Re: [PATCH v1 09/48] perf tests: Silence -Wshorten-64-to-32 warnings

Leo Yan
2025-04-02T14:35:46Z

On Tue, Apr 01, 2025 at 11:23:07AM -0700, Ian Rogers wrote:

[...]

> @@ -478,13 +478,14 @@ static int __cmd_test(struct test_suite **suites, int argc, const char *argv[],
> int err = 0;
>
> for (struct test_suite **t = suites; *t; t++) {
> - int i, len = strlen(test_description(*t, -1));
> + int i;
> + int len = (int)strlen(test_description(*t, -1));

Thanks for huge polish.

Just a concern from me. Throughout this patch, the methodology is not
consistent. Some changes update variable types which is fine for me.

But the case above it simply cast size_t to int. Should we update the
variable type as 'size_t' at here?

> if (width < len)
> width = len;
>
> test_suite__for_each_test_case(*t, i) {
> - len = strlen(test_description(*t, i));
> + len = (int)strlen(test_description(*t, i));
> if (width < len)
> width = len;
> num_tests += runs_per_test;
> diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
> index cf6edbe697b2..0c31d5ff77e2 100644
> --- a/tools/perf/tests/code-reading.c
> +++ b/tools/perf/tests/code-reading.c
> @@ -188,7 +188,7 @@ static int objdump_version(void)
> char *line = NULL;
> const char *fmt;
> FILE *f;
> - int ret;
> + ssize_t ret;
>
> int version_tmp, version_num = 0;
> char *version = 0, *token;
> @@ -295,7 +295,7 @@ static int read_via_objdump(const char *filename, u64 addr, void *buf,
> if (len) {
> pr_debug("objdump read too few bytes: %zd\n", len);
> if (!ret)
> - ret = len;
> + ret = (int)len;

A proper change is to update the function type to:

size_t read_via_objdump(...)

[...]

> diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
> index db004d26fcb0..2762794827ce 100644
> --- a/tools/perf/tests/pmu-events.c
> +++ b/tools/perf/tests/pmu-events.c
> @@ -609,7 +609,7 @@ static int __test_uncore_pmu_event_aliases(struct perf_pmu_test_pmu *test_pmu)
> pmu_add_sys_aliases(pmu);
>
> /* Count how many aliases we generated */
> - alias_count = perf_pmu__num_events(pmu);
> + alias_count = (int)perf_pmu__num_events(pmu);

Could we change the variable 'alias_count' to size_t type?

Or in another way, we need to update perf_pmu__num_events() with
returning int type.

My understanding is rather than using cast, we should polish code for
using consistent type for both variables and return values.

> /* Count how many aliases we expect from the known table */
> for (table = &test_pmu->aliases[0]; *table; table++)
> diff --git a/tools/perf/tests/sigtrap.c b/tools/perf/tests/sigtrap.c
> index a67c756f90b8..b7d7735f8a72 100644
> --- a/tools/perf/tests/sigtrap.c
> +++ b/tools/perf/tests/sigtrap.c
> @@ -154,13 +154,13 @@ sigtrap_handler(int signum __maybe_unused, siginfo_t *info, void *ucontext __may
> {
> if (!__atomic_fetch_add(&ctx.signal_count, 1, __ATOMIC_RELAXED))
> ctx.first_siginfo = *info;
> - __atomic_fetch_sub(&ctx.tids_want_signal, syscall(SYS_gettid), __ATOMIC_RELAXED);
> + __atomic_fetch_sub(&ctx.tids_want_signal, (pid_t)syscall(SYS_gettid), __ATOMIC_RELAXED);
> }
>
> static void *test_thread(void *arg)
> {
> pthread_barrier_t *barrier = (pthread_barrier_t *)arg;
> - pid_t tid = syscall(SYS_gettid);
> + pid_t tid = (pid_t)syscall(SYS_gettid);
> int i;
>
> pthread_barrier_wait(barrier);
> diff --git a/tools/perf/tests/switch-tracking.c b/tools/perf/tests/switch-tracking.c
> index 8df3f9d9ffd2..1f0f8321ae40 100644
> --- a/tools/perf/tests/switch-tracking.c
> +++ b/tools/perf/tests/switch-tracking.c
> @@ -140,8 +140,8 @@ static int process_sample_event(struct evlist *evlist,
>
> evsel = evlist__id2evsel(evlist, sample.id);
> if (evsel == switch_tracking->switch_evsel) {
> - next_tid = evsel__intval(evsel, &sample, "next_pid");
> - prev_tid = evsel__intval(evsel, &sample, "prev_pid");
> + next_tid = (int)evsel__intval(evsel, &sample, "next_pid");
> + prev_tid = (int)evsel__intval(evsel, &sample, "prev_pid");

