbose, let's just add a counter and use that
to determine whether to pass NULL or input, ok?
> err = insert_test(set, test_spec, is_glob_pattern);
> if (err)
> break;
> diff --git a/tools/testing/selftests/bpf/veristat.c
> b/tools/testing/selftests/bpf/veristat.c
> index 11ec1190d582..6808679827ac 100644
> --- a/tools/testing/selftests/bpf/veristat.c
> +++ b/tools/testing/selftests/bpf/veristat.c
> @@ -791,7 +791,7 @@ static int parse_stats(const char *stats_str, struct
> stat_specs *specs)
> if (!input)
> return -ENOMEM;
>
> - while ((next = strtok_r(state ? NULL : input, ",", &state))) {
> + for (next = strtok_r(input, ",", &state); next; next = strtok_r(NULL,
> ",", &state)) {
ditto, let's not duplicate strtok_r() calls
> err = parse_stat(next, specs);
> if (err) {
> free(input);
> @@ -1513,7 +1513,7 @@ static int parse_stats_csv(const char *filename, struct
> stat_specs *specs,
> *stat_cntp += 1;
> }
>
> - while ((next = strtok_r(state ? NULL : input, ",\n",
> &state))) {
> + for (next = strtok_r(input, ",\n", &state); next; next =
> strtok_r(NULL, ",\n", &state)) {
> if (header) {
> /* for the first line, set up spec stats */
> err = parse_stat(next, specs);
> --
> 2.34.1
>
