Re: [PATCH v3 1/3] bpf: Add new bpf map type to store the pointer to struct perf_event

From: Peter Zijlstra
Date: Mon Aug 03 2015 - 05:38:12 EST


On Thu, Jul 23, 2015 at 09:42:40AM +0000, Kaixu Xia wrote:
> +static struct perf_event *convert_map_with_perf_event(void *value)
> +{
> + struct perf_event *event;
> + u32 fd;
> +
> + fd = *(u32 *)value;
> +
> + event = perf_event_get(fd);
> + if (IS_ERR(event))
> + return NULL;
> +
> + /* limit the event type to PERF_TYPE_RAW
> + * and PERF_TYPE_HARDWARE.
> + */
> + if (event->attr.type != PERF_TYPE_RAW &&
> + event->attr.type != PERF_TYPE_HARDWARE)
> + return NULL;

Aside from the ref-leak already mentioned; please introduce something
like:

const struct perf_event_attr *perf_event_attrs(struct perf_event *event);

To avoid having to poke inside of the event outside of perf code.

> +
> + return event;
> +}
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