Em Fri, Jul 17, 2015 at 07:33:50PM +0300, Adrian Hunter escreveu:
> Currently the value of a PMU config term is silently
> truncated if it is too big. This is an impediment to
> validating the value for other criteria later on i.e.
> the user provides an invalid value that gets truncated
> to a valid one.
Applied
> The maximum value validation is only done for the
> parser where the error is passed back to the user. In
> other cases the silent truncation continues so as not
> to affect tools that perhaps rely on it.
>
> Signed-off-by: Adrian Hunter <adrian.hun...@intel.com>
> ---
> tools/perf/util/pmu.c | 30 +++++++++++++++++++++++++++++-
> 1 file changed, 29 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index d26ff0ab8410..29797fd9bedc 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -585,6 +585,18 @@ static void pmu_format_value(unsigned long *format,
> __u64 value, __u64 *v,
> }
> }
>
> +static __u64 pmu_format_max_value(const unsigned long *format)
> +{
> + int w;
> +
> + w = bitmap_weight(format, PERF_PMU_FORMAT_BITS);
> + if (!w)
> + return 0;
> + if (w < 64)
> + return (1ULL << w) - 1;
> + return -1;
> +}
> +
> /*
> * Term is a string term, and might be a param-term. Try to look up it's
> value
> * in the remaining terms.
> @@ -658,7 +670,7 @@ static int pmu_config_term(struct list_head *formats,
> {
> struct perf_pmu_format *format;
> __u64 *vp;
> - __u64 val;
> + __u64 val, max_val;
>
> /*
> * If this is a parameter we've already used for parameterized-eval,
> @@ -724,6 +736,22 @@ static int pmu_config_term(struct list_head *formats,
> } else
> return -EINVAL;
>
> + max_val = pmu_format_max_value(format->bits);
> + if (val > max_val) {
> + if (err) {
> + err->idx = term->err_val;
> + if (asprintf(&err->str,
> + "value too big for format, maximum is
> %llu",
> + (unsigned long long)max_val) < 0)
> + err->str = strdup("value too big for format");
> + return -EINVAL;
> + }
> + /*
> + * Assume we don't care if !err, in which case the value will be
> + * silently truncated.
> + */
> + }
> +
> pmu_format_value(format->bits, val, vp, zero);
> return 0;
> }
> --
> 1.9.1
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