selftests/bpf: Fix arg parsing in veristat, test_progs

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 counter to distinguish between strtok_r() calls.

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 <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/392d8bf5559f85fa37926c1494e62312ef252c3d.1722244708.git.tony.ambardar@gmail.com

diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
index ac7c66f..c217e12 100644 (file)
--- a/tools/testing/selftests/bpf/testing_helpers.c
+++ b/tools/testing/selftests/bpf/testing_helpers.c
@@ -221,13 +221,13 @@ int parse_test_list(const char *s,
                    bool is_glob_pattern)
 {
        char *input, *state = NULL, *test_spec;
-       int err = 0;
+       int err = 0, cnt = 0;
 
        input = strdup(s);
        if (!input)
                return -ENOMEM;
 
-       while ((test_spec = strtok_r(state ? NULL : input, ",", &state))) {
+       while ((test_spec = strtok_r(cnt++ ? NULL : input, ",", &state))) {
                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 11ec119..1ec5c4c 100644 (file)
--- a/tools/testing/selftests/bpf/veristat.c
+++ b/tools/testing/selftests/bpf/veristat.c
@@ -785,13 +785,13 @@ static int parse_stat(const char *stat_name, struct stat_specs *specs)
 static int parse_stats(const char *stats_str, struct stat_specs *specs)
 {
        char *input, *state = NULL, *next;
-       int err;
+       int err, cnt = 0;
 
        input = strdup(stats_str);
        if (!input)
                return -ENOMEM;
 
-       while ((next = strtok_r(state ? NULL : input, ",", &state))) {
+       while ((next = strtok_r(cnt++ ? NULL : input, ",", &state))) {
                err = parse_stat(next, specs);
                if (err) {
                        free(input);
@@ -1495,7 +1495,7 @@ static int parse_stats_csv(const char *filename, struct stat_specs *specs,
        while (fgets(line, sizeof(line), f)) {
                char *input = line, *state = NULL, *next;
                struct verif_stats *st = NULL;
-               int col = 0;
+               int col = 0, cnt = 0;
 
                if (!header) {
                        void *tmp;
@@ -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))) {
+               while ((next = strtok_r(cnt++ ? NULL : input, ",\n", &state))) {
                        if (header) {
                                /* for the first line, set up spec stats */
                                err = parse_stat(next, specs);