Change 'prev_tid' and 'next_tid' to pid_t type?

Thanks,
Leo

> cpu = sample.cpu;
> pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
> cpu, prev_tid, next_tid);
> @@ -262,9 +262,10 @@ static int compar(const void *a, const void *b)
> {
> const struct event_node *nodea = a;
> const struct event_node *nodeb = b;
> - s64 cmp = nodea->event_time - nodeb->event_time;
>
> - return cmp;
> + if (nodea->event_time == nodeb->event_time)
> + return 0;
> + return nodea->event_time < nodeb->event_time ? -1 : 1;
> }
>
> static int process_events(struct evlist *evlist,
> @@ -398,7 +399,7 @@ static int test__switch_tracking(struct test_suite *test __maybe_unused, int sub
>
> switch_evsel = evlist__add_sched_switch(evlist, true);
> if (IS_ERR(switch_evsel)) {
> - err = PTR_ERR(switch_evsel);
> + err = (int)PTR_ERR(switch_evsel);
> pr_debug("Failed to create event %s\n", sched_switch);
> goto out_err;
> }
> diff --git a/tools/perf/tests/vmlinux-kallsyms.c b/tools/perf/tests/vmlinux-kallsyms.c
> index 74cdbd2ce9d0..fbdb463e965d 100644
> --- a/tools/perf/tests/vmlinux-kallsyms.c
> +++ b/tools/perf/tests/vmlinux-kallsyms.c
> @@ -82,7 +82,7 @@ static bool is_ignored_symbol(const char *name, char type)
> return true;
>
> for (p = ignored_suffixes; *p; p++) {
> - int l = strlen(name) - strlen(*p);
> + ssize_t l = strlen(name) - strlen(*p);
>
> if (l >= 0 && !strcmp(name + l, *p))
> return true;
> @@ -313,7 +313,7 @@ static int test__vmlinux_matches_kallsyms(struct test_suite *test __maybe_unused
> * _really_ have a problem.
> */
> s64 skew = mem_end - UM(pair->end);
> - if (llabs(skew) >= page_size)
> + if (llabs(skew) >= (s64)page_size)
> pr_debug("WARN: %#" PRIx64 ": diff end addr for %s v: %#" PRIx64 " k: %#" PRIx64 "\n",
> mem_start, sym->name, mem_end,
> UM(pair->end));
> diff --git a/tools/perf/tests/wp.c b/tools/perf/tests/wp.c
> index 6c178985e37f..d5dd17eb5c05 100644
> --- a/tools/perf/tests/wp.c
> +++ b/tools/perf/tests/wp.c
> @@ -31,10 +31,10 @@ volatile u8 data2[3];
> #ifndef __s390x__
> static int wp_read(int fd, long long *count, int size)
> {
> - int ret = read(fd, count, size);
> + ssize_t ret = read(fd, count, size);
>
> if (ret != size) {
> - pr_debug("failed to read: %d\n", ret);
> + pr_debug("failed to read: %zd\n", ret);
> return -1;
> }
> return 0;
> --
> 2.49.0.504.g3bcea36a83-goog
>
>