Re: [PATCH v4 3/4] KVM: selftests: Add atoi_paranoid() to catch errors missed by atoi()

Sean Christopherson
2022-10-06T19:58:36Z

On Thu, Oct 06, 2022, Vipin Sharma wrote:
> +int atoi_paranoid(const char *num_str)
> +{
> + int num;
> + char *end_ptr;

Reverse fir-tree when it's convention:

char *end_ptr;

> +
> + errno = 0;
> + num = (int)strtol(num_str, &end_ptr, 10);
> + TEST_ASSERT(!errno, "strtol(\"%s\") failed", num_str);
> + TEST_ASSERT(num_str != end_ptr,
> + "strtol(\"%s\") didn't find any valid number.\n", num_str);

s/number/integer ? And should that be "a valid intenger", not "any valid integer"?
"any" implies that this helper will be happy if there's at least one integer,
whereas I believe the intent is to find _exactly_ one integer.

> + TEST_ASSERT(
> + *end_ptr == '\0',

Weird and unnecessary wrap+indentation.

> + "strtol(\"%s\") failed to parse trailing characters \"%s\".\n",
> + num_str, end_ptr);
> +
> + return num;
> +}
> diff --git a/tools/testing/selftests/kvm/max_guest_memory_test.c b/tools/testing/selftests/kvm/max_guest_memory_test.c
> index 9a6e4f3ad6b5..1595b73dc09a 100644
> --- a/tools/testing/selftests/kvm/max_guest_memory_test.c
> +++ b/tools/testing/selftests/kvm/max_guest_memory_test.c
> @@ -193,15 +193,15 @@ int main(int argc, char *argv[])
> while ((opt = getopt(argc, argv, "c:h:m:s:H")) != -1) {
> switch (opt) {
> case 'c':
> - nr_vcpus = atoi(optarg);
> + nr_vcpus = atoi_paranoid(optarg);
> TEST_ASSERT(nr_vcpus > 0, "number of vcpus must be >0");

Many users require a positive and or non-negative value, maybe add wrappers in
a follow-up?

nr_vcpus = atoi_positive(optarg);

and later down

targs->tfirst = atoi_non_negative(optarg);

We'll lose custom error messages, but I don't think that's a big deal. Definitely
not required, just a thought.

> diff --git a/tools/testing/selftests/kvm/set_memory_region_test.c b/tools/testing/selftests/kvm/set_memory_region_test.c
> index 0d55f508d595..c366949c8362 100644
> --- a/tools/testing/selftests/kvm/set_memory_region_test.c
> +++ b/tools/testing/selftests/kvm/set_memory_region_test.c
> @@ -407,7 +407,7 @@ int main(int argc, char *argv[])
>
> #ifdef __x86_64__
> if (argc > 1)
> - loops = atoi(argv[1]);
> + loops = atoi_paranoid(argv[1]);

This is a good candidate for atoi_positive().

> else
> loops = 10;
>
> diff --git a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c
> index 59ffe7fd354f..354b6902849c 100644
> --- a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c
> @@ -241,10 +241,10 @@ int main(int argc, char **argv)
> while ((opt = getopt(argc, argv, "hp:t:r")) != -1) {
> switch (opt) {
> case 'p':
> - reclaim_period_ms = atoi(optarg);
> + reclaim_period_ms = atoi_paranoid(optarg);
> break;
> case 't':
> - token = atoi(optarg);
> + token = atoi_paranoid(optarg);
> break;
> case 'r':
> reboot_permissions = true;
> --
> 2.38.0.rc1.362.ged0d419d3c-goog
>