On Mon, Apr 25, 2016 at 08:41:39PM -0300, Arnaldo Carvalho de Melo wrote:
>
> +int sysctl_perf_event_max_stack __read_mostly = PERF_MAX_STACK_DEPTH;
> +
> +static inline size_t perf_callchain_entry__sizeof(void)
> +{
> + return (sizeof(struct perf_callchain_entry) +
> + sizeof(__u64) * sysctl_perf_event_max_stack);
> +}
> @@ -1144,6 +1144,14 @@ static struct ctl_table kern_table[] = {
> .extra1 = &zero,
> .extra2 = &one_hundred,
> },
> + {
> + .procname = "perf_event_max_stack",
> + .data = NULL, /* filled in by handler */
> + .maxlen = sizeof(sysctl_perf_event_max_stack),
> + .mode = 0644,
> + .proc_handler = perf_event_max_stack_handler,
> + .extra1 = &zero,
> + },
you need to define a max value otherwise perf_callchain_entry__sizeof
will overflow. Sure it's root only facility, but still not nice.
1M? Anything above 1M stack frames would be insane anyway.
The rest looks good. Thanks!
