Re: [PATCH v3] perf pmu: Validate raw event with sysfs exported format bits

Jiri Olsa
2021-03-08T10:35:55Z

On Mon, Mar 08, 2021 at 11:15:06AM +0800, Jin Yao wrote:

SNIP

> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index 44ef28302fc7..03ab1e6d0418 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -1812,3 +1812,39 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu)
>
> return nr_caps;
> }
> +
> +void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config,
> + char *name)
> +{
> + struct perf_pmu_format *format;
> + __u64 masks = 0, bits;
> + char buf[100];
> + unsigned int i;
> +
> + list_for_each_entry(format, &pmu->format, list) {
> + /*
> + * Skip extra configs such as config1/config2.
> + */
> + if (format->value > 0)
> + continue;

sorry I did not notice before, but could you please use more direct
approach like:

if (format->value == PERF_PMU_FORMAT_VALUE_CONFIG) {
break;
}

this will be more obvious, also no need for the comment.. I spent some
time looking what's the value for ;-)

thanks,
jirka

> +
> + for_each_set_bit(i, format->bits, PERF_PMU_FORMAT_BITS)
> + masks |= 1ULL << i;
> + }
> +
> + /*
> + * Kernel doesn't export any valid format bits.
> + */
> + if (masks == 0)
> + return;
> +
> + bits = config & ~masks;
> + if (bits == 0)
> + return;
> +
> + bitmap_scnprintf((unsigned long *)&bits, sizeof(bits) * 8, buf, sizeof(buf));
> +
> + pr_warning("WARNING: event '%s' not valid (bits %s of config "
> + "'%llx' not supported by kernel)!\n",
> + name ?: "N/A", buf, config);
> +}
> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> index 8164388478c6..160b0f561771 100644
> --- a/tools/perf/util/pmu.h
> +++ b/tools/perf/util/pmu.h
> @@ -123,4 +123,7 @@ int perf_pmu__convert_scale(const char *scale, char **end, double *sval);
>
> int perf_pmu__caps_parse(struct perf_pmu *pmu);
>
> +void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config,
> + char *name);
> +
> #endif /* __PMU_H */
> --
> 2.17.1
>