Re: [PATCH v6 2/4] bpf: Add new bpf map type to store the pointer to struct perf_event

[Peter Zijlstra <peterz@infradead.org>]

On Tue, Aug 04, 2015 at 08:58:14AM +0000, Kaixu Xia wrote:
> +static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd)
> +{
> +	struct perf_event *event;
> +	struct perf_event_attr *attr;
> +
> +	event = perf_event_get(fd);
> +	if (IS_ERR(event))
> +		return event;
> +
> +	attr = perf_event_attrs(event);
> +	if (IS_ERR(attr)) {
		perf_event_release_kernel(event);
> +		return attr;
	}

And maybe I should do a tree wide:
s/perf_event_release_kernel/perf_event_put/, but that's not too
important and can be done at any time.

> +
> +	if (attr->type != PERF_TYPE_RAW &&
> +	    attr->type != PERF_TYPE_HARDWARE) {
> +		perf_event_release_kernel(event);
> +		return ERR_PTR(-EINVAL);
> +	}
> +	return event;
> +}